Rozprawy doktorskie na temat „Bio-oil energy”

Aquesta investigació ofereix un enfocament multidisciplinari, des d’un punt de vista ambiental, social, econòmic i tecnològic, per a estudiar nous usos de la biomassa forestal utilitzant diferents metodologies, com són els grups de discussió, l’anàlisi del cicle de vida i experimental en una planta pilot de piròlisi. En primer lloc, es realitza una avaluació integrada per mitjà de grups de discussió per a identificar les barreres polítiques, socials i ambientals que han impedit que els sistemes integrats de biomassa forestal hagin continuat desenvolupant‐se en el context mediterrani. Els resultats mostren que, tot i les grans oportunitats i apostes per aquests sistemes, és necessari considerar factors socioecològics específics, com ara els règims de propietat, la baixa productivitat dels boscos mediterranis, la feble capacitat institucional, logística i dificultats d'abastament i la falta de rendibilitat econòmica dels productes forestals, si la biomassa forestal ha de contribuir decisivament a la producció de fonts d'energia renovables a Europa. En segon lloc, es duu a terme una anàlisi del cicle de vida d'una planta de gasificació de biomassa forestal i de fusta de post‐consum. Aquest estudi mostra que la biomassa forestal necessita majors requeriments d'energia, degut principalment a una fase d'assecatge addicional que necessita per complir amb els requeriments d’entrada de la gasificació. Finalment, els aspectes tecnològics s’analitzen estudiant la piròlisi de la biomassa. Primer, s’aplica el model d'activació d’energies distribuïdes (DAEM) a la desvolatilització de la biomassa i els seus components. Posteriorment, s’estudia la piròlisi d’estelles de biomassa forestal en una planta pilot amb un reactor de cargol sense fi (10 kg/h) per a estudiar les condicions òptimes d'operació (temperatura de reacció, temps de residència de sòlids i flux màssic) i per a determinar les propietats fisicoquímiques dels productes obtinguts. Els resultats mostren que es pot aconseguir una piròlisi completa de les estelles de biomassa en aquest tipus de reactor i que el major rendiment per a la producció de líquid (59%) i les millors propietats dels productes s’obtenen en la temperatura més baixa estudiada (773 K) i aplicant temps de residència de sòlids de més de 2 minuts. La caracterització química del biooil mitjançant GC/MS mostra que els compostos més abundants són compostos polars volàtils, fenols i benzenediols. Es poden observar molt poques diferències en les propietats físiques de les diferents mostres de bio‐oil, el qual és similar al bio‐oil obtinguts en reactors semblants. Els balanços d'energia del procés de piròlisi de la planta pilot i d’una planta escalada (1500 kg/h) mostren que es necessita una unitat d'assecatge i una cambra de combustió de carbó si la piròlisi s’ha de realitzar en una planta mòbil, tot i que el procés és autosuficient energèticament quan el contingut d'humitat de la biomassa és inferior al 6%. L'anàlisi econòmica demostra que els costos totals de producció de biocombustible a la planta pilot escalada se situen entre 269 i 289 €/m3, depenent del cost de la biomassa (40‐50 €/tona). El punt d'equilibri de la planta de piròlisi és de 116 €/barril quan la biomassa es compra a 50 €/tona i 108 €/barril quan el cost de la biomassa és de 40 €/tona. A llarg termini, el bio‐oil ofereix un gran potencial com a vector energètic i en el futur escenari d’una biorefineria, un nou enfocament que s'estudia a través de la dissolució de la fusta en líquids iònics mitjançant microones. En conjunt, aquests nous usos representen una gran oportunitat per al sector forestal en el context mediterrani, ja que ofereixen productes d’alt valor afegit com és el bio‐oil. El bio‐oil és un vector energètic, tan versàtil com el petroli, i que pot ser la base per a una nova generació de biocombustibles de segona generació i, alhora, matèria primera per a biorefineries. A més, aquesta tesi també està relacionada amb la sostenibilitat social, suggerint accions i propostes associades amb el desenvolupament local i l’economia en xarxa i facilitant la presa de decisions, cosa que ajuda a fer un pas endavant cap a un coneixement global i integral de la sostenibilitat.
This research offers a multidisciplinary approach, from the environmental, social, economic and technological standpoint, to study different novel uses of forest biomass using different methodologies such as IA‐Focus Groups, Life Cycle Assessment and experimental in a pyrolysis pilot plant. First, an integrated assessment of forest biomass systems by focus groups methodology is carried out to identify what political, social and environmental barriers have prevented integrated forest biomass systems to be further developed in the Mediterranean context. Results show that while the opportunities and stakes are high, specific socio‐ecologic factors, such as property regimes, low productivity of Mediterranean forests, weak institutional capacity, logistics and supply difficulties and the lack of economic profitability of forest products, need to be taken into account if forest biomass is to contribute decisively to securing renewable sources of energy in Europe, integrating landscape planning with resource policies or mitigating climate change. Second, a life cycle assessment of a gasification plant using forest biomass and post‐consumer wood is performed. This study shows that forest biomass needs higher energy requirements due to mainly an additional drying stage in order to comply with the gasification demands. Finally, technological aspects are investigated by studying biomass pyrolysis. An application of the Distributed Activation Energy Model (DAEM) to biomass and biomass constituents’ devolatilisation is performed to study the thermal decomposition of biomass. Next, pine woodchips pyrolysis is carried out in an auger reactor pilot plant (10 kg/h) to study the optimal operation conditions (reaction temperature, solid residence time and mass flow rate) and to characterize the properties of the products obtained. Results show that complete woodchip pyrolysis can be achieved in the auger reactor and the greatest yields for liquid production (59%) and optimum product characterisation are obtained at the lowest temperature studied (773 K) applying solid residence times longer than 2 minutes. Bio‐oil GC/MS characterisation shows that the most abundant compounds are volatile polar compounds, phenols and benzenediols. Very few differences can be observed in the physical properties of the bio‐oil samples regardless of the operating conditions, and these properties are similar to bio‐oil obtained in other auger reactors. Energy balances of the pyrolysis process in the pilot plant and in a scaled up auger reactor mobile plant (1500 kg/h) show that a drying unit and a char combustor are needed if the pyrolysis has to be performed in a mobile plant, even though the process is energy‐independent when moisture content is lower than 6%. The economic assessment shows that total costs of producing bio‐oil in the scaled‐up pilot plant is between 269 and 289 €/m3 depending on the biomass cost (40‐50€/ton). The break‐even point of the pyrolysis plant is 116 €/barrel when the biomass is purchased at 50 €/ton and 108 €/barrel when the biomass cost is 40 €/ton. In the long term, bio‐oil offers great potential as an energy vector and in a biorefinery scenario, a novel approach that is studied by performing microwave‐assisted dissolution of wood in ionic liquids. On the whole, these novel uses offer great opportunity for the Mediterranean forestry sector, since they offer value‐added products such as bio‐oil. Bio‐oil represents a new energy carrier, which is as versatile as oil and which may be the basis for a new generation of secondgeneration biofuels and, in turn, raw material for biorefineries. This dissertation is also related to social sustainability by suggesting actions and proposals related to local development and the network economy, as well as facilitating decision‐making processes, which help to make a step forward to a global and integral knowledge of sustainability.

Orientador: Araí Augusta Bernárdez Pécora
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: O café é um importante produto na balança comercial brasileira e seu processamento gera a casca como um resíduo. O objetivo deste trabalho foi a caracterização física, termoquímica e fluidodinâmica da casca de café (coffea arábica, L) visando sua aplicação em processo de pirólise convencional em reator mecanicamente agitado e posterior caracterização das frações líquida e sólida geradas. O trabalho envolveu as seguintes etapas: (i) caracterização física e termoquímica da casca de café moída; (ii) ensaios fluidodinâmicos no leito contendo mistura binária casca de café-areia (5% de biomassa na mistura); (iii) ensaios de pirólise em reator mecanicamente agitado; e (iv) caracterização das frações sólida e líquida geradas no processo de pirólise. A etapa de caracterização das partículas envolveu a determinação da análise granulométrica, esfericidade, massas específicas, razão de Hausner, análise elementar, análise imediata, poder calorífico, análise termogravimétrica e diferencial térmica, análises da composição das cinzas e análise do teor de hemicelulose, celulose e lignina. Os ensaios de pirólise foram realizados seguindo um planejamento experimental composto central rotacional com objetivo de avaliar a influência da taxa de aquecimento (8 a 22 °C/min) e do tempo de estabilidade entre os estágios de aquecimento (1,2 a 6,8 min) sobre o rendimento da fração líquida. O maior rendimento da fração líquida foi de 56,5 %, obtido em uma taxa de aquecimento de 22°C/min e tempo de estabilidade entre os estágios de aquecimento de 4 min. Na etapa de caracterização do carvão vegetal gerado foram determinadas as massas especificas, análise elementar, análise imediata, poder calorífico, análise termogravimétrica e diferencial térmica, além da determinação da velocidade mínima de fluidização no leito contendo a mistura carvão-areia (5% de biomassa na mistura). A fração líquida foi submetida à análise de umidade, pH, poder calorífico e cromatografia gasosa acoplada a espectrometria de massa. Os resultados dos ensaios fluidodinâmicos mostraram que a presença de 5% (em massa) de casca de café no leito provoca o aumento da velocidade de mínima fluidização em 45%. Foi verificado que a casca de café possui um grande potencial como fonte energética para aplicação em processos de pirólise em função das propriedades do carvão e do líquido gerado em temperaturas superiores a 300oC. A composição e teor de cinzas da casca de café também fazem do carvão uma boa opção como fertilizante em função dos nutrientes presentes. Em todas as frações líquidas geradas foram observados compostos com aplicações industriais, mostrando que o óleo obtido através da pirólise da casca de café possui potencial não só como combustível, mas também como fonte de componentes para a indústria química
Abstract: Coffee is an important product in the Brazilian commercial balance and its processing generates husks as waste. In order to increase information available about coffee husks biomass and its energetic potential, this work presents an experimental study including: (i) physical and thermo-chemical characterization of grinded coffee husks; (ii) hydrodynamics tests to minimum fluidization velocity determination of the binary mixture coffee husks-sand (5% weight fraction of biomass); (iii) pyrolysis tests in a mechanically agitated bed; and (iv) characterization of pyrolysis solid and liquid products. The particle characterization step included the determination of particle size distribution, sphericity, densities, Hausner ratio, ultimate and proximate analysis, heating value, thermo-gravimetric analysis, thermo-differential analysis, ash composition, and hemicelluloses, cellulose and lignin content. The pyrolysis tests were carried out following a central composite rotate design of experiments in order to evaluate the heating rate (from 8 to 22oC/min) and the time between the heating stages (from 1.2 to 6.8min) on the bio oil yield. The bio-oil greatest yield was 56.5% that was obtained using a heating rate of 22oC/min and time between the heating stages of 4min. The bio-char characterization involved density, ultimate and proximate analyses, heating value, thermo-gravimetric analysis, differential thermal analyses and determination of the minimum fluidization velocity of the char-sand mixture (5% weight fraction of biomass). The liquid fraction was submitted to moisture, pH, heating value and gas chromatography (using a mass spectrometer) analysis. Results from hydrodynamics studies show that the presence of 5% biomass in the bed material increases the minimum fluidized bed velocity about 45%. Pyrolysis results show that coffee husks presents a good potential as feedstock to the process due to char and bio-oil (fractions obtained at temperatures higher than 300oC) properties. Additionally, results from ash characterization showed that the bio-char produced presents a good potential as fertilizer. High values chemical compounds were identified in the produced liquid fractions, showing that this product presents high potential, not only as a fuel, but also as a source of chemical compounds to the chemical industry
Mestrado
Termica e Fluidos
Mestre em Engenharia Mecânica

