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1

Schimming, Sarah McNew. "Design of solid catalysts for biomass upgrading." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/54265.

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The two main requirements for ceria-zirconia hydrodeoxygenation (HDO) catalysts are the presence of defect sites to bind oxygenates and the ability to adsorb and dissociate hydrogen. Two types of sites were identified for exchange of hydrogen and deuterium. The activation energy for one type of site was associated with H2-D2 exchange through oxygen defect sites. The activation energy for the second type of site was associated with H2-D2 exchange through hydroxyl groups and correlated with crystallite size. Ceria-zirconia can convert guaiacol, a model pyrolysis oil compound, with a high selectivity to phenol, an HDO product. Ceria-zirconia catalysts had a higher conversion of guaiacol to deoxygenated products as well as a higher selectivity towards phenol than pure ceria. They did not deactivate over the course of 72 hours on stream, whereas coking or the presence of water in the feed can cause serious decay of common HDO catalysts HDO. Therefore, ceria-zirconia catalysts are promising HDO catalysts for the first step of deoxygenation. The stability of supported Ru on ZrO2 in acidic or basic environments at reaction temperature is examined. In this study, the ruthenium dispersion is greatly increased by hydrothermal treatment in acidic and basic pH without alterations to the surface area, pore volume, pore size or crystal structure. An increase in Ru dispersion showed an increase in the selectivity to propylene glycol relative to ethylene glycol. A decrease in total Lewis acid site concentration was correlated with a decrease in the ethylene glycol yield. The conclusions of this study indicate that stability of catalysts in realistic industrial environments is crucial to the design of catalysts for a reaction.
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2

Laryea-Goldsmith, Rene. "Concurrent combustion of biomass and municipal solid waste." Thesis, Cranfield University, 2010. http://dspace.lib.cranfield.ac.uk/handle/1826/5580.

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This PhD research project is primarily an investigation of the gaseous pollutant emissions arising from concurrent combustion of biomass and municipal solid wastes materials, using a fluidized bed combustor. Of the wide range of biomass energy resources available, dried distillers’ grains with solubles and wheat straw were chosen as two example agricultural by-products of the human food supply chain. To consider an integrated waste management programme, a residual waste resource from a materials recycling facility was identified as a waste materials source that could be utilized after materials recycling was performed (which is a higher priority activity with respect to energy recovery). Cont/d.
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3

Becidan, Michaël. "Experimental Studies on Municipal Solid Waste and Biomass Pyrolysis." Doctoral thesis, Norwegian University of Science and Technology, Department of Energy and Process Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-1723.

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The introduction of this thesis (Chapters 1-9) presents the broader picture of waste management and thermal treatments (situation, trends and novel concepts) with a strong focus on nitrogen (N) in Chapter 6 (a summary of this chapter can be found on page 42). A new insight on N-functionalities is presented, mostly based on plant physiology publications widely ignored by the bioenergy world. N in biomass is found in a variety of chemical compounds and not only in protein compounds. An extensive literature survey concerning N-chemistry during pyrolysis of model compounds and biomass has also been done. A critical light is cast on these studies.

Paper I (or P-I) ([Becidan 2004]) presents preliminary results using the experimental set-up and shows its potential in thermal studies. The study of N-release was twofold: NOx release during combustion of biomass and NOx precursors (NH3 and HCN) release during pyrolysis of sewage sludge. The main results confirm known trends: N-release during combustion decreases with increasing fuel-N content; N-release as NH3 and HCN during pyrolysis is clearly dependent on temperature with increasing release with increasing temperature and NH3 as the main component at all conditions.

Paper II (or P-II) ([Skreiberg 2004]) presents modelling work realised to assess the potential for reduction of NOx emission formed from fuel-N by implementing staged air combustion. The results obtained from these chemical analysis of ideal reactors (Plug Flow Reactor and Perfectly Stirred Reactor) can be seen as a simplified CFD approach. The reduction potential is depending on a variety of factors and will therefore have to be assessed on a case-to-case basis. However, some conclusions can be drawn: (1) PSR mixing conditions are more favourable than PFR flow; (2) increasing fuel-N content will increase the relative NOx reduction potential; (3) increasing fuel-N fraction of NH3, or HNCO, compared to HCN will increase the NOx reduction potential; (4) increasing amounts of CO, and H2, will increase the NOx reduction potential, but it depends also on the fuel-N compounds; (5) one primary air stage is sufficient, unless also the fuel supply is staged. It is possible to further increase the NOx reduction with more primary air stages at some conditions, but the increase is limited; (6) increasing overall excess air ratio will decrease the NOx reduction potential; (7) increasing residence time will only significantly increase the NOx reduction potential until the main chemistry is completed. However, the time for completion of the main chemistry is significantly longer in a PSR compared to a PFR, and the effect of an increasing residence time is much more pronounced at optimum conditions in a PSR; (8) temperature is an important parameter. However, for a specific set of other parameters there exists an optimum temperature. The temperature in the primary air stage should be high enough to complete the main chemistry. The temperature needed to complete the main chemistry, and the fuel-N chemistry, in a PSR is higher than in a PFR for the same residence time. The temperature in the secondary air stage should be as low as possible, but high enough to ensure complete combustion.

Paper III (or P-III) ([Becidan 2007a]) looks at the products distribution and the main pyrolysis products of thermally thick and scarcely studied biomass residues samples. For all fuels, higher temperatures favour gas yield at the expense of char and liquid yields. High heating rate also promotes gas yield. The main gas components were CO2, CO, CH4, H2, C2H2, C2H6 and C2H4. An increase in temperature and heating rate leads to increasing yields for all the gases up to 825-900°C where CO2 and hydrocarbons yields show a clear tendency to stabilise, increase slightly or decrease slightly depending on the fuel. The gas release dynamics reveal important information about the thermal behaviour of the various components (cellulose, hemicellulose and lignin) of the biomass and are consistent with studies using TGA. The gross calorific value of the gas produced increases with increasing temperature reaching a plateau at 750-900ºC. This study provides valuable data of the thermal behaviour of thermally thick biomass samples which is of interest for further work in the area of combustion, gasification and pyrolysis in fixed beds. The study confirms the potential of those unexploited residues for production of energy carriers through pyrolysis.

Paper IV (or P-IV) ([Becidan 2007b]) proposes a more extensive study of N-release from 3 biomass residues (coffee waste, brewer spent grains, fibreboard). This study of N-behaviour during biomass pyrolysis of thermally thick samples provided several findings. At high heating rate, NH3 and HCN are the two N-containing compounds, NH3 being the main one at all conditions; NH3 release increases with increasing heating rate and temperature to reach a maximum at 825-900°C while HCN yield increases sharply with temperature without reaching a plateau in the temperature range studied. N-selectivity, N release pattern and N-compounds thermal behaviour are affected by the fuel properties, in all probability including N-functionalities. While the total N-conversion levels to (HCN+NH3) are similar for all fuels at high heating rate, the differences are very significant at low heating rate (more than 2-fold for NH3 and 3-fold for HCN). This can be related to the different fuel properties including N-functionalities. Several attempts have been made previously to correlate N-functionalities and N-release during pyrolysis. However no clear dependence has ever been established for biomass. Furthermore, the intricate and versatile nature of N in biomass samples and its interactions with emicellulose, cellulose and lignin prior to and during pyrolysis are difficult to elucidate.

A mechanism of cross-linking between a protein side group and cellulose during pyrolysis was proposed. Further work should focus on the use of the data obtained for improved modelling of biomass pyrolysis. In order to obtain more mechanistic insights the study of model compounds seems more appropriate but may have limited validity because of the intricate structure of “real” biomass. These two types of studies are therefore complementary to obtain a good overview of N-release.

Paper V (or P-V) ([Becidan 2007c]) presents the kinetics of decomposition of the three afore-mentioned biomass residues. The results can be summarised as such:

(1) The samples were studied at five different T(t) temperature programs. The temperature programs covered a wide range of experimental conditions: the experiments exhibited 10 – 14 times variation in time span, mean reaction rate and peak reaction rate.

The experiments on a given sample were described by the same set of model parameters. The optimal parameters were determined by the method of least squares. Three models were proposed that described equally well the behavior of the samples in the range of observations.

(2) A model built from three distributed activation energy reactions was suitable to describe the devolatilisation at the highly different T(t) functions of our study with only 12 adjustable parameters. The other two models contained simpler mathematical equations (first order and nth order partial reactions, respectively), accordingly their use may be more convenient when the coupling of kinetic and transport equations are needed. On the other hand, the simpler models needed higher numbers of parameters to describe the complexity of these wastes

(3) The reliability of the proposed models was tested in three ways: (i) the models provided good fits for all the five experiments of a sample; (ii) the evaluation of a narrower subset of the experiments (the three slowest experiments) provided approximately the same parameters as the evaluation of the whole series of experiments; (iii) the models proved to be suitable to predict the behavior of the samples outside of those experimental conditions at which the model parameters were determined. Check (iii) corresponded to an extrapolation to ca. four-time higher reaction rates from the domain of the three slowest experiments.

(4) The evaluated experiments included “constant reaction rate” (CRR) measurements. This type of temperature control involves a continuously changing heating rate. The simultaneous evaluation of linear, stepwise and CRR experiments proved to be advantageous in the determination of reliable kinetic models. (5) The samples had very different chemical compositions. Nevertheless, the same models described them equally well. Accordingly, the models and the strategies for their evaluation and validation can be recommended for a wider range of biomass studies.

Paper VI (or P-VI) ([Becidan 2007d]), this study on thermally thick biomass samples pyrolysis has investigated (1) temperature field, (2) weight loss at two scales (TGA and macro-TGA). The main findings are:

(a) Qualitative evaluation of the thermal history: three temperature regimes have been identified: (1) exponentially increasing temperature, (2) linearly increasing temperature (3) 2-slope increasing temperature with a flattening period. The regime at a given point will depend on the sample weight, the reactor temperature and the location in the sample.

(b) Quantitative evaluation of the thermal history: significant temperature gradients were measured, with a maximum radial gradient of 167°C/cm for coffee waste at a reactor temperature of 900°C. This will affect the pyrolysis process.

(c) The step-by-step pyrolysis chemistry was described and discussed (10°C/min heating rate). By use of a novel concept, i.e. intra-sample heating rate, the exothermic step of pyrolysis was shown. It is related to char and/or char-forming reactions.

(d) The comparative study of weight loss in TGA and macro-TGA (10°C/min heating rate, never done before to our knowledge) was performed to investigate the “scaling effect”. Pyrolysis time and pyrolysis rate differences were characterised and quantified.


Paper III reprinted with kind permission of Elsevier, sciencedirect. com
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4

González, Martínez María. "Woody and agricultural biomass torrefaction : experimental study and modelling of solid conversion and volatile species release based on biomass extracted macromolecular components." Thesis, Toulouse, INPT, 2018. http://oatao.univ-toulouse.fr/24326/1/gonzalez_martinez.pdf.

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Nowadays, there is an increasing awareness on the importance of biomass waste as a renewable source of energy, materials and chemicals. In this context, the European project MOBILE FLIP aims at developing and demonstrating mobile conversion processes suitable with variousunderexploited agro- and forest based biomass resources in order to produce energy carriers, materials and chemicals. One of these processes is torrefaction, which consists in a mild thermal treatment, occurring typically between 200 and 300°C during a few tens of minutes in a defaultoxygen atmosphere. The solid product obtained has thermal and processing properties closer to coal, and thus is suitable as fuel for combustion or gasification. During torrefaction, condensable coproducts are released, that may also be source of “green” chemicals. It is therefore crucial to characterize them to optimize the torrefaction process and design industrial units. Up to now, only few works have been focused on characterizing and modelling both solid and condensable species during torrefaction versus operating conditions and feedstock type. Furthermore, these studies typically include a reduced number of biomasses. Cellulose, hemicellulose and lignin,which constitute biomass macromolecular composition, are determining properties to predict biomass behaviour during torrefaction. However, torrefaction tests on these constituents are rare and always based on commercial compounds, which were proved as little representative of the native biomass. The objective of this study is to analyse the influence of biomass characteristics, mainly represented by the macromolecular composition in cellulose, hemicellulose and lignin, on the global behaviour of biomass in torrefaction, both in terms of solid mass loss and of productionprofiles of the volatile species released, in function of the operating conditions.14 biomasses from the main biomass families (deciduouswood, coniferous wood, agricultural byproductsand herbaceous crops) were selected for this study. An optimized extraction procedure was proposed to recover cellulose, hemicellulose and lignin fractions from 5 reference biomasses. Experiments were performed on a thermogravimetric analyzer coupled to a gas chromatography mass spectrometer device through a heated storage loop system (TGA-GC/MS). Solid degradation kinetics and volatile release profiles were followed during torrefaction experiments combining non-isothermal (200 to 300°C at 3°C/min) and isothermal (300°C, 30 min) conditions, ensuring the chemical regime thanks to the appropriate operating conditions. The results obtained with the raw materials demonstrated that biomass macromolecular composition is a main factor influencing biomass behavior in torrefaction. Consequently, the heterogeneity of the resource results in a diverse behavior in torrefaction, particularly in the case of agricultural biomasses. The results with the extracted components evidenced their very different behavior compared to thecommercial compounds, particularly in the case of cellulose. This suggests that a limitation could be induced by the common use in literature of commercial components for torrefaction modelling. The impact on the characterization of macromolecular components was also shown to be prevailing in their behavior in torrefaction, especially in the case of hemicellulose sugar composition and cellulose crystallinity. Furthermore, differences in release kinetics of volatile species during torrefaction were observed, even for volatiles belonging to the same chemical family (acids, furans, ketones). Derived from these results, a torrefaction model based on the additive contribution of extracted cellulose, hemicelluloses and lignin to the global behavior of biomass in torrefaction was proposed, and this for the 5 representative biomasses.
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5

Liew, Lo Niee. "Solid-state Anaerobic Digestion of Lignocellulosic Biomass for Biogas Production." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1306870552.

