The development of forest-based biorefineries has the potential to both provide a source of sustainable, low carbon fuel and increase the value drawn from wood residues to help revitalize the forest sector. There has been significant progress toward developing forest biorefining technologies, supported to some extent through government programs, though there are still several barriers to development. Realization of commercial-scale facilities however, will likely be limited by logistical constraints associated with maintaining a consistent supply of woody feedstock and the high capital cost of constructing the facility. To address this issue, mill clusters with sufficient processing capacity were located and evaluated for their suitability to house a forest biorefinery. Existing single-entity mill clusters in Canada were identified according to a set of criteria, and provide the basis for the analysis to determine feedstock supply costs and potential availability. The optimal biorefinery sites within each cluster were identified using a transportation module developed for this study and evaluated according to other factors that would affect the suitability of the site for a large scale forest biorefinery, such as access to markets, other available feedstocks and energy sources. There were four mill clusters identified in eastern Canada that have the potential to support a commercial forest biorefinery. A facility that is centrally located within one of the identified clusters would expect to have a feedstock cost ranging from approximately $95 to $110 per odt. A series of key informant interviews were carried out to further assess the cluster approach to forest biorefinery development. Interviewees generally agreed that the identified locations could potentially support a commercial biorefinery and suggested there are currently significant volumes of underutilized wood in these regions. Forest biorefinery development in the cluster regions, especially where there is mixed forest, should be further pursued. / Thesis (Master, Geography) -- Queen's University, 2013-12-30 17:39:57.326

Doctor of Philosophy / Department of Biological & Agricultural Engineering / Lisa R. Wilken / Microalgae are a potential feedstock for renewable and sustainable bioproducts and energy but there are significant scientific and engineering challenges to address before widespread acceptance of this platform. In particular, biorefining microalgae serves to maximize biomass valorization and minimize waste to improve process economics. The overall goal of this dissertation was the development of a biological-based microalgae biorefinery to enhance the economic feasibility of Chlamydomonas reinhardtii as a source of multiple products including native proteins and lipids. Specific objectives included accumulating biomass enriched in target biomolecules and determining processing strategies that eliminated the need to dry biomass, employed mild conditions to maintain extractability and quality, and minimized application of petroleum-derived and toxic solvents during extraction. The microalgae biorefinery developed included biomolecule accumulation, biomass harvesting, and targeted enzymatic degradation of the cell wall and organelles for release of native proteins and lipids. Biomass was cultivated, and kinetic studies indicated that 48 h nitrogen deprivation was adequate for protein and lipid accumulation. Four lytic enzymes were screened for their ability to permeate the C. reinhardtii cell wall and the C. reinhardtii-produced enzyme, autolysin, led to >85% cell disruption. TEM imaging confirmed cell disruption and retention of lipid droplets in organelle remnants indicating that protein, lipids, and starch could be distinctly partitioned and recovered. A design of experiments optimization study determined that incubation of disrupted biomass at pH 12 for 4 h at 45°C resulted in up to 65% of total protein released from disrupted biomass followed by 40-50% protein recovery with isoelectric precipitation. The cell disruption and protein extraction steps were subsequently integrated to minimize unit operations, processing time, and energy inputs. Secondary application of trypsin led to release of ~73% of total lipids (enriched in triacylglycerols) from the disrupted biomass. Characterization by thin layer chromatography and GC-FID of released lipids revealed similar profiles of enzymatically released lipids as compared to those released by conventional extraction procedures. Finally, the composition of released lipids indicated favorable combustion behavior, high oxidation stability, and suitability as biodiesel. The developed biological-based biorefinery is a promising step towards adoption of microalgae as a source of bioproducts to provide energy and food to meet the needs of a growing population. The second focus of the work was mitigation strategies for isolation of critical impurities (or potential co-products) while processing microalgae and plant hosts. Specific emphasis was placed on evaluating the impact of proteases, polysaccharides, phenolic compounds and pigments, phytic acid, and host cell proteins on the processing of microalgae and other plant hosts for extraction, recovery, and purification of therapeutic proteins. This review served as evaluation of the broader implications of application of the biorefinery to transgenic microalgae and other plants.

