Dissertations / Theses on the topic 'Biomass recovery'
To see the other types of publications on this topic, follow the link: Biomass recovery.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Biomass recovery.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Vanneste-Ibarcq, Clément. "Study of biomass powders in the context of thermal recovery processes." Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2018. http://www.theses.fr/2018EMAC0019/document.
Full textAbstract:
Certains procédés de production d’énergie nécessitent l’utilisation de poudres de biomasse, par exemple la gazéification en réacteur à flux entraîné (RFE). Cependant, les poudres de biomasse ont une mauvaise coulabilité. L’objectif de cette thèse est d’étudier leurs propriétés d’écoulement dans le contexte de la gazéification en RFE, à l’échelle du laboratoire et à l’échelle pilote. A l’échelle du laboratoire, des mesures en tambour rotatif, des tests de cisaillement et des mesures de densité ont été effectués. D’une part, une corrélation est mise en évidence entre la cohésion (issue des tests de cisaillement), la densité et l’angle d’avalanche (tiré des mesures en tambour). Ainsi, un paramètre difficile à obtenir comme la cohésion peut l’être à partir de mesures simples. D’autre part, l’influence de l’humidité sur la coulabilité des poudres de biomasse a été évaluée. L’humidité n’a pas d’effet significatif sous 15 % (en masse, base humide), car l’eau est adsorbée dans la structure de la biomasse ; les particules gonflent et ne sont pas liées par des ponts liquides. Un procédé de granulation humide est proposé. Un liant issu de déchets de biomasse est ajouté à la poudre pour former des granulés d’environ 1 mm. Leur forme sphérique diminue l’entrelacement des particules et leur faible polydispersité diminue le nombre de points de contact. Une amélioration de l’écoulement est observée à l’échelle labo. Une étude énergétique montre que la consommation énergétique du procédé peut descendre jusqu’à 12% du pouvoir calorifique inférieur, ce qui suggère une potentielle rentabilité économique du procédé. Enfin, la caractérisation à l’échelle supérieure est effectuée dans un pilote reproduisant l’injection en RFE. Les résultats montrent le rôle essentiel de la sphéricité et d’une faible polydispersité des particules. L’effet positif de la torréfaction et de la granulation sur la coulabilité est mis en évidenceSome power generation processes require the biomass to be finely ground, such as biomass gasification in entrained flow reactors. However, fine biomass powders are cohesive and present flow issues. This thesis aims to study the biomass powder flowability in the context of the entrained flow gasification process. Biomass powders are characterized both at laboratory scale and pilot scale. Characterization at lab scale consisted of rotating drum measurements, shear tests and density measurements. First, a correlation is found between the cohesion (derived from shear tests), the powder density and the avalanche angle (derived from the rotating drum measurements). Thus, parameters difficult to get such as the cohesion can be obtained with easy to perform measurements. Then, the influence of moisture content on wood powder flowability has been assessed. No significant effect of the water content is found below 15 wt% (wet basis). Below 15%, as water is adsorbed in the biomass structure, the particles swell without being linked by liquid bridges. A wet granulation method is proposed. Biomass waste binders are added to the powder to form granules around 1 mm. The spherical shape lowers the interlocking phenomenon. The low size dispersity of the grains decreases the number of contact points between particles. An improvement of the flowability at lab scale is observed. An energetic study of the granulation process is proposed, showing the energy consumption can be as low as 12% of the biomass Lowest Heating Value. Thus, the process is potentially economically profitable. Finally, characterization at pilot scale is performed with a device mimicking the injection in an entrained flow reactor. The results show the essential roles in the injection step of both the spherical shape and the narrow size distribution of the particles. The positive effect of torrefaction and granulation on the flowability is highlighted
2
Aulakh, Jaspreet Gallagher Thomas Vincent. "Implementing residue chippers on harvesting operation for biomass recovery." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SPRING/Forestry_and_Wildlife_Sciences/Thesis/Aulakh_Jaspreet_37.pdf.
Full text
3
Pena, Jenny Juliana. "Study of chars prepared from biomass wastes : material and energy recovery." Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2018. http://www.theses.fr/2018IMTA0104.
Full textAbstract:
L'objectif de la thèse est d'étudier la valorisation des chars de biomasse. Dans ce contexte de transition énergétique, les biomasses sélectionnées sont les écales de sarrasin et de millet, assez pu étudiées jusqu'à maintenant, produites localement pour contribuer au développement de l'économie circulaire et qui ne compromettent pas une filière de valorisation connue. Dans ce travail, la valorisation matière est abordée à travers la réutilisation de ces résidus dans des procédés d'épuration catalytique de syngaz ou dépuration de biogaz pour lesquels les polluants sont respectivement les goudrons et le sulfure d'hydrogène. Des bilans énergétiques relatifs à la production de ces chars ont été établis et des indicateurs d'efficacité énergétiques ont été calculés. Pour ce faire, les chars ont été produits à 500 °C puis caractérisés par des analyses chimiques et physiques. Afin de leur conférer de meilleures propriétés poreuses nécessaires pour les applications d'épuration de gaz en lit fixe, des activations ont été réalisées à 850 °C avec du CO₂ ou de la vapeur d'eau. Les écales de sarrasin se révèlent être une biomasse assez classique et la particularité des écales de millet est de présenter des taux élevés en silicium. Si les chars de pyrolyse ont montré une efficacité faible dans l'épuration des gaz, l'activation leur ouvre de nouvelles potentialités, notamment pour les écales de sarrasin qui s'apparentent alors à des charbons actifs. Les chars des écales de sarrasin démontrent leur intérêt lorsqu'ils sont activés à la vapeur d'eau pour la purification du syngaz et ils conservent leur pouvoir calorifique (PCI) que permet d'envisager une valorisation énergétique par gazéification. Ces résultats montrent également qu'en fonction de la nature de la biomasse et du type d'activation, les objectifs de valorisation matière et énergie sont parfois incompatiblesThe aim of the thesis is to study the valorization of chars prepared from biomass wastes. In this context of energy transition, the selected biomasses are the buckwheat and millet husks since they are barely studied until now. In addition these wastes are produced locally, contribute to the developement of the circular economy and to not compromise a known value chain. In this word, material recovery is approcached through the reuse of these residues in syngaz and biogas cleaning processus in order to remove key pollutants such as tars and hydrogen sulfide, respectively. Energy balances form the prodution fo these chars have been established and energy efficiency indicators have been calculated. The chars were produced at 500 °C and then characterized by chemical and physical analysis. In order to provide them porous properties necessary for fixed-bed gas cleaning applications, activations were carried out at 850 °C with CO₂ or steam. Buckwheat husks turn out to be a fairly conventional biomass and the particularity of millet husks is to have high levels of silicon. If pyrolysis chars have shown a low efficiency in the purification of gases, activation opens up new potential for them, especially for materials from buckwheat husks, which are similar to activated carbons. When activated with steam these chars show interesting efficiency for the purification of syngas and they conserve their calorific value (LHV) which makes it possible to consider an energy recovery through gasification. Results from this study also show that depending on the nature of biomass and type of activation, the material valorization and energy recovery are sometimes incompatible
4
Ekpo, Ugochinyere Ngozi. "The potential for recovery of nutrients from biomass by hydrothermal processing." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/13521/.
Full textAbstract:
Hydrothermal processing has received increased interest mostly in the area of waste conversion to higher density fuels. However in addition to energy generation from these materials, it has become a promising route for nutrient extraction and recovery from either the solid or aqueous products depending on the processing temperature. This research was carried out in phases with the aim to improve extraction of nitrogen and phosphorus from various nutrient-rich wet wastes and the potential to recover these nutrients by biological means or by adsorption unto biochar. The initial study was on various hydrothermal processing routes – thermal hydrolysis (TH), hydrothermal carbonisation (HTC), hydrothermal liquefaction (HTL) and supercritical water gasification (SCWG) at 170°C, 250°C, 350°C and 500°C respectively using high moisture and high nutrient feedstocks namely microalgae, digestate, swine manure and chicken manure. Experiments were conducted with 10:1 water: solid ratio and 1 hour residence time except for SCWG which was 30 minutes with 15:1 water: solid ratio. The fate of N, P and other inorganics from each feedstock during these processes were investigated as well as the product yields, composition of the aqueous products and solid products. The results indicate that feedstocks behave differently during hydrothermal processing with the composition and yields of by products depending largely on feedstock composition and processing temperature. Highest solid yields were obtained at lowest temperatures while highest gas yields were obtained at the highest temperature. HTL favour formation of highest biocrude. Aqueous products from lower temperatures contain higher P levels (mainly organic-P and less phosphate) and lower N levels (mainly organic-N and less NH3-N). At higher temperature it is vice versa. Extracted P depends on Ca, Mg and Fe in unprocessed feedstock. P is immobilised in solid product at higher temperatures. TOC in aqueous product decrease with increasing processing temperature. The effect of additives on nutrient extraction during low temperature processing –Thermal hydrolysis at 120°C and 170°C as well as HTC at 200°C and 250°C using different reagents - alkali (0.1M NaOH), mineral acid (0.1M H2SO4) and organic acids, (0.1M CH3COOH and 0.1M HCOOH) was investigated. All experiments were performed with 10:1 water: solid ratio in high pressure 600 mL Parr batch reactor for 1 hour. The nutrient mass flow balance during these processes, the composition of the aqueous product and solid products were investigated. The results indicate that TN is significantly affected by temperature rather than pH. NH3-N in aqueous product increases with increasing temperature while organic- N reduces. Phosphorus extraction is pH and temperature dependent and further enhanced with additives. Acidic conditions favour phosphorus extraction especially with H2SO4 at all temperatures; highest (94%) extracted using H2SO4 at 170°C and presents opportunity for nutrient recovery. Neutral or basic conditions immobilise P in hydrochar and offers potential route for manure management as P-loss is reduced in the environment. Mg, Na and K are mostly extracted into aqueous product, while Ca and P concentrate in solid product as temperature increases. Acidic conditions extracted higher levels of micronutrient compared to water or NaOH. Generally micronutrients were more in the solid for most additives except H2SO4 while Ni and Al were mostly in the solid products. Microwave pre-treatment of various feedstocks such as sewage sludge, microalgae, digestate and manures was performed with 15:1 water: solid ratio at 120°C for 15 minutes. Also the influence of additives on nutrient extraction from swine manure was also investigated. Results show that aqueous products contain significant levels of N and P; nitrogen mainly as organic-N rather than NH3-N for all feedstock while it was mainly as organic-P for sewage sludge and digestate and more as phosphate with microalgae and manures. High TP was extracted with acidic reagents rather than with water or NaOH. With most additives, N in aqueous product was mainly as organic-N than NH3-N while P in the aqueous product was mainly as phosphate rather than organic-P. Aqueous products contain most K and Na while the residues contain most Ca, Mg, P and micronutrients for most feedstocks. Acidic conditions most especially with H2SO4 extracted more Ca, Mg, P, Co, Mn, and Zn unlike neutral or alkaline conditions. In comparison with conventional heating, microwave heating generally extracted more nitrogen and phosphorus into the aqueous products. Biological recovery of nutrients using various SCWG aqueous waste streams showed significant autotrophic growth of Chlorella in the diluted aqueous products except for the aqueous product from SCWG of Chlorella diluted at 1:50. Chlorella was able to utilise ammonium as a source of nitrogen. Higher dilutions of 1:400 had insufficient nutrients to promote growth. Biomass obtained from 1:50 dilution of catalysed SCWG of S. latissimi, L.digitata, sewage sludge and 1:200 dilution of SCWG Chlorella were comparable with biomass obtained using the standard Bold’s Basal Media. The recovered biomass could be used as feedstock for biodiesel or lipid extraction. Physical recovery of phosphate from H2SO4 extracted aqueous products by adsorption using Mg modified biochar shows that phosphate adsorption is affected by concentration and pH. Highest adsorption was achieved with 250 mg/L while higher adsorption efficiency was achieved at pH 8 and 9 compared to pH 7, precipitating more calcium phosphate on the biochar. Phosphate adsorption did not occur at lower/acidic pH conditions. There was no likelihood of struvite precipitation as EDX analysis showed no additional nitrogen and Mg in the adsorbed chars.