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6

Ramadhan, Omar M. "Biomass derived oil : production, fractionation and structural investigation." Thesis, University of Manchester, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326043.

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7

Sattar, Anwar. "Hydrogen production from biomass for use in solid oxide fuel cells." Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/6335/.

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This thesis presents an investigation into the use of four biochars (wood, rapeseed, miscanthus and sewage sludge) to generate a hydrogen-rich syngas that can be utilised in solid oxide fuel cells. Experimental investigations are split into three sections; (i) biochar characterisation, (ii) biochar gasification and (iii) the use of syngas in a single, microtubular solid oxide fuel cell. Characterisation revealed that wood biochar had the highest carbon content at 71.58%, sewage sludge had the lowest at 30% and rapeseed had the highest mineral content. The effects of temperature on gasification were investigated over a temperature range of 650 - 850°C at a steam flow of 172 g min\(^-\)\(^1\) kg\(^-\)\(^1\) biochar and effects of steam flow at 850°C over a steam flow range of 54 - 277 g min\(^-\)\(^1\) kg\(^-\)\(^1\) biochar. Results revealed the transient behaviour of the process as well as the effects of temperature and steam flow. Dry gas yield increases with both temperature and steam flow, with wood biochar giving maximum values of 2.58 m\(^3\) kg\(^-\)\(^1\) at 850°C and 277 g min\(^-\)\(^1\) kg\(^-\)\(^1\) biochar. Hydrogen content decreases at high temperatures and peak hydrogen content, 58.7%, was achieved at 750°C from the rapeseed biochar. Syngas from wood and rapeseed biochars was collected and used in a microtubular solid oxide fuel cell. Gas from rapeseed had a negative effect on the fuel cell performance, leading to a 28% decrease in the performance over the 30 minutes of potentiostatic operation of 0.7 V. Gas from wood biochar was more suitable and was used in the solid oxide fuel cell for approximately 500 minutes, giving an initial electrical efficiency of 16.8% at 0.7 V.
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8

Recari, Ansa Javier. "Gasification of biomass and solid recovered fuels (SRFs) for the synthesis of liquid fuels." Doctoral thesis, Universitat Rovira i Virgili, 2017. http://hdl.handle.net/10803/450856.

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La gasificació és una tecnologia prometedora per l’aprofitament energètic de biomassa i residus, ja que permet convertir els combustibles sòlids en un gas de síntesi (syngas) amb diverses aplicacions. No obstant això, algunes limitacions encara impedeixen la completa implementació d’aquesta tecnologia a escala industrial, en particular per a la producció de combustibles líquids a partir del procés Fischer-Tropsch (FT). Els principals inconvenients estan relacionats amb la qualitat del syngas, per exemple una baixa relació H2/CO i la presència d’impureses (tar i contaminants menors), i depenen de la naturalesa del material i de les condicions d’operació del procés de gasificació. Aquesta tesi es centra en la millora de la qualitat del syngas de gasificació de biomassa i combustibles sòlids recuperats (CSRs) per a la producció de combustibles líquids. El treball es divideix en dos parts principals. La primera part consisteix en estudis experimentals de gasificació de biomassa i CSRs en un reactor de llit fluïditzat a escala de laboratori per tal d’analitzar la influència de les condicions d’operació (temperatura, agents de gasificació, etc.) en el rendiment del procés i la composició del gas. Ja que els CSRs contenen més quantitats de precursors de contaminants que la biomassa, es va desenvolupar un mètode per tal de determinar la concentració de HCl, H2S, HCN i NH3 en el syngas mitjançant la potenciometria d’ió-selectiu. També, es proposa l’aplicació d’un pretractament tèrmic (torrefacció) als materials de gasificació com un mètode per tal de millorar les propietats dels materials i disminuir l’emissió de contaminants en el syngas. Per últim, la segona part d’aquest treball consisteix en un estudi tecno-econòmic per estimar els costos d’inversió i d’operació de plantes de combustibles líquids FT a partir de la gasificació de biomassa i residus, partint dels resultats obtinguts experimentalment.
La gasificación es una tecnología prometedora para el aprovechamiento energético de biomasa y residuos ya que permite convertir los combustibles sólidos en un gas de síntesis (syngas) con múltiples aplicaciones. Sin embargo, ciertas limitaciones todavía impiden la completa implementación de esta tecnología a escala industrial, en particular para la producción de combustibles líquidos a partir del proceso Fischer Tropsch (FT). Los principales inconvenientes están relacionados con la calidad del syngas, por ejemplo una baja relación H2/CO y la presencia de impurezas (tar y contaminantes menores), y dependen de la naturaleza del material y de las condiciones de operación del proceso de gasificación. Esta tesis se centra en la mejora de la calidad del syngas de gasificación de biomasa y combustibles sólidos recuperados (CSRs) para la producción de combustibles líquidos. El trabajo se divide en dos partes principales. La primera parte consiste en estudios experimentales de gasificación de biomasa y CSRs en un reactor de lecho fluidizado a escala de laboratorio para evaluar la influencia de las condiciones de operación (temperatura, materiales de lecho, agentes de gasificación, etc.) en el rendimiento del proceso y la composición del gas. Debido a que los CSRs contienen mayores cantidades de precursores de contaminantes que la biomasa, se ha desarrollado un método para determinar la concentración de HCl, H2S, HCN y NH3 en el syngas mediante potenciometría de ion selectivo. Además, se propone la aplicación de un pretratamiento térmico (torrefacción) a los materiales de gasificación como un método para mejorar las propiedades de los materiales y disminuir la emisión de contaminantes en el syngas. Por último, la segunda parte consiste en un estudio tecno-económico para estimar los costes de inversión y de operación de plantas de combustibles líquidos FT a partir de la gasificación de biomasa y residuos, partiendo de los resultados obtenidos experimentalmente.
Gasification is a promising technology for energy exploitation of biomass and waste, converting carbonaceous fuels into a synthesis gas (syngas) with multiple applications. However, technical obstacles hinder the full implementation of this technology at industrial scale, particularly for the production of liquid fuels through Fischer-Tropsch (FT) synthesis. Those challenges are mainly related to the syngas quality, such as a low H2/CO ratio and the presence of impurities (tar and minor contaminants), strongly influenced by the nature of the feedstock and the operating conditions of the gasification process. This thesis focuses on the improvement of the syngas quality from gasification of biomass and solid recovered fuels (SRFs) aiming to produce liquid fuels. The present work is divided in two main blocks. The first block corresponds to biomass and SRFs gasification experiments in a lab-scale fluidized bed reactor in order to study the influence of key operating conditions (temperature, bed materials, gasification agents, etc.) on the gasification performance and gas composition. Since SRF materials contain higher amounts of contaminants precursors than biomass, a method to assess the concentration of HCl, H2S, HCN and NH3 in the syngas by means of ion-selective potentiometry was developed. The application of a thermal pretreatment (torrefaction) to the gasification feedstocks is proposed as a way to upgrade the feedstock properties and abate the release of contaminants in the syngas. The second part of this work consists in a techno-economic analysis that estimates capital and production costs of FT liquid fuel plants based on biomass and waste gasification, using as input the experimental results.
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9

Risnes, Håvar. "High Temperature Filtration in Biomass Combustion and Gasification Processes." Doctoral thesis, Norwegian University of Science and Technology, Faculty of Engineering Science and Technology, 2002. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-1485.

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High temperature filtration in combustion and gasification processes is a highly interdisciplinary field. Thus, particle technology in general has to be supported by elements of physics, chemistry, thermodynamics and heat and mass transfer processes. This topic can be addressed in many ways, phenomenological, based on the up stream processes (i.e. dust/aerosol formation and characterisation) or apparatus oriented.

The efficiency of the thermochemical conversion process and the subsequent emission control are major important areas in the development of environmentally sound and sustainable technology. Both are highly important for combustion and gasification plant design, operation and economy.

This thesis is divided into four parts:

I. High temperature cleaning in combustion processes.

II. Design evaluations of the Panel Bed Filter technology.

III. Biomass gasification

IV. High temperature cleaning of biomass gasification product gas

The first part validates the filter performance through field experiments on a full scale filter element employed to a biomass combustion process and relates the results to state of the art within comparable technologies (i.e. based on surface filtration). The derived field experience led to new incentives in the search for a simplified design featuring increased capacity. Thus, enabling both high efficiency and simplified production and maintenance. A thorough examination of design fundamentals leading to the development of a new filter geometry is presented.

It is evident that the up-stream process has significant influence upon the operation conditions of a filter unit. This has lead to a detailed investigation of some selected aspects related to the thermochemical conversion. Furthermore, the influence of fuel characteristics upon conversion and product gas quality is discussed.

The last part discusses the quality of biomass gasification product gas and requirements put upon the utilisation of this gas in turbines, diesel engines or other high temperature applications. Filtration experiments conducted on product gas derived from wood gasification are reported and discussed.

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Josephson, Alexander Jon. "Modeling Soot Formation Derived from Solid Fuels." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/7020.

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Soot formation from complex solid fuels, such as coal or biomass, is an under-studied and little understood phenomena which has profound physical effects. Any time a solid fuel is combusted, from coal-burning power plants to wildland fires, soot formation within the flame can have a significant influence on combustion characteristics such as temperature, heat flux, and chemical profiles. If emitted from the flame, soot particles have long-last effects on human health and the environment. The work in this dissertation focuses on creating and implementing computational models to be used for predicting soot mechanisms in a combustion environment. Three models are discussed in this work; the first is a previously developed model designed to predict soot yield in coal systems. This model was implemented into a computational fluid dynamic software and results are presented. The second model is a detailed-physics based model developed here. Validation for this model is presented along with some results of its implementation into the same software. The third model is a simplified version of the detailed model and is presented with some comparison case studies implemented on a variety of platforms and scenarios. While the main focus of this work is the presentation of the three computational models and their implementations, a considerable bulk of this work will discuss some of the technical tools used to accomplish this work. Some of these tools include an introduction to Bayesian statistics used in parameter inference and the method of moments with methods to resolve the 'closure' problem.
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11

Lind, Terttaliisa. "Ash formation in circulating fluidised bed combustion of coal and solid biomass /." Espoo, Finland : Technical Research Centre of Finland, 1999. http://www.vtt.fi/inf/pdf/publications/1999/P378.pdf.

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12

Norheim, Arnstein. "Experimental investigation of Solid Oxide Fuel Cells using biomass gasification producer gases." Doctoral thesis, Norwegian University of Science and Technology, Department of Energy and Process Engineering, 2005. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-1714.

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13

Tran, Khanh Cong. "Anaerobic digestion of microalgal biomass : effects of solid concentration and pre-treatment." Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/415791/.

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Microalgae have recently attracted considerable attention as a potential substrate for biofuel production. Through the anaerobic digestion process, microalgal biomass can be converted to biogas. Although the first work on anaerobic digestion of microalgae appeared in the 1950s, for a long time further information on AD of microalgae was scarce. This study assessed the potential for energy recovery from microalgal biomass grown in two large-scale systems in Spain: a closed tubular photobioreactor (PBR) and an open raceway. A series of digestion trials was carried out using freeze dried microalgae (FDA) from the PBR and fresh frozen microalgae (FFA) from the open raceway system as feedstock. Results from biochemical methane potential (BMP) assays showed that both feedstocks were poorly degraded and gave low methane yields. The specific methane yields of FDA and FFA were 0.161 and 0.220 L CH4 g-1 VS , respectively, which is only about 30% and 44% of the Theoretical Methane Potential (TMP) of these substrates based on their elemental composition. Digestion of FDA under semi-continuous conditions was stable at feedstock concentrations of up to 10% VS, equivalent to a hydraulic retention time of 20 days. Specific methane yields (SMY) were 0.11 - 0.12 L CH4 g-1 VS, corresponding to 69 - 75% of the value obtained from BMP. Digestion of FDA at 20% VS concentration gave only 0.09 L CH4 g-1 VS which is 56% of the value from BMP, or ~21% of the measured calorific value (CV). The digesters operating at 20% VS were able to achieve meta-stable operation at very high total ammonia nitrogen (TAN) concentrations of up to 12 g L-1 while showing reasonable methane production. They therefore showed a degree of adaptation to high TAN, but no evidence of improved biomass degradation even after operating periods in excess of 800 days. Results from the isotope labelling experiment indicated that syntrophic methanogenic pathway was the major route in high TAN concentration digesters. Digestion of FFA was stable at feedstock concentration of 4.33% VS and OLR up to 3.5 g VS L-1 day-1. SMY obtained under semi-continuous conditions was ~0.13 L CH4 g-1 VS, corresponding to 23% of the measured CV. A series of pretreatments were carried out on FFA, and the combined thermal-alkaline pretreatment (dosage of 3% w/w NaOH and incubated in water bath at 80 oC for 2 hours) enhanced SMY by 42% compared with that of untreated FFA obtained under batch condition. The results from semi-continuous condition indicated that some improvement was achieved with the thermal alkaline pretreatment, but there were also signs of inhibition due to the high alkaline dosages of 3% NaOH (w/w) required. There is clearly scope for optimisation of the treatment of feedstock and adaptation of the inoculum.
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Agarwal, Gaurav. "Solid Fuel Blend Pyrolysis-Combustion Behavior and Fluidized Bed Hydrodynamics." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/51677.

