Thesis (Ph. D.)--University of Washington, 1996. / Vita. Includes bibliographical references (leaves [149]-161).

Thesis (Ph. D.)--University of Oulu, 1988. / Includes bibliographical references (p. [65]-78).

The study introduces and demonstrates the viability of the continuous flow reactor (CFR) system for the production of bio-crude oil (BCO) from wet microalgae. Preliminary experiments conducted in the CFR system in hot compressed water (HCW) were successful in converting wet microalgae into liquid BCO. However, the synthesis and aggregation of high boiling point (HBP) components of BCO and the accumulation of char in the tubular piping of CFR system were identified as the limiting factor to the viability of the system. The aggregation of HBP components and the accumulation of char result to system blockage which prevents the continuous flow of the liquefaction product mixture in the CFR system. Inhibiting the reactions leading to the formation of HBP components and char will improve the performance of the CFR system. Therefore, the study seeks to incorporate co-solvents in the liquefaction reaction media in an attempt to inhibit or minimize the prevalence of HBP components of BCO. As such, different co-solvents were screened for their influence on improving the quality of BCO with respect to its boiling point profile (BPP), initial and final boiling point, as well as the amount of char recovered from each experiment. Only one co-solvent was chosen for further exploration in the CFR system. Batch liquefaction reactor’s (BLR) made up of stainless steel were used to carry out the co-solvent screening experiments. These experiments were carried out at a constant temperature (280 °C), pressure (75 bar), and co-solvent concentration (10 wt.%), at varying residence times. Solvent extraction with dichloromethane (DCM) was performed on the liquefaction product mixture to separate the products, viz. BCO, char and water soluble components. The extracted BCO was analysed through simulated distillation (SimDis) to obtain the BPP. The BPP properties of the BCO samples, from different liquefaction media, and the amount of char recovered were highly influenced by the addition of a co-solvent. The final boiling point (FBP) of tetralin, heptane, and n-octanol BCO products were significantly reduced to below 500 °C for all tested residence times except at 20 minutes. The residence time also proved to be influential in the processing of wet microalgae. n-Octanol was selected as the optimal performing co-solvent and was used for the continuous liquefaction of wet microalgae in the CFR system. The CFR system was modified by adding a co-solvent feed line into the continuous system since n-octanol was insoluble in water. The n-octanol pump was set at different flow rates, 0.2, 0.3, and 0.4 g/min, which resulted in a concentration of about 10 wt.% in the reactor feed. The concentration of n-octanol had a significant influence on the BPP of BCO components. The FBP’s were reduced with an increase in n-octanol concentration. The initial boiling point (IBP) of n-octanol BCO was increased to just above 100 °C which was required for the stability of the BCO product. The components of BCO were identified by GCMS. n-Octanol also proved to affect the composition of the BCO with respect to its components. HCW BCO components were significantly different from those identified from n-octanol BCO. A second co-solvent (tetralin) was used to prove whether the difference on the components of BCO was affected by n-octanol. The results proved that indeed the addition of different solvents in liquefaction reaction media favours the formation of different components. The amount of char formed was also reduced when using a co-solvent. A decrease in the oxygen/nitrogen compounds was also observed in the presence of a co-solvent, thus improving BCO properties.

Thesis--Auburn University, 2009. / Abstract. Vita. Includes bibliographical references (p. 65).

The batch distillation of crude wood oil by direct liquefaction was studied; azeotropic distillations and some characterization were also performed. It was found that 26-33 percent of the crude wood oil could be distilled by simple batch vacuum distillations with pressures from 50-300 mm Hg. With the use of ethylene glycol and glycerol 29-85 percent more oil was distilled partly due to the azeotrope formed which allows the oil to boil at a reduced pressure. The water liberated and the polymerization which took place during the distillations were studied. It was found that fluid catalytic cracking bottoms eliminates polymerization when it is co-distilled with the crude wood oil. A novel scheme for the separation of the phenolic fraction by azeotropic distillation is presented.