5
Johansson, Wilhelm. "Modeling of Wet Scrubber with Heat Recovery in Biomass Combustion Plants." Thesis, Linnéuniversitetet, Institutionen för byggd miljö och energiteknik (BET), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-95585.
Full textAbstract:
During combustion of biomass, particulate matter is emitted, which has severe health impacts on humans. The company ITK Envifront has developed a scrubber technology that cleans the flue gas while also recovering the flue gas energy, increasing the efficiency of the combustion plant. In this thesis, a simulation model was built in MATLAB according to the Finite Element Method. Validation of the model against 3 different facilities showed reasonable accuracy with a tendency to overestimate the scrubber heat recovery and a mean prediction deviation of approximately 7 %. The model was then used to make suggestions for process optimization. An increase of funnel height, and number of spray nozzles could increase the scrubbers heat recovery with up to 7 % and 8 %, respectively. Addition of moisture to the flue gas through evaporation of water droplets had the potential to increase scrubber efficiency with 10 %, and usage of the highest setting of the adjustable nozzle bank showed the potential to increase the efficiency with up to 5 % compared to the mid-setting. Furthermore, the process parameters of a scrubber with optimized running conditions, was compared to a scrubber with the current running conditions, through running of the developed model. The optimized running conditions showed an increase in scrubber efficiency with up to 14 %, resulting in an increase in scrubber heat recovery of approx. 90 kW at a boiler load of 3 MW. As a final conclusion, the developed model shows great potential to be used to as a toolbox to further investigate and optimize the scrubber design and operation. As a future work, it would be interesting to further model its performance regarding particle removal.
6
Fisher, Michael Bryan. "Development and study of dissolved gas flotation for biomass recovery after anaerobic treatment." Thesis, Loughborough University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366265.
Full text
7
Machado, Peter. "Feasibility of extracting solanesol from tobacco biomass as a byproduct following protein recovery." College Park, Md.: University of Maryland, 2008. http://hdl.handle.net/1903/8551.
Full textAbstract:
Thesis (M.S.) -- University of Maryland, College Park, 2008.Thesis research directed by: Dept. of Nutrition and Food Science. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
8
Simpson, Jessica R. "Effect of Cell Wall Destruction on Anaerobic Digestion of Algal Biomass." ScholarWorks@UNO, 2017. https://scholarworks.uno.edu/td/2433.
Full textAbstract:
Research was conducted using algal biomass obtained from the surface of a secondary clarifier at Bridge City Wastewater Treatment Plant and subsequently sent through an electrochemical (EC) batch reactor at various concentrations. The first objective was to achieve maximum cell wall destruction electrochemically using the EC batch reactor and determine the optimal detention time and voltage/current relationship at which this occurred. The second objective was to subject two algal mediums to anaerobic digestion: the algal medium without electrochemical disinfection and the algal medium after disinfection. Every three days, for 12 days, total solids were measured from each apparatus to determine if cell destruction increased, decreased or did not change the consumption rate of algae by anaerobic bacteria. The consumption rate of algae is directly proportional to the production of methane, which can be used as a source of biofuel.
9
Nyein, Chan. "Biomass Recovery of Swidden Fallow Forests in the Mountains of Myanmar and Lao PDR." 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/215659.
Full textAbstract:
Kyoto University (京都大学)0048
新制・課程博士
博士(地域研究)
甲第19833号
地博第189号
新制||地||66(附属図書館)
32869
京都大学大学院アジア・アフリカ地域研究研究科東南アジア地域研究専攻
(主査)教授 竹田 晋也, 教授 岩田 明久, 准教授 古澤 拓郎, 教授 神﨑 護
学位規則第4条第1項該当
10
Risén, Emma. "Sustainability Aspects of Bioenergy and Nutrient Recovery from Marine Biomass : Baltic Sea case studies." Doctoral thesis, KTH, Industriell ekologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-156377.
Full textAbstract:
Coastal areas around the world are experiencing environmental problems such as climate change and eutrophication. These, in turn, lead to emerging challenges with excessive amounts of biomass that impact coastal communities. Developing utilisation strategies for marine biomass is therefore highly relevant and forms part of the blue growth research field. In response to environmental concerns, as a waste management strategy and as part of blue growth research initiatives, several Baltic Sea coastal projects have been initiated in recent years to study utilisation of maritime biomass. However, the sustainability of these utilisation strategies has not been critically appraised. Therefore, the work presented in this thesis explored some key sustainability aspects of two Baltic Sea case studies utilising common reed (Kalmar, Sweden) and mass-occurring filamentous macroalgae (Trelleborg, Sweden) for biogas and biofertiliser recovery. Energy analyses suggested that both case studies could provide a positive energy balance and have the potential to achieve nutrient recovery. Moreover, a contingent valuation study in Trelleborg demonstrated considerable welfare benefits of biomass utilisation. These findings indicate that marine biomass utilisation strategies highlight potential to contribute to environmental and welfare benefits of these coastal communities.QC 20141126
11
Zhang, Yue. "Biosorption for heavy metal removal and recovery from dilute solutions by immobilized nonviable biomass." Thesis, University of Southampton, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.423377.
Full text
12
Donaj, Pawel. "Conversion of biomass and waste using highly preheated agents for materials and energy recovery." Doctoral thesis, KTH, Energi- och ugnsteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-34253.
Full textAbstract:
One of the greatest challenges of human today is to provide the continuous and sustainable energy supply to the worldwide society. This shall be done while minimizing all the negative consequences of the operation(s) to the environment and its living habitants including human beings, taking from the whole life cycle perspective. In this thesis work new solutions for treatment biomass and waste are analyzed. Based on the fundamental research on the conversion of various materials (biomass: straw pellets, wood pellets; and waste: plastic waste, ASR residues after pyrolysis), converted by means of different systems (pyrolysis in a fluidized bed reactor, gasification in a fixed-bed reactor using highly preheated agents) it is recommended to classify materials against their charring properties under pyrolysis, in order to find the best destination for a given type of fuel. Based on phenomenological research it was found that one of the important effects, affecting performance of downdraft gasifiers, is the pressure drop through the bed and grate. It affects, directly, the velocity profile, temperature distribution and of the height of the bed, especially for the grate with restricted passage surface, although it was not investigated in literature. The lower grate porosity, the higher conversion of fuel and heating value of gas is produced. However, the stability of the process is disturbed; therefore reducing the grate porosity below 20% is not recommended, unless the system is designed to overtake the consequences of the rising pressure inside the reactor. This work proposed the method for prediction of a total pressure drop through the fixed-bed downdraft gasifier equipped with a grate of certain porosity with an uncertainty of prediction ±7.10. Three systems have been proposed; one for the treatment of automotive shredder residue (ASR), one for the treatment of plastic waste (polyolefins) and one for biomass (wood/straw pellets). Pyrolysis is an attractive mean of conversion of non-charring materials (like plastic waste) into valuable hydrocarbons feedstock. It gives directly 15-30% gaseous olefins while the residue consisting of naphtha-like feedstock has to be reformed/upgraded to olefins or other chemicals (e.g. gasoline generation) using available petrochemical technologies. Pyrolysis of complex waste mixture such as ASR is an attractive waste pretreatment method before applying any further treatments, whereby useful products are generated (gaseous and liquid fuel) and char, rich in precious metals. The solid residues are meant for further treatment for energy and metals recovery. Gasification is a complementary method for handling pyrolysis residues. However, metals can be removed before gasification. Pyrolysis of charring materials, like biomass, is a very important step in thermo-chemical conversion. However, the char being approximately 25%wt. contains still very high caloric value of about 30MJ/kg. This in connection with the High Temperature Steam Gasification process is a very promising technology for biomass treatment, especially, above 900oC. This enhances the heat transfer towards the sample and accelerates kinetics of the gasification. This, in turn, improves the conversion of carbon to gas, increases the yield of the producer gas and reduces tar content. At higher steam to fuel ratio the process increases the yield of hydrogen, making it suitable for second-generation biofuels synthesis, whereas at lower steam to fuel ratio (S/F<2) the generated gas is of high calorific value making it suitable for power generation in a combined cycle.QC 20110607
13
Hall, Jennifer M. "Manipulation of N mineralisation/immobilisation dynamics to investigate poor fertiliser recovery in improved grass pasture on ombrotrophic peat." Thesis, University of Aberdeen, 1995. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU068793.
Full textAbstract:
The spring application of fertiliser N often fails to stimulate grass growth in improved grass pastures on peaty soils. Fertiliser utilisation efficiencies under these conditions have been found to be low, suggesting that available N is not taken up by the plant. Previous work has suggested that in this type of system, the soil microbial biomass may function as a strong sink for fertiliser N and therefore limit plant growth in the Spring. A series of laboratory based experiments utilising reconstituted and intact cores, and homogenised peat, was set up to identify the factors controlling the competition between N uptake by plants and N immobilisation by soil microorganisms following the addition of fertiliser N to peat. Microbial biomass N concentrations were determined in order to quantify the amount of N present in the microbial pool. The use of 15N labelled fertilisers and selective biocides provides a powerful tool with which to characterise the microbial population responsible for the immobilisation of N under these conditions. Improvement of a grass pasture at Sletill Hill has resulted in the formation of a distinct layer comprised of partially decomposed roots, underneath the surface vegetation and it was within this layer, that microbial immobilisation of fertiliser N was found to occur. Approximately 30% of applied N (equivalent to ca 50 kgN ha-1) was found within the microbial biomass in this layer, 30 days after the addition of fertiliser N. Intact cores were removed from Sletill Hill and maintained under controlled abiotic conditions. Water table level and temperature were found to be important in controlling the extent of microbial immobilisation of applied N. Lowering the water table level increased the quantity of N present in plant and microbial N pools, particularly at lower temperatures (8°C). At higher temperatures (20°C), plant uptake of N tended to be less due to a restriction on plant growth caused by 'droughty' soil conditions.
14
Gaur, Sarthak. "Development and evaluation of an effective process for the recovery of oil and detoxification of meal from jatropha curcas." Diss., Rolla, Mo. : Missouri University of Science and Technology, 2009. http://scholarsmine.mst.edu/thesis/pdf/Gaur_09007dcc806c289e.pdf.
Full textAbstract:
Thesis (M.S.)--Missouri University of Science and Technology, 2009.Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed August 31, 2009) Includes bibliographical references (p. 51-56).
15
Zhou, Long. "Microwave-assisted treatments of biomass : lignin isolation from lignocellulose and natural products recovery from bilberry presscake." Thesis, University of York, 2018. http://etheses.whiterose.ac.uk/22152/.
Full textAbstract:
Microwave thermal treatment has generated an increasing interest in biomass valorisation. In this research, softwood, hardwood and straw are processed by microwave-assisted acidolysis, producing high quality residual lignin without significant modification, especially softwood (purity 93%, yield 82%). Under equivalent conditions, microwave treatment produces lignin with higher yield and purity than conventional treatment. The aqueous hydrolysate is fermented by two oleaginous yeasts, Cryptococcus curvatus and Metschnikowia pulcherrima. Both yeasts could grow on the hydrolysate and produce an oil with similar properties to palm oil. This preliminary work demonstrates new protocols of microwave-assisted acidolysis and therefore offers an effective approach to produce high purity lignin and fermentable chemicals, which is a key step towards developing a zero-waste lignocellulosic biorefinery. In addition, microwave conversions (lab and pilot scale) of bilberry presscake, aiming to fulfill multiple chemicals recovery, were carried out using only water as the solvent, ensuring all products are suitable for food grade status applications. Microwave hydrolysis gives much higher yield of mono-/disaccharides than conventional extraction, with the yield of rhamnose particularly high (10.8%). Pilot scale microwave conversions are also carried out with high conversion. It is believed microwave hydrolysis offers an efficient and green approach to convert bilberry presscake into value-added products for food industry and biorefinery.
16
Matindi, Robert Kariuki. "Development of bioenergy systems and models for optimised recovery and delivery of biomass to biorefinery operations." Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/130761/2/Robert_Kariuki_Matindi_Thesis.pdf.