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As a carbon neutral and renewable source of energy, biomass carries a high potential to help sustain the future energy demand. The co-firing of coal and biomass mixtures is an alternative fuel route for the existing coal based reactors. The main challenges associated with co-firing involves proper understanding of the co-firing behavior of blended coal-biomass fuels, and proper understanding of advanced gasification systems used for converting such blended fuels to energy. The pyrolysis and combustion behavior of coal-biomass mixtures was quantified by devising laboratory experiments and mathematical models. The pyrolysis-combustion behavior of blended fuels was quantified on the basis of their physicochemical, kinetic, energetic and evolved gas behavior during pyrolysis/combustion. The energetic behavior of fuels was quantified by applying mathematical models onto the experimental data to obtain heat of pyrolysis and heat of combustion. Fuel performance models were developed to compare the pyrolysis and combustion performance of non-blended and blended fuels. The effect of blended fuel briquetting was also analyzed to find solutions related to coal and biomass co-firing by developing a bench scale fuel combustion setup. The collected data was analyzed to identify the effects of fuel blending and briquetting on fuel combustion performance, ignitability, flammability and evolved pollutant gases. A further effort was made in this research to develop the understanding of fluidized bed hydrodynamics. A lab scale cold-flow fluidized bed setup was developed and novel non-intrusive techniques were applied to quantify the hydrodynamics behavior. Particle Image Velocimetry and Digital Image Analysis algorithms were used to investigate the evolution of multiple inlet gas jets located at its distributor base. Results were used to develop a comprehensive grid-zone phenomenological model and determine hydrodynamics parameters such as jet particle entrainment velocities and void fraction among others. The results were further used to study the effect of fluidization velocity, particle diameter, particle density, distributor orifice diameter and orifice pitch on the solid circulation in fluidized beds.
Ph. D.
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15

Tanjore, Deepti Richard Thomas L. "Biological pretreatments of corn stover biomass through aerobic and anaerobic solid substrate fermentation." [University Park, Pa.] : Pennsylvania State University, 2009. http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-4318/index.html.

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16

Efika, Emmanuel Chidi. "Hydrogen rich syngas from the pyrolysis and gasification of solid waste and biomass." Thesis, University of Leeds, 2013. http://etheses.whiterose.ac.uk/4943/.

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Biomass and wastes are potential resources for the production of renewable hydrogen, synthetic fuels, chemicals and energy via pyrolysis and gasification. Waste biomass and refuse derived fuel (RDF), and their single components were investigated for pyrolysis to produce a hydrogen rich syngas with a bench scale fixed bed reactor. The samples were pyrolysed at different temperatures, heating rates and particle sizes to recover syngas, oil and char products. The waste biomass was investigated for steam pyrolysisgasification in a continuous screw kiln reactor to produce hydrogen. The samples were gasified at different temperatures, steam/biomass ratios, and in the presence of nickel catalysts. The effects of nickel loading on the catalyst, the catalyst/waste biomass ratio, the effects of different metal additives and the effect of in-situ CO2 capture were also investigated for hydrogen production and resistance to catalyst deactivation by coking. A commercial scale pyrolysis reactor was studied for the pyrolysis of real world wastes. FTIR and GC/MS analysis of the oils from the pyrolysis of waste biomass, RDF and their single components indicated that the oil product from high heating rate pyrolysis contained mostly aromatics and alkenes, while that from slow heating rate contained mostly oxygenates, alkanes and alkenes. Gaseous products from the waste biomass, RDF and their single components contained mostly CO, CO2, H2, CH4 and C2 – C4 gases. Increasing the pyrolysis temperature and heating rate both resulted in an increase in gas and hydrogen production while reducing the oil and solid char yields. The gas yield and hydrogen yield were increased with increasing nickel loading and catalyst to waste biomass ratio during steam pyrolysisgasification. The lowest tar yield of 0.01g of tar per m3 of gas and highest hydrogen yield of 55 vol% were achieved at catalyst/waste biomass ratio of 2. Ce and La promoted catalysts showed improved catalyst resistance to coking and increased hydrogen yield. CaO resulted in in-situ capture of CO2 however the H2 yield was not increased due to the deactivation of CaO by tar in. The commercial scale system resulted in conversion of wastes to syngas, oil and char however results were not comparable to laboratory scale results due to limitations in the commercial scale process.
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17

Mochulski, David. "Multiple reaction solid state kinetic parameter determination and its application to woody biomass." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/51179.

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The economic problem of sustainable and environmentally responsible energy production has prompted research into a number of potential alternatives to fossil fuels. Biomass gasification has been identified as one such alternative, but incomplete characterization of the process has hindered development. This thesis addresses the problem of predicting reaction rate behavior in the case of woody biomass and aids in identifying optimal feedstock composition. Black cottonwood (Populus trichocarpa) and Lodgepole pine (Pinus contorta) samples were characterized in terms of their primary component composition (lignin, cellulose, and hemicellulose) and then subjected to gasification experiments. This consisted of pyrolysis, under a nitrogen atmosphere, and then gasification, under a dry air atmosphere, while undergoing a linear temperature program in a thermogravimetric analyzer (TGA). Inspection of the experimental data indicated the presence of three simultaneous reactions. The data was then analyzed to recover the isoconversional activation energy trend, pre-exponential factors, and reaction mechanisms. Results indicated that the contributions of the three reactions did not correspond directly to lignin, cellulose, and hemicellulose contents, but, in the case of nitrogen pyrolysis, could be predicted by the knowledge of these components. Regarding air gasification, no significant correlations between reaction rate behavior and primary wood component fraction were found. Qualitatively, the work showed that the rate at which pyrolysis occurs is increased by high cellulose and hemicellulose contents, and decreased by large lignin contents. A detailed kinetic model describing both Poplar and Lodgepole pine pyrolysis behavior was also recovered and is reported in the body of the thesis.
Applied Science, Faculty of
Chemical and Biological Engineering, Department of
Graduate
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18

Bansal, Sunil. "Evaluation of different agricultural biomass for bioethanol production." Thesis, Kansas State University, 2010. http://hdl.handle.net/2097/4623.

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Master of Science
Department of Grain Science and Industry
Praveen V. Vadlani
In our study, five different bioenergy crops: wheat straw (Triticum aestivum), forage sorghum stover (sorghum bicolor), switchgrass (Panicum virgatum), miscanthus (Miscanthus giganteus) and sweet sorghum baggase (Sorghum bicolor) were evaluated for bio-ethanol production at 20% (w/v) initial substrate concentration under separate hydrolysis and fermentation (SHF) process. The substrates were ground to pass through 600µm mesh size and treated with 2% (w/v) NaOH at 121oC for 30 minutes. The washed and neutralized pretreated residues were subjected to saccharification using cellulase and β-glucosidase enzymes (ratio 1:1.25) at concentrations of 25 filter paper unit (fpu)/g and 31.25fpu/g, respectively, in pH 5.0 citrate buffer in an orbital incubator shaker at 150 rpm for 72 h. The hydrolysate obtained was centrifuged and supernatant was collected for fermentation. Fermentation was performed in shake flasks using Saccharomyces cerevisiae at 10% (w/v) inoculum concentration at 100 rpm for 24 h. Alkali treatment was effective in delignification of all the biomass feedstocks. The highest percent removal on raw biomass basis was attained for sorghum stover BMR-DP (81.3%, w/w) followed by miscanthus (79.9%, w/w), sorghum stover BMR-RL (69.2 %, w/w), wheat straw (68.0 %, w/w), switchgrass (66.0%, w/w), and sorghum baggase (65.4%, w/w). Glucan saccharification varied from 56.4-72.6 % (w/w) corresponding to a glucose levels of 0.45-0.34 g/g of dry substrate. Highest saccharification was observed for wheat straw while lowest was observed for miscanthus after 48 hours of hydrolysis. A maximum final ethanol concentration of 4.3% (w/v) was observed for wheat straw followed by sorghum baggase (4.2%), sorghum RL-BMR (3.6%), miscanthus (3.4%), sorghum DP-BMR (3.4%), and switchgrass (3.2%). From our studies, it is evident that high substrate concentration used for enzymatic hydrolysis was able to provide high final ethanol concentration. The lignin content and its arrangement in different biomass feedstocks may have affected saccharification and subsequent ethanol production. Bulk density and flowability are the two major key parameters that should be addressed to reduce processing cost of biomass for bioethanol production. Pelleting of biomass can increase the bulk density, thereby reducing the handling and transportation costs. In addition to above study, I analyzed the changes in chemical composition due to pelletization and pretreatment, and its effect on ethanol production by comparing unpelleted and pelleted biomass ethanol production efficiency. Wheat straw and big bluestem pelleted and unpelleted biomass were compared for their ethanol production efficiency. Pelleted and unpelleted wheat straw (Triticum aestivum) and bigblue stem (Andropogon gerardii Vitman) at a substrate concentration of 10% (w/v) were subjected to 2% NaOH treatment at 1210C for 30 min and the resulting residues were analyzed for changes in chemical composition. Saccharification of residue was done at substrate concentration of 12% (w/v) for 48 h. The sugars obtained were fermented to ethanol using Saccharomyces cerevisiae. Pelletization did not significantly affect the chemical composition of biomass in terms of glucan, xylan and lignin content. Delignification of pelleted biomass was greater than unpelleted biomass. Pelletization did not influence final ethanol production for both substrates.
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Abdul, Manan Musaalbakri. "Design aspects of solid state fermentation." Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/design-aspects-of-solid-state-fermentation(d64ea506-85ee-424f-9bca-531488e3e3c7).html.

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Solid state fermentation (SSF) refers to the microbial fermentation, which takes place in the absence or near absence of free water, thus being close to the natural environment to which the selected microorganisms, especially fungi, are naturally adapted. The current status of SSF research globally was discussed in terms of articles publication. This was followed by discussion of the advantages of SSF and the reason for interest in SSF as a notable bioprocessing technology to be investigated and compared to submerged fermentation (SmF) for the production of various added-value products. SSF also proved to be a potential technology to treat solid waste produced from food and agricultural industry and to provide environmental benefits with solid waste treatment. A summary was made of the attempts at using modern SSF technology for future biorefineries for the production of chemicals. Many works were carried out in the Satake Centre for Grain Process Engineering (SCGPE), University of Manchester, to prove the strategy of using SSF for the production of hydrolysate rich in nutrients for sequel microbial fermentation with or without adding any commercial nutrients. The research findings presented in this thesis are based on a series of SSF experiments carried out on systems varying in complexity from simple petri dishes to our own design of bioreactor systems. They were conducted to assess a solution for biomass estimation, enzymes production, and successful mass and heat transfer. A proper technique for inoculum transfer prior to the start of the fermentation process was developed. In SSF, estimation of biomass presents difficulties as generally the fungal mycelium penetrates deep and remains attached with the solid substrate particles. Although many promising methods are available, the evaluation of microbial growth in SSF may sometimes become laborious, impractical and inaccurate. Essentially, this remains another critical issue for monitoring growth. In these studies, measurement of colour changes during SSF are presented as one of the potential techniques that can be used to describe growth, complementary to monitoring metabolic activity measurement, such as CER, OUR and heat evolution, which is directly related to growth. For the growth of Aspergillus awamori and Aspergillus oryzae on wheat bran, soybean hulls and rapeseed meal, it was confirmed that colour production was directly proportional to fungal growth. This colourimetric technique was also proved to be a feasible approach for fungal biomass estimation in SmF. This new approach is an important complementation to the existing techniques especially for basic studies. The key finding is that the colourimetric technique demonstrated and provided information of higher quality than that obtained by visual observation or spores counting. The effect of aeration arrangements on moisture content, oxygen (O2), mass and heat transfer during SSF was investigated. A. awamori and A. oryzae were cultivated on wheat bran in newly designed four tray solid state bioreactor (SSB) systems. The new tray SSB systems were: (1) single circular tray SSB, (2) multi-stacked circular tray SSB, (3) Single rectangular tray SSB and (4) multi-square tray SSB. The purpose was to study the effect, on heat and water transfer, of operating variables, fermentation on the perforated base tray and internal moist air circulation under natural and forced aeration. Temperature, O2 and carbon dioxide were measured continuously on-line. Enzyme activity, moisture content and biomass were also measured. The results suggest that the air arrangements examined have a remarkable effect on the quantity of biomass produced using measurement of spores and enzymes production. The strategy presented in these studies allowed quantitative evaluation of the effect of forced internal moist air circulation on the removal of metabolic heat. With the proposed strategy, it was possible to maintain the bed temperatures at the optimum level for growth. However, the effect on moisture content was very different for the two fungi. It was found that the ability of A. oryzae to retain moisture was much higher than that of A. awamori. This is possibly due to the higher levels of chitin in A. oryzae. Greater spores and enzymes (glucoamylase, xylanase and cellulase) production was observed for A. awamori in multi-stacked circular tray and multi-square tray SSB systems compared to the conventional petri dishes and the other two systems. A. oryzae was excellent in producing protease in the same bioreactors. A direct technique of establishing a correlation between fungal growth and CER, OUR, heat evolved was proven successful in this work. The information obtained from CER and OUR led to the estimation of respiratory quotient (RQ). RQ describes the state of the fungal population in the tray SSB and gives an indication of fungal metabolic behaviour. RQ values < 1 were obtained from 38 experiments using four tray SSB systems for the two fungi. A kinetic model based on CO2 evolution instead of biomass concentration was examined in order to simplify the required experiments for kinetic model development. A Gompertz model was used to fit the integrated CO2 data and predict the quantity of CO2 evolution in all experiments. A correlation was found between the heat evolution and CER. The performances of tray SSB systems can be improved by constructing them as multi-trays. The multi-tray systems improved the mass transfer considerably compared with single tray systems. In addition, the multi-tray systems allowed precise measurement of the gradients of CO2, enzymes, spores and fungal biomass. In addition, the air arrangements using moistened air were successful in maintaining moisture content, adequate O2 supply and control of temperature, and hence, increased the productivity of both fungi. Overall A. awamori and A. oryzae have their own ability and performance to degrade and utilise the complex compositions contained in the solid substrate and fermentation conditions may lead to possible comparisons. In addition, multi-stacked circular tray and multi-square tray SSB systems demonstrated an excellent system for further investigations of mass transfer and possibly for large scale operation, though considerable optimisation work remains to be done, for example the height/diameter ratio and total number of trays should be optimised.
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20

Lin, Long. "Technical, Microbial, and Economic Study on Thermophilic Solid-state Anaerobic Digestion of Lignocellulosic Biomass." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1500505570855855.

