Algal biodiesel is a biodegradable and sustainable alternative to traditional petroleum fuels. Algal biodiesel is synthesised from algal lipids via transesterification and has many desirable physical properties for fuel use. Current photobioreactors are inefficient. This thesis looks to increase efficiency and reduce energetic running costs. This was undertaken by the design, construction and trialling of an LED photobioreactor. The controlled growth of the algae, specifically Chlorella emersonii, using pulsed monochromatic or bi-chromatic light conditions with comparison to continuous white light to improve light economy is explored in this thesis. The prediction of biodiesel profile from the growth conditions is also investigated for Chlorella emersonii. Chapter 1 is a general introduction to the area of algal biodiesel. This introductory chapter reviews the current literature regarding microalgae growth conditions and control, processing microalgae to produce biodiesel and photobioreactor designs for the controlled growth of algae. The known effects of different light sources and types on algal growth are also reviewed. Chapter 2 concerns the pulsing-LED vertical airlift photobioreactor design, construction and testing, including an overview of the system constructed and the process of design to combat specific issues. Results from the testing of the photobioreactor are reported in this chapter which include analysis of the resultant fatty acid methyl ester (FAME) profile of algae grown under various pulsed mono-chromatic and bi-chromatic light conditions and the comparison to continuous white light. This chapter draws together the hypotheses and stand-alone observations reported in the current literature allowing direct comparisons for different light conditions and conclusions to be reported which include the effect on resultant FAME profile and not just lipid percentage. Chapter 3 explores the effect of environmental factors on the fatty acid methyl ester composition of the algal biodiesel. This chapter describes the effect of carbon dioxide, nitrate, phosphate and iron levels, length of culture and the effect of supplementary carbon sources on Chlorella emersonii growth and resultant FAME composition. The result of synergetic effects of nutrient levels and length of algal cultivation are analysed in addition to the stage of algal growth and its impact on FAME profile. Chapter 4 details the procedures used for the growth of algae, the production of the algal biodiesel and the development of techniques used for analysis of the resultant biodiesel. The techniques and conditions employed for the growth of the algae as well as the extraction and transesterification of the algal lipids are explained.

The main aim of this project was to develop bioinformatics tools to rapidly identify novel cellulases sequences for use in next generation biofuels production. Firstly, a detailed analysis of the sequences and folds of structurally elucidated cellulases was undertaken. From this analysis it was discovered that cellulases are structurally diverse and are classified into 19 different CA TH superfamilies. The study of cellulase fold space was subsequently utilized for the development of a cellulase specific fold recognition tool, CellulaseFOLD. CellulaseFOLD was found to be over 30% faster than the fastest leading fold recognition tool (HHsearch) for the detection of cellulases. In addition, from the evaluation of 3 cellulase containing proteomes, the CellulaseFOLD method achieved a higher percentage coverage of cellulase sequences when compared to HHsearch. Secondly, FunFOLD a ligand binding site residue prediction tool and a novel metric for its evaluation (the Binding-site Distance Test - BDT score), were developed. The FunFOLD method showed a significant improvement over the best available servers and was shown to be competitive with the top methods. In addition, the BDT score was determined to be a more robust score than the previous metric for ligand binding site evaluation (the MCC score) and was subsequently adopted by official assessors at CASP9. Thirdly, a comprehensive analysis of binding site residues for all structurally elucidated cellulases was undertaken. From this study it was concluded that aromatic residues such as tryptophan were important in saccharide binding. Furthermore, cellulase binding sites contained a higher percentage of charged residues, when compared to the entire cellulase structure. Fourthly, a ligand binding site quality assessment tool, FunFOLDQA, was developed, which assesses predictions prior to the availability of experimental data. The FunFOLDQA score was shown to be highly correlated to both the MCC and BDT metrics. Thus, FunFOLDQA can be utilized to assess binding site predict quality in the absence of experimental data. Finally, both the general (FunFOLD and FunFOLDQA) and cellulase specific algorithms (CellulaseFOLD and the cellulase binding site data) were utilized to assess case study sequences, identified as potential cellulases, from 3 proteomes under intense study in the biofuels industry.