Thesis (MScEng)--Stellenbosch University, 2011.
ENGLISH ABSTRACT: Increasing oil prices along with the climate change threat have forced governments, society and the energy sector to consider alternative fuels. Biofuel presents itself as a suitable replacement and has received much attention over recent years. Thermochemical conversion processes such as pyrolysis is a topic of interest for conversion of cheap agricultural wastes into clean energy and valuable products. Fast pyrolysis of biomass is one of the promising technologies for converting biomass into liquid fuels and regarded as a promising feedstock to replace petroleum fuels. Corn residues, corn cob and corn stover, are some of the largest agricultural waste types in South Africa amounting to 8 900 thousand metric tonnes annually (1.7% of world corn production) (Nation Master, 2005). This study looked at the pyrolysis kinetics, the characterisation and quality of by-products from fast pyrolysis of the corn residues and the upgrading of bio-oil. The first objective was to characterise the physical and chemical properties of corn residues in order to determine the suitability of these feedstocks for pyrolytic purposes. Secondly, a study was carried out to obtain the reaction kinetic information and to characterise the behaviour of corn residues during thermal decomposition. The knowledge of biomass pyrolysis kinetics is of importance in the design and optimisation of pyrolytic reactors. Fast pyrolysis experiments were carried out in 2 different reactors: a Lurgi twin screw reactor and a bubbling fluidised bed reactor. The product yields and quality were compared for different types of reactors and biomasses. Finally, a preliminary study on the upgrading of bio-oil to remove the excess water and organics inorder to improve the quality of this liquid fuel was performed. Corn residues biomass are potential thermochemical feedstocks, with the following properties (carbon 50.2 wt. %, hydrogen 5.9 wt. % and Higher heating value 19.14 MJ/kg) for corn cob and (carbon 48.9 wt. %, hydrogen 6.01 wt. % and Higher heating value 18.06 MJ/kg) for corn stover. Corn cobs and corn stover contained very low amounts of nitrogen (0.41-0.57 wt. %) and sulphur (0.03-0.05 wt. %) compared with coal (nitrogen 0.8-1.9 wt. % and sulphur 0.7-1.2 wt. %), making them emit less sulphur oxides than when burning fossil fuels. The corn residues showed three distinct stages in the thermal decomposition process, with peak temperature of pyrolysis shifting to a higher value as the heating rate increased. The activation energies (E) for corn residues, obtained by the application of an iso-conversional method from thermogravimetric tests were in the range of 220 to 270 kJ/mol. The products obtained from fast pyrolysis of corn residues were bio-oil, biochar, water and gas. Higher bio-oil yields were produced from fast pyrolysis of corn residues in a bubbling fluidised bed reactor (47.8 to 51.2 wt. %, dry ash-free) than in a Lurgi twin screw reactor (35.5 to 37 wt. %, dry ash-free). Corn cobs produced higher bio-oil yields than corn stover in both types of reactors. At the optimised operating temperature of 500-530 °C, higher biochar yields were obtained from corn stover than corn cobs in both types of reactors. There were no major differences in the chemical and physical properties of bio-oil produced from the two types of reactors. The biochar properties showed some variation in heating values, carbon content and ash content for the different biomasses. The fast pyrolysis of corn residues produced energy products, bio-oil (Higher heating value = 18.7-25.3 MJ/kg) and biochar (Higher heating value = 19.8-29.3 MJ/kg) comparable with coal (Higher heating value = 16.2-25.9 MJ/kg). The bio-oils produced had some undesirable properties for its application such as acidic (pH 3.8 to 4.3) and high water content (21.3 to 30.5 wt. %). The bio-oil upgrading method (evaporation) increased the heating value and viscosity by removal of light hydrocarbons and water. The corn residues biochar produced had a BET Brynauer-Emmet-Teller (BET) surface area of 96.7 to 158.8 m2/g making it suitable for upgrading for the manufacture of adsorbents. The gas products from fast pyrolysis were analysed by gas chromatography (GC) as CO2, CO, H2, CH4, C2H4, C2H6, C3H8 and C5+ hydrocarbons. The gases had CO2 and CO of more than 80% (v/V) and low heating values (8.82-8.86 MJ/kg).
AFRIKAANSE OPSOMMING: Die styging in olie pryse asook dreigende klimaatsveranderinge het daartoe gelei dat regerings, die samelewing asook die energie sektor alternatiewe energiebronne oorweeg. Biobrandstof as alternatiewe energiebron het in die afgope paar jaar redelik aftrek gekry. Termochemiese omskakelingsprosesse soos pirolise word oorweeg vir die omskakeling van goedkoop landbou afval na groen energie en waardevolle produkte. Snel piroliese van biomassa is een van die mees belowende tegnologië vir die omskakeling van biomassa na vloeibare brandstof en word tans gereken as ’n belowende kandidaat om petroleum brandstof te vervang. Mielieafval, stronke en strooi vorm ’n reuse deel van die Suid Afrikaanse landbou afval. Ongeveer 8900 duisend metrieke ton afval word jaarliks geproduseer wat optel na ongeveer 1.7% van die wêreld se mielie produksie uitmaak (Nation Master, 2005). Hierdie studie het gekk na die kinetika van piroliese, die karakterisering en kwaliteit van by-produkte van snel piroliese afkomstig van mielie-afval asook die opgradering van biobrandstof. Die eerste mikpunt was om die fisiese en chemiese karakteristieke van mielie-afval te bepaal om sodoende die geskiktheid van hierdie afval vir die gebruik tydens piroliese te bepaal. Tweendens is ’n kinetiese studie onderneem om reaksie parameters te bepaal asook die gedrag tydens termiese ontbinding waar te neem. Kennis van die piroliese kinetika van biomassa is van belang juis tydens die ontwerp en optimering van piroliese reaktore. Snel piroliese ekspermente is uitgevoer met behulp van twee verskillende reaktore: ’n Lurgi twee skroef reaktor en ’n borrelende gefluidiseerde-bed reaktor. Die produk opbrengs en kwaliteit is vergelyk. Eindelik is ’n voorlopige studie oor die opgradering van bio-olie uitgevoer deur te kyk na die verwydering van oortollige water en organiese materiaal om die kwaliteit van hierdie vloeibare brandstof te verbeter. Biomassa afkomstig van mielie-afval is ’n potensiële termochemiese voerbron met die volgende kenmerke: mielie stronke- (C - 50.21 massa %, H – 5.9 massa %, HHV – 19.14 MJ/kg); mielie strooi – (C – 48.9 massa %, H – 6.01 massa %, HHV – 18.06 MJ/kg). Beide van hierdie materiale bevat lae hoeveelhede N (0.41-0.57 massa %) and S (0.03-0.05 massa %) in vergelyking met steenkool N (0.8-1.9 massa %) and S (0.7-1.2 massa %). Dit beteken dat hieride bronne van biomassa laer konsentrasies van swael oksiedes vrystel in vergelyking met fossielbrandstowwe. Drie kenmerkende stadia is waargeneem tydens die termiese afbraak van mielie-afval, met die temperatuur piek van piroliese wat skuif na ’n hoër temperatuur soos die verhittingswaarde toeneem. Die waargenome aktiveringsenergie (E) van mielie-afval bereken met behulp van die iso-omskakelings metode van TGA toetse was in die bestek: 220 tot 270 kJ/mol. Die produkte verkry deur Snel Piroliese van mielie-afval was bio-olie, bio-kool en gas. ’n Hoër opbrengs van bio-olie is behaal tydens Snel Piroliese van mielie-afval in die borrelende gefluidiseerde-bed reakctor (47.8 na 51.2 massa %, droog as-vry) in vergelyking met die Lurgi twee skroef reakctor (35.5 na 37 massa %, droog as-vry). Mielie stronke sorg vir ’n hoër opbrengs van bio-olie as mielie strooi in beide reaktore. By die optimum bedryfskondisies is daar in beide reaktor ’n hoër bio-kool opbrengs verkry van mielie stingels teenoor mielie stronke. Geen aansienlike verskille is gevind in die chemise en fisiese kenmerke van van die bio-olie wat geproduseer is in die twee reaktore nie. Daar is wel variasie getoon in die bio-kool kenmerkte van die verskillende Snel Piroliese prosesse. Snel piroliese van mielie-afval lewer energie produkte, bio-olie (HVW = 18.7-25.3MJ/kg) en bio-kool (HVW = 19.8-29.3 MJ/kg) vergelykbaar met steenkool (HVW = 16.2-25.9 MJ/kg). Die bio-olies geproduseer het sommige ongewenste kenmerke getoon byvoorbeeld suurheid (pH 3.8-4.3) asook hoë water inhoud (21.3 – 30.5 massa %). Die metode (indamping) wat gebruik is vir die opgradering van bio-olie het gelei tot die verbetering van die verhittingswaarde asook die toename in viskositeit deur die verwydering van ligte koolwaterstowwe en water. Die mielie-afval bio-kool toon ’n BET (Brunauer-Emmet-Teller) oppervlakte area van 96.7-158.8 m2/g wat dit toepaslik maak as grondstof vir absorbante. The gas geproduseer tydens Snel Piroliese is geanaliseer met behulp van gas chromotografie (GC) as CO2, CO, H2, CH4, C2H4, C2H6, C3H8 and C5+ koolwaterstowwe. Die vlak van CO2 en CO het 80% (v/V) oorskry en met lae verhittingswaardes (8.82-8.86 MJ/kg).