There are many problems associated with the use of fossil fuels to produce fuels and chemicals, and lignocellulosic biomass stands as a promising alternative fuel/chemical feedstock. Large scale processing of biomass will likely take place in high temperature liquid water due to the low vapor pressure and polar nature of carbohydrates. However, little is known about the material stability of these catalysts in high temperature aqueous phase environments. This dissertation aims to investigate the structural integrity of some common catalytic materials under typical biomass reforming conditions. There are 3 main objectives of this study: 1) identify potentially stable candidates from commonly used materials, 2) understand the mechanism(s) by which these catalysts degrade, 3) design/modify catalysts in an effort to increase their hydrothermal stability. The two main materials investigated in this work are zeolites (faujasite, ZSM-5) and γ-Al2O3 as these are commonly used as catalysts and catalyst supports. A number of physicochemical techniques were used to characterize the materials as a function of treatment time at conditions relevant for biomass reforming. For zeolites, the major findings are that ZSM-5 framework is highly stable whereas faujasite stability depends on the Si/Al ratio, where silicon rich materials are less stable. For γ-Al2O3 based catalysts, it was found that the alumina support hydrates and undergoes a phase transformation to form crystalline boehmite (AlOOH) with a subsequent loss in surface area and Lewis acid sites. When metal particles are present on the support, the phase change kinetics are slowed. The role of metal precursor on the stability of γ-Al2O3 supported catalysts was also explored, and it was found that the precursor used in catalyst synthesis changes the boehmite formation kinetics and also affects alumina support dissolution. The final thrust aims to stabilize a Pt/γ-Al2O3 catalyst by depositing silicon on the catalyst surface. The silicon modification is effective in protecting the catalyst from boehmite formation upon exposure to hot liquid water while also stabilizing metal particles against sintering. Additionally, an increase in turnover number for hydrogen production via aqueous phase reforming of sorbitol was observed.

No description available.

Live green microalgae Chlorella pyrenoidosa was introduced in the anode of microbial fuel cell (MFC) to act as an electron donor. The electrogenic capability of algae Chlorella pyrenoidosa was investigated in two models of algal microbial fuel cells (MFCs) constructed with carbon electrodes and no mediator. The mechanism was studied by results of ATP inhibitor (Resveratrol) and protonophore (2, 4-dinitrophenol), which supporting the important role of mitochondria in electricity generation. The results of different light intensity and algae concentration indicate that low concentration of 106 (OD680nm) and low light intensity (2500 Lux) generated higher electricity. In the oxygen controlled study, it was found that oxygen generated by algae in anode was a limiting factor for electricity generation. Electricity generation was observed in two chamber algae MFC lasting at least for 24 hours. Results might provide a platform for the development of self-sustainable algal culturing microbial fuel cell (MFC). Electricity was found to increase in response to 4-nitrophenol (4NP) and 4-nitroanaline (4NA) for both measurements of current and open circle voltage (OCV). The positive response of algae to 4NP in increasing the 4NP production and electricity generation in MFC proposed the possible application in the detection of E.coli, as 4NP is involved in the intermediate step of the detection process. Results indicate Algae MFC was suitable for the detection of E. coli. of concentration higher than 106 using OCV measurement. Keywords: Electricity generation, Chlorella pyrenoidosa, Microbial fuel cell.

This thesis examined the conversions of biomass and biomass components to petrochemicals and total aliphatic gasoline like products. There are three major projects of the thesis. Since biomass is very complicated, to understand the thermal decomposition pathways of biomass, the pyrolytic behaviors of various biomass components including lignin and cellulose under different reaction were investigated in the first phase. Due to complexity and limited volatility, the thermal decomposition products from biomass bring insurmountable obstacles to the traditional analysis methods such as GC-MS, UV and FT-IR. Therefore, precise characterization of the whole portion of thermal decomposition products has significant impacts on providing insight into the pyrolysis pathways and evaluating the upgrading processes. Various NMR methods to characterize different functional groups presented in liquid and solid pyrolysis products by 1H, 13C, 31P, 2D-HSQC and solid state 13C-NMR were introduced in the second phase. Nevertheless, the major drawback towards commercialization of pyrolysis oils are their challenging properties including poor volatility, high oxygen content, molecular weight, acidity and viscosity, corrosiveness and cold flow problems. In situ upgrading the properties of pyrolysis oils during thermal conversion process by employing zeolites has been discussed in the third phase. The further hydrogenation of pyrolysis oils to total aliphatic gasoline like products by heterogeneous catalysis in “green medium” – water has also been examined in the third project.