Currently biomass covers around 85% of the total renewable energy supply of the United Kingdom together with landfill gas and waste combustion. However its potential is still underutilized. Indeed, its conversion in fuels, energy and chemicals could revitalize rural economies, limit the dependence on foreign oil imports, and improve the environment by reducing fossil fuel consumption and thus reducing greenhouse gases. Recently, new pathways to convert the biomass into intermediate liquid namely bio-oil have been investigated. Pyrolysis is a promising technology to produce renewable fuels from biomass especially decentralized at point of production. However, the quality of bio-oil still remains a major limitation in terms of oxygen content and calorific value. The overall aim of this project was to contribute to the understanding of the engineering aspects in which biomass could be economically converted to chemicals, fuels and energy using catalytic pyrolysis to enhance the quality of the bio-oil. This can enable the production of intermediate bio-liquids with properties similar to those of petroleum, allowing the use of the existing crude-oil refinery settings for bio-oil upgrading into fuels. The integration of the bio-oil into a crude-oil refinery would sensibly decrease the economical disadvantage of biomass compared to fossil fuels. This work proposes an innovative three-step catalytic process that converts biorefinery residues, such as spent grains, into bio- oil by catalytic pyrolysis. The water insoluble fraction of the bio-oil (WIBO) is converted into a solid residue that possesses similar characteristics to those of coal, and a liquid product called bio-crude by a process name Thermo-t similar to the visbreaking process used to upgrade the quality of crude-oil heavy distillation residues. The water fraction (WSBO) is then converted into alcohols and alkanes using hydrogenation reactions. Despite the fact that the original biomass contains undesirable high oxygen (39-46 wt%) and moisture contents, there was a clear improvement in the properties of the bio-oils generated by catalytic pyrolysis that presented oxygen content of 26- 31 wt% and the final Thermo-t residue as the oxygen content was reduced by over 70% to 9-14 wt% on average. Catalytic pyrolysis was able to produce a bio-oil with less oxygen and nitrogen, high aliphatics and hydrogen using activated serpentine and olivine at low temperatures (370-430 QC). The activated materials seem to be beneficial to the bio-oil energy content that increase from less than 20 MJ/kg in the original biomass to 24-26 MJ/kg and finally to 29-37 MJ/kg after Thermo-t process. About 70-74% of starting energy remains in the bio-oil using ACOL and ACSE at 430 QC, respectively, while only 52% is retained using alumina at the same temperature. Finally, bio-crudes and bio-cokes from Thermo- t process retain 30 and 36% of the starting energy, respectively. The WSBO can be catalytically hydro-treated by Aqueous Phase Processing in a 1st stage at temperatures lower than 130 QC to reduce the organics removed as solid depositions to only 7 wt%, avoiding the typical catalyst deactivation of traditional hydro-treating technology. Then, in a 2nd stage at 220-250 QC, 93% of the partially deoxygenated bio-oil functionalities, such as ketones, aldehydes, aromatics and sugars are converted in much more stable functionalities that leave a final product with acidity and stability much compatible with current fossil fuels. Overall, this study has shown that there is a great technical scope for converting biomass into high-value products that can help to off-set fossil fuels.