Full textAbstract:
This research explores the feasibility of recovering cane residue and bagasse as well as siting and sizing of a bio-refinery in Australia. It provides a framework that integrates spatial distribution of biomass supply, bio-refinery size and site locations, logistical flows and process engineering by integrating economic, environmental and social values using versatile and integrated approaches of stochastic multi-objective optimization, simulation and techno-economic modelling to design a recovery and energy production systems using sugarcane derived biomass. These approaches enabled the analysis of key techniques required to significantly reduce the uncertainties associated with the cost and industrial engineering impacts of lignocellulose biomass as a feedstock for the renewable production of fuels, chemicals and bio power.
17
Häggström, Gustav. "Experimental studies of ash transformation processes in thermochemical conversion of P-rich biomass and sludge." Licentiate thesis, Luleå tekniska universitet, Energivetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-78593.
Full textAbstract:
The efficient use of resources and sustainable recovery of various materials are important to minimize the anthropogenic impact on the climate and environment. One such resource is the phosphorus present in manure and sewage sludge. Various technologies are currently being developed to recover the phosphorus for the use of fertilizers in agricultural applications. Thermochemical conversion presents an opportunity to recover energy from these materials. At the same time, elements can be recovered in ash fractions, potentially harmful organic substances can be destroyed and heavy metals fractionated from the P. Mono-combustion of sewage sludge mainly produce apatite, which is not plant available and useful for fertilization. Co-combustion/-gasification with other fuels enables modification of ash transformation pathways and also remedy potential problems, such as bed agglomeration, associated with e.g. agricultural residues used as fuels. This thesis aims to increase the current knowledge in ash transformation of phosphorus-rich materials in cocombustion/-gasification with woody and agricultural fuels in process temperatures relevant for fluidized bed systems. The work focuses on i) possibility for formation of plant-available K-bearing phosphates ii) the effect of fuel ash composition and chemical association of P in the fuel on the distribution and speciation of P and iii) interaction of P-rich ash with bed material in fluidized beds. Experiments were carried out in bench-scale bubbling fluidized bed (BFB), macro-TGA (thermogravimetric analysis) combustion reactors and a dual fluidized bed (DFB) gasification reactor. Fuels studied were mixtures of chicken litter together with wheat straw and bark, and mixtures of digested sewage sludge combined with wheat straw and sunflower husk. Ash fraction and bed materials were collected and analyzed using ICP-OES/MS, SEM-EDS and XRD techniques. For the mixture of chicken litter and K- and Si-rich wheat straw, combusted in BFB, P and Si together with K and Ca formed homogeneous ash particles with large amounts of potentially amorphous iv content. A similar behavior was observed in sewage sludge and wheat straw mixtures where P and Si were likely present in a melt that is amorphous after extraction. In addition to these particles, P was also found in crystalline compounds such as hydroxyapatite, whitlockite and CaKPO4. For mixtures with Ca-rich bark, most of the phosphate formed was in the form of hydroxyapatite. In the interaction of ash with bed material, P captures Ca and K in phosphates, decreasing the interactions of these elements with the bed material, and thus can decrease the risk for bed agglomeration. The findings show that it is possible to modify the ash transformation of P towards K-bearing phosphates by co-combustion. Furthermore, they suggest that it is possible to recover most of the phosphorus in coarse ash fractions through co-combustion of P-rich materials with agricultural fuels. This means that P and volatile heavy metals can be separated into different ash fractions. This also increases the possibility of utilizing existing boilers for recovery of P as well as increased their flexibility to different fuels. To further validate the agricultural value of the produced ashes, plant growth studies have to be performed.
18
Papalexandrou, Tryfon. "Integrated Energy Recovery Scenarios of Biomass Residues in the Non-interconnected Island of Crete : A Pre-Feasibility Study in Greece." Thesis, KTH, Industriell ekologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-174024.
Full textAbstract:
The cornerstone of our production system is based on the concept “take, make, waste”. Moreover, the manufacture of a product requires the input of energy and raw materials which produce waste and products. The latter ultimately end up becoming wastes. In other words, the root problem of this production system is that is designed on a linear, one-way cradle-to grave model (McDonough, W. and Braungart, M., 2002). This approach coupled with the population explosion and our thirst for growth has led to an unprecedented pressure to the environment. The consequences are multiple; climate change, dwindling energy resources and waste generation. This study lies in two pillars: the concept of sustainable development and the waste management hierarchy. The idea was how these two fundamental concerns (energy generation and waste production) could be tackled. This study assesses the availability of biomass residues and wastes in the off-grid island of Crete with the aim to ‘close the loop’ by converting waste to an energy resource. In addition, the exploration of the most sustainable energy generation solutions was attempted in order to drive forward the synergies between biomass waste production and energy generation. The collected information was extracted from the literature about agricultural, livestock, Municipal Solid Waste (MSW) and Industrial & Commercial (I&C) waste. It is also based on numerous interviews to waste management associations, the Greek Ministry of Rural Development & Food and all the Waste Water Treatment Plants in the island were analysed in order to shed light on the potential energy generation from all the aforementioned biomass sources and its contribution to the electric energy production system of Crete. It is considered that the biomass potential in Crete is a sleeping giant. There is considerable potential for biomass-to-energy technologies in Crete providing improved rural energy services based on agricultural residues. From the findings of this study it appears that the biomass potential is more than estimated in previous papers. Based on the findings it is concluded that the largest portion of Crete’s biomass potential is agricultural residues and animal wastes. The utilisation of low-cost biomass power in Crete could help provide cleaner, more efficient energy services and to reduce the island’s economic and environmental vulnerability. Biomass can provide both base load power and turn into liquid transportation fuels and contributes to reducing energy dependence due to import fuel from the mainland. In terms of the study’s goal to select the most sustainably viable biomass-to-energy technologies, that was based on the multi-criteria methodology. A number of integrated biomass-to-energy alternatives were assessed against technical, environmental, financial and social criteria with the aim to assist the regional authority’s decision making process of energy generation planning. From the final screening of the integrated biomass-to-energy alternatives it was concluded that the best in a descending order technologies from the regional authority’s standpoint are: F - Anaerobic digestion & Fuel cell; E – Anaerobic digestion & Gas engine; C - Gasification & Gas engine; A – Combustion & Steam turbine; and B – Gasification & Steam turbine.
19
Ometto, Francesco. "Microalgae to energy : biomass recovery and pre-treatments optimisation for biogas production integrated with wastewater nutrients removal." Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/8403.
Full textAbstract:
The increasing concern about water quality and energy demand promotes the development of innovative and low-cost processes to improve the nutrient uptake and energy efficiency of existing wastewater treatments (WWT). In this context, the inclusion of a microalgae system (MAS) in the flowsheet of a WWT plant represents a sustainable alternative to conventional technologies, as it combines a low-cost nutrient uptake system with the production of biomass suitable for biofuel production. However, at present, the energy required to cultivate and process the algae cells is often too high to justify their use. The adoption of a low energy harvesting system and an efficient energy conversion process are the sine qua non requirements to guarantee the sustainability of the process. In this thesis, current and innovative harvesting technologies for large scale applications have been reviewed to identify the optimal working conditions of each system and their link to the main characteristics of the algae suspension. In particular, the performance of the Ballasted Dissolved Air Flotation (BDAF) system was investigated using different algae and compared to the conventional Dissolved Air Flotation (DAF). BDAF was demonstrably a very viable harvesting method where the use of floating microspheres as ballasting agents allowed significant coagulant savings, reduced the level of energy dissipation within the flotation chamber, and lowered the overall carbon emissions and the process costs. Cont/d.
20
Antunes, Ana Paula Martins. "Removal and recovery of gold and platinum from aqueous solutions utilising the non-viable biomass Asolla filiculoides." Thesis, Rhodes University, 2002. http://hdl.handle.net/10962/d1003726.
Full textAbstract:
Waste water from the mining industry is generally extremely complex and contains numerous species which influence the adsorption of the metals to any biomass. A variety of factors need to be addressed before treatment is considered viable. It is also beneficial to establish the binding characteristics of the metal of interest to maximise its interaction with the biomass to be utilised. Azalia filiculaides was investigated in the adsorption of gold(III), lead(II), iron(ID), copper(II) and platinum (IV). In batch studies, the optimum biomass and initial gold(III) concentrations were found to be 5 gIL and 8 mgIL respectively. The adsorption of gold(ID) is principally pH-dependent with optimal removal at pH 2. Lead(II), iron(III) and copper(II) did not compete with gold(III) adsorption under equimolar and simulated effluent conditions. Halides, with increasing affinity for gold (chloride < bromide < iodide), can affect gold uptake with the soft base, iodide, exhibiting the most inhibition (25%) and the hard base, chloride, O%. Mercaptoethanol (soft base) showed no interference in gold(III) adsorption while the presence of sulphate (hard base) and sulphite (borderline base) showed that concentrations in excess of 1 0 mM may adversely affect gold(ill) uptake, most likely due to competition for cationic sites on the biomass. Column studies, better suited to high volume treatment, indicated that a flow-rate of 5 mL/min and an initial gold(ill) concentration of 5 mgIL was optimal. Competitive effects between lead, iron, copper and gold again showed little or no interference. The halides, chloride, bromide and iodide, affect gold(ill) uptake similarly to the batch studies, while the bases mercaptoethanol and sulphate minimally affect gold(III) binding with sulphite severely hampering adsorption (70% inhibition). To optimise gold desorption, preliminary batch studies indicated that a ratio of 1:1 of adsorbentdesorbent was optimal, whilst gas purging of thiourea with oxygen, air and nitrogen decreased gold elution in proportion to decreased amounts of oxygen. A series of desorbents were utilised, in column studies, to optimise and determine the speciation of bound gold. The presence of an oxidant with thiourea enhanced desorption greater than 3 fold when compared with thiourea alone. Thiourea desorption studies, aided by the oxidant, suggest that gold is present in the + I and 0 oxidation states. Ultimately thiourea, perchloric acid and hydrochloric acid was found to be the most optimal elutant for gold (J 00% recovery). For selective metal recovery oflead and copper, pre-washing the plant material with water, utilising an acid (0.3 M nitric acid), pumping in an up-flow mode, and recycling the desorbent six times was found to be optimal elutant for gold (J 00% recovery). Cost analysis of utilising elutant versus incinerating the biomass for gold recovery indicated the latter as the most economical. Over a 5 cycle adsorption and desorption series, acid desorption before each adsorption cycle was found to result in greater than 92% desorption for lead and 96% for copper. Gold recovery was 97% with incineration. A preliminary study with gold effluent (Mine C) indicated that nickel and sulphate was removed in batch and column studies. Gold removal was found to be 100% and 4% in batch and column studies respectively. Adsorption of gold in the effluent study was accompanied by the release ofHt. Modifying the plant material with various reagents failed to identify the primary binding sites and the role of polysaccharides, proteins and lipids in gold(ill) uptake. The mode of gold binding is suggested as being initially ionic, this is very rapid, with the interaction of the anionic complex, [AuCI₄]". with the cationic biomass (PH 2). This eventually leads to the displacement of the chloride ligand(s) initiating covalent binding. Spectral studies of the chemical interaction between gold and the representative tannins indicated the protonated hydroxy groups to be responsible. All evidence suggests that the binding mechanisms of gold are not simple. Preliminary adsorption studies of platinum by Azalia filiculaides were conducted. Batch studies indicated that J gIL biomass concentration, initial platinum concentration of 20 mgIL and pH 2 are optimal, while the column studies indicated a flow-rate of! 0 rnL/min and initial platinum concentration of 20 mgIL as optimal. In the platinum effluent study, platinum showed a removal of 23 % and 2 J % for the batch and column studies respectively. Again adsorption was accompanied by //' release. Azalia filiculaides demonstrated its feasibility in the removal of gold and platinum from simulated as well as waste water solutions. Its potential viability as a biosorbent was demonstrated by the high recovery from synthetic solutions of greater than 99% for gold (2-10 mgIL), and greater than 89% for platinum (20 mgIL).