The main objective of this study was to investigate two of the possible exploitation routes of anaerobic digestion (acid-phase and methane-phase) for the treatment of sugar-beet processing wastes, while producing valuable biobased products. For this purpose, four sets of laboratory experiments were carried out in a stepwise fashion: First, in the biochemical methane potential (BMP) assay (Set-up 1) wastewater and beet-pulp were efficiently digested (63.7&ndash / 87.3% COD removal and 69.6&ndash / 89.3% VS reduction) in batch anaerobic reactors. Secondly, wastewater and beet-pulp could simultaneously be converted to VFAs in acidogenic anaerobic reactors with considerable acidification degrees (43.8&ndash / 52.9%), optimizing the operational conditions (Set-up 2). Then, the produced VFAs were recovered by liquid-liquid extraction (Set-up 3), in which highest VFA recoveries (60.7&ndash / 97.6%) were observed at 20% trioctylphosphine oxide (TOPO) in kerosene with KD values ranging between 1.54 and 40.79 at pH 2.5. Finally, methane-phase anaerobic digestion was evaluated in two different reactor configurations, namely fed-batch continuously mixed reactor (FCMR) and anaerobic sequencing batch reactor (ASBR) (Set-up 4). Methane production yield of 255 &plusmn / 11 mL/g COD-added was increased to 337 &plusmn / 15 mL/g COD-added (32.2% increase in methane yield) when configuration was changed from FCMR to ASBR. In addition, tCOD removal was increased from 68.7 &plusmn / 2.2 to 79.7 &plusmn / 1.1%. Based on the result obtained in this study, it is postulated that, biorefining of sugar-beet processing wastes by anaerobic digestion can not only be a solution for environmental related problems, but also contribute to resource conservation and sustainable production via valuable bio-based product formation.

No description available.

The development of a biorefining process acknowledges the feedstock characterization as it can often dictate the process technology. The maturity stages of agricultural feedstocks also have the potential for altering the process conditions. Thus, the variability of growth stages at 4-6 leaf, flowering, milk and soft dough were assessed for use of immature cereal crops in a green biomass biorefinery. Hence, the primary objective of this project was to evaluate the composition of green biomass at different harvest stages. Four varieties of triticale, two wheat varieties and two rye varieties were analyzed for starch, protein, phenols, fatty acids and sterols. To further characterize the feedstocks, an alternate extraction strategy was explored based on solvent polarity. It was found that for triticale varieties, the milk to soft dough harvest stages showed a decrease in proteins and phenols content and an increase in starch content. This could potentially provide benefit to organic acid production through fermentation. / Bioresource and Food Engineering

Biofuels have been identified as one of several GHG emission strategies to reduce the use of fossil fuels in the transport sector. Fast pyrolysis of biomass is one approach to producing second generation biofuels. The bio-oil product of fast pyrolysis can be upgraded into essential gasoline and diesel range products with conventional refinery technologies. Thus, it is important to assess their techno- economic and environmental performance at an early stage prior to commercialisation. This research was conducted with the goal of evaluating and comparing the techno-economic and environmental viability of the production of biofuels from fast pyrolysis of biomass and upgrading of bio-oil via two refinery technologies, viz. hydroprocessing and zeolite cracking. In order to achieve this aim, process models of fast pyrolysis of biomass and bio-oil upgrading via hydroprocessing and zeolite cracking were developed. The fast pyrolysis model was based on multi-step kinetic models. In addition, lumped kinetic models of the hydrodeoxygenation reactions of bio-oil were implemented. The models were verified against experimental measurements with good prediction and formed the foundation for the development of a 72 t/day fast pyrolysis plant model in Aspen Plus®. Several strategies were proposed for the two pathways to enhance energy efficiency and profitability. All in all, the results revealed that the hydroprocessing route is 16% more efficient than the zeolite cracking pathway. Moreover, the hydroprocessing route resulted in a minimum fuel selling price of 15% lower than that from the zeolite cracking pathway. Sensitivity analysis revealed that the techno-economic and environmental performance of the both pathways depends on several process, economic and environmental parameters. In particular, biofuel yield, operating cost and income tax were identified as the most sensitive techno-economic parameters, while changes in nitrogen feed gas to the pyrolysis reactor and fuel yield had the most environmental impact. It was concluded that hydroprocessing is a more suitable upgrading pathway than zeolite cracking in terms of economic viability, energy efficiency, and GHG emissions per energy content of fuel produced.