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21

Adeniyi, Olalekan David. "The use of biomass in molten carbonate and solid oxide direct carbon fuel cells." Thesis, University of Sheffield, 2011. http://etheses.whiterose.ac.uk/1964/.

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A direct carbon fuel cell (DCFC) is a special type of high temperature fuel cell that uses solid carbon as fuel and air as oxidant. Researches in the area of the DCFC have focused on using fuel derived from petroleum products, coal and activated carbon but this current research investigates the use of biomass carbon fuel in a single cell DCFC. Six different biomasses were investigated (miscanthus, switchgrass, wheat, spruce, poplar and willow). The biomasses were subjected to pyrolysis reaction at 800oC, 7oC/min with particle sizes of 0.50 mm to 1.00 mm, yielding 25 wt.% biomass carbon. The two electrolyte systems investigated were; molten carbonate electrolyte direct carbon fuel cell (MCDCFC) and solid oxide electrolyte direct carbon fuel cell (SODCFC) and these were tested using hand and ball milled biomass carbon fuels (HM and BM). The overall electrochemical reactions of the biomass carbon fuels in the SODCFC were better than those of the MCDCFC. The BM biomass fuels performed better in the SODCFC while the HM biomass fuels performed better in the MCDCFC. In terms of the open circuit voltage, miscanthus fuel (1.24 V) had the best value for SODCFC while willow fuel (0.83 V) for MCDCFC. The best peak power density was recorded for miscanthus fuel (77.41 mW/cm2) in the SODCFC and willow fuel (18.48 mW/cm2) in the MCDCFC. Miscanthus fuel (180.52 mA/cm2) gave the maximum current density for the SODCFC while spruce fuel (73.02 mA/cm2) for the MCDCFC. For the current density at 80% voltage efficiency miscanthus fuel (100 mA/cm2) was superior for the SODCFC and willow fuel (6.67 mA/cm2) for MCDCFC. Miscanthus fuel (0.66 V) showed the highest voltage at peak power for the SODCFC and willow fuel (0.48 V) for the MCDCFC. The overall energy strategy considering two major routes of electricity generation from biomass were investigated. The first route is the burning of biomass in a power plant to generate 6.5 MJ of electricity and the second is the DCFC integrated route using biomass to generate 12.8 MJ of electricity. The DCFC integrated route gave superior outputs of energy generation with an overall conversion efficiency of 70% when compared with the 35% of the first route.
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22

Brown, Dan Lee. "Comparison of Solid-State to Liquid Phase Anaerobic Digestion of Lignocellulosic Biomass for Biogas Production." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1341870854.

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23

Kim, Hyung Rae. "Chemical Looping Process for Direct Conversion of Solid Fuels In-Situ CO2 Capture." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1250605561.

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24

Friberg, Rasmus. "A new measurement method to analyse the thermochemical conversion of solid fuels." Doctoral thesis, KTH, Materials Science and Engineering, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3014.

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The firing of fuel wood has been identified as one of themain causes of pollutant emissions from small-scale (<100kW) combustion of wood fuels. The emissions are a result ofinsufficient combustion efficiency. This thesis presents a newmeasurement method to analyse the thermochemical conversion ofbiofuels in general, as well as to explain the main reason ofthe inefficient combustion of fuel wood in particular.

In general, small-scale combustion of biofuels are carriedout by means of packed-bed combustion (PBC)technology. Acomprehensive literature review revealed that textbooks,theories, and methods in the field of thermochemical conversionof solid fuels in the context of PBC are scarce. This authorneeded a theoretical platform for systematic research on PBC ofbiofuels. Consequently, a new system theory - the three-stepmodel - was developed, describing the objectives of, theefficiencies of, and the process flows between, the leastcommon functions (subsystems) of a PBC system. The three stepsare referred to as the conversion system, the combustionsystem, and the heat exchanger system (boiler system). A numberof quantities and concepts, such as solid-fuel convertibles,conversion gas, conversion efficiency, and combustionefficiency, are deduced in the context of the three-step model.Based on the three-step model a measurement method washypothetically modelled aiming at the central physicalquantities of the conversion system, that is, the mass flow andstoichiometry of conversion gas, as well as the air factor ofthe conversion system. An uncertainty propagation analysis ofthe constitutive mathematical models of the method was carriedout. It indicated that it should be possible to determine themass flow and stoichiometry of conversion gas within the rangesof relative uncertainties of ±5% and ±7%,respectively. An experimental PBC system was constructed,according to the criteria defined by the hypothetical method.Finally, the method was verified with respect to total massflow of conversion gas in good agreement with the verificationmethod. The relative error of mass flow of conversion gas wasin the range of ±5% of the actual value predicted by theverification method.

One experimental series was conducted applying the newmeasurement method. The studied conversion concept correspondedto overfired, updraft, horizontal fixed grate, and verticalcylindrical batch reactor. The measurements revealed newinformation on the similarities and the differences in theconversion behaviour of wood chips, wood pellets, and fuelwood. The course of a batch conversion has proven to be highlydynamic and stochastic. The dynamic range of the air factor ofthe conversion system during a run was 10:1. The empiricalstoichiometry of conversion gas during a run was CH3.1O:CH0O0. Finally ,this experimental series revealed one ofthe main reasons why fuel wood is more difficult to burn thanfor example wood pellets. The relatively dry fuel wood (12-31g/m2,s) displayed a significantly lower time-integratedmean of mass flux of conversion gas than both the wood pellets(37-62 g/m2,s) and the wood chips (50-90 g/m2,s). The higher the mass flux of conversion gasproduced in the conversion system, the higher the combustiontemperature for a given combustion system, which in turn ispositively coupled to the combustion efficiency.

In future work the method will be improved so thatmeasurements of combustion efficiency can be carried out. Othertypes of conversion concepts will be studied by the method.

Keywords: Packed-bed combustion, thermochemical conversionof biomass, solid-fuel combustion, fuel-bed combustion, gratecombustion, biomass combustion, gasification, pyrolysis,drying.

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Mason, Patrick Edward. "On the combustion of solid biomass fuels for large scale power generation : investigations on the combustion behaviour of single particles of pulverised biomass fuel." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/15490/.

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Biomass is classed as a renewable resource. Depending on the means of production, it can be sustainable and can provide net benefits regarding CO2 emissions by displacing fossil fuels as an energy source. A significant biomass energy conversion technology is combustion in conventional thermal power stations. This can be implemented in large scale plants such as those which dominated electricity generation throughout the 20th century. While these power stations were generally fuelled by the erstwhile ‘King Coal’, the technology is not exclusive to it. Coal consumption can be displaced in these types of plants by either co-firing biomass with coal or full conversion to biomass. Currently, in the UK, the vast majority of the biomass fuel consumed for power generation is imported pelletized forestry wood. However, sustainability and domestic energy security concerns have created interest in using other resources including energy crops such as short rotation coppice willow and miscanthus, agricultural by-products such as wheat straw and olive residue. The variation in the properties of these fuels presents a number of technical challenges which conventional power plant must overcome to achieve ‘fuel flexibility’. Along with other technical challenges regarding the operation of conventional thermal power plant, these formed the basis of the Research Councils UK funded consortium grant (EPSRC, 2012) entitled Future Conventional Power. As a consortium partner in this project, the University of Leeds led research tasks associated with fuel flexibility. Much of the research presented in this thesis was based on the objectives set out in the Future Conventional Power project and was financially supported though this grant. Two particular challenges provide the incentive for the investigations presented in this thesis and can be summarised as: • assessing the variability in fuel combustion behaviour and control of burn-out efficiency for different fuels • understanding the behaviour of potassium during the combustion of biomass fuels to aid in the prediction of ash behaviour, emissions and associated operational problems Both these points were addressed with a series of experimental studies. In addition, a model of the combustion of single particles was developed for validating and interpreting the results. A range of fourteen solid biomass fuels, typical of those likely to be used in large scale power plant, were selected for the experimental studies. The composition and fundamental characteristics of these fuels, obtained by standard analytical techniques, are presented. In the first experimental study, single particles were exposed to a methane flame, simulating biomass combustion in a furnace. Measurements of ignition delay, volatile burning time and char burn-out time were undertaken using high speed image capture. Particle surface temperatures were measured by infra-red thermal imaging. Analysis of the data identified correlations between the biomass fundamental characteristics, particle size, and the observed combustion profiles. Empirical expressions for the duration of each combustion stage are obtained from the data. From these, a “burn-out” index is derived which provides a useful indication of the relative milling requirements of different fuels for achieving effective burn-out efficiency. A similar experimental method was used in the second study in which the gas-phase potassium release patterns from single particles of various biomass fuels were measured by use of flame emission spectroscopy. The observed potassium release patterns for the various fuel samples are presented. The release patterns revealed qualitative differences between different fuel types. Relationships between the initial potassium content, peak rate of release and the fractions of potassium released at each stage of combustion were identified. These were subsequently used for comparing with results of modelled potassium release. A third experimental study investigated the variation in thermal conductivity between different types of solid biomass using a technique and apparatus developed specifically for the study. The results showed variation of thermal conductivity between different types of biomass which had been similarly homogenised and densified. The thermal conductivity of small particles of each fuel was derived. The resulting data provides useful values for thermal modelling of biomass particles and is used subsequently in a combustion model. Elements of each of the experimental studies were used in a detailed model of single particle combustion. In this, the particle was modelled as a series of concentric spherical layers which enabled calculation of internal mass diffusion and heat transfer. Devolatilisation and char oxidation were approximated with single step reaction kinetics. A volatilisation and diffusion mechanism was adopted to simulate the release of gas-phase potassium from the particle. The output from the model was compared and validated using data from the experimental studies. The modelling produced confirming evidence that the assumed mechanisms for gas-phase potassium release were valid and provided a tool for future investigation of the subject.
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Kuhn, John N. "Investigation of catalytic phenomena for solid oxide fuel cells and tar removal in biomass gasifiers." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1186755244.

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27

Nowak, Piotr [Verfasser], and Helmut [Akademischer Betreuer] Seifert. "Combustion of biomass and solid recovered fuels on the grate / Piotr Nowak ; Betreuer: Helmut Seifert." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2019. http://d-nb.info/1205736999/34.

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Kuhn, John. "Investigation of catalytic phenomena for solid oxide fuel cells and tar removal in biomass gasifiers." The Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=osu1186755244.

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Petricoski, Silvia Maccari. "Briquetes produzidos com mistura de podas urbanas, glicerina e resíduos de processamento de mandioca." Universidade Estadual do Oeste do Paraná, 2017. http://tede.unioeste.br/handle/tede/2969.

