Lignin is the second most abundant biopolymer on Earth, right after cellulose, with a highly complex chemical structure that hinders its possible utilizations. Applications that utilize lignin in different manners are of great interest, due to its inexpensive nature. Present work is based on the notion of converting lignin into different biofuels that have only a few, however important, advantages over lignin as a direct energy source. The first part of current work (pyrolysis) details the analysis of lignin from a relatively new lignin isolation process called LignoBoost. It is obtained from the pulp and paper industry via CO₂ precipitation of lignin from black liquor (BL). This method is environment friendly, results lignin with minimal oxidation, eliminates the main bottleneck of the Kraft cycle (recovery boiler capacity), and yet leaves enough lignin in the process stream to recover pulping chemicals and generate energy for the pulp mill. Pyrolysis had converted this lignin into bio-oil with high aliphatic content and low oxidation level, all advantageous for application as liquid fuel. The second part of this dissertation proved the theory that lignin degradation and lipid accumulation metabolic pathways can be interconnected. Gram-positive Rhodococcus opacus species, DSM 1069 and PD630 were used to evaluate lignin to lipid bioconversion, starting with ethanol organosolv and Kraft lignin. This conversion is a first step in a multistep process towards biodiesel production, which includes transesterification, after lipids are extracted from the cells. Results clearly indicated that the lignin to lipid bioconversion pathway is viable, by cells gaining up to 4 % of their weight in lipids, while growing solely on lignin as a carbon and energy source.

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.

No description available.

<p>Lignocellulosic biomass represents an important renewable resource for biofuels production. Lignocellulosic biomass is comprised of cellulose, hemicellulose and lignin. Lignocellulosics are highly recalcitrant to enzymatic degradation and due to its complex nature a range of enzymes are required to synergistically hydrolyse biomass. Many microorganisms are capable of producing these enzymes as part of their hemicellulolytic hydrolysis system(s). The aim of this study was the characterisation of a thermophilic actinobacterial isolate (ORS10), capable of producing hemicellulosic enzymes, and the cloning and characterization of a hemicellulosic enzyme produced by the isolate. Phylogenetic analyses clustered ORS10 with species of the genus Streptomyces. BLAST analysis revealed that ORS10 was most closely related to Streptomyces achromogenes (99% identity). A small-insert genomic library was constructed and a putative acetylxylan esterase (AXEase) gene, axe10, was identified. The enzyme, Axe10, has moderate similarity to &alpha / /&beta / hydrolase proteins, and contains an esterase/lipase superfamily conserved domain and a typical AXEase catalytic triad. The axe10 gene was sub-cloned into an expression vector [pET21a(+)] and a 28.7 kDa protein with demonstrated AXE activity was purified from E. coli Rosetta (DE3) pLysS. Axe10 displayed optimum activity at 37oC and pH 7.0. Despite being derived from a thermophilic Streptomyces species Axe10 was not thermostable. However, given the relative novelty of Axe10, further characterisation and assessment of this enzyme is warranted.</p>

Algae are primary producers in aquatic ecosystems and are thus the most important organisms in maintaining ecosystem functioning and stability. The usage of algae by humans is quite extensive; they act as an ingredient in aquaculture feed, a potential biomedical resource, as a fertiliser and as a nutritional source. Recently, algae have been identified as a third generation biofuel feedstock for fuel generation which essentially means that algae are more efficient, net carbon neutral and have less impacts on the environment. Algae as organisms are extremely sensitive to changes in the immediate environment. The interaction of parameters with each other causes minute changes in the environment which may alter the algae biomass present and the lipids that can be extracted from the biomass. The focus of this study is to model and determine which conditions maximise algal biomass and the subsequent lipids that can be extracted from the biomass. This will allow biofuel producers to understand which conditions are the best for harvesting algae in artificial conditions or harvesting algae from the wild. Furthermore, the model developed has broad application for biofuel specialists, pollution remediation specialists and biologists. This model developed is able to determine the present state of the algal bloom and uses the present state to predict the future state of bloom hence determining the optimal conditions to harvest. The model was developed under optimal ranges described by the Food and Agriculture Organisation (FAO) and designed to replicate the most common combinations of parameters present in the wild. For the purposes of this study, various combinations of parameters within their optimal ranges that is temperature (18 – 24°C), salinity (20 – 24 p.p.t.) and photoperiod (25 – 75% light exposure) were assessed. The model was run for 72 hours with sampling every 6 hours. Every six hours, algal growth was measured by the biomass present (chloro-pigments used as estimators); this was done by fluorescence. Lipids were then extracted from algal biomass using the Bligh and Dyer method (1959). Spline curves were fitted to the data and analysis performed using Mathematica 8.0. It was found that photoperiod was the most important variable in controlling algal growth. Furthermore, lipids extracted from biomass were at their highest when algae were exposed to the conditions 75% light exposure, 21°C and 22 p.p.t. These conditions would allow for the highest amount of biofuel to be produced. Generally, algae biomass trend graphs mimic lipid trend graphs over the 72 hour period that is when lipids are at their maximum, biomass concentrations are at their maximum. It can be concluded from time model that the best time to harvest biomass is 48 hours from the initial start time of algal growth to gain the highest amount of lipids for biofuel production. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2012.