Com a crescente demanda de energia no mundo, a busca por novas fontes alternativas de energia tem motivado novos estudos por fontes energéticas renováveis que permitam substituir gradualmente os combustíveis fósseis, responsáveis por emissões de níveis de poluentes superiores aos associados aos biocombustíveis. O aumento populacional aliado à melhoria da eficiência do tratamento de esgoto implica diretamente o aumento da produção do lodo de esgoto, que é o principal resíduo sólido gerado nessas estações. O lodo de esgoto pode ser aplicado em processos tecnológicos, como a pirólise, a gaseificação e a combustão, para produção de energia alternativa. A pirólise é uma tecnologia promissora, favorece a produção de quatro frações quando aplicada ao lodo residual: bio-óleo (fração líquida orgânica), fração aquosa, fração sólida e gasosa, com elevado potencial combustível. Este artigo tem como objetivo avaliar o processo de pirólise aplicado a lodo residual doméstico como uma fonte alternativa de energia e identificar as condições de processo que resultaram em maiores rendimentos do bio-óleo produzido.
With the growing demand for energy in the world, the search for new sources of energy have motivated new studies about renewable energy sources that allow us to replace fossil fuels gradually, as they are responsible for higher levels of pollutants emission if compared to biofuels. Population growth together with the improvement of sewage treatment efficiency, that directly impacts the growth of sewage sludge production, which is the main solid waste generated in the Sewage Treatment Stations. The sludge can be used in technological processes, like pyrolysis, gasification and combustion, in order to produce alternative energy. The pyrolysis applied in sludge is a promising technology that favor the production of four fractions: biooil (organic liquid fraction), water fraction, solid fraction and gas fraction, showing a high fuel potential. This paper aims to evaluate the pyrolysis process applied to domestic sludge as an alternative source of energy and identify the process conditions that resulted in better efficiency of the biooil produced.

Lignin is an important component of biomass accounting for up to 30% by weight but up to 40% of the total energy content of the plant. As the push towards alternative fuels develops, more and more amounts of lignin will be gathered and used predominately as low grade boiler fuel to run primary processes. We argue there is usefulness in the conversion of lignin into value added specialty chemicals and fuels. In this work, a new approach for hydrodeoxygenation of lignin model compounds using platinum as the catalyst and organic solvent as the reaction medium was conducted, and the results were compared with those obtained using water as the reaction medium. It is shown that the organic solvent, with its increased hydrogen solubility, is able to hydrogenate the model compound with the same effect at lower temperature, hydrogen pressure, and time.

Doctor of Philosophy
Department of Biological and Agricultural Engineering
Wenqiao Yuan
Donghai Wang
Corncobs were used as the feedstock to investigate the effect of operating conditions and crude glycerol (solvent) on bio-oil production. The highest bio-oil yield of 33.8% on the basis of biomass dry weight was obtained at 305°C, 20 min retention time, 10% biomass content, 0.5% catalyst loading. At selected conditions, bio-oil yield based on the total weight of corn cobs and crude glycerol increased to 36.3% as the crude glycerol/corn cobs ratio increased to 5. Furthermore, the optimization of operating conditions was conducted via response surface methodology. A maximum bio-oil yield of 41.3% was obtained at 280°C, 12min, 21% biomass content, and 1.56% catalyst loading. A highest bio-oil carbon content of 74.8% was produced at 340°C with 9% biomass content. A maximum carbon recovery of 25.2% was observed at 280°C, 12min, 21% biomass content, and 1.03% catalyst loading. The effect of biomass ecotype and planting location on bio-oil production were studied on big bluestems. Significant differences were found in the yield and elemental composition of bio-oils produced from big bluestem of different ecotypes and/or planting locations. Generally, the IL ecotype and the Carbondale, IL and Manhattan, KS planting locations gave higher bio-oil yield, which can be attributed to the higher total cellulose and hemicellulose content and/or the higher carbon but lower oxygen contents in these feedstocks. Bio-oil from the IL ecotype also had the highest carbon and lowest oxygen contents, which were not affected by the planting location. In order to better understand the mechanisms of hydrothermal conversion, the interaction effects between cellulose, hemicellulose and lignin in hydrothermal conversion were studied. Positive interaction between cellulose and lignin, but negative interaction between cellulose and hemicellulose were observed. No significant interaction was found between hemicelluose and lignin. Hydrothermal conversion of corncobs, big bluestems, switchgrass, cherry, pecan, pine, hazelnut shell, and their model biomass also were conducted. Bio-oil yield increased as real biomass cellulose and hemicellulose content increased, but an opposite trend was observed for low lignin content model biomass.

Thesis (MScEng (Process Engineering))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: The world’s depleting fossil fuels and increasing greenhouse gas emissions have given rise to much research into renewable and cleaner energy. Biomass is unique in providing the only renewable source of fixed carbon. Agricultural residues such as Sugarcane Bagasse (SB) are feedstocks for ‘second generation fuels’ which means they do not compete with production of food crops. In South Africa approximately 6 million tons of raw SB is produced annually, most of which is combusted onsite for steam generation. In light of the current interest in bio-fuels and the poor utilization of SB as energy product in the sugar industry, alternative energy recovery processes should be investigated. This study looks into the thermochemical upgrading of SB by means of pyrolysis. Biomass pyrolysis is defined as the thermo-chemical decomposition of organic materials in the absence of oxygen or other reactants. Slow Pyrolysis (SP), Vacuum Pyrolysis (VP), and Fast Pyrolysis (FP) are studied in this thesis. Varying amounts of char and bio-oil are produced by the different processes, which both provide advantages to the sugar industry. Char can be combusted or gasified as an energy-dense fuel, used as bio-char fertilizer, or upgraded to activated carbon. High quality bio-oil can be combusted or gasified as a liquid energy-dense fuel, can be used as a chemical feedstock, and shows potential for upgrading to transport fuel quality. FP is the most modern of the pyrolysis technologies and is focused on oil production. In order to investigate this process a 1 kg/h FP unit was designed, constructed and commissioned. The new unit was tested and compared to two different FP processes at Forschungszentrum Karlsruhe (FZK) in Germany. As a means of investigating the devolatilization behaviour of SB a Thermogravimetric Analysis (TGA) study was conducted. To investigate the quality of products that can be obtained an experimental study was done on SP, VP, and FP. Three distinct mass loss stages were identified from TGA. The first stage, 25 to 110°C, is due to evaporation of moisture. Pyrolitic devolatilization was shown to start at 230°C. The final stage occurs at temperatures above 370°C and is associated with the cracking of heavier bonds and char formation. The optimal decomposition temperatures for hemicellulose and cellulose were identified as 290°C and 345°C, respectively. Lignin was found to decompose over the entire temperature range without a distinct peak. These results were confirmed by a previous study on TGA of bagasse. SP and VP of bagasse were studied in the same reactor to allow for accurate comparison. Both these processes were conducted at low heating rates (20°C/min) and were therefore focused on char production. Slow pyrolysis produced the highest char yield, and char calorific value. Vacuum pyrolysis produced the highest BET surface area chars (>300 m2/g) and bio-oil that contained significantly less water compared to SP bio-oil. The short vapour residence time in the VP process improved the quality of liquids. The mechanism for pore formation is improved at low pressure, thereby producing higher surface area chars. A trade-off exists between the yield of char and the quality thereof. FP at Stellenbosch University produced liquid yields up to 65 ± 3 wt% at the established optimal temperature of 500°C. The properties of the bio-oil from the newly designed unit compared well to bio-oil from the units at FZK. The char properties showed some variation for the different FP processes. At the optimal FP conditions 20 wt% extra bio-oil is produced compared to SP and VP. The FP bio-oil contained 20 wt% water and the calorific value was estimated at 18 ± 1 MJ/kg. The energy per volume of FP bio-oil was estimated to be at least 11 times more than dry SB. FP was found to be the most effective process for producing a single product with over 60% of the original biomass energy. The optimal productions of either high quality bio-oil or high surface area char were found to be application dependent.
AFRIKAANSE OPSOMMING: As gevolg van die uitputting van fossielbrandstofreserwes, en die toenemende vrystelling van kweekhuisgasse word daar tans wêreldwyd baie navorsing op hernubare en skoner energie gedoen. Biomassa is uniek as die enigste bron van hernubare vaste koolstof. Landbouafval soos Suikerriet Bagasse (SB) is grondstowwe vir ‘tweede generasie bio-brandstowwe’ wat nie die mark van voedselgewasse direk affekteer nie. In Suid Afrika word jaarliks ongeveer 6 miljoen ton SB geproduseer, waarvan die meeste by die suikermeulens verbrand word om stoom te genereer. Weens die huidige belangstelling in bio-brandstowwe en ondoeltreffende benutting van SB as energieproduk in die suikerindustrie moet alternatiewe energie-onginningsprosesse ondersoek word. Hierdie studie is op die termo-chemiese verwerking van SB deur middel van pirolise gefokus. Biomassa pirolise word gedefinieer as die termo-chemiese afbreking van organiese bio-materiaal in die afwesigheid van suurstof en ander reagense. Stadige Pirolise (SP), Vakuum Pirolise (VP), en Vinnige Pirolise word in hierdie tesis ondersoek. Die drie prosesse produseer veskillende hoeveelhede houtskool en bio-olie wat albei voordele bied vir die suikerindustrie. Houtskool kan as ‘n vaste energie-digte brandstof verbrand of vergas word, as bio-houtskoolkompos gebruik word, of kan verder tot geaktiveerde koolstof geprosesseer word. Hoë kwaliteit bio-olie kan verbrand of vergas word, kan as bron vir chemikalië gebruik word, en toon potensiaal om in die toekoms opgegradeer te kan word tot vervoerbrandstof kwaliteit. Vinnige pirolise is die mees moderne pirolise tegnologie en is op bio-olie produksie gefokus. Om die laasgenoemde proses te toets is ‘n 1 kg/h vinnige pirolise eenheid ontwerp, opgerig en in werking gestel. Die nuwe pirolise eenheid is getoets en vegelyk met twee verskillende vinnige pirolise eenhede by Forschungszentrum Karlsruhe (FZK) in Duitsland. Termo-Gravimetriese Analise (TGA) is gedoen om die ontvlugtigingskenmerke van SB te bestudeer. Eksperimentele werk is verrig om die kwaliteit van produkte van SP, VP, vinnige pirolise te vergelyk. Drie duidelike massaverlies fases van TGA is geïdentifiseer. Die eerste fase (25 – 110°C) is as gevolg van die verdamping van vog. Pirolitiese ontvlugtiging het begin by 230°C. Die finale fase (> 370°C) is met die kraking van swaar verbindings en die vorming van houtskool geassosieer. Die optimale afbrekingstemperatuur vir hemisellulose en sellulose is as 290°C en 345°C, respektiewelik, geïdentifiseer. Daar is gevind dat lignien stadig oor die twede en derde fases afgebreek word sonder ‘n duidelike optimale afbrekingstemperatuur. Die resultate is deur vorige navorsing op TGA van SB bevestig. SP en VP van bagasse is in dieselfde reaktor bestudeer, om ‘n akkurate vergelyking moontlik te maak. Beide prosesse was by lae verhittingstempo’s (20°C/min) ondersoek, wat gevolglik op houtskoolformasie gefokus is. SP het die hoogste houtskoolopbrengs, met die hoogste verbrandingsenergie, geproduseer. VP het hootskool met die hoogste BET oppervlakarea geproduseer, en die bio-olie was weens ‘n dramatiese afname in waterinhoud van beter gehalte. Die meganisme vir die vorming van ‘n poreuse struktuur word deur lae atmosferiese druk verbeter. Daar bestaan ‘n inverse verband tussen die kwantiteit en kwaliteit van die houtskool. Vinnige pirolise by die Universiteit van Stellenbosch het ‘n bio-olie opbrengs van 65 ± 3 massa% by ‘n vooraf vasgestelde optimale temperatuur van 500°C geproduseer. Die eienskappe van bio-olie wat deur die nuwe vinnige pirolise eenheid geproduseer is het goed ooreengestem met die bio-olie afkomstig van FZK se pirolise eenhede. Die houtskool eienskappe van die drie pirolise eenhede het enkele verskille getoon. By optimale toestande vir vinnige pirolise word daar 20 massa% meer bio-olie as by SP en VP geproduseer. Vinnige pirolise bio-olie het ‘n waterinhoud van 20 massa% en ‘n verbrandingswarmte van 18 ± 1 MJ/kg. Daar is gevind dat ten opsigte van droë SB die energie per enheidsvolume van bio-olie ongeveer 11 keer meer is. Vinnige pirolise is die mees doeltreffende proses vir die vervaardiging van ‘n produk wat meer as 60% van die oorspronklike biomassa energie bevat. Daar is gevind dat die optimale hoeveelhede van hoë kwaliteit bio-olie en hoë oppervlakarea houtskool doelafhanklik is.