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Throughout history, several sources and forms of energy have been used for production of goods and services. especially energy generated from fossil fuels such as oil. Due to the limits of their world reserves; CO2 emissions and ecological disasters from oil well drilling, it is crucial to think in renewable and sustainable sources of energy: those that naturally reconstitute themselves in a short period of time. One the alternatives for solving this problem is the energy coming from biomasses, whether animal or vegetable origin, it can be used to production of energy. The briquette is considered a solid biofuel, made from compaction of lignocellulosic residues much used to energy generation. This paper aimed to study production of briquettes from mixtures of urban pruning waste - RPU, from glycerine and cassava bagasse (Manihot esculenta). A prototype drier was used through solar heating to reduce humidity of RPU and cassava samples. Afterwards, samples of RPU, cassava bagasse and glycerin were mixed, yielding the treatments T1 (100% RPU), T2 (92% RPU and 8% Cassava bagasse), T3 (97% RPU and 3% Glycerin), T4 (89% RPU, 8% Cassava bagasse and 3% Glycerin) and T5 (94.5% RPU, 4% Cassava bagasse and 1,5% Glycerin). Then the analyzes of physical, chemical and energetic parameters the briquettes were carried out. The moisture content of the briquettes was lower in T1 treatment (7.935%). T2 treatment had lower fixed carbon value (16.858%) volatile content (66.520%) and higher ash content (16.621%). The percentages of C, H and N did not differ statistically between the treatments. The values of the upper, lower and useful calorific value were higher on T3 (18.973 MJ kg-1); (17,480 MJ kg-1) and (15,980 MJ kg-1) respectively. The apparent density was higher in T1 (1183 kg m-3) as well as energy density (20778.76 MJ m-3). Treatment T2 had the highest mechanical strength (1,281 kgf cm-2). The results, therefore, showed that treatments T1, T2 and T3 were more efficient, producing briquettes with properties that meet specifications of the market, besides presenting great energetic potential, being good substitutes for firewood. Based on information collected in Vera Cruz do Oeste - PR in 2015, approximately 76.92 t ano-1 of briquettes from urban pruning residues could be produced, thus contributing to generation of revenue in the value of R$ 23,614.44.
Ao longo da história, diversas foram as fontes e as formas de energia utilizadas para a produção de bens e de serviços, em especial a energia gerada a partir de combustíveis fósseis, como o petróleo. Em função dos limites de suas reservas mundiais; as emissões de CO2, e os desastres ecológicos a partir da perfuração de poços de petróleo, é fundamental pensar em fontes de energia renováveis e sustentáveis: aquelas que se reconstituem naturalmente, num curto período de tempo. Uma das alternativas para a solução deste problema é a energia proveniente das biomassas, seja de origem animal ou vegetal, que pode ser utilizada na produção de energia. O briquete é considerado um biocombustível sólido, feito a partir da compactação de resíduos lignocelulósicos muito utilizado para a geração de energia. Neste trabalho objetivou-se estudar a produção de briquetes a partir de misturas de Resíduos de Podas Urbanas - RPU, glicerina e bagaço de mandioca (Manihot esculenta). Para a redução da umidade das amostras de RPU e de mandioca, foi utilizado um secador via aquecimento solar. Posteriormente, as amostras dos RPU, do bagaço de mandioca e a glicerina foram misturadas gerando os tratamentos, T1 (100% RPU), T2 (92% RPU e 8% Bagaço de mandioca), T3 (97% RPU e 3% Glicerina), T4 (89% RPU, 8% Bagaço de mandioca e 3% Glicerina) e T5 (94,5% RPU, 4% Bagaço de mandioca e 1,5% Glicerina). Em seguida, foram realizadas as análises de parâmetros físicos, químicos e energéticos dos briquetes. O teor de umidade dos briquetes foi menor no tratamento T1 (7,935%). O tratamento T2 teve menor valor de carbono fixo (16,858%) e teor de voláteis (66,520%) e maior teor de cinzas (16,621%). As porcentagens de C, H e N não diferiram estatisticamente entre os tratamentos. Os valores do poder calorífico superior, inferior e útil foram maiores no tratamento T3 (18,973 MJ kg-1); (17,480 MJ kg-1) e (15,980 MJ kg-1) respectivamente. A densidade aparente foi maior no tratamento T1 (1.183 kg m-3) bem como a densidade energética (20.778,76 MJ m-3). O tratamento T2 teve a maior resistência mecânica (1,281 kgf cm-2). Os resultados, portanto, demonstraram que os tratamentos T1, T2 e T3 foram mais eficientes, produzindo briquetes com propriedades que atendam as especificações do mercado, além de apresentarem grande potencial energético, sendo bons substitutos à lenha. Com base nas informações coletadas no Município de Vera Cruz do Oeste - PR no ano de 2015, poderiam ser produzidos aproximadamente 76,92 t ano-1 de briquetes oriundos de resíduos de podas urbanas, contribuindo desta forma para a geração de receita no valor de R$ 23.614,44.
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30

BERNARD, KIVUMBI. "EVALUATION OF POSSIBLE GASIFIER-ENGINE APPLICATIONS WITH MUNICIPAL SOLID WASTE (A CASE STUDY OF KAMPALA)." Thesis, KTH, Kraft- och värmeteknologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-98777.

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Gasification of biomass for electricity power generation has been a proven technology in a number of countries in the world. MSW consists of biomass, glass, plastics, metallic scrap and street debris. Biomass constitutes the highest proportion of MSW and being an energy resource, implies that it can contribute tremendously to the energy needs of any country since every country is endowed with this resource which is generated in enormous tonnes per day. The challenge would then be the choice of the technology to harness this abundant energy resource subject to financial and environmental constraints.    In Uganda, MSW gasification for power generation has never been implemented in spite of the 500-600 tonnes of MSW collected per day, the biomass component of the MSW comprising 88%. MSW is instead collected in skips, transported by trucks to a landfill were it is deposited and left to decompose releasing methane (CH4) and carbon dioxide (CO2) gases which are highly potent greenhouse gases. In this regard, the many tonnes per day of MSW collected in Kampala city (area of the study) portray significant potential of generating producer gas using the technology of gasification to run engines for power generation and this study evaluated possible gasifier-engine system applications for power generation. Experiments were carried out  at the Faculty of Technology, Makerere University to determine biomass characteristics (e.g. moisture content, ash content) and gasification parameters(e.g. lower heating value)  of MSW required for gasifier-engine applications. After establishing the lower heating value of the producer gas from MSW, a theoretical design of a gasifier-engine system was investigated for possible applications with the biomass component of MSW and an economic analysis was done to assess the feasibility of the project.
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31

Modolo, Regina Célia Espinosa. "Valorization of solid wastes from cellulose and paper industry." Doctoral thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/13961.

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Doutoramento em Ciências e Engenharia do Ambiente
This thesis reports in detail studies of industrial solid wastes valorization as alternative raw materials. All tested wastes are classified as non-hazardous and are generated in the pulp and paper process, including primary sludge, dregs, grits, lime mud and bottom ash (this generated in a process that occurs in parallel to the production of cellulose, whose aim is the production of energy to supply the plant through the combustion of forest biomass in fluidized bed). A detailed general characterization was performed at each waste and according to their characteristics, they were selected some applications in materials with potential use, specifically in Fibercement, Bituminous Mixture for regularization layer and industrial mortars (rendering mortars and cementitious-adhesive). After decided to application each waste was specifically tested to proceed the setting up of formulations containing different content of waste in replacement of the raw conventional material. As an isolated case, the bottom ash was tested not only as an alternative raw material for construction materials, but also it was tested for its use in fluidized bed in which the waste is generated as raw material. Both dregs and bottom ash had undergone special treatment to make possible to obtain a better quality of waste in order do not compromise the final product characteristics and process. The dregs were tested in bituminous mixtures as received and also washed (on the laboratory scale to remove soluble salts) and bottom ash were washed and screened in industrial scale (for removal of soluble salts, especially chlorides and coarse fraction particles elimination - particles larger than 1 mm size). The remaining residues form used in such as received avoiding additional costs. The results indicated potential and some limitations for each application to the use of these wastes as alternative raw material, but in some cases, the benefits in relation to valorization overlap with its limitations in both aspects, environmental and economic.
O presente trabalho reporta detalhadamente estudos de valorização de resíduos sólidos industriais como matérias-primas alternativas. Todos os resíduos testados são classificados como não perigosos e são gerados no processo de produção de celulose (pasta) e papel, nomeadamente lamas primárias, dregs, grits, lamas de carbonato e cinzas de fundo, estas geradas num processo que ocorre em paralelo à produção de celulose, cujo objectivo é a produção de energia para abastecimento da fábrica através da combustão de biomassa florestal em leito fluidisado. Uma caracterização geral minuciosa foi realizada a cada resíduo e de acordo com as suas características, seleccionaram-se três aplicações em materiais com potencial de utilização: Fibrocimento, Mistura betuminosa para camada de regularização e argamassas industriais (reboco de projecção e cimento-cola). Após o devido enquadramento do resíduo e aplicação, cada resíduo foi caracterizado especificamente para que se procedesse a definição de formulações contendo diferentes percentuais de resíduos em substituição da matéria-prima convencional. Como um caso isolado, as cinzas de fundo foram testadas, não somente como matéria prima alternativa em materiais de construção, como também testou-se a sua reutilização em leito fluidisado no qual o resíduo é gerado. Tanto os dregs como as cinzas de fundo passaram por um tratamento específico para que fosse possível obter uma melhor qualidade do resíduo com o objectivo de não comprometer as características do produto final e processo. Os dregs foram testados em base tal e qual e lavados em escala laboratorial (para remoção de sais solúveis) e as cinzas de fundo foram lavadas em escala industrial (para remoção de sais solúveis, nomeadamente cloretos) e crivadas em escala laboratorial e industrial para eliminação da fracção grosseira do resíduo (partículas de dimensão superior a 1 mm). Os demais resíduos formam usados em base tal e qual, evitando assim custos adicionais. Os resultados obtidos em cada aplicação indicam potencialidades e limitações relativamente ao uso desses resíduos como matéria-prima alternativa, porém em alguns casos, as vantagens relativamente a valorização se sobrepõem às suas limitações, tanto nos aspectos ambientais, como económicos.
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32

Xu, Fuqing. "Experimental Studies and Modeling of Solid-State Anaerobic Digestion for Enhanced Methane Production from Lignocellulosic Biomass." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1406143408.

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33

Tavares, Priscilla Torquato. "Caracterizações física e química de resíduos sólidos da cajucultura e avaliação do potencial energético em processos de conversão térmica." Universidade Federal da Paraíba, 2016. http://tede.biblioteca.ufpb.br:8080/handle/tede/8791.

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The exponential increase in energy demand and the growing need for sustainable energy production require diversification of energy sources. Biomass has stood out due to their economic and physicochemical particulars, and may be considered as the energy source of the future. Agricultural waste is a form of biomass suitable for energy production. The cultivation and beneficiation of cashew generated, in 2015, between 1.4 and 1.5 million tons of cashew nut shell (CNS) and between 4.2 and 5.0 million tons of cashew apple bagasse (CAB) (IBGE, 2016). Therefore, the use of these waste for energy purposes would reduce disposal issues of these and could substitute others fuels in industries. The objective of this study is to verify the possibility of using solid waste from cashew culture as an alternative and renewable energy source in thermal conversion processes, characterizing them physically and chemically (immediate analysis, elemental analysis, density measurement, calculation of calorific value, SEM and XRF), and verifying the probability of ash melt. Furthermore, the thermal behavior of the residues was evaluated by thermogravimetric analysis carried out in inert and oxidizing atmosphere in order to analyze the processes of pyrolysis and combustion, respectively. The thermal behavior of waste was evaluated by thermal gravimetric analysis. CNS is more energetic than the CAB, because despite having the same H/C ratio (0.13), CNS has lower O/C ratio (0.67) than CAB (0.89). The N and S found were high for both CAB (3.59 and 0.98%, respectively) and CNS (0.85% and 0.89 respectively), indicating the release of pollutants during thermochemical conversion which must be contained. The CAB and the CNS showed a high density, high volatile matter content and low ignition temperature, 167 ºC and 199 ºC respectively, as well as low ash content, 3.55 and 2.16% for CAB and CNS, respectively. The pyrolysis curve showed that there were three major peaks for CNS, relating to the degradation of hemicellulose, cellulose and lignin fraction, respectively; while for CAB it was observed the presence of a well defined peak at 300 ºC, representing the superposition of simultaneous degradation of lignocellulosic components. During the combustion, there are three peaks for CNS, which indicates loss of hemicellulose, cellulose and lignin, predominantly, and for CAB there were two predominant peaks, corresponding to the loss of the hemicellulose and cellulose to the oxidation of the cellulose. In conclusion, it was found that the solid wastes in question have potential to be used as an alternative and renewable energy source and may collaborate with energy diversification, giving a sustainable disposal for cashew cultivation residues.
O aumento da demanda energética e a crescente necessidade de produção sustentável de energia tem mostrado a importância da diversificação das fontes energéticas. A biomassa tem se destacado por suas características econômicas, físicas e químicas, podendo ser considerada como a fonte energética do futuro. Os resíduos agrícolas são uma forma de biomassa apropriada para produção energética. A geração de resíduos proveniente do cultivo e beneficiamento do caju produziu em 2015, no Brasil, entre 1,4 e 1,5 toneladas de casca de castanha de caju (CCC) e entre 4,2 e 5,0 toneladas de resíduo de pseudofruto de caju (BC). Portanto, a utilização de resíduos sólidos da cajucultura para produção de energia, reduziria a problemática da destinação desses resíduos e poderia substituir a lenha para aplicação energética utilizada no próprio beneficiamento ou em outras indústrias. O objetivo deste trabalho é verificar a possibilidade de utilização dos resíduos sólidos da cajucultura como fonte alternativa e renovável de energia em processos de conversão termoquímica, por meio das caracterizações física e química (análise imediata, análise elementar, densidade, poder calorífico, microscopia eletrônica de varredura e fluorescência de raios X), observando também a probabilidade de fusão das cinzas. O comportamento térmico dos resíduos foi avaliado por meio de análise termogravimétrica. A CCC é mais energética que o BC, pois apesar de possuírem a mesma relação H/C (0,13), a CCC possui menor relação O/C (0,67) que o BC (0,89). Os teores de N e S encontrados foram altos para ambos BC (3,59 and 0,98%, respectivamente) e CCC (0,85% and 0,89 respectivamente), indicando lançamento de poluentes durante a conversão termoquímica que deve ser contida. Verificou-se que os resíduos analisados apresentam potencial para utilização em processos de conversão térmica, devido a alta densidade, elevado percentual de voláteis, baixa temperatura de ignição (BC = 167 ºC e CCC = 199 oC). Observou-se também um baixo teor de cinzas (BC = 3,55% e CCC = 2,16%), com probabilidade de baixas temperaturas de fusão destas, devido à elevada concentração de potássio (BC = 61,29 e CCC = 50,57%). O comportamento térmico das amostras mostrou que durante a pirólise, há três picos principais de perda de massa para a casca da castanha de caju (CCC) (em torno de 240, 300 e 440 °C) e um pico bem definido para o bagaço de caju (BC) (em torno de 300 °C); já durante a combustão, verificaram-se três picos predominantes para a CCC (aproximadamente 240, 450 e 490 °C), o que indica a perda de hemicelulose, celulose e lignina, predominantemente, e dois picos preponderantes para o BC (300 e 500 °C, aproximadamente), correspondendo à perda da hemicelulose e celulose para a oxidação da celulose. Os resíduos sólidos em questão tem potencial para serem usados como fonte alternativa de energia renovável e podem colaborar com a diversificação energética, dando um descarte sustentável aos resíduos da cajucultura.
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34

Zhuang, Jun. "ECONOMIC ANALYSIS OF CELLULASE PRODUCTION BY CLOSTRIDIUM THERMOCELLUM IN SOLID STATE AND SUBMERGED FERMENTATION." UKnowledge, 2004. http://uknowledge.uky.edu/gradschool_theses/170.