Fossil fuels continue to deplete with use as they are irreplaceable. In addition, the environmental impact with the continuous use of these conventional fuels has generated global concern due to the production of harmful emission gases. An alternative source of energy has become inevitable. Technological advancements in the area of biomass use for both aviation and power generation are at different levels of development. There is however the need for an integrated approach to assess gas turbine engine behaviour in terms of performance, emission and economics when they are running on biofuels. The current research work is concerned with finding alternative fuel resources for use on stationary gas turbine engines for power generation with the necessary identification of suitable biofuels using a multidisciplinary approach. A techno-economic, environmental and risk assessment (TERA) model comprising the performance, emissions, economics and risk modules has been developed. There had been several simulations of two gas turbine engines (GTEs) to ascertain the effects of both ambient and operating conditions and the effect of fuel types on the engines. These simulations were done with the use of an in-house code-the Turbomatch and a code developed for the steam cycle which is employed for the combined cycle simulation. Cont/d.

Lignin, a byproduct of the chemical pulping can be gasified to produce fuel gas and value-added products. Two lignins, MeadWestvaco (MWV) lignin and Sigma Aldrich (SA) lignin, were studied using two different reactors. A laminar entrained flow reactor (LEFR) was used initially to determine the effect of lignin type, temperature and residence time on char yield and fixed carbon conversion during pyrolysis and gasification. During both pyrolysis and gasification, the maximum decrease in char yield took place in the initial stage of the reaction and there was little change at longer residence times. There was not much difference between pyrolysis and gasification in the residence times obtained in the LEFR. Furthermore, a thermogravimetric analyzer (TGA) was used to study the effect of lignin type on pyrolysis and gasification. The reaction rates and char yields were affected by the lignin composition. Lignin pyrolysis showed similar behavior until 600°C but only the high-ash SA lignin showed secondary pyrolysis reactions above 600°C. Carbon gasification reactions were delayed in SA lignin. Na2CO3 addition made the primary pyrolysis reaction occur at a lower rate and enhanced the rate for secondary pyrolysis reactions. Fourier Transform Infrared (FTIR) Spectroscopy results showed that the significant loss of spectral detail started at different temperatures for MWV lignin and SA lignin. Kinetic parameters obtained using differential and Coats - Redfern integral method were comparable at lower temperatures but varied at high temperatures. Na2CO3 addition decreased the activation energy of primary pyrolysis.

Thesis (M.E.)--University of Canterbury, 2008. / Typescript (photocopy). Includes bibliographical references (p. 194-196). Also available via the World Wide Web.