21
Godawitharana, Sampath, and Rohitha Rajaratne. "Technical and Financial Viability of Utilizing Waste Heat for Chilled Water Production and Biomass for Heating Applications in Hospitality Industry." Thesis, KTH, Kraft- och värmeteknologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-101392.
Full textAbstract:
The purpose of the thesis is to determine the potential of lessening the high energy cost in the hospitality industry so that the industry could stay alive after a three decades of civil war in Sri Lanka. The hospitality industry is a significant contributor to the country’s economic growth. Tourism industry has much hope of recovering in the year 2010. Improved tourism would also benefit larger part of Sri Lankan population as they are directly and indirectly employed to serve the tourism industry. Sri Lanka has a high electricity production cost as it depends heavily on the imported fossil fuel. Survival of hospitality industry would depend on the manner in which the energy cost - the second highest overhead in hotels is managed. If the industry survives, Sri Lanka would receive more foreign exchange and thereby improve country’s foreign currency reserve which could contribute to high growth rate. As electricity production is mainly depending on thermal, the volatility of world crude oil prices is directly affecting the country’s electricity prices. However, low dependence on the grid would help the hospitality industry to mitigate the energy cost. As the electricity and diesel costs -the highest and the next - are considerable portions in energy cost in hospitality industry, the study aims to discuss the possible ways of mitigating such costs. Measurements done by the presenters found that the usage of electricity for air conditioning system does constitute most of the electricity consumption for a hotel whilst most of the diesel consumption is for thermal applications. If Air Conditioning (AC) can be operated without electricity and thermal applications could be operated using abundantly available alternative energy sources then the overall energy costs of hospitality industry could be reduced thereby making higher profits. This would ensure industry survives and country gets more foreign exchange. Study and calculations done by the presenters proved that operating of generators only for electricity production is not viable, due to high fossil fuel cost, however if its high exhaust temperature which is wasted otherwise, could be utilized for operation of absorption chillier then the dependence of grid electricity for air conditioning could be minimized. Further studies also revealed that if water cooled generator is used for such purpose instead of air cooled, and then the hot water requirement of hotel also could be fulfilled, thus mitigating the dependence of fossil fuel which is used otherwise for hot water production. Study also revealed that if thermal energy could be fed with biomass- Sri Lanka being a tropical country is blessed with abundantly available biomass - then the dependency on the fossil fuel for thermal applications could be avoided. This would not only mitigate the second highest energy cost for hotels but also create less carbon foot print, more environmental friendly and produce less noxious exhaust gases thereby creating an advertisement to attract tourists who longing to support green hotels
22
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.
Full textAbstract:
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.
23
Oliveira, Jéssica Alves de. "Estabelecimento de bananeira (Musa sp.) em solo degradado /." Ilha Solteira, 2018. http://hdl.handle.net/11449/154511.
Full textAbstract:
Orientador: Ana Maria Rodrigues CassiolatoResumo: O solo degradado em estudo originou-se pela retirada da sua camada superficial, que compreende a vegetação, a matéria orgânica, os nutrientes e os microrganismos, cujos processos são essenciais para o solo ser considerado produtivo. Sua recuperação é importante para manter o equilíbrio da biodiversidade de flora e fauna e protege-lo contra a erosão, entre outros fatores. O objetivo deste trabalho foi o condicionamento do subsolo pela adição de cinza de biomassa de cana-de-açúcar, da inoculação de fungo micorrízico arbuscular (FMA – Glomus clarum) e da inoculação de fungos e de bactéria solubilizadores de fosfato, buscando uma técnica para a recuperação de solos degradados. A bananeira (Musa sp. cv. Mysore) foi utilizada como planta indicadora para as modificações que ocorreram no solo. O delineamento experimental foi em blocos casualizados, em esquema fatorial 2 x 2 x 3 + 2, com 4 repetições por tratamento, totalizando 12 tratamentos, com 4 repetições (bloco). O primeiro fator foi com e sem inoculação de FMA, o segundo foi com e sem adição de cinza proveniente da queima do bagaço de cana-de-açúcar, o terceiro foi com e sem inoculação de fungos e de bactéria solubilizadores de fosfato, e dois tratamentos adicionais, área conservada de Cerrado (SCRC) e área degradada sem intervenção (ADSI). Após 67 e 274 dias do plantio foram avaliados os atributos químicos e microbiológicos do solo na camada de 0,0 a 0,10 m, além da altura, do diâmetro, do índice relativo de clorofila e do P t... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The degraded soil under study originated by the removal of the superficial layer, which includes vegetation, organic matter, nutrients and microorganisms, whose processes are essential for the soil to be considered productive. Its recovery is important to maintain the balance of biodiversity of flora and fauna and protect it against erosion, among other factors. The objective of this work was the subsoil conditioning by the addition of sugarcane biomass ash, the inoculation of arbuscular mycorrhizal fungi (AMF - Glomus clarum) and the inoculation of fungi and bacteria phosphate solubilizers, searching for a technique for recovery of degraded soils. The banana plants (Musa sp. cv. Mysore) was used as an indicator plant for the changes that occurred in the soil. The experimental design was a randomized complete block design, with a 2 x 2 x 3 +2 factorial scheme, with 4 replicates per treatment, in a total of 12 treatments, with 4 replicates (block). The first factor was with and without AMF inoculation, the second was with and without ash added from the burning of sugarcane bagasse, the third was with and without inoculation of fungi and bacteria phosphate solubilizers and two controls area, Cerrado conservation area (CCAR) and degraded area without intervention (DAWI). After 67 and 274 days of planting, the soil chemical and microbiological attributes were evaluated in the 0.0 to 0.10 m layer, as well as the height, diameter, relative chlorophyll index, and total leaf P. The a... (Complete abstract click electronic access below)
Mestre
24
Daragon, Guillaume. "Etude des voies de valorisation de la vinasse par combustion en mélange avec des biomasses." Thesis, Mulhouse, 2015. http://www.theses.fr/2015MULH7972.
Full textAbstract:
L’industrie, quel que soit son domaine d’activité, produit une quantité importante d’effluents chargés, couramment appelés coproduits. La gestion et le traitement de ces eaux usées sont aujourd’hui strictement encadrés car leurs propriétés physiques et leurs compositions chimiques interdisent leurs rejets directs vers le milieu naturel. Cependant, la présence en forte concentration de certains éléments valorisables tels que les sels minéraux ou des composés organiques dans certains de ces effluents, leurs confèrent alors de nouvelles propriétés qui trouvent échos dans diverses applications (fertilisation des sols, alimentation animale, méthanisation, co-compostage, etc.). Le carbone étant le constituant majoritaire de tout combustible, une valorisation thermique par combustion en chaudière biomasse des effluents organiques semble être une alternative envisageable. L’objet de cette thèse est l’étude de cette voie de valorisation énergétique et de la faisabilité de cette application. Du fait de leur état liquide, les effluents seuls sont de mauvais combustibles comparés aux biomasses standards (plaquettes forestières, paille, etc.). Les travaux de recherche se concentrent donc sur l’étude et la caractérisation de biomasses en tant que support d’imprégnation, puis sur la formulation d’un co-combustible homogène imprégné d’un effluent organique industriel. Les biomasses sont en effet connues dans la littérature pour avoir des propriétés d’adsorption et d’absorption intéressantes. Une étude paramétrique à l’échelle du laboratoire a été menée afin de quantifier la capacité d’imprégnation et la sélectivité de différents types de biomasse vis-à-vis de l’effluent choisi. Le but était également de déterminer les paramètres qui influençaient l’imprégnation afin de modéliser les phénomènes. Suite à cela, des essais à l’échelle pilote sur une installation de combustion de 40 kW ont été effectués en vue de vérifier la conformité des combustibles imprégnés en termes d’émissions à la cheminée et dans l’optique de préparer le changement d’échelle pour une potentielle application industrielleImportant amounts of organic effluents, also called wastewaters or byproducts, are produced whatever the type of industry which is considered. Nowadays, the wastewaters management and treatment are strictly controlled since the physical properties and the chemical composition of these byproducts disallow the direct reject through natural media. However, the presence of some specific compounds confers to effluents new advantages and opens the door to several applications (such as soil fertilization, cattle feed, methanization, co-composting, etc.). Carbon being the main component of every fuel, the thermal valorization of these organic effluents by combustion in a standard biomass boiler seems to be possible. The study of this recovery method and its feasibility are the subjects of the thesis here. Due to their liquid state, effluents alone cannot be considered as fuels compared to standard biomass (woodchips, straw, etc.). Therefore research works are focused on study and characterization of biomasses as impregnation base, then formulation of fuels impregnated with an industrial organic effluent. Indeed, the adsorptive and absorptive properties of biomasses are well-known in the literature. A parametric study at laboratory scale was carried out in order to quantify the impregnation capacity of different types of biomass regarding the effluent. The main goal was also to highlight the parameters which influence the impregnation in order to modeling the phenomenon. Then impregnation and combustion tests were performed at pilot scale using a biomass boiler of 40 kW to ensure the conformity of impregnated fuels in terms of stack emissions. This part of the work was conducted with the perspective of preparing the process scale-up for a potential industrial utilization
25
Zaebst, Thomas Winter. "Recovery status of a cypress (Taxodium distichum)-water tupelo (Nyssa aquatica) wetland seven years after harvest disturbance." Thesis, This resource online, 1997. http://scholar.lib.vt.edu/theses/available/etd-08222008-063023/.
Full text
26
Scherer, Daniel [Verfasser], and P. [Akademischer Betreuer] Nick. "Pulsed electric field (PEF)-assisted protein recovery from microalgae biomass for food and feed applications / Daniel Scherer ; Betreuer: P. Nick." Karlsruhe : KIT-Bibliothek, 2019. http://d-nb.info/1199459437/34.
Full text
27
Elsayed, Sherif [Verfasser], and J. [Akademischer Betreuer] Sauer. "Gasification of algal biomass in supercritical water with the potential of energy and nutrients recovery / Sherif Elsayed ; Betreuer: J. Sauer." Karlsruhe : KIT-Bibliothek, 2019. http://d-nb.info/1200471172/34.
Full text
28
Elsayed, Sherif H. N. [Verfasser], and J. [Akademischer Betreuer] Sauer. "Gasification of algal biomass in supercritical water with the potential of energy and nutrients recovery / Sherif Elsayed ; Betreuer: J. Sauer." Karlsruhe : KIT-Bibliothek, 2019. http://d-nb.info/1200471172/34.
Full text
29
Meyer, Joseph Freeman. "Recovery boiler superheater corrosion - solubility of metal oxides in molten salt." Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47742.
Full textAbstract:
The recovery boiler in a pulp and paper mill plays a dual role of recovering pulping chemicals and generating steam for either chemical processes or producing electricity. The efficiency of producing steam in the recovery boiler is limited by the first melting temperature of ash deposits that accumulate on the superheater tubes. Above the first melting temperature, the molten salt reacts with the protective oxide film that develops and dissolves it. The most protective oxide is determined by evaluating how little it dissolves and how its solubility changes in the molten salt. Solubility tests were done on several protective oxides in a known salt composition from a recovery boiler that burns hardwood derived fuel. ICP-OES was used to measure concentration of dissolved metal in the exposure tests while EDS and XRD were used to verify chemical compositions in exposure tests. NiO was found to be the least soluble oxide while Cr₂O₃ and Al₂O₃ had similar solubility with Fe₂O₃ being less soluble than Cr₂O₃ but more soluble than NiO. Exposure tests with pure metals and selected alloys indicated that even though Fe₂O₃ has little solubility, it is not a protective oxide and causes severe corrosion in stainless steels. The change in performance of iron based alloys was due to the development of a negative solubility gradient for Fe₂O₃ where Fe₂O₃ precipitated out of solution and created a continuous leaching of oxide. Manganese was found to be beneficial in stainless steels but its role is still unknown. Nickel based alloys were found to be least corroded due to nickel's low solubility and because it did not form a negative solubility gradient.
30
Mamede, Mauricio Cuba dos Santos 1983. "Avaliação econômica e ambiental do aproveitamento energético de resíduos sólidos no Brasil." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/265334.