Mallee biomass is considered to be a second-generation renewable feedstock in Australia and will play an important role in bioenergy development in Australia. Its production is of large-scale, low cost, small carbon footprint and high energy efficiency. However, biomass as a direct fuel is widely dispersed, bulky, fibrous and of high moisture content and low energy density. High logistic cost, poor grindability and mismatch of fuel property with coal are some of the key issues that impede biomass utilisation for power generation. Therefore, innovations are in urgent need to improve biomass volumetric energy densification, grindability and good fuel matching if co-fired with coal. Biomass pyrolysis is a flexible and low-cost approach that can be deployed for this purpose. Via pyrolysis, the bulky biomass can be converted to biomass-derived high-energy-density fuels such as biochar and/or bio-oil. So far there has been a lack of fundamental understanding of mallee biomass pyrolysis and properties of the fuel products.The series of study in this PhD thesis aims to investigate the production of such high-energy- density fuels obtained from mallee pyrolysis and to obtain some new knowledge on properties of the resultant fuels and their implications to practical applications. Particularly, the research has been designed and carried out to use pyrolysis as a pretreatment technology for the production of biochar, bio-oil and bioslurry fuels. The main outcomes of this study are summarised as follows.Firstly, biochars were produced from the pyrolysis of centimetre-sized particles of mallee wood at 300-500°C using a fixed-bed reactor under slow-heating conditions. The data show that at pyrolysis temperatures > 320°C, biochar as a fuel has similar fuel H/C and O/C ratios compared to Collie coal which is the only coal being mined in WA. Converting biomass to biochar leads to a substantial increase in fuel mass energy density from ~10 GJ/tonne of green biomass to ~28 GJ/tonne of biochars prepared from pyrolysis at 320°C, in comparison to 26 GJ/tonne for Collie coal. However, there is little improvement in fuel volumetric energy density, which is still around 7-9 GJ/m[superscript]3 in comparison to 17 GJ/m[superscript]3 of Collie coal. Biochars are still bulky and grinding is required for volumetric energy densification. Biochar grindability experiments have shown that the fuel grindability increases drastically even at pyrolysis temperature as low as 300°C. Further increase in pyrolysis temperature to 500°C leads to only small increase in biochar grindability. Under the grinding conditions, a significant size reduction (34-66 % cumulative volumetric size <75 μm) of biochars can be achieved within 4 minutes grinding (in comparison to only 19% for biomass after 15 minutes grinding), leading to a significant increase in volumetric energy density (e.g. from ~8 to ~19 GJ/m[superscript]3 for biochar prepared from pyrolysis at 400°C). Whereas grinding raw biomass typically result in large and fibrous particles, grinding biochar produce short and round particles highly favourable for fuel applications.Secondly, it is found that the pyrolysis of different biomass components produced biochars with distinct characteristics, largely because of the differences in the biological structure of these components. Leaf biochars showed the poorest grindability due to the presence of abundant tough oil glands in leaf. Even for the biochar prepared from the pyrolysis of leaf at 800°C, the oil gland enclosures remained largely intact after grinding. Biochars produced from leaf, bark and wood components also have significant differences in ash properties. Even with low ash content, wood biochars have low Si/K and Ca/K ratios, suggesting these biochars may have a high slagging propensity in comparison to bark and leaf biochars.Thirdly, bio-oil and biochar were also produced from pyrolysis of micron-size wood particle using a fluidised-bed reactor system under fast-heating conditions. The excellent grindability of biochar had enabled desirable particle size reduction of biochar into fine particles which can be suspended into bio-oil for the preparation of bioslurry fuels. The data have demonstrated that bioslurry fuels have desired fuel and rheological characteristics that met the requirements for combustion and gasification applications. Depending on biochar loading, the volumetric energy density of bioslurry is up to 23.2 GJ/m[superscript]3, achieving a significant energy densification (by a factor > 4) in comparison to green wood chips. Bioslurry fuels with high biochar concentrations (11-20 wt%) showed non-Newtonian characteristics with pseudoplastic behaviour. The flow behaviour index, n decreases with the increasing of biochar concentration. Bioslurry with higher biochar concentrations has also demonstrated thixotropic behaviour. The bioslurry fuels also have low viscosity (<453 mPa.s) and are pumpable at both room and elevated temperatures. The concentrations of Ca, K, N and S in bioslurry are below the limits of slurry fuel guidelines.Fourthly, bio-oil is extracted using biodiesel to produce two fractions, a biodiesel-rich fraction (also referred as bio-oil/biodiesel blend) and a bio-oil rich fraction. The results has shown that the compounds (mainly phenolic) extracted from bio-oil into the biodiesel-rich fraction reduces the surface tension of the resulted biodiesel/bio-oil blends that are known as potential liquid transport fuels. The bio-oil rich fraction is mixed with ground biochar to produce a bioslurry fuel. It is found that bioslurry fuels with 10% and 20% biochar loading prepared from the bio-oil rich fraction of biodiesel extraction at a biodiesel to bio-oil blend ratio 0.67 have similar fuel properties (e.g. density, surface tension, volumetric energy density and stability) in comparison to those prepared using the original whole bio-oil. The slurry fuels have exhibited non-Newtonian with pseudoplastic characteristics and good pumpability desirable for fuel handling. The viscoelastic behaviour of the slurry fuels also has shown dominantly fluid-like behaviour in the linear viscoelastic region therefore favourable for atomization in practical applications. This study proposes a new bio-oil utilisation strategy via coproduction of a biodiesel/bio-oil blend and a bioslurry fuel. The biodiesel/bio-oil blend utilises a proportion of bio-oil compounds (relatively high value small volume) as a liquid transportation fuel. The bioslurry fuel is prepared by mixing the rest low-quality bio-oil rich fractions (relatively low value and high volume) with ground biochar, suitable for stationary applications such as combustion and gasification.Overall, the present research has generated valuable data, knowledge and fundamental understanding on advanced fuels from mallee biomass using pyrolysis as a pre-treatment step. The flexibility of pyrolysis process enables conversion of bulky, low fuel quality mallee biomass to biofuels of high volumetric energy density favourable to reduce logistic cost associated with direct use of biomass. The significance structural, fuel and ash properties differences among various mallee biomass components were also revealed. The production of bioslurry fuels as a mixture of bio-oil and biochar is not only to further enhance the transportability/handling of mallee biomass but most importantly the slurry quality highly matched requirements in stationary applications such as combustion and gasification. The co-production of bioslurry with bio-oil/biodiesel extraction was firstly reported in this field. Such a new strategy, which uses high-quality extractable bio-oil compounds into bio-oil/biodiesel blend as a liquid transportation fuel and utilises the low-quality bio-oil rich fraction left after extraction for bioslurry preparation, offers significant benefits for optimised use of bio-oil.

In the search for fossil fuel alternatives the production of bio-oil through the pyrolysis of biomass is one method which has shown evidence of scalability, meaning that the technology could be scaled up for the processing of biomass on the order of tons per day. Pyrolysis is the thermal degradation of compounds in the absence of oxygen. Of particular interest is the pyrolysis of sustainable energy crops such as Loblolly pine (Pinus taeda). The goal of this study is to develop a new method of characterizing the fast pyrolysis of biomass for the advancement of reactor design. The objectives are to determine bulk kinetic coefficients for the isothermal fast pyrolysis of biomass, evaluate the interchangeability of fast and slow pyrolysis kinetic parameters and compare generally accepted pyrolysis mechanisms derived from a common data set. A technical objective is to apply the most suitable derived kinetic parameters to model pyrolysis within a moving bed reactor. A novel fast pyrolysis micro-reactor is presented along with its design and development process. The micro-reactor allows for the control over both temperature and residence time of the reacting biomass. This system provides the experimental data for the characterization of biomass pyrolysis kinetic parameters. Thermal validation tests are presented and experimental yield results are given for raw Loblolly Pine, Avicel cellulose and Beechwood xylan for the derivation of kinetic descriptors. Cellulose and xylan results show good agreement with literature when the proper experimental conditions are met and whole wood pyrolysis results clearly demonstrate the dissimilarity between fast and slow pyrolysis apparent kinetic rates. The experimental results are then used to evaluate five different pyrolysis kinetic model configurations: single component global pyrolysis, two component global pyrolysis, product based pyrolysis, pseudo-component based pyrolysis and pseudo-component pyrolysis with an intermediate solid compound. Pseudo-component models are of particular interest because they may provide a generalized model, parameterized by the fractional composition of cellulose, hemicellulose and lignin in biomass species. Lignin pyrolysis yields are calculated to evaluate the suitability of a pseudo-component parallel non-competing superposition pyrolysis model. Lignin yields are estimated by taking the difference between whole wood pyrolysis and predicted cellulose and hemicellulose pyrolysis behaviors. The five models are then evaluated by comparison of predicted yields to the results for the pyrolysis of Scots pine (Pinus sylvestris) and Norway spruce (Picea abies). Model evaluations show that pseudo-component superposition is not suitable as a generic pyrolysis model for the fast pyrolysis of biomass observed using the micro-reactor. Further analytical evaluations indicate that the assumption of parallel non-competing reactions between pseudo-components is not valid. Among the other models investigated the intermediate solid compound model showed the best fit to the verification experimentation results followed closely by the two component global model. Finally, the derived kinetic parameters are applied to the design of moving bed vacuum pyrolysis reactors which provide for the separation of heat and mass transfer pathways, resulting in the reduction of char entrainment and secondary reactions within collected bio-oils. Reaction kinetics and porous bed heat and mass transfer are accounted for within the bed model. Model development and predictive results are presented and sensitivity to activation energy variations investigated.