Organic concentrate from municipal solid waste obtained from an autoclave separation process were used to carry out fermentation, gasification and pyrolysis to assess their potential for renewable energy production. Fermentation was a very promising process, where maximum enzymatic hydrolysis conversion of 53% of the cellulose and hemi-cellulose was found using a particle size range of 150-300 um hydrolyzed in a 100 ml buffer solution containing 6 per cent summer OC sample with 90 mg cellulase at pH 4.8 held at 40°C for 12 hours. The findings indicate that 152 L of ethanol could be obtained from a ton of the summer OC sample (Li et al., 2011b). The gasification experiment indicated a 1:1 ratio of H2: CO produced at 800°C using diluted air with steam. Pyrolysis of the summer OC sample was carried out using a bench-scale fluidized bed reactor at 350-540 °C comparing AI203 with activated olivine sand as bed materials. A maximum oil yield of 50% was obtained using the activated olivine sand at 400°C while only 45% was obtained at 500 °C using A1203• The calorific value of the bio-oil at 500°C was 29 MJ/kg using activated olivine sand while the blo-oil using AI203 was 23 MJ/kg. The blo-oils using activated olivine sand at 400°C were less aromatic and contained less nitrogen compared to the oils obtained using AI203 at 400°C (Li et al., 2011a). In addition, a bench-scale fixed bed reactor was used to carry out pyrolysis of the summer OC samples at 460-540 °C and a maximum oil yield of 44% was obtained at 500°C with a reaction time of 60 minutes. In conclusion, the MSW OC samples obtained from Estech have great potentials to be used as a renewable resource.

A series of detailed studies have been performed to further understand the characteristics of biomass for solid fuel combustion purposes. The characterisation work was carried out in three separate (but interrelated) parts studying each of the different forms/stages of biomass during combustion i.e. original raw biomass, biomass char and biomass ash, respectively. These findings were examined and correlated to see if predictions about combustion behaviour could be made. The effects of blending biomass and coal on milling performance and ash behaviour were also investigated to show the relevance of co-milling and co-firing. The lignocellulosic components, i.e. lignin, cellulose and hemicellulose are the key constituents of plants cell wall, and hence form the major part of biomass. The contributions of these components on biomass behaviour were explored by analysing a matrix of samples with varying lignocellulosic compositions including; a base suite of 11 biomass samples with different lignocellulose contents; samples pre-treated chemically to alter their compositions; pseudo biomass samples synthesised by mixing commercially obtained lignin, cellulose and hemicellulose in different weight percentages. All raw samples, both treated and untreated, as well as their corresponding char samples prepared via the fast heating drop tube furnace and slow heating muffle furnace, were analysed to determine their respective thermal properties, structural characteristics, grindability, etc. Ash samples were characterised using the sinter strength test and the newly developed PAnG (Picture Analysis and Graphing) advanced ash fusion test. The former was originally devised for coal ash characterisation whilst the latter was designed to accommodate the large variability in fuels. The PAnG test incorporates dilatometry and sinter strength test by means of image analysis. It is believed that lignin, cellulose and hemicellulose play a significant role in determining the characteristics of biomass. Results have shown that the data of raw biomass, biomass char and biomass ash correlate well with that of lignocellulosic composition. The major components of biomass, particularly cellulose and/or lignin, reflect the various behaviours of biomass in different ways, and hence can be used as a potential predictive tool. Depending on the original unblended fuel, the blending of biomass and coal at different weight percentages can have favourable effects on fuel properties.

Lignocellulosic materials are promising alternative feedstocks for bioethanol production. This dissertation focuses on 2nd generation bioethanol production from lignocellulosic biomass. The first part of this thesis examined the enzymatic production of fennentable sugars from a range of lignocellulosic biomass and agricultural residues e.g. miscanthus, switchgrass, reedcanary grass, wheat straw, cassava peel and millet straw. The 2n part analysed supply of feedstocks in Nigeria with respect to bioethanol yield and models the potential supply in specific geographical locations with a view to establishing commercial cellulosic ethanol facilities. The overall goal of the dissertation is to evaluate cellulosic feedstock availability in Nigeria and their potential for bioethanol production. In this study the Van Soest detergent fibre analysis method was used to determine the chemical composition of a range of feedstocks. Barley and wheat straw showed the highest cellulose content while switchgrass had the highest hemicellulose. The theoretical ethanol yield based on cellulose content for the herbaceous energy crops and agricultural residue showed that barley straw had the highest potential yield of 145.35 IIton and cassava peels