Full textAbstract:
Orientador: Joaquim Eugênio Abel SeabraDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
Made available in DSpace on 2018-08-24T03:08:04Z (GMT). No. of bitstreams: 1 Mamede_MauricioCubadosSantos_M.pdf: 2829646 bytes, checksum: d25947395cd77eda7c39cdaf8fe0b8b6 (MD5) Previous issue date: 2013
Resumo: Considerando-se a necessidade de aprofundar o conhecimento da gestão de resíduo sólido municipal (RSM) e seus efeitos no ambiente natural e sobre a viabilidade econômica, este trabalho procurou contribuir analisando diferentes rotas de aproveitamento energético de RSM no contexto brasileiro. Foram utilizadas as características de geração de RSM de 81 municípios brasileiros, com vistas à comparação de dois cenários distintos: cenário Combustível, com a combinação das tecnologias de digestão anaeróbia (D.A.) - com foco na produção de combustível veicular - e combustível derivado de resíduo (CDR), para utilização industrial; e cenário Eletricidade, com a aplicação das tecnologias de D.A. - com foco no uso do biogás em motor estacionário - e incineração, com geração elétrica em ciclo Rankine. Na avaliação econômica, realizou-se fluxo de caixa com entradas e saídas financeiras para a obtenção dos indicadores valor presente líquido (VPL) e taxa interna de retorno (TIR). Ao final realizou-se uma análise de sensibilidade, variando custos e receitas considerados, composição do RSM, além de analisar a tarifa de tratamento necessária para zerar o VPL de cada tecnologia. Na análise ambiental foi utilizada a avaliação do ciclo de vida (ACV) para consolidar os inventários dos cenários, considerando-se uso de materiais, energia, além das emissões durante a construção e operação das unidades, com posterior avaliação do impacto do ciclo de vida (AICV) pelo software SIMAPRO, no método CML 2, para sete categorias de impacto (acidificação, aquecimento global, eutrofização, depleção abiótica, depleção da camada de ozônio, toxicidade, e oxidação fotoquímica). Os resultados majoritariamente indicaram melhores desempenhos econômico e ambiental do cenário Combustível. Há vantagens econômicas e ambientais na comercialização do biogás veicular para frota automotiva à produção de eletricidade a partir do mesmo, apesar de maior necessidade de investimento e maior complexidade tecnológica. As emissões do composto orgânico e do uso de combustíveis auxiliares perfazem as maiores cargas ambientais desta tecnologia. A incineração permite diminuir significativamente o volume do RSM, entretanto é a tecnologia mais cara das analisadas e colabora significativamente com a toxicidade humana pela emissão de metais pesados. Os investimentos na planta de CDR são muito menores, entretanto há a produção significativa de rejeitos que necessitam ser gerenciados, implicando em maiores custos e emissões de transporte e disposição destes. Ainda, incertezas de comercialização do CDR podem comprometer a viabilidade do cenário. Ademais, a análise indicou significativa sensibilidade em relação às variações na composição do RSM, principalmente com relação à fração reciclável, a qual influencia diretamente o poder calorífico inferior (PCI) do CDR e incineração, e portanto as receitas obtidas. Menores taxas de adesão da população ao programa de coleta seletiva implicam em maior fluxo de materiais incinerados e de CDR, sendo a última beneficiada economicamente, devido ao maior PCI. Com exceção do CDR, as demais tecnologias necessitam de maiores tarifas de tratamento para sua viabilidade econômica comparado à atividade de aterro sanitário, que é relativamente baixa comparada à praticada em países europeus. O deslocamento de combustíveis traz maior benefício comparado ao deslocamento da matriz elétrica nacional, que é majoritariamente hidrelétrica
Abstract: Considering the necessity to deepen the knowledge about municipal solid waste (MSW) management and its effects on the natural environmental and economic performance, this work assessed different alternatives of energy recovery from MSW in Brazil. The characteristics of MSW generated in 81 Brazilian municipalities were used for the comparison of two different scenarios: Fuel scenario, with combined use of anaerobic digestion (A.D.) - focused on the production of biomethane - and refuse derived fuel (RDF), for industrial utilization; and Electricity scenario, with the employment of A.D. - focused on biogas use in stationary engines - and incineration, with electricity generation through the Rankine cycle. For the economic assessment, a cash flow analysis was carried out to evaluate the feasibility indicators net present value (NPV) and internal rate of return (IRR). Sensitivity analyses were performed varying costs and revenues, MSW composition, besides the analysis of the break even gate fee for achieving a zero NPV for each technology. For the environmental analysis, the life cycle assessment (LCA) technique was employed to consolidate the inventory of each scenario, accounting for the use of materials, energy, and the emissions during the construction and operation of the plants. The life cycle impact assessment, modeled in SIMAPRO, was based on the CML 2 method considering seven impact categories (acidification, global warming, eutrophication, abiotic depletion, ozone layer depletion, toxicity, and photochemical oxidation). For the majority of the municipalities, the Fuel scenario showed better economic and environmental performance. The commercialization of biogas as vehicle fuel has economic and environmental advantages over the production of electricity, despite the higher investments and technology complexity. The emissions from the organic compost and the use of auxiliary fuels are the main environmental burdens related to this technology. The incineration has the advantage of significantly reduce the volume of MSW, but it is the most expensive technology analyzed and contributes to human toxicity through the emissions of heavy metals. The required investments in the RDF plant are much smaller, although it produces significant amounts of rejects that need to be managed, implying in higher costs and emissions due to transportation and final disposal. Moreover, the uncertainty in commercializing RDF could affect the economic performance of the scenario. Furthermore, the analysis indicated significant sensitivity with respect to waste composition, mainly recyclables fraction, which has direct effects on the low calorific value (LCV) of RDF and incineration fuel, therefore affecting the revenues. Lower participation rates in the source separation program imply in grater fluxes of materials to be incinerated and production of RDF, with better economic performance for the RDF plant, because of the higher LCV. With the exception of RDF, the others technologies require higher gate fees, compared to landfill, in order to reach economic viability because of the lower fees for disposal in Brazil compared with European countries. Regarding the environmental analysis, the displacement of fuels leads to greater benefits when compared with the displacement of electricity, which is basically hydroelectricity
Mestrado
Planejamento de Sistemas Energeticos
Mestre em Planejamento de Sistemas Energéticos
31
Seiler, Troy J. "Modeling carbon allocation, growth and recovery in scrub oaks experiencing aboveground disturbance." Master's thesis, University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5039.
Full textAbstract:
Allocation of assimilated carbon amongst plant metabolic processes and tissues is important to understanding ecosystem carbon cycles. Due to the range of spatio-temporal scales and complex process interactions involved, direct measurements of allocation in natural environments are logistically difficult. Modeling approaches provide tools to examine these patterns by integrating finer scale process measurements. One such method is root:shoot balance, where plant growth is limited by either shoot activity (i.e. photosynthesis) or root activity (i.e. water and nutrient uptake). This method shows promise for application on frequently disturbed systems which perturb aboveground biomass and thus create imbalances in root and shoot activities. In this study, root:shoot balance, allometric relationships and phenological patterns were used to model carbon allocation and growth in Florida scrub oaks. The model was tested using ecosystem gas exchange (i.e. eddy covariance) and meteorological data from two independent sites at Merritt Island National Wildlife Refuge, FL which experienced two different types of disturbance events: a prescribed burn in 2006 and wind damage from Hurricane Frances in 2004. The effects of the two disturbance events, which differed greatly in magnitude and impact, were compared to identify similarities and differences in plant allocation response. Model results and process-based sensitivity analysis demonstrated the strong influence of autotrophic respiration on plant growth and allocation processes. Also, fine root dynamics were found to dominate partitioning trends of carbon allocated to growth. Overall, model results aligned well with observed biomass trends, with some discrepancies that suggest fine root turnover to be more dynamic than currently parameterized in the model.; This modeling approach can be extended through the integration with more robust process models, for example, mechanistic photosynthesis, nitrogen uptake and/or dynamic root turnover models.ID: 029810098; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.S.)--University of Central Florida, 2011.; Includes bibliographical references (p. 66-73).
M.S.
Masters
Biology
Sciences
32
Win, Maung Aye. "Ecological Studies on Locally-managed Mangrove Forests in Taninthayi Region, Myanmar." Kyoto University, 2020. http://hdl.handle.net/2433/253396.
Full text
33
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.
Full textAbstract:
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.
34
Forchheim, Daniel [Verfasser], and M. [Akademischer Betreuer] Türk. "Optimisation of the reaction parameters in a batch reactor and a CSTR for the recovery of phenol from hydrothermal biomass liquefaction / Daniel Forchheim. Betreuer: M. Türk." Karlsruhe : KIT-Bibliothek, 2014. http://d-nb.info/1056955856/34.
Full text
35
Trischler, Johann. "Strategic raw material supply for the particleboard-producing industry in Europe : Problems and challenges." Doctoral thesis, Linnéuniversitetet, Institutionen för skog och träteknik (SOT), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-53700.
Full textAbstract:
Particleboard was invented to increase the utilization of wood and it soon became an important core material for furniture production. Nowadays, other industries such as the pulp and papermaking industry and the thermal energy recovery industry claim the same type of raw material. This leads to increasing competition and higher prices than in the past when that kind of wood raw material was widely available and of low price. The particleboard-producing industry is therefore seeking opportunities to reduce the competition and ensure the future supply of lignocellulosic raw material for their products. The purpose of the work summarised in this thesis was to investigate the strategic supply of lignocellulosic raw materials for particleboard production and to evaluate alternatives for the supply of lignocellulosic raw material for particleboard production. To encompass the complex field of strategic raw material supply, several publications have considered different stages along the supply chain. These papers range from empirical studies to practical tests on a laboratory scale. In this thesis, some of the papers are linked together, building the base for the overall results. The results show that the task of increasing the supply of lignocellulosic raw material as primary raw material source is limited by several factors, but that improved product design coupled with a suitable recycling concept can greatly increase the availability of lignocellulosic raw material as a secondary source. Alternatively, the use of non-wood plants might be an opportunity to substitute wood as raw material but there are still some problems relating to the particle properties which must be overcome first.
36
Urbano, Andrea Rose. "Long-term forest carbon storage and structural development as influenced by land-use history and reforestation approach." ScholarWorks @ UVM, 2016. http://scholarworks.uvm.edu/graddis/448.
Full textAbstract:
Temperate forests are an important carbon sink, yet there is uncertainty regarding land-use history effects on biomass accumulation and carbon storage potential in secondary forests. Understanding long-term biomass dynamics is important for managing forests as carbon sinks and for co-benefits such as watershed protection and biodiversity. However there are many unanswered questions regarding these dynamics in northeastern U.S. forests: How have secondary forests of the U.S. Northeast recovered post nineteenth century agricultural abandonment? How has the region's extensive land-use history influenced long-term structural development and aboveground carbon storage? To answer these questions, we employed a longitudinal study based on twelve years of empirical data (2001-2013) from the Marsh-Billings-Rockefeller (MBR) National Historical Park in Woodstock, VT. MBR Park was the first parcel of land to actively be reforested in the eastern U.S., and as such, its diverse forest mosaic reflects a history of alternate reforestation approaches and varied successional trajectories indicative of secondary forest recovery occurring across the broader northeastern forest landscape. We also used 150 years of documentary data from park management records. This research evaluates the effects of reforestation approaches (planting vs. natural regeneration), management regimes (long-term low-to-intermediate harvest intensities at varied harvest frequencies), and stand development pathways on biomass outcomes. We generated biometrics representative of stand structural complexity, including the H' structural diversity index, and aboveground biomass (live trees, snags, and downed coarse woody debris pools) estimates. Multivariate analyses evaluated the predictive strength of reforestation approach, management history, and site characteristics relative to aboveground carbon pools and stand structural complexity.
Classification and Regression Tree (CART) analysis ranked reforestation approach (plantation or natural regeneration) as the strongest predictor of long-term mean total aboveground carbon storage, while harvest frequency, and stand age were selected as secondary variables. CART ranked forest percent conifer (a metric closely associated with reforestation approach) as the strongest predictor of H' index, while harvest intensity, and harvest frequency were selected as secondary variables. Increases in harvest intensity can significantly reduce aboveground carbon storage. Our results suggest that a variety of long-term recovery pathways converge on high levels of aboveground carbon storage, including both conifer plantations and naturally regenerated hardwood stands, but choice of silvicultural management approach can dramatically alter those trajectories. Importantly, total aboveground biomass (i.e., carbon) co-varied with H' (r2 = 0.25), and thus, our dataset showed a positive relationship between forest carbon storage and structural complexity, supporting the concept of multifunctional forestry emphasizing late-successional habitats.