This thesis investigates the cost of electricity generation using bio-oil produced by the fast pyrolysis of UK energy crops. The study covers cost from the farm to the generator’s terminals. The use of short rotation coppice willow and miscanthus as feedstocks was investigated. All costs and performance data have been taken from published papers, reports or web sites. Generation technologies are compared at scales where they have proved economic burning other fuels, rather than at a given size. A pyrolysis yield model was developed for a bubbling fluidised bed fast pyrolysis reactor from published data to predict bio-oil yields and pyrolysis plant energy demands. Generation using diesel engines, gas turbines in open and combined cycle (CCGT) operation and steam cycle plants was considered. The use of bio-oil storage to allow the pyrolysis and generation plants to operate independently of each other was investigated. The option of using diesel generators and open cycle gas turbines for combined heat and power was examined. The possible cost reductions that could be expected through learning if the technology is widely implemented were considered. It was found that none of the systems analysed would be viable without subsidy, but with the current Renewable Obligation Scheme CCGT plants in the 200 to 350 MWe range, super-critical coal fired boilers co-fired with bio-oil, and groups of diesel engine based CHP schemes supplied by a central pyrolysis plant would be viable. It was found that the cost would reduce with implementation and the planting of more energy crops but some subsidy would still be needed to make the plants viable.

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Universidade Federal do Rio Grande do Norte
Biomass is considered the largest renewable energy source that can be used in an environmentally sustainable. From the pyrolysis of biomass is possible to obtain products with higher energy density and better use properties. The liquid resultant of this process is traditionally called bio-oil. The use of infrared burners in industrial applications has many advantages in terms of technical-operational, for example, uniformity in the heat supply in the form of radiation and convection, with a greater control of emissions due to the passage of exhaust gases through a macroporous ceramic bed. This paper presents a commercial infrared burner adapted with an ejector proposed able to burn a hybrid configuration of liquefied petroleum gas (LPG) and bio-oil diluted. The dilution of bio-oil with absolute ethanol aimed to decrease the viscosity of the fluid, and improving the stability and atomization. It was introduced a temperature controller with thermocouple modulating two stages (low heat / high heat), and solenoid valves for fuels supply. The infrared burner has been tested, being the diluted bio-oil atomized, and evaluated its performance by conducting energy balance. The method of thermodynamic analysis to estimate the load was used an aluminum plate located at the exit of combustion gases and the distribution of temperatures measured by thermocouples. The dilution reduced the viscosity of the bio-oil in 75.4% and increased by 11% the lower heating value (LHV) of the same, providing a stable combustion to the burner through the atomizing with compressed air and burns combined with LPG. Injecting the hybrid fuel there was increase in the heat transfer from the plate to the environment in 21.6% and gain useful benefit of 26.7%, due to the improved in the efficiency of the 1st Law of Thermodynamics of infrared burner
A biomassa ? considerada a maior fonte renov?vel de energia, podendo ser usada de forma ambientalmente sustent?vel. A partir da pir?lise da biomassa ? poss?vel a obten??o de produtos com maior densidade energ?tica e propriedades de uso melhores. O l?quido resultante do seu processo ? tradicionalmente chamado de bio-?leo. A utiliza??o de queimadores infravermelhos em aplica??es industriais apresenta muitas vantagens do ponto de vista t?cnico-operacional, como por exemplo, homogeneidade no fornecimento de calor, na forma de radia??o e convec??o, apresentando um maior controle das emiss?es devido ? passagem dos gases de exaust?o atrav?s de um leito cer?mico macroporoso. O presente trabalho apresenta um queimador infravermelho comercial adaptado com um ejetor proposto capaz de queimar numa configura??o h?brida de g?s liquefeito de petr?leo (GLP) e bio-?leo dilu?do. A dilui??o do bio-?leo com ?lcool et?lico absoluto teve como principal objetivo diminuir a viscosidade do fluido, e melhorar a estabilidade e a atomiza??o. Foi introduzido um controlador de temperatura com termopar modulando dois est?gios (fogo baixo/alto), e eletrov?lvulas para alimenta??o dos combust?veis. O queimador infravermelho foi submetido a testes e ensaios, sendo atomizado o bio-?leo dilu?do, e avaliado o seu desempenho mediante a realiza??o de balan?o de energia. Como m?todo de an?lise termodin?mica para estimativa de carga foi utilizado uma placa de alum?nio localizada na sa?da dos gases de combust?o, sendo a distribui??o de temperaturas medida por termopares. A dilui??o reduziu a viscosidade do bio-?leo em 75,4% e aumentou em 11% o poder calor?fico inferior do mesmo, propiciando ao queimador uma combust?o est?vel atrav?s da atomiza??o com o ar comprimido e queima conjunta com GLP. Injetando o combust?vel h?brido houve aumento na transfer?ncia de calor da placa para o meio ambiente em 21,6% e ganho energ?tico ?til de 26,7%, em fun??o da melhora na efici?ncia da 1? Lei da Termodin?mica do queimador infravermelho

The aim of this study was to evaluate the potential of Hancornia speciosa (known as mangaba in Brazil) seeds for the production of bio-oil, in order to minimize the pollution problems caused by the inappropriate disposal of this residue and add value to this material which poses an environmental risk. The study was divided into two parts: the characterization of the biomass (through elemental analysis (CHN), infrared spectroscopy (FTIR-ATR), thermogravimetry (TG), and the moisture, ash, protein, oil, fiber, cellulose, hemicellulose and lignin contents); and the characterization of the bio-oil (thermogravimetry, infrared spectroscopy and gas chromatography/mass spectrometry-CG/MS). The mangaba seeds had a moisture content of 7.78±0.03%, high quantities of carbon (58.07%) and oxygen (27.18%), a calorific value of 23.45 MJ kg-1 and contained ash (1.87±0.06%), oil (27.33±0.37%), protein (12.10±1.60%) fiber (11.98±0.46%), cellulose (17.07%), hemicellulose (22.57%) and lignin (10.16%). The thermogravimetric curve for the sample showed a mass loss of around 90% up to a temperature of 450 °C. In the pyrolysis experiments the variables included temperature (450 and 600 °C), sample mass (5 and 11 g) and prior heating (with or without). The best conditions for the bioproduction of the bio-oil were 600 °C, 11 g of seeds and prior heating of the furnace. The characterization of the samples by FTIR allowed the presence of functional groups such as phenols, alcohols, ketones, acids, alkanes, alkenes, amides, nitriles and esters to be identified. The CG/MS analysis confirmed the results obtained with the infrared spectroscopy, with carboxylic acids and hydrocarbonates (~ 90%) being qualitatively identified as the major components, besides the presence of other compounds such as furanes, phenols, nitriles, aldehydes, ketones, alcohols, esters and amides.
O presente trabalho teve como objetivo avaliar o aproveitamento das sementes de mangaba para a produção de bio-óleo, a fim de minimizar problemas de poluição devido à disposição inadequada dos resíduos e agregar valor a este passivo ambiental. O trabalho foi dividido em duas partes: caracterização da biomassa (análise elementar (CHN), espectroscopia de infravermelho (FTIR-ATR), termogravimetria (TG), teor de umidade, cinzas, proteínas, teor de óleo, fibras, celulose, hemicelulose e lignina) e caracterização do bio-óleo (termogravimetria, infravermelho e cromatografia gasosa/espectrometria de massas-GC/MS). As sementes de mangaba apresentaram teor de umidade de 7,78±0,03%, alta quantidade de carbono (58,07%) e oxigênio (27,18%), poder calorífico (23,45 MJ kg-1), teor de cinzas de 1,87±0,06%, teor de óleo 27,33±0,37%, proteínas 12,10±1,60%, fibras 11,98±0,46%, celulose (17,07%), hemicelulose (22,57%) e lignina (10,16%). A curva termogravimétrica da amostra apresentou cerca de 90% de perda de massa até a temperatura de 450 °C. Os experimentos de pirólise incluíram como variável temperatura (450 e 600 °C), massa de amostra (5 e 11 g), com ou sem aquecimento prévio. A melhor condição para a produção de bio-óleo foi a 600 °C, 11g de semente e com aquecimento prévio do forno. Através da caracterização da amostra em FTIR foi possível identificar a presença de grupos funcionais como fenóis, alcoóis, cetonas, ácidos, alcanos, alcenos, amidas, nitrilas e ésteres. Por outro lado, as análises de GC/MS confirmaram os resultados obtidos com o infravermelho, sendo identificados qualitativamente os ácidos carboxílicos e hidrocarbonetos (~ 90%) como componentes majoritários, além de serem encontrados outros compostos como furanos, fenóis, nitrilas, aldeídos, cetonas, alcoóis, ésteres e amidas.