A pesquisa por meio de projetos e planos, que induzem ações de sustentabilidade e inovação, tem alavancado o processo de desenvolvimento de vários países. Porém, neste movimento estão presentes conflitos, contradições e interesses que trazem resultados por vezes não desejados. As necessidades de preservação e conservação da natureza e os impactos ambientais no cotidiano das sociedades requerem mudanças de comportamento das empresas e do governo. Investimentos em pesquisa, ciência e tecnologia são fundamentais para estimular inovações e para estabelecer os limites dos usos e das formas de apropriação dos recursos naturais. Nesta dissertação, a partir de um projeto de natureza técnica, fez-se uma análise para verificar como os pesquisadores inserem a própria pesquisa nos contextos econômico, social, ambiental e político. O projeto analisado, intitulado "Florestas Energéticas na Matriz de Agroenergia Brasileira", coordenando pela Embrapa Florestas faz parte do Plano Nacional de Agroenergia, o qual é desdobramento das políticas públicas na busca de fontes alternativas de energia. O marco teórico de apoio para as discussões demandou a escolha de temas, tais como: ciência, tecnologia, sociedade, desenvolvimento, florestas, biomassa, inovação e sustentabilidade. A pesquisa foi de natureza qualitativa, com análise documental e bibliográfica, explorando recursos analíticos da lingüística e da interdisciplinaridade. Foram levantados termos que expressam aspectos estruturais do projeto: ambiental, econômico, social, e político. Após definidos os objetivos e os procedimentos metodológicos, foram trabalhados temas do desenvolvimento e tecnologia no contexto da economia brasileira. As discussões abrangeram os temas do projeto analisado, em especial os tópicos de florestas, biomassa, exploração, produção, consumo da madeira e resíduos. Assim, foi possível expor a compreensão de sustentabilidade e dos limites dos recursos naturais enquanto instrumentos de apoio para a elaboração de projetos de pesquisa. Os resultados da análise do projeto de pesquisa (Florestas Energéticas e os cinco projetos componentes) apontaram que o grande motivador das políticas públicas foi o aspecto econômico, e os demais aspectos; social, ambiental, e político, o complementaram. Assim, pode-se afirmar que os conteúdos temáticos dos textos apresentam um repertório variado e amplo da questão energética, nos propósitos de ações sustentáveis. As argumentações que se encontram no marco teórico fazem parte da esfera das atividades propostas pelo projeto, o que permite inferir vínculos e articulações entre os estudiosos e os pesquisadores do projeto. Na parte social, o projeto prevê a utilização de mão-de-obra e a geração de renda, e como conseqüência, melhoria da qualidade de vida. Nele, o termo "desenvolvimento sustentável" refere-se à questão socioeconômica e ambiental e pode representar as escolhas das gerações futuras no sentido de dar continuidade às ações pela vida. Na essência dos discursos que a ele se referem, destaca-se a atividade da silvicultura para a produção energética, a qual contribui com o equilíbrio dos processos naturais e industriais. Vale destacar o importante papel das políticas públicas na concretização de ações favoráveis às fontes alternativas e renováveis, e às pesquisas e investimentos, que repercutem na conservação e preservação do ambiente. / Research through projects which induce actions of sustainability and innovation, has promoted the development process of many countries. However, conflicts, contradictions and interests, which sometimes bring unwanted results, are present in this movement what may output some unwanted results. The need for preservation and conservation of nature and the environmental impacts on societies require changes on the behavior of corporations and government. Investments in research, science and technology are essential to stimulate innovation and to establish the limits of the uses and forms of appropriation of natural resources. In this dissertation, a technical research project was analyzed to check how the researchers inserted their own research in economic, social, environmental and political contexts. The analyzed project entitled "Florestas Energéticas na Matriz de Agroenergia Brasileira" is coordinated by Embrapa Florestas as part of the National Plan of Agro-energy (Plano Nacional de Agroenergia) which is an outcome of Brazilian public policies for alternative sources of energy. The theoretical basis for this research involved the selection of keywords such as: science, technology, society, development, forests, biomass, innovation and sustainability. This research was of qualitative nature with the analysis of documents and bibliography, exploring analytic resources from linguistics and interdisciplinarity. Words which express structural aspects of the project such as environment, economy, society and public politicies where identified. After the definition of objectives and methodological procedures, were addressed themes of development and technology in the context of the Brazilian economy. The discussions covered topics of the project, in special that ones related to forest biomass, exploration, production, consumption and waste wood. Thus, is was possible to expose an understanding of sustainability and the limits of natural resources as support instruments for the development of research projects. The results of the analysis of the research project (Florestas Energéticas and its five component projects) pointed out that the greatest motivator of public policies was the economic aspect while other aspects such as social, environmental and political were complementary to it. Thus, it can be assured that the thematic contents of the texts present a wide and varied repertoire on energies towards sustainable actions. The arguments found at the theoretical basis are included on the actives proposed on the project, which allows inferring on links and connections among researchers acting inside and outside of the project frame. On the social impact, the project foresees the use of manpower and income generation, and a consequence, improvement on quality of life. In it the term "sustainable development" refers to the socioeconomic and environmental issues. They may represent the choices of future generations in order to give continuity to the actions towards life. In essence of the discussions that refer to it, there is a highlight on forestry for energy production activities; which contributes to the balance of natural and industrial processes. It is worth noting the important role of public policy in the implementation of actions supportive of alternative and renewable sources, and also supportive of researches and investments that impact on environment conservation and preservation.

The aim of this thesis was to evaluate and compare the production capacity of the two hybrids of maize (Zea mays L.) genotypes and selected sorghum (Sorghum Adams). For the evaluation of this experiment there was based a plot on the piece of land of South Bohemia University in České Budějovice. The samples were picked up before harvest to compare the evaluated high - yielding indicators. The number of samples depended on the desired dry matter content in biomass. During corn harvest the yield of biomass was determined, and yield and share of corncobs, dry matter content of biomass and corncobs, and yield of dry biomass. At the harvest of sorghum the yield of biomass was determined, the content of dry matter and yield of dry matter in biomass. Out of one-year experiment it was found out a slower increase of dry matter content in sorghum hybrids in comparison with the corn maize hybrids. Selected hybrids reached optimal values of solids dry matter content for the production of high quality silage.