37
Vasconcelos, Maria Cecília Alves de. "AVALIAÇÃO DOS INDICADORES QUÍMICOS E BIOLÓGICOS DE QUALIDADE DO SOLO DE CERRADO DEGRADADO APÓS O CULTIVO DE LEGUMINOSAS." Pontifícia Universidade Católica de Goiás, 2015. http://localhost:8080/tede/handle/tede/2545.
Full textAbstract:
Made available in DSpace on 2016-08-10T10:44:45Z (GMT). No. of bitstreams: 1
MARIA CECILIA ALVES DE VASCONCELOS.pdf: 1811097 bytes, checksum: 7225cbf224da270e10a80f038703183e (MD5)
Previous issue date: 2015-03-11Among the parameters used by the scientific community, the biomass evaluation is the most precise one in terms of presenting the biological components of the soil. Intending to evaluate the potential of the legumes Campo Grande Stylo, calopo (Calopogonium mucunoides) and pigeon pea regarding the recovery of damaged soil, sixteen plats of these legumes were planted in latin square form for later microbial biomass analysis. The microbial biomass was analyzed according to the Vance et. (1987) principles. No significant differences were found compared to the fallow, although circumstances like the lack of precipitation, the time of the year and the production of dry matter affected the microbial biomass development. The studied legumes that presented the largest microbial biomass production were the Campo Grande Stylo and the calopo (Calopogonium mucunoides), showing a trend of improvement compared to the fallow. Despite the stress factors, the microbial biomass showed a trend of improvement on the plats where the legumes were seeded, and it can be considered a prior parameter of agrisystem changes.
Dentre os parâmetros utilizados pela comunidade científica, o que apresenta maior sensibilidade na caracterização dos componentes biológicos do solo é a avaliação de biomassa microbiana (BMS). Com o objetivo de avaliar o potencial das leguminosas Calopogônio, Estilosantes e feijão Guandu na recuperação dos solos degradados e na melhoria da biomassa microbiana, foi realizado o plantio das leguminosas e posterior análise da biomassa microbiana em dezesseis canteiros distribuídos em um quadrado latino. A biomassa microbiana foi analisada conforme os princípios de Vance et. (1987). Não foram encontradas diferenças significativas em relação ao pousio, porém fatores como a baixa pluviosidade, época de plantio e produção de massa seca influenciaram o desenvolvimento da BMS. As leguminosas estudadas que apresentaram maior produção de BMS foram o Estilosantes e o Calopogônio, evidenciando uma tendência de aumento em relação ao pousio. Mesmo com fatores de estresse, a biomassa microbiana nos canteiros com as leguminosas evidenciou um potencial de aumento, podendo ser considerado um parâmetro que antecede alterações no agrosistema.
38
Sanmiguel, Herrera Valentina. "A method to recover algal biomass using membrane technologies." Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/52956.
Full textAbstract:
Environmental awareness has increased significantly during the past years and the need to replace fossil fuels with a more sustainable alternative has become a priority in the modern society. Algal biofuels have shown to have a good productivity compared to other biomass feedstock options but the high cost- low-efficiency cultivation process has proven to be a challenge. The purpose of this project is to use membrane technologies to recover algal biomass more efficiently. This technology would significantly reduce the water usage and energy input to the algal biomass production process.
In this study, the Derjaguin-Landau-Verwey-Overbeek (DLVO) model derived using the Surface Element Integration (SEI) technique was used to identify the interaction energy between 3 microalgae species and 5 hollow fiber membrane materials. The results suggested that Scendesmus Obliquous would have the lowest energy barrier (-2.7834 kT) with a Poly(vinylbutyral) (PVB) hollow fiber membrane, therefore it would have a greater initial number of algal cells attaching to the membrane, compared to the other microalgae and membrane materials studied. Further work needs to be completed in order to integrate algae growth and biomass harvesting into the actual model.
39
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.
Full textAbstract:
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.
40
Manninen, O. (Outi). "The resilience of understorey vegetation and soil to increasing nitrogen and disturbances in boreal forests and the subarctic ecosystem." Doctoral thesis, Oulun yliopisto, 2016. http://urn.fi/urn:isbn:9789526211732.
Full textAbstract:
Abstract Climate change and its warming effects on vegetation and soils are a widely recognized phenomenon. In addition to warming, the understorey vegetation in northern environments has been subjected to several environmental changes, such as increasing nitrogen (N) and other disturbances. This thesis examines the effects of N-fertilization and disturbances on the vegetation biomass and abundance, plant community composition and plant, soil and microbial N and C pools. Seedling establishment of the most common dwarf shrubs (deciduous Vaccinium myrtillus, evergreens V. vitis-idaea and Empetrum nigrum ssp. hermaphroditum) was investigated after artificial disturbance treatments (vegetation and soil removal). These studies were conducted in the boreal and subarctic ecosystems and in the forest-tundra ecotone in northern Finland. N-fertilization and disturbances enhanced the amount of graminoids in plant communities, and the recovery ability of graminoids was enhanced after N-fertilization, which homogenized the vegetation and resulted in a new stable state in the plant community. The recovery ability of evergreen dwarf shrubs was low after disturbances. Disturbances created habitats for seed germination, but the seedling establishment of dwarf shrubs studied was still limited by seed availability. N-fertilization had no effect on microbial biomass. Instead, microbial biomass decreased with disturbance treatment in the boreal forest. However, the concentration of N increased in above-ground vegetation, both after N-fertilization and disturbance without any indication of N immobilization, suggesting that plant species captured the available N effectively for their recovery. The study shows that the likely outcome of N enrichment, when combined with disturbances, is the enhanced growth of graminoids. The seedling establishment does not compensate for the reduction of the vegetative recovery of evergreen dwarf shrubs, which makes evergreen dwarf shrubs sensitive to environmental changes. As the understorey is more resilient to perturbations in the boreal forest than in the subarctic ecosystem, these results emphasize the sensitivity of the vegetation to simultaneous environmental changes in the northernmost ecosystems. Moreover, microbial properties are more resilient to environmental changes than is above-ground vegetationTiivistelmä Ilmaston muutos ja siitä aiheutuvan lämpenemisen vaikutus kasvillisuuteen ja maaperään on laajasti tunnustettu ilmiö. Lämpenemisen lisäksi pohjoisten alueiden aluskasvillisuuteen kohdistuu useita muutospaineita, kuten lisääntynyt typpipitoisuuden nousu ja kasvillisuutta muokkaavat häiriöt. Tässä tutkimuksessa mitattiin lisääntyneen typpipitoisuuden ja häiriöiden vaikutus kasvillisuuden biomassaan ja runsauteen sekä yhteisörakenteeseen, sekä kasvilajeihin, maaperään ja mikrobibiomassaan sitoutuneen typen ja hiilen määrään. Lisäksi tutkittiin yleisimpien varpukasvien (lehtensä pudottava mustikka, ikivihreät puolukka ja variksenmarja) siemenellistä lisääntymistä kokeellisen häiriön (kasvillisuuden tai maaperän poisto) jälkeen. Tutkimukset tehtiin boreaalisessa ja subarctisessa ekosysteemeissä sekä metsänrajaympäristössä Pohjois-Suomessa. Typpilannoitus ja häiriöt lisäsivät heinien määrää kasviyhteisöissä. Lisäksi typpilannoitus edisti heinien kasvullista palautumiskykyä häiriön jälkeen, joka johti kasvillisuuden homogenisoitumiseen ja kasviyhteisön uuteen tasapainotilaan. Häiriöt heikensivät ikivihreiden varpujen kasvullista palautumista häiriön jälkeen. Häiriö loi sopivia elinympäristöjä siementen itämiselle, mutta tutkittujen lajien siementen määrä rajoitti siemenellistä lisääntymistä. Typpilannoitus ei vaikuttanut mikrobibiomassaan, mutta häiriö vähensi mikrobibiomassaa boreaalisessa ekosysteemissä. Kuitenkin kasvien typen pitoisuudet lisääntyivät sekä lannoituksen että häiriön jälkeen ilman viitteitä typen sitoutumisesta mikrobibiomassaan. Tämä viittaa siihen, että kasvit käyttävät maaperän typen tehokkaasti häiriön jälkeiseen palautumiseen. Väitöskirjan mukaan typen lisääntyminen häiriöiden yhteydessä edistää heinien esiintymistä. Koska ikivihreiden varpujen siemenellinen lisääntyminen ei kompensoi häiriöstä kasvulliselle palautumiselle aiheutuvaa haittaa, ovat ikivihreät varvut erityisen herkkiä häiriöille. Aluskasvillisuus on vastustuskykyisempi ympäristön muutoksille boreaalisessa kuin subarktisessa ekosysteemissä, mikä korostaa pohjoisimpien alueiden herkkyyttä yhtäaikaisille ympäristön muutoksille. Maaperän olosuhteet ovat kasvillisuutta kestävämpiä ympäristön muutoksille
41
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.
Full text
42
Coll, Montserrat Josep. "Avaluació dels esculls artificials i de les reserves marines com a eines de gestió dels recursos íctics litorals a les Illes Balears." Doctoral thesis, Universitat de les Illes Balears, 2013. http://hdl.handle.net/10803/113367.
Full textAbstract:
Aquesta tesi doctoral ha demostrat que els esculls artificials (ARs) de les Balears presentaren una colonització del 74% de les espècies en els primers 17 mesos de fondeig, i que el substrat original del lloc determinà la velocitat de colonització. El principal efecte dels ARs ha estat el de concentrar peixos de mida mitjana i grossa, si bé s’ha demostrat que aquest efecte no ha incrementat el risc de sobreexplotació en l’àrea d’influència.
Les reserves marines de Balears han servit per recuperar les poblacions de peixos d’interès pesquer, tant a zones de màxima protecció com a zones parcialment protegides. La determinació de la capacitat de càrrega a les zones de màxima protecció i la determinació dels factors ambientals que la determinen ha permès avaluar l’estat de conservació del litoral pel que respecta els peixos amb interès pesquer.Esta tesis doctoral ha demostrado que los arrecifes artificiales (ARs) de Baleares presentaron una colonización del 74% de las especies en los primeros 17 meses de fondeo, si bien el substrato original del lugar determinó la velocidad de colonización. El principal efecto de los ARs ha sido el de concentrar peces de tamaño medio y grande, si bien se ha demostrado que este efecto no ha incrementado el riesgo de sobreexplotación en el área de influencia. Las reservas marinas de Baleares han servido para recuperar las poblaciones de especies de interés pesquero, tanto en las zonas de máxima protección como en zonas parcialmente protegidas. La determinación de la capacidad de carga en las zonas de máxima protección y el análisis de los factores ambientales que la determinan ha permitido evaluar el estado de conservación del litoral balear por lo que respecta a las especies de peces con interés pesquero
43
Sidou, Ney Barros de Avelino. "Adensamento do palhiço da cana-de-açucar utilizando helicoides conicos." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/257005.