I världens omvandling mot en bioekonomi kommer lignocellulosa material spela en stor roll i ersättningen av fossila resurser. Lignin är den mest tillgängliga källan av förnybara och naturligt förekommande aromatiska ämne och den utgör 15–30% av ved. Det lignin som är för nuvarande tillgängligt i marknaden är begränsat i sina appliceringar på grund av ämnets komplexa och outforskade kemisk struktur. I ett försök att bidra till ’lignin-först’ bioraffinaderi konceptet, undersöker detta arbete effekten av urea och karboxymetylering som förbehandlingsmetoder på utbyte av lignin såväl som de kemiska och fysiska egenskaperna av lignin. Karaktäriseringstekniker som Fourier-transform infra-red och nuclear magnetic resonance spectroscopy används för att analysera den kemiska strukturen av ligninet efter extraktion. Det resulterade i att båda förbehandlingsmetoder ökade utbytet av lignin med mellan 1% och 16%. Urea förbehandlingen hade ingen effekt på den kemiska strukturen av varken fibrer eller lignin. Men, karboxymetylering förbehandlingen ändrade i kemiska strukturen av lignin genom att lägga till karboxymetyl-grupper i både den alifatiska och den fenoliska regionen. Medans att öka förbehandlingstiden ökade utbyte i båda förbehandlingsmetoder, hade detta effekten att minska mängden kvantifierbara bindningar mellan enheterna för karboxymetylering förbehandlingen. Dessa diskuterade metoder har potential att användas i valorisering av lignin. / In the world’s transformation towards a bioeconomy, lignocellulosic biomass plays a key role as a substitute for fossil-based resources. Lignin is the most abundant source of renewable and naturally occurring aromatics and it constitutes 15-30% of lignocellulosic biomass. The technical lignin currently available on the market is limited in its applications because of its complex and poorly understood chemical structure. To contribute to the lignin-first biorefinery concept, this work investigates the effect of urea and carboxymethylation pretreatments on the yield as well as the chemical and physical properties of lignin. Characterization techniques such as Fourier-transform infra-red and nuclear magnetic resonance spectroscopy were utilized to analyze the molecular structure of the lignin product after extraction. It was shown that both pretreatment methods resulted in higher yields between 1% and 16%. The urea pretreatment had no effect on the chemical structure of the fibers nor the lignin. However, carboxymethylation altered the chemical structure of the lignin by adding carboxymethyl groups in both the aliphatic and phenolic regions. While increasing the pretreatment time increased the yield for both pretreatment methods, in the case of carboxymethylation it reduced the amount of quantifiable inter-unit linkages. Overall, the pretreatment methods discussed have potential use for lignin valorization.

Increasing demand for energy and transportation fuel has motivated researchers all around the world to explore alternatives for a long-term sustainable source of energy. Biomass is one such renewable resource that can be converted into various marketable products by the process of biorefining. Currently, research is taking strides in developing conversion techniques for producing biofuels from multiple bio-based feedstocks. However, the greatest concern with emerging processes is the long-term viability as a sustainable source of energy. Hence, a framework is required that can incorporate novel and existing processes to validate their economic, environmental and social potential in satisfying present energy demands, without compromising the ability of future generations to meet their own energy needs. This research focuses on developing a framework that can incorporate fundamental research to determine its long-term viability, simultaneously providing critical techno-economic and decision support information to various stakeholders. This contribution links various simulation and optimization models to create a decision support tool, to estimate the viability of biorefining options in any given region. Multiple disciplines from the Process Systems Engineering and Supply Chain Management are integrated to develop the comprehensive framework. Process simulation models for thermochemical and biochemical processes are developed and optimized using Aspen Engineering Suite. Finally, for validation, the framework is analyzed by combining the outcomes of the process simulation with the supply chain models. The developed techno-economic model takes into account detailed variable costs and capital investments for various conversion processes. Subsequently, case studies are performed to demonstrate the applicability of the decision support tool for the Jackson Purchase region of Western Kentucky. The multidisciplinary framework is a unique contribution in the field of Process Systems Engineering as it demonstrates simulation of process optimization models and illustrates its iterative linking with the supply chain optimization models to estimate the economics of biorefinery from multi-stakeholder perspective. This informative tool not only assists in comparing modes of operation but also forecasts the effect of future scenarios, such as, utilization of marginal land for planting dedicated energy crops and incorporation of emerging enzymatic processes. The resulting framework is novel and informative in assisting investors, policy makers and other stakeholders for evaluating the impacts of biorefining. The results obtained supports the generalizability of this tool to be applied in any given region and guide stakeholders in making financial and strategic decisions.