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Dependence on foreign oil remains a serious issue for the U.S. economy. Additionally, automobile emissions related to petroleum-based, fossil fuel has been cited as one source of environmental problems, such as global warming and reduced air quality. Using agricultural and forest biomass as a source for the biofuel ethanol industry, provides a partial solution by displacing some fossil fuels. However, the use of high cost enzymes as an input is a significant limitation for ethanol production.Economic analyses of cellulase enzyme production costs using solid state cultivation (SSC) are performed and compared to the traditional submerged fermentation (SmF) method. Results from this study indicate that the unit costs for the cellulase enzyme production are $15.67 per kilogram ($/kg) and $40.36/kg, for the SSC and SmF methods, respectively, while the market price for the cellulase enzyme is $36.00/kg. Profitability analysis and sensitivity analysis also provide positive results.Since these results indicate that the SSC method is economical, ethanol production costs may be reduced, with the potential to make ethanol a viable supplemental fuel source in light of current political, economic and environmental issues.
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35

Bradfield, Frances Louise. "Examination of the thermal properties of municipal solid waste and the scalability of its pyrolysis." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86670.

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Thesis (MEng)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: Concerns surrounding the world’s current dependence on quickly depleting fossil fuels and their negative environmental impacts have brought about much research into renewable and sustainable energy sources. With population and economic growth not only is this dependence increasing but there is an increasing production of waste by society in general. With space becoming a premium commodity and environmental protection a necessity, landfilling of the majority of the world’s waste is no longer feasible. Thus, research is being carried out into waste-to-energy (WTE) processes and refuse derived fuels (RDF). This study focuses on thermochemical conversion, specifically pyrolysis of solid wastes as a means of energy product recovery. Before a specific waste stream can be used in WTE or RDF contexts its composition and degradation behaviour needs to be investigated. For this reason, a full physical characterisation of the municipal solid waste (MSW) from the Stellenbosch municipality was carried out. It was found that the composition of waste differs between areas within the municipality but the composition of the waste in general compares well with international data. It was found that six main components present in the recyclables stream; namely high and low density polyethylene (HD/LDPE), poly(ethylene terephthalate) (PET), glossy paper, office paper and newspaper would be suitable for thermochemical conversion. The thermal properties and pyrolytic degradation of these six components were investigated by multi heating rate thermogravimetric analysis (TGA) from which kinetic parameters (activation energy, pre-exponential factor and kinetic rate constants) were calculated by a differential isoconversional method. The volatiles released during degradation were identified by way of online mass spectrometry (TGA-MS) yielding six individual kinetic schemes. In order to gauge to what extent milligram pyrolytic experimentation (TGA-MS) can be used to predict larger scale pyrolytic behaviour, runs were performed on one plastic (HDPE) and one paper (glossy paper) sample on a gram scale pyrolytic plant under both slow and vacuum conditions. It was found that, especially for high thermal conductivity samples, yields on gram scale experimentation can be accurately predicted on a milligram scale. Further, the compositions of slow pyrolysis oils from glossy paper, obtained by gas chromatography–mass spectrometry (GC-MS), were compared to TGA-MS results as well as off gases captured from TGA runs by thermal desorption (TGA/TD-GC-MS). It was found that TGA-MS and TGA/TD-GC-MS can be used to predict the main functional groups in pyrolysis oil produced on a gram scale. Thus small scale experimentation can be used to determine the suitability of different waste components for pyrolytic conversion.
AFRIKAANSE OPSOMMING: Kommer oor die wêreld se huidige afhanklikheid van fossielbrandstowwe en die negatiewe uitwerking op die omgewing het baie navorsing oor hernubare en volhoubare energie bronne meegebring. Bevolking en ekonomiese groei veroorsaak 'n toename in hierdie afhanklikheid en in die produksie van afval deur die samelewing. Daar is baie min onbenutte grond oop en die beskerming van die omgewing het noodsaaklik geword. Dus is storting van die meeste van die wêreld se afval nie meer ‘n aanvaarbare opsie nie. As gevolg daarvan word daar tans navorsing in afval-tot-energie (ATE) prosesse en afval afgeleide brandstowwe (AAB) gedoen. Hierdie studie fokus op die termochemiese omskakeling van afval, spesifiek pirolise, as 'n methode vir energie-produk hernuwing. Voordat 'n spesifieke afvalstroom gebruik kan word as 'n AAB moet die samestelling en afbrekings gedrag eers ondersoek word. Daarom is 'n volledige fisiese karakterisering van die munisipale afval (MA) van Stellenbosch munisipaliteit uitgevoer. Resultate het getoon dat daar ‘n verskil in die samestelling van afval tussen die gebiede binne die munisipaliteit is. Afgesien daarvan vergelyk die samestelling van die afval in die algemeen goed met internasionale data. Daar is gevind dat daar ses belangrike komponente teenwoordig is in die herwinbare stroom wat geskik sou wees vir termochemiese omskakeling, naamlik; hoë en lae digtheid poliëtileen (HD/LDPE), poli(etileen tereftelaat) (PET), glans, kantoor en koerant papier. Die termiese eienskappe en termiese afbreking van hierdie ses komponente is ondersoek deur middel van multi-verhittimgs tempo termogravimetriese analise (TGA) waaruit kinetiese parameters (aktiveringsenergie, pre-eksponensiële faktor en kinetiese snelheidskonstantes) deur 'n differensiële omskakelings metode bereken is. Die vlugtige komponente wat tydens die afbreking vrygestel is, is geïdentifiseer deur aanlyn-massaspektrometrie (TGA-MS) wat ses individuele kinetiese skemas verskaf. Om vas te stel tot watter mate milligram pirolitiese eksperimente (TGA-MS) gebruik kan word om op ‘n groter skaal die pirolitiese gedrag te kan voorspel, is eksperimentele lopies op een plastiek- (HDPE) en een papier (glans papier) monster op 'n laboratorium skaal pirolise opstelling onder stadige- en vakuum omstandighede uitgevoer. Daar is gevind dat, veral met hoë hitte geleiding komponente, die opbrengs op gram skaal eksperimente akkuraat voorspel kan word op ‘n milligram skaal. Verder was die samestelling van die stadige pirolise olies uit glans papier, wat verkry word deur gaschromatografie-massaspektrometrie (GC-MS), vergelyk met TGA-MS resultate sowel as af-gasse gevang van TGA lopies deur termiese desorpsie (TGA/TD-GC –MS). Daar is gevind dat TGA-MS en TGA/TD-GC-MS gebruik kan word om die belangrikste funksionele groepe in pirolise olie, wat op 'n gram skaal geproduseer word, te voorspel. Dus kan milligram eksperimente gebruik word om die geskiktheid van afval komponente vir pirolitiese omskakeling te bepaal.
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36

Arabaci, Selin. "First And Second Law Analyses Of A Biomass Fulled Solid Oxide Fuel Ceel-micro Turbine Hybrid System." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12610152/index.pdf.

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Fuel cells are direct energy conversion devices to generate electricity. They have the lowest emission level of all forms of electricity generation. Fuel cells require no combustion of the fuel. The thermal energy gained from fuel cells may be utilized in micro turbines (gas turbines). In this work, first and second law analyses are performed on a hybrid system consisting of a solid oxide fuel cell (SOFC) combined with a micro turbine to be able to find an optimum point of pressure and corresponding mass ratio to gain maximum work output. Also another system with same equipments only without a gas turbine is investigated to see the effects of gas turbine. The analyses are performed utilizing a code written in MATLAB for each of the equipments. Fuel used is biomass with a certain concentration. To be able to use biomass in a fuel cell-micro turbine hybrid cycle, it is gasified and converted into a certain calorific value gas, with the use of gasifiers. In this study fluidized bed gasifier is utilized since it has the advantage of good mixing and high heat transfer leading to a uniform bed condition. Desulphuration and gas filter units will be implemented in order to clean the producer gas before being used in hybrid system. For a certain percentage of the fuel that may pass through the fuel cell without being used, a combustor is utilized. Optimum point mass and pressure ratios for system are MR = 0.6411 and Pr = 8. Gas turbine supplies more power and higher efficiency to the system. There are different choices for fuel selection in hybrid systems. The reason why biomass is examined among these is that it decreases the depletion of energy carriers and reduces the environmental impact.
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37

Iqbal, Qaiser. "Quantification of fungal biomass growth during citric acid production by «Aspergillus niger» on expanded clay solid substrate." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=19292.

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The growth of fungi on sugar rich wastes can be an economical way of producing citric acid. Nevertheless, conditions for the optimum production of citric acid still need to be established. Using Aspergillus niger, the objective of the present study was to measure the effect on citric acid accumulation and fungal biomass, of sugar and nitrogen supplementation namely as glucose and ammonium, respectively. An inert solid substrate (Hydroton® or HSS) made of expanded clay and wetted with a nutrient solution was used to grow A. niger ATCC12846 and measure its fungal biomass with fermentation time. Citric acid accumulation and fungal biomass were measured during 168 h of fermentation with glucose concentrations ranging 0 to 475 g (kg HSS)-1 and ammonium ranging from 2 to 16 g (kg HSS)-1. Fungal biomass growth was monitored by measuring the change of total volatile solids (TVS) less residual glucose and citric acid, and; organic nitrogen accumulation. Glucose and ammonium had a significant effect (P < 0.10) on both fungal biomass and citric acid accumulation. For citric acid, the highest concentration of 52 g and yield of 14% were obtained with 475 and 250 g glucose (kg HSS)-1 and 8 g of N (kg HSS)-1. Nevertheless, only the glucose concentration of 475 g (kg HSS)-1 resulted in citric acid accumulation continuing after reaching a peak in fungal biomass. This high glucose concentration could have yielded more citric acid by using a pH of 5.5 during spore germination and of 2.0 during fungal biomass growth. Because the C:N ratio of the fungal biomass was observed to vary with nitrogen supplementation, it is not recommended to use organic N to quantify fungal biomass.
La fermentation de champignons sur des résidus riches en sucre pourrait être une façon économique de produire de l'acide citrique, à condition de bien maîtriser les paramètres de fermentation. La présente étude avait comme objectif d'évaluer l'effet de la charge de sucre, soit en glucose, et d'azote, soit en ammonium, sur la biomasse du champignon Aspergillus niger ATCC12846 et sur sa production d'acide citrique. De l'argile expansée (Hydrotron® ou HSS) fut utilisée comme substrat solide pour le champignon A. niger ATCC 12846. Le substrat fut humecté d'une solution offrant différents taux de glucose, de 0 à 475 g (kg HSS)-1 et d'azote sous forme d'ammonium, de 2 à 16 g (kg HSS)-1. La biomasse fongique fut obtenue en mesurant la masse volatile totale moins la masse résiduelle de glucose et la masse d'acide citrique, et; l'augmentation de la masse d'azote organique. Le taux de glucose et d'ammonium a eu un effet significatif sur la biomasse fongique et la production d'acide citrique pendant les 168 h de fermentation. Une concentration en glucose de 475 et 250 g (kg HSS)-1 maximisaient la concentration de 52 g (kg HSS)-1 et le rendement de 14% en acide citrique, respectivement, avec 8g d'azote (kg HSS)-1. Par contre, seulement la concentration en glucose de 475 g (kg HSS)-1 permettait d'accumuler de l'acide citrique après avoir atteint le plus de biomasse. Un rendement supérieur exigerait un meilleur contrôle du pH à 5.5 pendant le développement des spores et à 2.0 pendant la fermentation. Puisque le ratio C:N de la biomasse fluctuait avec la concentration d'azote dans la solution, il n'est pas recommandé d'utiliser l'azote organique pour suivre l'évolution de la biomasse.
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38

Romero, Millán Lina. "Steam gasification of tropical lignocellulosic agrowaste : impact of biomass characteristics on the gaseous and solid by-products." Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2018. http://www.theses.fr/2018EMAC0011.