The search for alternatives to the fossil oil and concern about environmental pollution has increasingly supported the importance of biofuels. The production of bio-oil from aquatic plants (water hyacinth) has become as interesting alternative due to its rapid growth rate, robust nature and unrelated to the food chain. The present work aimed to study the application of conventional and catalytic pyrolysis to convert aquatic plants like Eichhornia crassipes (EC) and Eichhornia azurea (EA) in bio-oil, employing Ferrierite and Y zeolite as catalysts. These plants were obtained in Aracaju-SE and Itabaiana-SE, respectively. The micropyrolys is were performed at three temperatures (400, 500 and 600 °C). The catalytic micropyrolysis using Ferrierite and Y zeolite was performed in the same condition applying 1 and 5% of catalysts w/w. The bio-oils solutions obtained were characterized by GC/MS and GC-FID. The micropyrolysis performed in the absence of catalyst showed similar chromatographic profiles to the biomasses tested, with the composition of bio-oils showing phenolic compounds, acids and alcohols. With Ferrierite as catalyst at 5% in the micropyrolysis and performing a study from the total area of the obtained chromatograms was observed the higher yield by GC-FID caused by the increased formation of small molecular mass compounds from biomasses. However, when used 1% of the same catalyst to EC was not observed a very significant difference in relation with no catalyst pyrolysis. To the EA in this condition was observed a significant yield reduction when performed at 500 °C. When used Y catalyst for EA pyrolysis a smaller yield was observed at all studied temperatures that shows a significantly inhibited formation of compounds derived from these lignocelullosic biomasses. However for the EC catalytic pyrolysis with 5% of Y catalyst at 500 °C we observed the largest decrease in the yield from the chromatograms area. The bio-oils characterization gave compounds identified belong to the following classes: alcohol, phenol, and sugar acids. The bio-oils from catalytic pyrolysis of EC and EA biomass showed a high content of phenolic compounds and acidic compounds.
A procura por soluções alternativas para a substituição total ou parcial do petróleo e a preocupação com a poluição ambiental tem reforçado cada vez mais a importância da produção de biocombustíveis. Neste sentido a produção de bio-óleo a partir de plantas aquáticas tornou-se uma alternativa interessante. Estas plantas são invasoras e possuem alta taxa de crescimento, natureza robusta e não tem relação com a cadeia alimentar. Neste trabalho, biomassas provenientes de plantas aquáticas, obtidas em Itabaiana-SE e Aracaju-SE, das espécies crassipes (EC) e azurea (EA), ambas do gênero Eichhornia, foram submetidas a micropirólise convencional a três temperaturas, 400, 500 e 600 ºC, e catalítica empregando catalisadores do tipo zeólita Ferrierita e Y nas proporções de 1 e 5%. As soluções de bio-óleos produzidas foram caracterizadas por CG/EM e CG-FID. Na micropirólise realizada na ausência de catalisador foi observado semelhança na composição química do bio-óleo para todas as condições testadas. Empregando 5% de catalisador Ferrierita na micropirólise, e realizando um estudo da área total dos cromatogramas obtidos foram observados aumentos significativos a 400 ºC para EC (+53,74%) e para a EA (+43,67%). A 1% deste mesmo catalisador para a EC houve diminuição da área total nas três temperaturas, enquanto que para EA houve diminuição na área total a 500 ºC (-48,09%). Quando empregado a zeólita Y nas duas proporções foi observado menor capacidade de produção de bio-óleo para EA em todas as temperaturas estudadas. A maior diminuição de área foi a 600 ºC (-25,70%) a 1% de catalisador e quando utilizado 5% foi a 500 ºC (-84,34%), ou seja, houve a inibição significativa na formação de bio-óleo. Para a EC foi observado a maior diminuição da capacidade de conversão térmica catalítica desta biomassa em bio-óleo na condição de 5% de zeólita Y, a 500 ºC (-33,23%) e na condição de 1% de zeólita Y, a 600 ºC (-46,77%). Os principais compostos identificados nos bio-óleos obtidos foram das classes do álcoois, fenóis, ácidos e açúcares. O bio-óleo obtido por pirólise catalítica das biomassas EC e EA apresentou um alto teor de compostos fenólicos e ácidos.

In order to reduce over-dependency on fossil fuels and to create an environment that is free of non-degradable plastics, and most importantly to reduce greenhouse gas emission, bio-based products are being developed from renewable resources through intense research to substitute conventional petrochemical-based plastics with renewable alternatives and to replace synthetic fibers with natural fibers. Many authors have done quite a lot of work on synthesizing polymers from renewable origin. Polylactic acid (PLA) has been developed and characterized, and it was found that it has enormous potential and can serve as an alternative to conventional thermoplastics in many applications. Modification of the plant oil triglycerides has been discussed by many authors, and research is still going on in this area. The challenge is how to make these renewable polymers more competitive in the market, and if possible to make them 100% bio-based. There is also a major disadvantage to using a bio-based polymer from plant oils because of the high viscosity, which makes impregnation of fibers difficult. Although natural fibers are hydrophilic in nature, the problem of compatibility with the hydrophobic matrix must be solved; however, the viscosity of the bio-based resin from plant oils will complicate the situation even more. This is why many authors have reported blending of the renewable thermoset resin with styrene. In the process of solving one problem, i.e reducing the viscosity of the renewable thermoset resin by blending with reactive diluents such as styrene, another problem which we intended to solve at the initial stage is invariably being created by using a volatile organic solvent like styrene. The solution to this cycle of problems is to synthesize a thermoset resin from plant oils which will have lower viscosity, and at the same time have higher levels of functionality. This will increase the crosslinking density, and they can be cured at room temperature or relatively low temperature. In view of the above considerations, the work included in this thesis has provided a reasonable solution to the compounded problems highlighted above. Three types of bio-based thermoset resins were synthesized and characterized using NMR, DSC, TGA, and FT-IR, and their processability was studied. The three resins were subsequently reinforced with natural fibers (woven and non-woven), glass fibers, and Lyocell fiber and the resulting natural fiber composites were characterized by mechanical, dynamic mechanical, impact, and SEM analyses. These composites can be used extensively in the automotive industry, particularly for the interior components, and also in the construction and furniture industries. Methacrylated soybean oil (MSO), methacrylic anhydride-modified soybean oil (MMSO), and acetic anhydride-modified soybean oil (AMSO) were found to be suitable for manufacture of composites because of their lower viscosity. The MMSO and MSO resins were found to be promising materials because composites manufactured by using them as a matrix showed very good mechanical properties. The MMSO resin can completely wet a fiber without the addition of styrene. It has the highest number of methacrylates per triglyceride and high crosslink density.
Akademisk avhandling för avläggande av teknologie doktorsexamen vid Chalmers Tekniska högskola försvaras vid offentlig disputation, den 6:e maj, Chalmers, KE-salen, Kemigården 4, Göteborg, kl. 10.00.