La création de nouvelles enzymes pour l’hydrolyse de la biomasse est une stratégie clé pour ledéveloppement du bioraffinage. Dans ce contexte, les xylanases de la famille GH11 sont déjàdéployées dans de nombreux procédés industriels et donc bien positionnées pour jouer un rôleimportant dans ces procédés. La cible de cette étude, la xylanase GH11 (Tx-Xyl) de la bactérieThermobacillus xylanilyticus, est une enzyme thermostable et donc une bonne candidate pour destravaux d’ingénierie visant l’amélioration de son activité sur des substrats ligno-cellulosiques.Dans cette étude, deux stratégies d’ingénierie des enzymes ont été employées afin d’obtenir denouvelles informations portants sur les relations structure-fonction au sein de Tx-Xyl. La premièrestratégie a consisté en l’utilisation d’une approche de mutagenèse aléatoire, couplée à l’emploi deméthodes de recombinaison in vitro. Ces travaux avaient pour objectif d’améliorer la capacitéhydrolytique de Tx-Xyl sur la paille de blé. La deuxième stratégie mise en oeuvre s’est appuyée surune approche semi-rationnelle visant la création d’une enzyme chimérique, qui bénéficierait d’uneamélioration des interactions enzyme-substrat au niveau du sous-site -3.Le premier résultat majeur de cette thèse concerne le développement d’une méthode de criblagequi permet l’analyse à haut débit de banques de mutants pour la détection de variants quiprésentent une activité hydrolytique accrue directement sur paille de blé. A l’aide de ce crible, nousavons pu analyser plusieurs banques de mutants, représentant un total de six générations demutants, et identifier une série de combinaisons de mutations différentes. D’un côté, un variant,comportant deux mutations silencieuses, permet une meilleure expression de Tx-Xyl, alors qued’autres enzymes mutées présentent des modifications intrinsèques de leurs aptitudes catalytiques.Comparés à l’enzyme parentale Tx-Xyl, certains mutants solubilisent davantage les arabinoxylanes dela paille et, lorsqu’ils sont déployés avec un cocktail de cellulases, participent à une réactionsynergique qui permet un accroissement du rendement des pentoses et du glucose libérés.A l’aide d’une approche semi-rationnelle, une séquence de 17 acides aminés en provenance d’unexylanase GH11 fongique a été ajoutée à l’extrémité N-terminale de Tx-Xyl, afin de créer de nouveauxbrins β. L’enzyme chimérique a pu être exprimée avec succès et caractérisée. Néanmoins, l’analysede ses propriétés catalytiques a révélé que celle-ci ne présente pas davantage d’interactions avec sonsubstrat dans le sous-site -3, mais les résultats obtenus fournissent de nombreux renseignements surles relations structure-fonction au sein de l’enzyme. De plus, ces travaux nous permettent depostuler que Tx-Xyl posséderait un site de fixation secondaire pour les xylanes, un élement jusqu’iciinsoupçonné dans cette enzyme. Par ailleurs, l’analyse de nos résultats nous permet de proposer uneexplication rationnelle pour l’échec de notre stratégie initiale / Engineering new and powerful enzymes for biomass hydrolysis is one area that will facilitate thefuture development of biorefining. In this respect, xylanases from family GH11 are already importantindustrial biocatalysts that can contribute to 2nd generation biorefining. The target of this study, theGH11 xylanase (Tx-Xyl) from Thermobacillus xylanilyticus is thermostable, and is thus an interestingtarget for enzyme engineering, aiming at increasing its specific activity on lignocellulosic biomass,such as wheat straw. Nevertheless, the action of xylanases on complex biomass is not yet wellunderstood, and thus the use of a rational engineering approach is not really feasible.In this doctoral study, to gain new insight into structure-function relationships, two enzymeengineering strategies have been deployed. The first concerns the development of a randommutagenesis and in vitro DNA shuffling approach, which was used in order to improve the hydrolyticpotency of Tx-Xyl on wheat straw, while the second strategy consisted in the creation of a chimericenzyme, with the aim of probing and improving -3 subsite binding, and ultimately improvinghydrolytic activity.The first key results that has been obtained is the development of a novel high-throughputscreening method, which was devised in order to reliably pinpoint mutants that can better hydrolyzewheat straw. Using this screening method, several generations of mutant libraries have beenanalyzed and a series of improved enzyme variants have been identified. One mutant, bearing silentmutations, actually leads to higher gene expression, while others have intrinsically altered catalyticproperties. Testing of mutants has shown that some of the enzyme variants can improve thesolubilization of wheat straw arabinoxylans and can work in synergy with cellulose cocktails torelease both pentose sugars and glucose.Using a semi-rational approach, 17 amino acids have been added to the N-terminal of Tx-Xyl, withthe aim of adding two extra β-strands coming from a GH11 fungal xylanase. A chimeric enzyme hasbeen successfully expressed and purified and its catalytic properties have been investigated.Although this approach has failed to create increased -3 subsite binding, the data presented revealsimportant information on structure-function relationships and suggest that Tx-Xyl may possess ahitherto unknown secondary substrate binding site. Moreover, a rational explanation for the failureof the original strategy is proposed.