Full textAbstract:
Orientador: Oscar Antonio BraunbeckDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola
Made available in DSpace on 2018-08-12T03:37:50Z (GMT). No. of bitstreams: 1 Sidou_NeyBarrosdeAvelino_M.pdf: 3333411 bytes, checksum: 7ee0df98caa4c049f526e9c40d2c553e (MD5) Previous issue date: 2007
Resumo: O aumento da capacidade produtiva de energia elétrica por meios renováveis em curto prazo é fundamental para ao desenvolvimento de paises como o Brasil e o uso da fitomassa remanescente da cana-de-açúcar é uma opção viável e abundante em nosso país,entretanto, os métodos de recolhimento do palhiço não estão totalmente estabelecido havendo, então, a necessidade de novas propostas de métodos de recolhimento que atendam as necessidades qualitativas para o uso do palhiço como fonte energética. Uma unidade de testes foi construída para avaliar o comportamento mecânico do palhiço quando submetido ao princípio de adensamento por helicóides cônicos. Com esta unidade teste, foram realizados 16 ensaios combinando duas distâncias entre as helicóides, duas velocidades relativas, dois níveis de pressão de restrição e duas inclinações de taliscas. Os resultados experimentais mostraram relações entre pressão e densidade condizentes com a bibliografia. As pressões aplicadas na direção de carregamento mostraram relação exponencial de variação com as pressões registradas em direção perpendicular à mesma, atingindo valores máximos de 0,3 N.mm.-2. O princípio mecânico de adensamento por helicóides cônico mostrou-se eficaz para o adensamento do palhiço atingindo densidades aparentes entre 188,8 kg.m.-3 e 293,5 kg.m.-3. Os coeficientes de atrito determinados foram elevados, variando entre 3,7 e 1,16, e apresentaram uma tendência de queda com o aumento da pressão a qual o palhiço estava sendo submetido. Os valores experimentais de densidade, pressão normal e coeficientes de atrito gerados por uma talisca com comprimento de 200 mm foram alimentados ao modelo de simulação o qual a simulou valores de densidade para comprimentos de talisca longos o suficiente para atingir a densidade final desejada. Verificou-se que os valores da densidade final próximos de 200 kg.m-3 que puderam ser obtidos com adensadores de altura reduzida, com peso e complexidade construtiva inferiores aos das enfardadoras convencionais.
Abstract: This thesis aimed to show that agricultural producers could widen their role as consumers of agricultural lime - in Brazil, 70% of farmable soil is considered to be acid and require liming - and that such consumption would contribute to its sustainability, providing gains in the economic, social and environmental spheres. In addition, the use of agricultural lime is a practice considered important and should include family sized farms, currently on the margins of this market, considering that at the moment the greatest consumers of this corrective are the large and medium sized producers of soybean, corn, sugarcane, citrus products, coffee and cattle. In order to make such a strategy viable, both the potential supply and potential demand of this material were characterized. In Brazil, the productive park already installed consists of more than 300 companies, operating at an average of 57% of their total capacity, and there are reserves of calcareous rocks distributed throughout the Federation in satisfactory quantity and quality. Whilst the annual market potential for consumption of this material was estimated as 75 million tons, current consumption is only 17 million tons, corresponding to 22% of the real need of the Country's soils. The public and private policies developed up to the present time supporting the use of this material, were then analysed, and finally a group of actions were proposed, aiming at constructing a policy directed at the consumption of agricultural lime, with emphasis on family farms.
Mestrado
Maquinas Agricolas
Mestre em Engenharia Agrícola
44
Silva, Graziela Har Minervini. "Efeito de diferentes intensidades de pastejo ao banco de sementes do solo em campos no sul do Brasil." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/131883.
Full textAbstract:
Os ecossistemas campestres co-evoluíram com distúrbios como a herbivoria e o fogo. Assim, estes fatores são importantes no surgimento e manutenção de características da comunidade, podendo modificar os processos de sucessão. Em áreas perturbadas, as sementes que persistem no solo participam da regeneração natural. Diante da alta taxa de conversão dos campos nativos no sul do Brasil em áreas de uso intensivo (lavoura ou plantios de espécies arbóreas), bem como do manejo pastoril com alta pressão animal, aumenta o interesse em estudos relacionados ao banco de sementes do solo (BSS), buscando compreender a sua função nas comunidades vegetais e na regeneração de áreas degradadas. O conhecimento já existente sobre BSS em biomas campestres do hemisfério sul ainda é incipiente. Grande parte dos trabalhos feitos em campos sul-americanos compararam o BSS entre áreas de vegetação pastejadas e áreas abandonadas, sendo poucos os que utilizaram diferentes intensidades de pastejo, apesar de efeitos claros de diferentes intensidades de pastejo sobre a composição e estrutura da vegetação. Em vista disto, foi avaliado, neste trabalho, o BSS em um experimento em campo submetido a diferentes intensidades de pastejo, em duas estações (primavera e outono), utilizando o método de emergência de plântulas. Também foi feito o levantamento da vegetação estabelecida para avaliar a similaridade com o BSS. Em total, foram encontradas 103 espécies no BSS e 162 na vegetação estabelecida. No BSS, a porcentagem de espécies de caráter ruderal foi alta. Diferenças significativas em termos de densidade e riqueza do BSS foram encontradas somente entre o tratamento com maior intensidade de pastejo e os demais. De forma geral, a semelhança entre o BSS e a vegetação estabelecida foi baixa. Assim, estes resultados indicam que o BSS tem um papel limitado na recuperação da vegetação campestre típica após distúrbios mais severos e que, aparentemente, a intensidade do manejo não tem um impacto muito grande para o BSS. Apesar disso, o BSS é importante pelo armazenamento das características naturais dos ambientes, agregando funções à regeneração da comunidade vegetal.Grassland ecosystems co-evolved with disturbances such as fire and herbivory, and these factors are important for emergence and maintenance of community features areas. After disturbances, the seeds that persist in the soil contribute to regeneration processes. However, increasing conversion of natural grasslands into areas of intensive use (agriculture and exotic tree plantations), as well as overgrazing make the study of the regeneration of grassland vegetation after these severe disturbances an important research topic. Our knowledge on the role of the soil seed bank (SSB) in grassland biomes in the southern hemisphere still is incipient. The majority of studies realized in South American grassland compared the SSB between grazed and abandoned areas, and few consider different intensities of grazing, despite clear effects of different grazing intensities on vegetation composition and structure. In view of this, in this study, the SSB was evaluated in a grassland experiment under different intensities of grazing in two seasons (spring and autumn), using the seedling emergence method. In spring, a survey of the established vegetation was conducted to evaluate the similarity with the SSB. In total, we found 103 species in the SSB and 162 in established vegetation. The SSB was mostly composed of ruderal species. Grass species dominant in aboveground vegetation were largely absent in the SSB. Significant differences regarding SSB richness and density were only found between the treatment with higher intensity of grazing and the others, and overall composition did not differ among treatments. In general, the similarity between the SSB and established vegetation was low. Our results indicate that the SSB has a limited role in the recovery of natural grassland vegetation after more severe disturbances. Apparently, the intensity of management does not have a very large impact on the SSB or on the similarity between SSB and established vegetation. Nevertheless, the SSB is important for storage the natural characteristics of environments, adding functions to the regeneration of the plant community.
45
Vonk, Gwendal. "Caractérisation de la gazéfication de combustibles solides de récupération (CSR) en vue d'optimiser leur utilsation dans une unité de cogénération par gazogène." Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1S075/document.
Full textAbstract:
La gazéification est un procédé de conversion thermochimique permettant de convertir un combustible solide en gaz de synthèse (syngaz), composé notamment de H2 et CO. L’utilisation de déchets non-dangereux sous forme de CSR doit, en plus de fournir une énergie avec de bons rendements, respecter les normes environnementales. Nos travaux évaluent les performances énergétiques et environnementales de la gazéification à l’air de CSR (bois, pneus, plastiques, boues de STEP) en réacteurs en lit fixe co-courant à l’échelle pilote et industrielle. Les méthodes d’analyse utilisées permettent un suivi de la composition du syngaz, ainsi que des polluants (soufrés, azotés, goudrons, métaux lourds) dans les effluents du procédé, par rapport à une ressource propre (bois brut). Les performances de gazéification du CSR Bois sont identiques au Bois. Cependant un ajout de 20%m de CSR Pneus, Plastique ou Boues de STEP à du CSR Bois conduit à une diminution de H2 et CO compensée par une augmentation d’hydrocarbures légers (CH4, C2), conduisant à un pouvoir calorifique similaire, compris entre 4,9 et 5,4 MJ/Nm3. Les performances de gazéification sont légèrement plus fiables avec les mélanges de CSR, entre 35 et 49% alors qu’elles atteignent 48 à 52% pour le Bois et le CSR Bois. Par rapport au Bois, seuls les composés azotés sont en plus grand nombre pour le CSR Bois. Pour les mélanges de CSR, les teneurs en goudrons, composés soufrés et azotés sont plus élevées. De plus, les teneurs en métaux lourds sont plus élevées dans les fines particules que dans les charbons, demandant probablement un traitement particulierGasification is a thermochemical conversion process converting solid fuel into synthetic gas (syngas), containing H2 and CO. Sorting waste to produce SRF aims to allow a better energy recovery of waste, while satisfying environmental regulations. This study focuses on energetic and environmental performances of the air gasification of SRF (wood, tire, plastics, sewage sludge) using downdraft fixed bed reactors at pilot and industrial scale. Analytical procedures allow quantification of syngas composition as well as pollutant contents (sulfur, nitrogen, tars, heavy metals) in gasification outlet streams, considering raw wood as a reference. SRF Wood gasification performances are identical to Raw Wood. However adding 20%w of SRF Tire, Plastics or Sewage Sludge to SRF Wood leads to a decrease in H2 and CO contents, balanced by an increase in light hydrocarbons (CH4, C2), resulting in a similar syngas calorific value, ranging between 4.9 and 5.4 MJ/Nm3. Gasification performances are slightly lower with SRF mixes, ranging between 35 and 49%, while reaching 48 to 52% for Raw Wood and SRF Wood. Compared to Wood, only nitrogen containing pollutants are in higher concentrations with SRF Wood. In the case of SRF mixes, tars, sulfur and nitrogen containing pollutants are in higher concentrations. Moreover, heavy metals contents are higher in fine particles than in chars, resulting in a particular post-treatment
46
Gaudêncio, Hiara Ruth da Silva Câmara. "Uso de cinza de olaria e composto orgânico de macrófita aquática na recuperação de solos degradados." Universidade Federal Rural do Semi-Árido, 2016. http://bdtd.ufersa.edu.br:80/tede/handle/tede/541.
Full textAbstract:
Submitted by Socorro Pontes (socorrop@ufersa.edu.br) on 2017-01-16T15:03:50Z
No. of bitstreams: 1
HiaraRSCG_DISSERT.pdf: 1989229 bytes, checksum: e4965a0c31e89207c1535ca74caaff9e (MD5)Made available in DSpace on 2017-01-16T15:03:50Z (GMT). No. of bitstreams: 1 HiaraRSCG_DISSERT.pdf: 1989229 bytes, checksum: e4965a0c31e89207c1535ca74caaff9e (MD5) Previous issue date: 2016-02-25
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The intensification of human activity for economic purposes has caused environmental impacts increasingly significant, for example, the suppression of vegetation and as a result soil impoverishment. In this sense, this research aimed to evaluate the use of pottery ash and organic macrophyte compound in the recovery of degraded soils. Thus, the experiment was conducted in a greenhouse with experimental design in a factorial arrangement of 5x5, being five doses of the compound of water hyacinth and five doses of ash with three replications, where the volume of soil corresponded to 2 dm³ and ash doses corresponded to 0, 1, 3, 5 and 10% of the volume of each vessel and the water hyacinth compound at 0, 5, 10, 20 and 30%. After mixing the composition of soil, compound and gray equivalent to each treatment, these were placed in plastic vessels, incubated for 20 days and then held the transplanting of Jucá seedlings (Libidibia ferrea). On the occasion of collection, the plants were cut at ground level, dry in forced-air oven at 70° C to constant weight, weighed, crushed in a grinder to obtain the dry matter of shoot (MSPA) and they were subsequently mineralized by nitric digestion. In the extracts were determined the total content of Fe, Zn, Mn, Cu, Cd and Pb. After removal of the plants, the soil in each vessel was air dried, homogenised and a sample was removed for performing analysis of Fe, Zn, Mn, Cu, Cd and Pb. The addition of ash and compound doses contributed to the increase in pH, which consequently influenced the absorption of heavy metals by plants as well as in their growth
A intensificação da atividade humana para fins econômicos tem ocasionado impactos ambientais cada vez mais significativos, como por exemplo, a supressão vegetal e por consequência o empobrecimento do solo. Nesse sentido, esta pesquisa teve como objetivo avaliar o uso de cinza de olaria e composto orgânico de macrófita aquática na recuperação de solos degradados. Assim, o experimento foi conduzido em casa de vegetação com delineamento experimental em esquema fatorial 5x5, sendo cinco doses do composto de aguapé e cinco doses de cinza com três repetições, onde o volume de solo correspondeu a 2 dm³ e as doses de cinza corresponderam à 0, 1, 3, 5 e 10% do volume de cada vaso e às de composto de aguapé à 0, 5, 10, 20 e 30%. Após a mistura da composição solo, composto e cinza equivalente a cada tratamento, esta foi colocada em vasos plásticos, incubados 20 dias e em seguida realizado o transplantio das mudas de Jucá (Libidibia ferrea). Por ocasião da coleta, as mudas foram cortadas ao nível do solo, secas em estufa de circulação forçada de ar a 70°C até peso constante, pesadas, trituradas em moinho para obtenção da matéria seca da parte aérea (MSPA) e posteriormente foram mineralizadas por digestão nítrica. Nos extratos foram determinados os teores totais de Fe, Zn, Mn, Cu, Cd e Pb. Após a retirada das mudas, o solo de cada vaso foi seco ao ar, homogeneizado e quantificado os teores de Fe, Zn, Mn, Cu, Cd e Pb. A adição das doses de cinza e o composto contribuíram para o aumento do pH, que consequentemente influenciou na absorção dos metais pesados pelas mudas, bem como no crescimento das mesmas
2017-01-16
47
Wang, Ming-Yung, and 王明勇. "Modeling and Optimization of Biomass Gasifier with Waste Heat Recovery via Thermoelectric Effect." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/59832189449147112643.