Harvesting solar energy can potentially be a promising solution to the energy crisis now and in the future. However, material and processing costs continue to be the most important limitations for the commercial devices. A key solution to these problems might lie within the development of bio-hybrid solar cells that seeks to mimic photosynthesis to harvest solar energy and to take advantage of the low material costs, negative carbon footprint, and material abundance. The bio-photoelectrochemical cell technologies exploit biomimetic means of energy conversion by utilizing plant-derived photosystems which can be inexpensive and ultimately the most sustainable alternative. Plants and photosynthetic bacteria harvest light, through special proteins called reaction centers (RCs), with high efficiency and convert it into electrochemical energy. In theory, photosynthetic RCs can be used in a device to harvest solar energy and generate 1.1 V open circuit voltage and ~1 mA cm-2 short circuit photocurrent. Considering the nearly perfect quantum yield of photo-induced charge separation, efficiency of a protein-based solar cell might exceed 20%. In practice, the efficiency of fabricated devices has been limited mainly due to the challenges in the electron transfer between the protein complex and the device electrodes as well as limited light absorption. The overarching goal of this work is to increase the power conversion efficiency in protein-based solar cells by addressing those issues (i.e. electron transfer and light absorption). This work presents several approaches to increase the charge transfer rate between the photosynthetic RC and underlying electrode as well as increasing the light absorption to eventually enhance the external quantum efficiency (EQE) of bio-hybrid solar cells. The first approach is to decrease the electron transfer distance between one of the redox active sites in the RC and the underlying electrode by direct attachment of the of protein complex onto Au electrodes via surface exposed cysteine residues. This resulted in photocurrent densities as large as ~600 nA cm-2 while still the incident photon to generated electron quantum efficiency was as low as %3 × 10-4. 2- The second approach is to immobilize wild type RCs of Rhodobacter sphaeroides on the surface of a Au underlying electrode using self-assembled monolayers of carboxylic acid terminated oligomers and cytochrome c charge mediating layers, with a preferential orientation from the primary electron donor site. This approach resulted in EQE of up to 0.06%, which showed 200 times efficiency improvement comparing to the first approach. In the third approach, instead of isolated protein complexes, RCs plus light harvesting (LH) complexes were employed for a better photon absorption. Direct attachment of RC-LH1 complexes on Au working electrodes, resulted in 0.21% EQE which showed 3.5 times efficiency improvement over the second approach (700 times higher than the first approach). The main impact of this work is the harnessing of biological RCs for efficient energy harvesting in man-made structures. Specifically, the results in this work will advance the application of RCs in devices for energy harvesting and will enable a better understanding of bio and nanomaterial interfaces, thereby advancing the application of biological materials in electronic devices. At the end, this work offers general guidelines that can serve to improve the performance of bio-hybrid solar cells.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Lignocellulosic biomass use for obtaining biofuels has been showing itself with much more evidence during these past years through cellulosic ethanol and biooils, biogases and biochars. Aquatic plants of lignocellulosic basis, Eichhornia crassipes species, commonly known by water hyacinth, represent a major environmental problem due to their invasive nature and their high proliferation rate. In this work we evaluated the possibility of use this biomass source from pyrolysis in a rotary kilns reactor in three different temperatures. The results evidence that the major yield of the liquid fraction (bio-oil + acid extract) was obtained at 500 ºC (42.11%). For 400 ºC and 600 ºC, the biochar and biogas had major production, 37.78% and 42.36%, respectively. Bio-oils characterization by GC/MS produced in microscale allowed an investigation upon the scale-up phenomenon under the bio-oils composition. The results show that, in qualitative terms, the chemical composition of bio-oils was not changed, however, at semiquantitative aspect, show they are produced in distinguish relative percentages. The mainly chemical classes identified in biooils were: acids, alcohols, phenols and sugar derivatives. Bio-oils showed in average, 68% of calorific power of the fuels derived from petroleum, glimpsing enforcement on the energetic area. In the produced biochars, with yields between 37% and 26%, the increase on pyrolysis temperature has provided an increase upon carbon concentration, and a decreasing upon the hydrogen and oxygen concentrations, reflecting in high aromaticity of the materials. These materials ware tested in some aspects about the soils management, nutritional function and water retention. In view of this, the water hyacinth pyrolysis has associated sustainability concepts and green chemistry, putting concepts of renewable energetic sources together and glimpsing an environmental problems inhibition, to offer an alternative to the 2nd generation of bio-fuels production.
O uso de biomassas lignocelulósicas para a obtenção de biocombustíveis apresenta-se com muito mais evidência nos últimos anos através do etanol celulósico e de bio-óleos, biogás e biocarvão. As plantas aquáticas de base lignocelulósica da espécie Eichhornia crassipes, popularmente conhecida por aguapé, representam um grande problema ambiental devido ao seu caráter invasor e sua alta taxa de proliferação. Neste trabalho avaliou-se a possibilidade de aproveitamento dessa fonte de biomassa a partir do processo de pirólise em um reator cilindro rotativo em três diferentes temperaturas. Os resultados demonstraram que o maior rendimento da fração líquida (bio-óleo + extrato ácido) foi obtido a 500 ºC (42,11%). Para as temperaturas de 400 e 600 ºC, o biocarvão e o biogás tiveram maior produção, 37,78% e 42,36%, respectivamente. A caracterização por CG/EM dos bio-óleos produzidos em microescala permitiram investigar o efeito de scale-up sob a composição dos bio-óleos. Os resultados mostraram que em termos qualitativos, a composição química dos bio-óleos não foi alterada, no entanto, no aspecto semiquantitativo mostraram que são produzidos em percentuais relativos distintos. As principais classes químicas identificadas nos bio-óleos foram: ácidos, álcoois, fenóis e derivados de açúcares. Os bio-óleos apresentaram em média 68% do poder calorífico do combustível derivado de petróleo, vislumbrando uma aplicação na área energética. Nos biocarvões produzidos, com rendimento variando de 37% a 26%, o aumento da temperatura de pirólise proporcionou um aumento na concentração de C, e uma diminuição nas concentrações de H e O, refletindo em maior aromaticidade dos materiais. Estes materiais foram testados sob alguns aspectos quanto ao manejo de solos, função nutricional e retenção de água. À vista disto, a pirólise de aguapé relacionou conceitos de sustentabilidade e química verde, unindo o conceito de fontes de energias renováveis com a inibição de problemas de cunho ambientais, ao oferecer uma biomassa alternativa para a produção de biocombustíveis de 2ª geração.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The current work aimed to investigate the production of ethyl esters which result from the esterification reactions of oleic acids (AO) and transesterifiction of residual fried oils (ORF), both in supercritical ethanol throught non-catalic method. The experiments were carried out in a packed bead reactor operated in continuous mode. The esterification reactions were carried out under a temperature from 200 to 325ºC, pressure of 15 and 20 MPa and molar reason AO: ethanol in the range of 1:3 to 1:12. From the results on, was possible to note, that the temperature and the pressure influenced positively the conversion on the esterification reaction of oleic acid, with an income of 93, 5%, observed under 325°C and 20Mpa, in a reaction that last 40 minutes. The excess of alcohol in the reactional system didn´t provide significant differences in the conversions, with the optimum molar reason, defined in 1:6 (AO: ethanol). The transesterification reactions, were carried out with pauses of temperatures from 275 to 325ºC, pressure fixed of 20MPa, adopting the mass reason of ORF to ethanol of 1:0.5 and 1:1, varying the residence time, leading the determination of great conditions to the ethyl esters synthesis. Notable results in the alcoholysis reactions were observed at 325ºC, mass ratio of ORF to ethanol at 1:1 and residence time of 40 minutes. Using the molar ratio ORF: ethanol selected as the best suitable, was also evaluated the effect of the water addition to the reactional medium (0, 5 and10% of water relative to the ethanol mass), in order to investigate the technical viability of the use of low quality and costs of the raw materials containing water in the composition. The effect of addition of deco- hexane solvent (0, 5, 10 and 20% of hexane compared to the substrates mass), as well the effect of addition of soy bio-fuel (0, 20 and 40% of soy bio-fuel compared to substrates mass), were also investigated, in order to improve the performance of the reaction. Notable incomes were observed in the reaction with 5% of water addition and 20% of hexane. The best results related to the soy bio-fuel addition to the reactional medium were observed in the reactions carried out with 40% of soy bio-fuel, however, taking into consideration the amount of esters added to the process, the condition considered great was with 20% soy bio-fuel.. From the best conditions of the process, the kinetic daalcoholise super-critical was investigated with the reactions conducted with the residence time from 0 to 70 minutes and the notable results were: 83% in ethyl esters, obtained in 300ºC, 70 minuts of reaction, using 5% of water, 87% in ethyl esters observed in 300ºC, 70minutes of reaction, using 20% of hexane and 82% in ethyl esters obtained in 325ºC, 50 minutes of reaction, using 20% of soy bio-fuel. Lastly, the stability of the daalcoholise reactional medium was investigated. Temperatures of reaction till to 300ºC resulted in decomposition <10% with residence time of 20 minutes. However, the reactions with longer residence time, showed a higher ratio of decomposition of the constituents of the reactional medium.
O presente trabalho teve como objetivo investigar a produção de ésteres etílicos nas reações de esterificação do ácido oleico (AO) e transesterificação de óleo residual de fritura (ORF), ambas em etanol supercrítico pelo método não catalítico. Os experimentos foram realizados em um reator tubular com leito empacotado operado em modo contínuo. As reações de esterificação foram conduzidas com temperatura na faixa de 200 a 325ºC, pressão de 15 e 20 MPa e razão molar AO:etanol na faixa de 1:3 a 1:12. A partir dos resultados, foi possível observar que a temperatura e a pressão influenciaram positivamente a conversão nas reações de esterificação do ácido oleico, com rendimentos de 93,5%, observados a 325ºC e 20 MPa, em 40 minutos de reação. Já o excesso de álcool no sistema reacional não proporcionou diferenças significativas nas conversões, com a razão molar ótima, definida em 1:6 (AO:etanol). As reações de transesterificação foram conduzidas no intervalo de temperatura de 275 a 325ºC, pressão fixa de 20 MPa, adotando razão mássica de ORF para etanol de 1:0,5 e 1:1, variando-se o tempo de residência, possibilitando a determinação das condições ótimas para a síntese de ésteres etílicos. Resultados apreciáveis nas reações de álcoolise foram verificados em 325ºC, razão mássica de ORF para etanol de 1:1 e tempo de residência de 40 minutos. Utilizando a razão mássica ORF:etanol selecionada como a mais adequada, ainda foi avaliado o efeito da adição de água ao meio reacional (0, 5 e 10% de água em relação à massa do etanol), visando investigar a viabilidade técnica da utilização de matérias-primas de menor qualidade e menor custo que contenham água em sua composição. O efeito da adição de co-solvente hexano (0, 5, 10 e 20% de hexano em relação à massa dos substratos) bem como o efeito da adição de biodiesel de soja (0, 20 e 40% de biodiesel de soja em relação à massa dos substratos) também foram investigados, buscando melhorar o desempenho da reação. Rendimentos apreciáveis foram observados nas reações com 5% de adição água e 20% de hexano. Os melhores resultados referentes à adição de biodiesel de soja ao meio reacional foram observados nas reações conduzidas com 40% de biodiesel de soja, porém, levando-se em conta a quantidade de ésteres adicionada ao processo, a condição considerada ótima foi de 20% de adição de biodiesel de soja. A partir das melhores condições de processo, a cinética da álcoolise supercrítica foi investigada com reações conduzidas com tempo de residência na faixa de 0 a 70 minutos e os resultados apreciáveis foram de: 83% em ésteres etílicos, obtidos em 300°C, 70 minutos de reação, utilizando 5% de água, 87% em ésteres etílicos observados em 300°C, 70 minutos de reação, utilizando 20% de hexano e 82% em ésteres etílicos alcançados em 325°C, 50 minutos de reação, utilizando 20% de biodiesel de soja. Por fim, a estabilidade dos componentes do meio reacional da alcoólise foi investigada. Temperaturas de reação de até 300ºC resultam em decomposições <10% com tempo de residência de 20 minutos. Porém, as reações com tempos de residência mais longos, apresentaram taxas de decomposição dos constituintes do meio reacional mais elevadas.

碩士
國立中興大學
應用經濟學系所
100
The rapid growth of bio-energy production has increased derived demand on energy crops and has pushed its prices. Such development on bio-energy has functions to prevent shortage of supply of fossil fuels leads to soaring energy prices and reduce greenhouse gas emissions. The main purpose of this study is applying Vector Error Correction Model to investigate the relationships between the crude oil price, corn price and ethanol price during the period January 1986 to June 2011. Structural change issue is also taken into the consideration in this study. The empirical results show that the lagged change of corn price has significant positively affected the ethanol price while the lagged change of crude oil price has significant positively affected the ethanol price too. However the relationships between the crude oil price and corn price are not found. On the other hand, recently studies have pointed out that the production of ethanol will reduce crude oil prices and the empirical result has similarly finding. The empirical results indicate the ethanol substitution elasticity on crude oil price is 3.2146, which mean when the ethanol average consumption increased by 1 gallons can reduce the crude oil price of $ 0.3111 per gallon.

碩士
明新科技大學
企業管理研究所
97
The purpose of the study was to investigate the relationship of the prices between oil and Bio-Energy Crop. Daily future prices of New York light crude oil, Chicago corn, Chicago wheat, Chicago soybean were used as data, collected from January 4, 2000 to August 29, 2008. This thesis aims to empirically investigate the impact of the American Clean Energy and Security Act of 2004 on the prices interaction among crude oil future and the above three Bio-Energy Crop futures. Unit Roots Test, Cointegration and Granger Causality Test of statistical methods were adopted to analyze the long-term balanced trend and short-term leading and backward relationship. The results show that the oil futures and the above three Bio-Energy Crop futures were not Cointegrated, and had no cause-effect relationship before 2004. However there was Single-tasking Granger causality after 2004. It was concluded that the rise in oil prices would affect the prices of corn, wheat and soybean.

碩士
逢甲大學
環境工程與科學所
100
This study investigated the feasibility of enhanced energy yield and bio-oil production in a catalytic pyrolysis of sewage sludge by controlling different particle size (ranged between 0.3 mm and 2.0 mm) and catalysts addition ratio (0%~15%) in a batch fixed-bed system .The experiments were conducted by controlling the pyrolysis temperature at 500℃ and adding Fe/Mn sludge derived from drinking water treatment plant used as a tested catalyst. The experimental results indicated that the bio-oil production increased from 13.44 wt.% to 15.96 wt.% with an decrease in particle size of sewage sludge from 0.8~2.0 mm to 0.3~0.5 mm. Based on the results of energy density, the energy density of bio-oil was also slightly increased from 0.74 to 0.79. It can concluded that reducing particle size of sewage sludge can promote the efficiency of pyrolysis reaction and enhance the energy yield and energy density of bio-oil In the case of larger particle size range (0.8 mm~2.0 mm) and adding Fe/Mn sludge catalyst, the Fe/Mn sludge could act as a catalyst to promote the efficiency of char conversion, but also reduce bio-oil yield. This is because large amounts of gaseous products generated by the secondary pyrolysis of bio-oil. The bio-oil production decreased from 13.44 wt.% to 10.97 wt.% with Fe/Mn sludge addition increasing from 0 wt.% to 15 wt.%. However, in the case of smaller particle size range (0.3 mm~0.5 mm), the bio-oil production increased from 15.96 wt.% to 16.09 wt.% with an increase in Fe/Mn sludge addition. In addition, the energy density of bio-oil was insignificantly influenced by adding Fe/Mn sludge. In summary, in the case of larger particle size of sewage sludge, the catalyst addition effects on the bio-oil yield in catalytic pyrolysis were relatively significant. That is, in the case of smaller particle size of sewage sludge, the particle size effects on bio-oil yield more important than that of catalysts addition. According to the characteristic results of bio-oil, the H/C and O/C ratio of bio-oil were ranged from 1.48 to 1.66 and from 0.09 to 0.26, respectively. The ageing potential of the bio-oil could be higher due to the bio-oil containing higher oxygen content. The tested catalyst can reduce the viscosity of bio-oil, but also the viscosity of bio-oil decreasing with an increase in catalyst addition. In the case of 15% catalyst addition, the viscosity of light bio-oil was ranged between 491 cP and 734 cP. It can comply with current criteria of diesel fuel and fuel oil. Based on the analysis results of functional groups of bio-oil, the tested catalyst can decrease the yield of oxygenated and cyclic compounds of light bio-oil. Meanwhile, the tested catalyst could also promote cyclic compounds to convert into chain compounds of heavy bio-oil. In addition, the tested catalyst can enhance aliphatic compounds content and decrease contents of nitrogenous, oxygenated compounds and/or aromatic compounds in bio-oil. Therefore, the Fe/Mn sludge used in this research can act as a usable catalyst that it can help upgrade the bio-oil in pyrolysis of sewage sludge.