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Dans le contexte économique de la plupart des pays en voie de développement, la gazéification sous vapeur d’eau de résidus agricoles lignocellulosiques pourrait être un procédé intéressant, à la fois pour la génération d’énergie dans des régions isolées et pour la production des produits à valeur ajoutée. Étant donné que la disponibilité des résidus agricoles est souvent saisonnière, différents types de biomasse doivent être utilisés pour assurer le fonctionnement des installations de gazéification. A cet égard, ce travail est axé sur la compréhension de l'impact des caractéristiques de la biomasse sur le procédé de gazéification et les propriétés des sous-produits gazeux et solides. Trois biomasses lignocellulosiques à composition macromoléculaire et inorganique différentes ont été sélectionnées pour cette étude : coques de noix de coco (CS), bambou guadua (BG) et coques de palmier à huile (OPS). La cinétique de décomposition thermique des biomasses a été étudiée sur une échelle thermogravimétrique sous atmosphère inerte et sous vapeur d’eau. Malgré les différences dans la structure macromoléculaire des échantillons, la composition inorganique s’est avérée être le paramètre le plus important influençant la réactivité et la cinétique de gazéification. L'impact bénéfique des métaux alcalins et alcalino-terreux a été confirmé, ainsi que l'effet inhibiteur du Si et du P. Plus précisément, le ratio K/(Si+P) est considéré approprié pour décrire et comparer le comportement des biomasses pendant la gazéification sous vapeur d’eau. En conséquence, une nouvelle approche pour la modélisation de la cinétique de gazéification à partir de la composition inorganique de l’échantillon a été proposée. La validité du ratio K/(Si+P) pour classifier et prédire le comportement des biomasses a également été confirmée par des expériences dans un réacteur à lit fluidisé à l’échelle laboratoire. Les échantillons avec un ratio K/(Si+P) au-dessus de 1 ont montré des réactivités de gazéification supérieures à celles des échantillons dont le ratio était inférieur à 1, et donc, une production de gaz et un rendement énergétique plus élevés. De plus, la composition inorganique a non seulement impacté le taux de gazéification des échantillons, mais également les propriétés du sous-produit solide. En particulier, une réactivité de gazéification plus élevée est liée à des chars avec une surface spécifique et un nombre de groupes fonctionnels plus importants. Une température de 850°C et une fraction de vapeur de 30% dans l’agent de réaction ont été identifiées comme les conditions les plus adaptées à la production simultanée de gaz combustible et de char pouvant être valorisé dans des applications agricoles. Le modèle de gazéification sous vapeur d'eau et les résultats expérimentaux présentés dans ce travail peuvent être une référence pour des applications réelles de gazéification travaillant avec différents types de résidus. Par ailleurs, dans le contexte présenté, la gazéification sous vapeur d’eau de déchets lignocellulosiques peut améliorer l’accès à l’énergie des zones rurales isolées, en promouvant simultanément le développement de projets productifs susceptibles de générer de nouveaux revenus pour les communautés locales
In the context of most developing countries, steam gasification could be a very interesting process for both energy generation in isolated areas and the production of value-added products from lignocellulosic agrowaste. Considering that the availability of agricultural residues is often seasonal, gasification facilities should operate with different feedstocks. In consequence, this work is focused on the understanding of the impact of biomass characteristics on the gasification process and the properties of the gaseous and solid by-products. Three lignocellulosic agrowastes with different macromolecular structure and inorganic composition were selected for this study: Coconut shells (CS), bamboo guadua (BG) and oil palm shells (OPS). The thermal decomposition kinetics of the selected feedstocks was analyzed in a thermogravimetric scale under inert and steam atmosphere. Despite the differences in their macromolecular composition, inorganics showed to be the most important parameter influencing the steam gasification reactivity and kinetics of the samples. The beneficial impact of AAEM was confirmed, as well as the inhibitory effect of Si and P. More specifically, the ratio K/(Si+P) proved to be suitable to describe and compare the steam gasification behavior of lignocellulosic agrowastes. In accordance, a new kinetic modeling approach was proposed to predict the gasification behavior of samples, from the knowledge of their inorganic composition. The validity of the ratio K/(Si+P) to classify and predict the biomass steam gasification behavior was also confirmed from experiments in a lab-scale fluidized bed gasifier. Samples with K/(Si+P) above 1 exhibited higher gasification reactivities compared to samples with ratios below 1, resulting in greater gas yields and higher gas efficiencies. Moreover, inorganics impacted not only the gasification rate of the samples, but also the properties of the gasification solid by-products. In particular, higher gasification reactivities were related to greater char surface areas and contents of oxygenated surface functional groups. A temperature of 850°C and a steam fraction of 30% in the reacting atmosphere proved to be the most suitable gasification conditions for the simultaneous production of fuel gases for energy applications, and a valuable char that could be valorized in soil amendment applications. The gasification model and experimental results presented in this work might be an important reference for real gasification applications working with different kind of residues, when both the gaseous and solid by-products valorization is intended. Moreover, in the presented context, steam gasification of lignocellulosic agrowaste may improve the energy access in rural isolated areas, and simultaneously promote the development of productive projects that could generate new incomes for local communities
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39

WONGCHANAPAI, Suranat. "Development of Direct Internal Reforming Solid Oxide Fuel Cell Model and its Applications for Biomass Power Generation." 京都大学 (Kyoto University), 2013. http://hdl.handle.net/2433/174926.

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40

Cortez, Cristiane Lima. "Estudo do potencial de utilização da biomassa resultante da poda de árvores urbanas para a geração de energia - estudo de caso: AES Eletropaulo." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/86/86131/tde-13092011-151318/.

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No Brasil e em muitos países, principalmente países em desenvolvimento, os resíduos de poda urbana são na sua grande maioria depositados em aterros ou lixões contribuindo para a produção de metano, esgotamento das áreas dos aterros, contaminação do solo e dos lençóis freáticos. Assim, considerando o crescente problema ambiental e a busca pelo desenvolvimento sustentável, a nova Política Nacional de Resíduos Sólidos, recentemente regulamentada, proíbe, a partir de 2014, dispor em aterro sanitário qualquer tipo de resíduo que seja passível de reutilização ou reciclagem. Há premente necessidade do estudo e quantificação do potencial de utilização dos resíduos de poda urbana, quer pela reutilização, reciclagem pela compostagem ou aproveitamento energético. A utilização dos resíduos de poda urbana como fonte de energia, desde que viável econômica e tecnicamente, apresenta aspectos benéficos ao país: aumenta a segurança do sistema elétrico com a geração descentralizada a custos competitivos, reduz a importação de combustíveis fósseis, capta recursos internacionais decorrentes da possível venda de Certificados de Emissão de Carbono para os países do Anexo 1 (caso seja considerado do tipo Mecanismo de Desenvolvimento Limpo, conforme prevê o Protocolo de Quioto) e pode até colaborar para reduzir o desmatamento de florestas nativas para fins energéticos. Esta tese utiliza como subsídios os resultados obtidos no projeto de Pesquisa & Desenvolvimento Aneel Estudo do Potencial de Utilização da Biomassa Resultante da Poda e Remoção de Árvores na Área de Concessão da AES Eletropaulo; financiado pela Agência Nacional de Energia Elétrica (ANEEL) e desenvolvido pelo Centro Nacional de Referência em Biomassa (Cenbio) do Instituto de Eletrotécnica e Energia (IEE) da Universidade de São Paulo (USP) em parceria com a AES Eletropaulo. Assim, este trabalho analisa a atual situação de destinação dos resíduos de poda urbana e apresenta várias formas de aproveitamento como a reintegração destes resíduos aos respectivos ciclos biogeoquímicos (pela obtenção de composto orgânico por processo de compostagem), sua reutilização (artesanato ou obras de arte, bancos de jardins, etc.) ou seu aproveitamento energético, quer como lenha, carvão vegetal, briquete, ou in natura como combustível de usina termoelétrica. Sendo o objetivo central desta tese, estudar o potencial de utilização dos resíduos de poda urbana para a geração de energia elétrica, são analisados técnica, econômica e ambientalmente duas tecnologias: ciclo a vapor e digestão anaeróbia. Desta forma, a geração de energia elétrica proveniente da usina termoelétrica (ou melhor, uma pequena central termoelétrica) se mostrou mais viável economicamente do que a gerada na planta de digestão anaeróbia dos resíduos de poda urbana. Assim, espera-se que os resultados desta tese contribuam para que o pode público possa selecionar a tecnologia mais adequada para tratar os resíduos de poda urbana sob sua responsabilidade, além de adotar medidas de incentivos para esta prática.
In Brazil and in many countries, mainly in the development ones, the residues from urban pruning are, in its majority, deposited in landfills or dumps, contributing for methane production, exhaustion of the landfills areas, contamination of soil and of groundwaters. Therefore, considering the aggravating and increasing environmental problem and the search for sustainable development and the compliance with the new National Policy for Solid Residues, recently regulated, and which forbids, from 2014 on, to dispose in landfill any kind of residue that is suitable for reuse or recycling, there is an urgent need for study and quantification of the utilization potential of the urban pruning residues, whether by means of reutilization, recycling by means of composting or energy use. The use of urban pruning residues as energy source, as long as it presents itself as economically and technically viable, presents very beneficial aspects to the country: it increases the electric system security with the decentralized generation at competitive costs, reduces the importation of fossil fuels, attracts international resources due to the possible sale of Carbon Emission Certificates to the Annex 1 countries (in case it is considered as a Clean Development Mechanism, as established by the Kyoto Protocol) and it can even contribute to reduce the deforestation of native forests for energy finalities. This thesis uses, as subsidies, the results obtained in the Study of the Potential Use of Biomass from Trees Pruning and Removal on AES Eletropaulo\'s Concession Area Aneel Research & Development project; financed by the Brazilian Electricity Regulatory Agency (ANEEL) and developed by the Brazilian Reference Center on Biomass (Cenbio) of the Institute of Electrotechnics and Energy (IEE) of the University of São Paulo (USP) in partnership with AES Eletropaulo. This way, this essay analyzes the current situation of urban pruning residues destination and presents several ways of utilization such as the reintegration of such residues to the respective biogeochemical cycles (by the obtainment of organic compound by means of composting process), their reuse (handicraft or works of art, park benches, etc.) or its energy utilization, whether as firewood, charcoal, briquette or in natura as fuel for thermoelectric plants. Since the main objective of this thesis is to study the utilization potential for the urban pruning residues for electric power generation, two technologies are technically, economically and environmentally analyzed: steam cycle and anaerobic digestion. This way, the electric power generation proceeding from the thermoelectric plant (or rather, a small thermoelectric central) showed itself as more economically viable than the one generated at the anaerobic digestion plant of the urban pruning residues. Therefore, it is expected that the results from this thesis can contribute for the public power to be able to choose the most adequate technology in order to treat the urban pruning residues under its responsibility, besides adopting measurements for incentives for this practice.
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41

Serutla, Bokhabane Tlotliso Violet. "Potential for energy recovery and its economic evaluation from a municipal solid wastes landfill in Cape Town." Thesis, Cape Peninsula University of Technology, 2016. http://hdl.handle.net/20.500.11838/2463.

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Thesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2016.
Landfill gases, principally methane, CH4 are produced from the decomposition of the municipal solid wastes deposited on landfill sites. These gases can be captured and converted into usable energy or electricity which will assist in addressing energy needs of South Africa. Its capture also reduces the problems associated with greenhouse gases. The aim of this study is to estimate gases that can be produced from the Bellville landfill site in Cape Town. The landfill gas capacity was estimated using Intergovernmental Panel on Climate Change (IPCC) model. The IPCC model showed that 48 447m3/year of landfill gas capacity was determined only in 2013. The LFGTE process plant is designed in a manner of purifying landfill gas, which at the end methane gets up being the only gas combusted. As a matter of fact 14 544kg/year of gases which consists mainly methane gets combusted. The average energy that can be produced based on the generated landfill gas capacity (methane gas) is 1,004MWh/year. This translates to R1. 05million per year at Eskom’s current tariff of R2.86 /kWh) including sales from CO2 which is a by-product from the designed process plant. A LFGTE process plant has been developed from the gathered information on landfill gas capacity and the amount of energy that can be generated from the gas. In order, to start-up this project the total fixed capital costs of this project required amounted up to R2.5 million. On the other hand, the project made a profit amounted to R3.9million, the Net profit summed up to R1. 3million and the payback time of Landfill Gas ToEnergy (LFGTE) project is 4years.The break-even of the project is on second year of the plant’s operation. The maximum profit that this project can generate is around R1. 1million. The life span of the plant is nine years. Aspen plus indicated that about 87% of pure methane was separated from CO2 and H2S for combustion at theabsorption gas outletstream. I would suggest this project to be done because it is profitable when by-products such as CO2 sales add to the project’s revenues.
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42

Sandström, Malin. "Structural and solid state EMF studies of phases in the CaO–K2O–P2O5 system with relevance for biomass combustion." Doctoral thesis, Umeå universitet, Tillämpad fysik och elektronik, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-858.