Full textAbstract:
博士國立臺灣大學
機械工程學研究所
102
Based on fossil fuels in the world have limited, and usage keeps increase in the present there are quick to shorten its serviceable life. For this tendency, all countries are research and development in alternative energy sources, which includes wind energy, solar energy, hydrogen energy, ocean currents, tides, and the biofuels of this article discussion. Due to the front mention different kinds of alternative energy development would require special equipment and need to spend a great deal of money, but solid biomass fuels fixed-bed gasifier would easy to assemble and construct. It can be promoted the application of biomass fuel of agriculture wastes in local rural area. Computational Fluid Dynamic (CFD) modeling applications of the biomass gasification process help to optimize the gasifier. This study aims to investigate the impact of several physical parameters on the behavior of gasification in a fixed-bed downdraft gasifier. To that end, the study presents a comparison of the results computed using the Fire Dynamics Simulator (FDS) model with the experimental results of biomass gasification. Therefore, different sets of simulations and experiments have been performed to examine the effects of initial moisture content, equivalence ratio, high heating value (HHV), and cold gas efficiency (CGE). At the optimum operation, the equivalence rate is 0.3, the HHV can reach 5.71 MJ/m3, and the produced hydrogen concentration is 26.53 vol%. For an initial moisture content of 11.18%, the measured CGE is 66.85%, which is within the range of 65.07% to 70.44%. In general, the initial moisture content of the rice husks is suggested in between 10% to 20%. Meanwhile FDS is also application on biomass gasifier venting duct temperature distribution for investigated searching the best position of the modules to enhance the system thermal efficiency. The electrical characteristic of TEG modules at temperature difference 140℃, the maximum voltage can reach 1.33V and 1.83V at 1Ω and 5Ω respectively, however the output power attain 1.37W is higher than cooling pump power waste 0.45W, and the TEG power per unit area can reach 857W/m2. The overall results indicate that the FDS model can effectively simulate and analyze gasification performance inside the gasifier, and the performance of an improved downdraft gasifier system (IDGS) is improved by higher cold gas efficiency.
48
Ferreira, Catarina Castro. "Phaeodactylum tricornutum biorefinery: a sustainable approach to valorize microalgae biomass towards biomolecules recovery." Master's thesis, 2021. http://hdl.handle.net/1822/71957.
Full textAbstract:
Dissertação de mestrado em BiotecnologiaMicroalgae superior ability to sustain harsh, stressing or limiting conditions is widely known, while being also a unique source of specific and valuable biocompounds. Microalgae extracts’ potential has been well recognized for their interesting functional and bioactive properties, showing specially interesting features for skin care products’ manufacturing mainly as thickening, water-binding and antioxidant agents. The expanding interest in addressing a more sustainable and eco-friendly product development results in a growing community searching for natural-based formulations. However, microalgae potential and usefulness are dependent on the extraction techniques applied. The selection of the preferential method presents a major impact on the final product quality, which should exceed costumer’s requests, while simultaneously offering an economically appealing process. Thus, this thesis aimed at acknowledging Phaeodactylum tricornutum potential, by ultimately providing important information for the formulation of an algae-based cosmeceutical product. The present work focused on achieving two different main fractions accountable for bioactive and technological functions, underlying P. tricornutum growth conditions impact and designing the extraction methodology, including ohmic heating (OH) as a potential alternative to conventional extraction processes. Firstly, an adaptive laboratory evolution (ALE) taking advantage of UV-C mutagenesis was performed in P. tricornutum cultures. Although the results did not allow a clear positive impact in global extracts’ antioxidant activity, it presented as a potentially useful tool to enhance lipidic extraction. In order to explore the OH-based and conventional extraction implications on the microalgae extracts properties, water and different ethanol/water mixtures were used as solvents, addressing a polarity spectrum. P. tricornutum functionality was evaluated by relating the extracts composition (assessed by intrinsic fluorescence analysis, SDS-PAGE electrophoresis, FTIR and gel permeation chromatography) with their thermal, rheological and emulsifying behavior. Bioactive potential was analyzed by three different antioxidant activity measuring tests (FRAP, ABTS and DPPH) and a viability assay in normal and cancer cell lines. This diatom extracts showed promising technological and bioactive potential, with interesting gelling, emulsification and antioxidant capacities. Extracts showed different biochemical and performance profiles, depending on the solvent used. Generally, no significant effects were observed for OH application, having this process lower energy consumptions. In conclusion, the major goals of the present work were successfully accomplished, underlining P. tricornutum extracts potentiality not only for cosmeceutical industry, but also for functional foods development.
A grande capacidade das microalgas para subsistir à exposição a condições severas ou limitantes é amplamente conhecida, constituindo uma fonte singular de biocompostos específicos e de valor acrescentado. O potencial dos seus extratos, no que concerne às propriedades funcionais e bioativas, encontra-se bem estabelecido, com características interessantes para o cuidado da pele, enquanto agentes de consistência, hidratação e antioxidantes. O interesse crescente por metodologias mais sustentáveis culmina numa maior procura por formulações naturais. Todavia, o potencial e a utilidade das microalgas encontram-se dependentes das técnicas de extração aplicadas. A seleção do método de extração preferencial constitui um fator determinante para a qualidade do produto final, o qual deverá exceder os requisitos do consumidor, enquanto oferece um processo economicamente apelativo. Desta forma, esta tese objetivou evidenciar o potencial da microalga Phaeodactylum tricornutum, ao fornecer úteis informações para a formulação de um produto cosmecêutico natural. Procurou-se obter duas frações, responsáveis por funções bioativas e tecnológicas, explorando o impacto das condições de crescimento em culturas de P. tricornutum e estabelecendo uma metodologia de extração, que inclui o aquecimento óhmico (OH) como potencial alternativa aos processos de extração convencionais. Inicialmente, implementou-se uma evolução laboratorial adaptativa (ALE) acoplada à mutagénese por UV-C nas culturas de P. tricornutum. Apesar dos resultados não evidenciarem um claro impacto positivo na atividade antioxidante dos extratos, esta estratégia apresentou-se potencialmente útil no aumento da extração lipídica. Utilizou-se a água e diferentes misturas de etanol/água como solventes para explorar os efeitos da extração baseada em OH e convencional nas propriedades dos extratos, com objetivando-se um espetro de polaridade. A funcionalidade de P. tricornutum foi avaliada relacionando a composição dos extratos (estabelecida por fluorescência intrínseca, eletroforese SDS-PAGE, FTIR e cromatografia de permeação em gel) com o seu comportamento térmico, reológico e emulsificante. A triagem do seu potencial bioativo baseou-se em três ensaios de determinação de atividade antioxidante (FRAP, ABTS e DPPH) e num ensaio de viabilidade em linhas celulares normais e de cancro. Os extratos demonstraram potencial tecnológico e bioactivo, com interessantes capacidades de gelificação, emulsificação e antioxidante. O seu perfil bioquímico e de atuação foi dependente do solvente utilizado. Na generalidade, não se observaram efeitos significativos aquando da aplicação de OH. Em suma, os objetivos delineados foram cumpridos, reconhecendo-se o potencial dos extratos de P. tricornutum para a indústria cosmecêutica, bem como para o desenvolvimento de alimentos funcionais.
A presente dissertação inseriu-se no âmbito dos Projetos ALGAVALOR (Lisboa 2020, ALGARVE 2020, FEDER, COMPETE 2020, PT2020) e OH2O (FCT, COMPETE 2020, PT2020)
49
WU, QIU-YE, and 吳秋曄. "The recovery of heavy metals--Ag, Cu, Ni--from plating wastewaters by fungal biomass." Thesis, 1991. http://ndltd.ncl.edu.tw/handle/17344076485548182677.
Full text
50
Wang, Yen-Chi, and 王彥棋. "Autoclaving treatment of municipal solid waste for the recovery of biomass and its reutilization." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/00752957131342061006.
Full textAbstract:
碩士國立臺灣大學
環境工程學研究所
99
Autoclaving treatment of municipal solid waste (MSW) for the recovery of organic fibre material (OFM) and its reutilization was investigated in this study. High-temperature and high-pressure saturated steam was used to hydrolyze the OFM of MSW, and break the long chain structure of hemicllulose and cellulose into small fragments. Meanwhile, the plastics were softened and shrunken into small lumps by the heating of steam. Therefore, autoclaving process can effectively reduce the volume of MSW. Besides, the heating value of autoclaved MSW (noted as AMSW) only decreased slightly. Thus the energy density of AMSW per volume increased. After autoclaving, the OFM can be easily separated from the AMSW by a vibratory screen according to the size diference between OFM, plastics and the other inorganic contents, obtaining the homogenous OFM. The autoclaving experiments were conducted at 135, 155 and 165 ℃ with various operating times of 15, 30 and 60 minutes. The results indicated that the energy of steam at 135 ℃ was not enough to reduce the volume of MSW sufficiently, while slightly decreased the heating value of AMSW, therefore reducing the energy density. At 155 ℃, the volume of MSW reduced significantly, so the energy density increased effectively. Comparing with 155 ℃, 165 ℃ did not further increase the energy density of AMSW. Hence, autoclaving at a higher temperature of 165 ℃ was not suitable because it consumed more energy without further improvement. In order to achieve an effective volume reduction, the operating time must be at least 60 minutes incorporation with rotational shredding at proper rotating speed, say, 7 rpm. The rotational shredding can provide a shear stress to break down the OFM into small size. Therefore, the suitable operating conditions of autocalving of MSW is 155 ℃, 60 minutes with 7 rpm rotation. The moisture content of the AMSW was 72 ~ 77%, while the proper moisture content of materials for screening is 50 ~ 60%. Thus, a decrease of the moisture content of AMSW before screening is required. After the dehydration using a centrifuge, the moisture content of dewatered AMSW (DAMSW) decreased to 56%, suitable for screening. About 46 wt.% of DAMSW, which is OFM can be separated from the DAMSW employing 1 cm x 1 cm sieve. The separated OFM obtained was further pelleted to reduce the volume, while increase the energy density. The proper moisture content of OFM for pelleting was found to be about 20 ~ 25 wt.%. The pelleted OFM with dry-basis heating value of 3,891 kcal kg-1 and density of 1,346 kg m-3 can be used as fuel for the combustion device, coal-fired boiler and co-firing cement furnace. Further torrefaction of the OFM obtained did not increase its energy density, suggesting no need of subsequent torrefaction. The information obtained is useful for the proper design and operation of autoclaving of MSW and the subsequent treatments for the better recovery and reutilization of the biomass of OFM from MSW.