The thermal conversion of biomass to biochar has been studied for over 100 years (Laboratory et al., 1978). Over the past two decades it has gained momentum in environmental and energy research (Stavi & Lal, 2013). Concerns over climate change, poverty, declining agricultural production, fertiliser shortage, and fuel generation are all topics that biochar and bio-oils have aimed to address. Optimisation of biochar and bio-oils production, however, has received relatively little attention from a whole-of-system approach. The work undertaken in this thesis aims to address these limitations and provide a system that maximises the conversion of woody biomass to biochar and bio-oils.

Recent developments in converting biomass to bio-chemicals and liquid fuels provide a promising sight to an emerging biofuels industry. Biomass can be converted to energy via thermochemical and biochemical pathways. Thermal degradation processes include liquefaction, gasification, and pyrolysis. Among these biomass technologies, pyrolysis (i.e. a thermochemical conversion process of any organic material in the absence of oxygen) has gained more attention because of its simplicity in design, construction and operation. This research study focuses on comparative assessment of two types of pyrolysis processes and catalytic upgrading of bio-oil for production of transportation fuel intermediates. Slow and fast pyrolysis processes were compared for their respective product yields and properties. Slow pyrolysis bio-oil displayed fossil fuel-like properties, although low yields limit the process making it uneconomically feasible. Fast pyrolysis, on the other hand, show high yields but produces relatively less quality bio-oil. Catalytic transformation of the high-boiling fraction (HBF) of the crude bio-oil from fast pyrolysis was therefore evaluated by performing liquid-phase reactions at moderate temperatures using Pt/HZSM-5 catalyst. High yields of upgraded bio-oils along with improved heating values and reduced oxygen contents were obtained at a reaction temperature of 200°C and ethanol/HBF ratio of 3:1. Better quality, however, was observed at 240 °C even though reaction temperature has no significant effect on coke deposition. The addition of ethanol in the feed has greatly attenuated coke deposition in the catalyst. Major reactions observed are esterification, catalytic cracking, and reforming. Overall mass and energy balances in the conversion of energy sorghum biomass to produce a liquid fuel intermediate obtained sixteen percent (16 wt.%) of the biomass ending up as liquid fuel intermediate, while containing 26% of its initial energy.

The significance of bio fuels production is increasing as fossil fuels are being depleted and energy security is gaining importance in the final energy mix. Moreover, bio fuel production offers the potential to alleviate concerns regarding global warming and air pollution. The process scheme design and parameter value choices used in this analysis are exclusively based on research domain literature by considering the state of the art of pyrolysis technology. Henceforth, the results should not be interpreted as optimal performance of mature technology, but as the most likely performance given the current state of scientific knowledge. The purpose of this thesis is to study and assess the technical and economic models for the conversion of woody biomass to valuable biofuel products via fast pyrolysis. The mass rate of wood is considered as 100,000 t/y. Bio fuel production from pyrolysis is energy intensive process. Therefore, heat and energy requirement calculation for the process and optimum heat integration is necessary to improve the overall thermodynamic efficiencies for wood biomass pyrolysis. Three different cases are discussed in this thesis: 1. fast pyrolysis at 500 oC, 2. fast pyrolysis at 1000 oC   and 3. Slow pyrolysis at 500 oC.    Literature study was conducted for different pyrolysis processes and based on their findings and results a model was developed on excel for the calculation of mass and energy balance. Mass balance results shows that the process can be selected on the basis of final product required. It was found that fast pyrolysis at 500 oC is used when bio oil is the priority product, for maximizing the syngas yield fast pyrolysis at high temperature 800-1000 oC is preferred. Similarly slow pyrolysis is used for maximizing bio char yield. It was also found that raw material type and its pretreatment also has strong influence on the pyrolysis process and final composition of bio fuels. Heat flux and energy streams for the pyrolysis scheme are also designed and syngas was selected to fulfil the heat requirements for different processes alongside with pyrolysis such as drying and grinding. It was found out that syngas combustion and heat recovery from the condenser will be able to fulfill the heat demand for pyrolysis process. However the specific heat requirement for fast and slow pyrolysis process varies. According to the calculations heat flux requirement for slow pyrolysis is higher than the fast pyrolysis. An explanation for this variability of the heat for wood pyrolysis is exothermic primary char formation process competing with an endothermic volatile formation process which makes it as overall endothermic process. But pretreatment of wood or biomass in fast pyrolysis is extra burden on the total heat demand for fast pyrolysis. Economic assessment for the pyrolysis plants is also conducted through literature survey of already installed plants and it was found out that pyrolysis is more feasible for large production facilities. The trends shows that capital costs increase with the increase of plant size but the capital cost curve moves towards a straight line after reaching the certain value the production cost per gallon of bio fuel decreases with the increase of plant capacity. The cost of biofuel is extremely sensitive to variations in operating cost (for example, cost of feed stock such as wood and selling price of products) but is not significantly affected by the variations in capital cost.

Rising world petroleum prices and global warming are contributing to interest in renewable energy sources, including energy produced from agricultural crops and waste sources of biomass. A network of small mobile pyrolysis units may be the most cost effective system to convert biomass from agricultural feedstocks to bio-crude oil. Mobile pyrolysis units could be moved to the feedstock production fields thereby greatly simplifying feedstock logistics. In the North Central (NC) region of the U.S., possible feedstocks are corn stover, energy sorghum, and switchgrass. A grid-based Geographic Information System (GIS) program was developed to identify optimum locations for mobile pyrolysis units based on feedstock availability in the NC region. Model builder was used to automate the GIS analysis. Network analysis was used to find the best route to move the mobile pyrolysis units to new locations and to identify the closest refinery to transport the bio-crude oil. To produce bioenergy from feedstocks, the removal of biomass from agricultural fields will impact the hydrology and sediment transport in rural watersheds. Therefore, the hydrologic effects of removing corn stover from corn production fields in Illinois (IL) were evaluated using the Soil Water Assessment Tool (SWAT). The SWAT model was calibrated and validated for streamflow and sediment yields in the Spoon River basin in IL using observed data from the USGS. The modeling results indicated that as residue removal rates increased, evapotranspiration (ET) and sediment yields increased, while streamflows decreased. Biochar is a carbon-based byproduct of pyrolysis. To ensure that the mobile pyrolysis system is economically and environmental sustainable, the biochar must be land applied to the feedstock production fields as a soil amendment. An assessment of hydrologic changes due to the land application of biochar was made using the SWAT model in the Spoon River basin and changes in soil properties due to incorporation of biochar into the soil obtained from laboratory experiments by Cook et al. (2012). Model simulations indicated that a biochar application rate of 128 Mg/ha decreased water yield, and sediment yield in surface runoff and increased soil moisture and ET.

碩士
東海大學
管理碩士在職專班
96
With the weekly-data time series of crude oil spot price, and the spot prices of three kinds of bio-fuel crops, i.e. soybean, corn and wheat, as the endogenous variables, and the weekly-data time series of the U.S. dollar index as the exogenous variable, this thesis aims to empirically investigate the impact of the U.S. Energy Independence and Security Act of 2007 on the prices interaction among crude oil spots and the above three bio-fuel crops spots. All the data collected for investigation are from 01/03/2003 to 14/03/2008. The research results show that, before 2006, the crude oil spot price and the above three bio-fuel crops spot prices were not cointegrated; however, after 2006, they were cointegrated, meaning there was a long run equilibrium relationship among them. The author thinks it was the U.S. Energy Independence and Security Act of 2007 and people’s psychology of expecting the enforcement of that policy since 2006 that caused this long run equilibrium state among the above variables. By further using the Vector Error Correction Model(VECM) to analyze the short run interaction among the above variables, it is shown that, corn spot price will return to the long run equilibrium state promptly after a short run deviation from the long run equilibrium state, hinting the liquidity of corn spots seems slower than that of corn futures; while in the prices interaction among crude oil spots and bio-fuel crops spots, crude oil spot price apparently had a strong influence on the spot prices of soybean and corn, and a two-way effect between crude oil spot price and corn spot price was found; however, no evident prices interaction was found between wheat spots and crude oil spots. Interaction among the prices of soybean, corn, and wheat, was also found, whether the interaction was caused by the direct or cross effect of price variation of the previous periods of respective variables; it was found that soybean spot price has the highest effect, and next comes with wheat. In addition, the continued depreciation of U.S. dollar during the period investigated was the main reason that caused the uprising of soybean and wheat spot prices. The analysis results of impulse response functions show that after 2006, the impulse responses of the price rates of return of all the above variables descended quickly to zero within 2 to 3 periods(weeks), indicating a strong relationship of short run error correction among the price rates of return of all the above variables. Lastly, the analysis results of the forecasted variance decomposition show that after 2006, the price rates of return of soybean spots and crude oil spots had more power in self explanation, with a level of more than 90%; the exogeneity of the price rates of return of corn spots and wheat spots was relatively weaker; the price rate of return of crude oil spots was accounted by the price rates of return of soybean spots and corn spots to the extent with 1.62% and 4.28% respectively, indicating that the effect of adopting corn-based bio-fuel as an alternative of crude oil was higher than that of soybean-based bio-fuel.

The potential use of enzymes in industrial synthesis of epoxidized soybean oil has been limited through the high cost of the enzyme catalyst, in this work we evaluate the effectiveness of chemo enzymatic epoxidation of high oleic soybean oil (HOSBO) using lipase B from Candida antarctica (CALB) on immobilization support Immobead 150 and H₂O₂ in a solvent-free system. Additionally, we evaluated the production decay rates for hydrolytic activity and epoxide product formation over consecutive batches to determine half-life of the enzyme catalyst.

Batch epoxidation of HOSBO using CALB on 4wt% loading shows yields higher than 90% after 12 hrs. of reaction, and with a correlation to the consumption of double bonds suggesting that the reaction is selective and limiting side product reactions. Non-selective hydrolysis of oil was not found beyond the initial hydrolysis degree of raw HOSBO. Evaluations of decay given by epoxide product formation and released free fatty acids shows a half-life of the enzyme catalyst on these activities is of 22 ad 25 hrs. respectively. Finally, we evaluated the physical parameters influencing this decay, and found that H₂O₂ presence is the most important parameter of enzyme inactivation with no significant effect from its slowed addition. We propose a new reactor configuration for the analysis of the specific steps on epoxide formation through peracid intermediates.