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Fosfaters reaktioner i energiomvandlingsprocesser är kritisk för den generella processen som helhet, för askrelaterade problem, emissioner liksom för en effektiv och hållbar användning av askan. Denna avhandling är en sammanställning och diskussion med utgångspunkt i åtta artiklar som behandlar strukturella och termodynamiska studier på faser i CaO-K2O-P2O5-systemet, vilka är av relevans inom förbränning av biomassa. Målsättningen med denna avhandling var: i) att sammanställa och granska tillgängliga strukturella och termodynamiska data i CaO-K2O-P2O5-systemet samt att identifiera avsaknad av data, ii) att fylla i dessa luckor med grundläggande termodynamiska, strukturella och fasstabilitets studier samt iii) att visa på användning samt fördelarna med dessa nya data vid praktisk tillämpning. En initial litteraturundersökning i CaO-K2O-P2O5-systemet visade att det saknades både strukturella och termodynamiska data. När det gällde tillgängliga termodynamiska data var situationen särskilt otillfredsställande. Det fanns endast data för några kalcium– och kaliumfosfater med varierande tillförlitlighet. Situationen beträffande pulverröntgen för fasidentifiering var bättre, fast fördunklad av det faktum att strukturellt liknande fasövergångar ofta förekommer i det undersökta systemet. Däremot fattades det tillfredställande enkristallstrukturdata för ternära faser i det undersökta systemet. Enkristallröntgendiffraktion användes för att bestämma strukturerna för CaK2P2O7, CaKP3O9, Ca10K(PO4)7 och CaKPO4. Faserna CaK2P2O7 and CaKPO4 tillsammans med Ca3(PO4)2, KPO3 och K4P2O7 studerades med pulverröntgendiffraktion och termiska analysmetoder för att klargöra fasmodifikationer och övergångstemperaturer. Gibbs bildningsenergi bestämdes för Ca(PO3)2, Ca2P2O7, Ca3(PO4)2, Ca10K(PO4)7, CaK2P2O7, CaKPO4 och CaK4(PO4)2 med ems-metodik och yttriastabiliserad zirkonia som fast elektrolyt och Ni/Ni3P som hjälpsystem. Både de strukturella och termodynamiska data användes sedan vid analyser i ett förbrännningexperiment av olika sädesslag. Framtagna data användes både vid identifiering och även vid kvantifiering av bildade faser i biomassaresterna.
The behaviour of phosphates in thermochemical biomass conversion processes are critical for the general process chemistry, for ash related problems, for emissions as well as for an efficient, sustainable and beneficial use of the ash residues. This thesis is a summary and a discussion of eight papers dealing with structural and thermodynamical studies of phases in the CaO-K2O-P2O5 system, with relevance for biomass combustion. The objectives were: i) to compile and review the available structural and thermodynamical data of phases in the CaO-K2O-P2O5 system as well as to identify existing gaps in the field of these data, ii) to fill in as many as possible of the gaps by fundamental thermodynamic, structural and phase stability studies and iii) to demonstrate the uses and the benefits of the new data in practical applications. An initial review of the CaO-K2O-P2O5 system showed that both structural information and thermodynamic data were lacking. The situation regarding the available thermodynamic data was especially unsatisfactory, data could only be found for some few calcium phosphates and a few potassium phosphates with varying reliability. Concerning powder X-ray diffraction patterns for phase identification the situation was better, though obscured by the fact that structurally close related phase transitions often occur in the studied system. However, adequate single crystal structural data of ternary phases in the system was completely missing. Crystal structures of CaK2P2O7, CaKP3O9, Ca10K(PO4)7 and CaKPO4 were determined by single-crystal X-ray diffraction. The phases CaK2P2O7 and CaKPO4 were together with Ca3(PO4)2, KPO3 and K4P2O7, investigated by powder X-ray diffraction and thermal analysis to elucidate phase modifications and transitions temperatures. Gibbs standard energy of formation was determined for Ca(PO3)2, Ca2P2O7, Ca3(PO4)2, Ca10K(PO4)7, CaK2P2O7, CaKPO4 and CaK4(PO4)2 by solid state emf measurements with yttria stabilised zirconia as solid electrolyte and Ni/Ni3P as auxiliary solid couple. Both the structural and thermodynamical data were subsequently utilised in analysis of a combustion experiment of cereal grains. The data were also used to both identify and quantify the phases formed in biomass combustion residues.
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43

Plankenbühler, Thomas [Verfasser]. "The impact of fine fuel particles on ash deposition in solid biomass combustion: Experiments and CFD modelling / Thomas Plankenbühler." München : Verlag Dr. Hut, 2019. http://d-nb.info/1190422042/34.

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44

Sheets, Johnathon P. "Development of a Biomass-to-Methanol Process Integrating Solid State Anaerobic Digestion and Biological Conversion of Biogas to Methanol." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1493807817862038.

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45

Losi, Lorenzo. "Impact assessment of an innovative process for levulinic acid production from biomass." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019.

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A large part of energy carriers and chemicals of our society come from fossil fuels; due to their critical exploitation and environmental concerns, alternative solutions should be promoted. The goal of this work is to understand the environmental impacts of different supply chains of levulinic acid production. To enable this comparison, a cradle-to-gate LCA was conducted on different kinds of biomasses, under an innovative thermochemical process called Biofine. The study concerns biomass not only of agri-food origin (corn stover, barley straw, wheat straw), but also deriving from the waste collection supply chain (organic fraction of municipal solid waste). Results show that biochemicals production from waste-derived biomass represent the lowest environmental impact solution, compared to the supply chain with biomass of agri-food origin. For agri-food biomasses, the impacts deriving from the agricultural phase are orders of magnitude more significant than those of the industrial phase, while the transport phase is the least impacting in absolute terms. For waste-derived biomasses, transport is the most impacting phase of the entire supply chain.
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46

Silva, Ana Filipa Martins Cláudio da. "Extraction of added-value products from biomass using ionic liquids." Doctoral thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14174.

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Doutoramento em Engenharia Química
The main purpose of this thesis is to investigate the potential of ionic liquids (ILs) as a new class of extractive solvents for added-value products from biomass. These include phenolic compounds (vanillin, gallic, syringic and vanillic acids), alkaloids (caffeine) and aminoacids (L-tryptophan). The interest on these natural compounds relies on the wide variety of relevant properties shown by those families and further application in the food, cosmetic and pharmaceutical industries. Aiming at developping more benign and effective extraction/purification techniques than those used, a comprehensive study was conducted using aqueous biphasic systems (ABS) composed of ILs and inorganic/organic salts. In addition, ILs were characterized by a polarity scale, using solvatochromic probes, aiming at providing prior indications on the ILs affinity for particular added-value products. Solid-liquid (S-L) extractions from biomass and using aqueous solution of ILs were also investigated. In particular, and applying and experimental factorial design to optimize the operational conditions, caffeine was extracted from guaraná seeds and spent coffee. With both types of extractions it was found that it is possible to recover the high-value compounds and to recycle the IL and salt solutions. Finally, aiming at exploring the recovery of added-value compounds from biomass using a simpler and more suistainable technique, the solubility of gallic acid, vanillin and caffeine was studied in aqueous solutions of several ILs and common salts. With the gathered results it was possible to demonstrate that ILs act as hydrotropes and that water can be used as an adequate antisolvent. This thesis describes the use of ILs towards the development of more effective and sustainable processes.
O principal objetivo desta tese recai sobre a utilização de líquidos iónicos (LIs) como uma nova classe de solventes para a extração de compostos de valor acrescentado a partir da biomassa. Nestes compostos estão incluídos os compostos fenólicos (vanilina e ácidos gálico, siríngico e vanílico), alcaloides (cafeína) e aminoácidos (L-triptofano). O interesse da extração destes compostos naturais está relacionado com as suas excelentes propriedades e consequente interesse para aplicação nas indústrias alimentar, de cosmética e farmacêutica. De forma a desenvolver uma técnica de extração/purificação mais benigna e eficiente do que as habitualmente utilizadas, foram estudados vários sistemas aquosos bifásicos (SABs) constituídos por LIs e sais orgânicos/inorgânicos. Foi também criada uma escala de polaridades para os LIs, através da determinação de parâmetros solvatocrómicos, para se poder avaliar a afinidade de diferentes LIs para compostos de valor acrescentado. Para além do uso de SABs, realizaram-se extrações do tipo sólido-líquido a partir de biomassa e utilizando soluções aquosas de LIs. Neste contexto, otimizou-se a extração da cafeína, quer de sementes de guaraná quer de borras de café, utilizando um planeamento fatorial para o efeito. Mostrou-se ainda que em ambos os tipos de extrações estudados é possível recuperar os compostos de valor acrescentado e reciclar as soluções de LI e sal utilizadas durante o processo extrativo. Por fim, com o propósito de explorar a recuperação dos compostos de valor acrescentado utilizando técnicas mais simples e sustentáveis, foram determinadas as solubilidades do ácido gálico, vanilina e cafeína em diversas soluções aquosas de LIs e sais. Foi possível demonstrar que os LIs atuam como hidrótropos e, deste modo, pode-se utilizar água como um anti-solvente adequado. Esta tese descreve a aplicação de LIs no desenvolvimento de processos extrativos mais eficientes e sustentáveis.
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47

Majumder, Ankita Mrinmoy. "Fe2O3-based Oxygen Carriers for Gaseous and Solid-Fueled Chemical Looping Processes." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1459859074.

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48

Nguyen, Van Chuc. "Catalytic production and esterification of aqueous solution of lactic acid." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1136.

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Cette thèse porte sur la production d'acide lactique par conversion de la biomasse lignocellulosique catalysée par des acides de Lewis solides dans l'eau puis l'estérification d'acide lactique aqueux avec de l'éthanol. La conversion de la cellulose est étudiée en autoclave, en utilisant comme catalyseurs, de la zircone et de l'alumine contenant du W ou Sn (ZrW, AlSn) et différents hydroxydes métalliques. L'étude de la conversion de la cellulose en acide lactique en présence de ZrW non calcinée, ZrW calcinée, Zr(OH)4 et ZrO2, montre que la phase active du catalyseur est constituée de Zr4+, les centres acides de Lewis et de groupes hydroxyles. Les performances catalytiques des catalyseurs AlSn, préparés à partir de chlorure d'étain comme précurseur, dépendent fortement de la présence résiduelle de chlorure, ce qui favorise la formation d'acide lévulinique. Les hydroxydes de certains métaux de transition se sont révélés être des catalyseurs solides efficaces pour la conversion de la cellulose en acide lactique. Il a été observé que le rendement en acide lactique dépend de la concentration et de la basicité des groupes OH superficiels des hydroxydes de métaux de transition et de la présence de sites acides de Lewis. L'estérification de l'acide lactique, à différentes concentrations en l'eau, a été étudiée en présence d'Amberlyst 15, de charbon sulfoné et d'oxyde de graphène pour étudier l'activité et la tolérance à l'eau de catalyseurs solides acides à base de carbone. Il est montré, par calorimétrie d'adsorption d'ammoniac, que l'oxyde de graphène présente des sites superacides et qu'il conduit à la plus grande activité et tolérance à l'eau. L'augmentation de la teneur en eau montre un fort effet inhibiteur sur l'activité du charbon sulfoné alors que d'Amberlyst 15 et l'oxyde de graphène sont plus tolérants. Les catalyseurs ne sont pas stables dans des conditions d'estérification, en présence d'eau
This thesis reports the synthesis of lactic acid from lignocellulosic biomass catalyzed by solid Lewis acid catalysts in water and then esterification of aqueous lactic acid solutions with ethanol. The cellulose conversion was tested in autoclave, in hot water, using zirconia and alumina containing W or Sn (ZrW, AlSn) and different solid metal hydroxides. The conversion of cellulose to lactic acid using uncalcined ZrW, calcined ZrW, Zr(OH)4 and ZrO2 shows that the active surface of the catalyst consists of Zr4+ Lewis centers and OH groups. The catalytic performances of AlSn catalysts, prepared from Sn chloride as precursors, strongly depend on the residual amount of chloride which favors the formation of levulinic acid. Some hydroxides of transition metals were disclosed as efficient solid catalysts for the conversion of cellulose to lactic acid. The yield of lactic acid was observed to depend on the concentration and the basicity of the superficial OH groups and on the presence of Lewis acid sites. The esterification of lactic acid, at different concentrations in water, was studied using Amberlyst 15, sulfonated carbon and graphene oxide to evaluate the activities and water tolerance of carbon based solid catalysts. Graphene oxide, shown by calorimetry of NH3 adsorption to exhibit super-acid sites, leads the highest activity and water tolerance. Increasing amounts of water has a strong inhibiting effect on the activity of sulfonated carbon and less influence on activity of Amberlyst 15 and graphene oxide. However, all catalysts were not stable in esterification conditions, in presence of water
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Bühle, Lutz [Verfasser]. "Biological and chemical parameters and life cycle assessment of the integrated generation of solid fuel and biogas from biomass / Lutz Bühle." Kassel : Kassel University Press, 2014. http://d-nb.info/1057854662/34.

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Sandström, Malin. "Structural and solid state EMF studies of phases in the CaO-K₂O-P₂O₅ system with relevance for biomass combustion /." Umeå : Energy Technology and Thermal Process Chemistry, Umeå University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-858.

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