Orientador: Fernando Luis Fertonani / Coorientador: Iêda Aparecida Pastre Fertonani / Banca: Hernane da Silva Barud / Banca: Marcelo de Freitas Lima / Resumo: O Brasil é líder na produção de cana-de-açúcar e a cada ano o setor vem crescendo e buscando novas formas para diversificar a planta de produção. Tal fato que o nome da indústria evoluiu de sucroalcooleira para sucroenergéticas devido à importância da co-geração de energia a partir da queima do bagaço nas caldeiras. A bioeletricidade de cana-de açúcar caminha a passos constantes e segue com vários projetos pelo país, devido as usinas estarem próximas dos centro e distribuição/consumo. Outra empresa que busca esta diversificação da sua planta são as industrias de papel e celulose, principalmente dos seus rejeitos (lignina). Este trabalho tem como objetivo extrair lignina diferentes variedades de cana-de-açúcar para identificar a variedade que tem melhor rendimento na extração da lignina e rendimento energético, comparar com o bagaço misto (mistura de várias variedades) e por fim desenvolver imunossensores por meio da reação entre antígenos e anticorpos sobre superfícies condutoras de nanografite a partir da mistura de lignina de bagaço de cana e lignina Kraft. A grande questão é a aplicação eletroquímica com o desenvolvimento de imunossensores devido a alta sensibilidade e principalmente pelo baixo custo e utilização em área clínica. A partir do presente estudo pode-se inferir que a variedade SP83-2847 possui o maior rendimento na extração da lignina, já em relação a perda calorífica a variedade SP84-1431 obteve o maior valor e a RB86-7515 o menor. Após a extração da lignina o bagaço resultante contento celulose e hemicelulose apresentou ser mais estável termicamente. As Técnicas de Raios-x e infravermelho confirmaram a extração da liginina, além de demostrar que existe resquício da fração de celulose e hemicelulose na lignina extraída e que o mesmo ocorre quando extraímos a lignina, uma fração fica na celulose... / Abstract: Brazil is a leader in sugarcane production, growing each year and looking for new ways to diversify the plant production. By the way, the industries names evolved from sugar and alcohol to sugar and energy due to its importance in energy cogeneration from bagasse burning in boilers. The cane bioeletricity walks in constant steps and continues with various projects around the country, because the plants are close downtown and distribution and consumption centers. Another company seeking this diversification of the plant are the industries of pulp and paper especially its residues (lignin). This project aims to extract lignin from different varieties of sugarcane to identify the the best performer in the extraction and energy efficiency compared with the mixed bagasse sample (mixture of several varieties) and finally develop immunosensors through the reaction between antigens and antibodies on conductive nanographite surfaces from Kraft lignin and bagasse's lignin mixture. The great question is the development of immunosensors due to high sensitivity and especially the applicability in the clinical area. From this study it can infer that the SP83-2847 variety has the highest extraction yield of lignin, as compared to loss heat the variety SP84-1431 obtained the highest value and the lowest was the RB86-7515. After lignin extraction, the resulting residue containing cellulose and hemicellulose showed to be more thermally stable. XRD and FTIR results confirmed lignin extraction and demonstrated that there is remnant cellulose and hemicellulose fraction of extracted lignin and the same occurs when we extract lignin, a fraction remains in cellulose. The electrode constructed from the composite kraft lignin-nonographite modified with copper showed electrochemical activity, mechanical stability and electrochemistry. These were applied to investigate uric acid in simulated blood ... / Mestre