had the lowest yield of 94.28 IItone because starch was not taken into account. The study also analysed varietal variation in chemical composition of wheat straw from a HGCA Recommended list Trial. Cordiale had the highest cellulose content. Cordiale and Alchemy had significantly higher ethanol yield than all the other varieties studied. Oakley, Deben and Consort had significantly lower ethanol yield than the other varieties. Using wheat straw as a model feedstock, biomass pre-treatment conditions eg acid vs alkali concentration, solid loading, temperature and residence time were optimized. The optimization showed that reducing sugar yield from NaOH pre-treated wheat straw was 2x higher than that from acid pre-treated wheat straw. The optimal pre-treatment conditions for wheat straw were 3% NaOH and132°C for 40 minutes A range of agricultural residues were examined regional wise based on the six zones in Nigeria for their potential for lignocellulosic ethanol production while forestry and grassland resources were evaluated on national basis. Agricultural residues were split into two including field residues and processing residues. In evaluating field residue, provisions were made to account for current uses in terms of soil cover and animal feed, which are the two existing uses for field residues. From the findings, maize stalk and cassava peel are two of the major processing residues available for use. Maize stalk when used as a single feedstock can only power 18 commercial bioethanol processing facilities in the North and only 7 facilities in the South. Cassava peel as a single feedstock, can power 13 bioethanol facility in the North where 9 of them would be based in the North central but power 20 facilities in the South, where they are evenly spread across the 3 Southern zones. When the total agricultural residues produced in each zone are put together in the scenario where the bioethanol processing facilities are based on multi-feedstocks, 44 - 54 ethanol processing facilities could be sited in each northern zone and only 16 - 19 facilities southern. Based on 2008 petrol consumption of 9.5 billion litres in Nigeria, a 10% blend would require 950 million litres of bioethanol per annum. Using the entire field and processing residues examined in this study produces 6.7 billion litres of bioethanol per annum which exceeds the 10% mandate. Therefore Nigeria has enough agricultural residues to exceed its bioethanol blending requirement but the big issue is collection and financial return to the fanner. Fuel wood and sawdust were evaluated at national level for lack of regional data. Potentially, fuelwood can power 153 ethanol processing facilities, sawdust can power 7 and the grassland resource can power 542 bioethanol processing facilities. There is considerable potential to cultivate purposely grown energy crops eg switchgrass and miscanthus for lignocellulosic ethanol production exists. This is dependent on identifying species suited to the climate, geographical zones and potential for genetic improvement in these species and potential for improving production via management practices.

One of the impacts of climate change is the emergence of food, energy and water shortages which can be circumvented through intensified technologies in agriculture, energy and chemical/biological processes. Furthermore, depleting fossil fuel reserves requires the establishment of alternative sustainable energy resources. Biomass based energy and chemicals technology is an important component of sustainable development which can be integrated with food and water generation. However, due to distributed nature of biomass, biomass based energy technology needs to be distributed generation which would benefit from low temperature and pressure operation. Syngas produced from gasification of waste/biomass can be. converted to power or liquid fuel after cleaning. Although process intensification (PI) is still in its infancy, potentially, it is highly suitable for the distributed production of power and liquid fuels. The objective of this study is to develop a syngas-to-liquid fuel conversion process suitable for distributed production using principles of PI through the intensification of Fischer Tropsch Synthesis (FTS). The first approach was by using structured catalysts in monolithic forms for FTS. The second approach was to couple the structured catalyst with non thermal plasma by using dielectric barrier discharge (DBD) in hybrid FTS reactors. A hybrid reactor was designed and fabricated to test this novel catalytic system. Co and Co/Cu catalysts were prepared and characterised using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and transmission electron microscopy. The reactor was used in the FTS using H, and CO under various processing conditions (temperature, pressure, Hz/CO molar ratio, gas flowrate and plasma power) and the products were analysed using gas chromatography. It is shown that Co/Cu catalyst in plasma assisted FTS was feasible, converting up to 38% of CO at 90W, 1 bar, Hz/CO= 2, 25ml/min and 25°C. This conversion was obtained at 230°C and 6 bar in conventional FTS. This research showed that DBD in FTS enables running the reaction at room temperature and atmospheric pressure avoiding the risks and costs associated with high pressure processes. It was also shown that plasma affected the activity of the catalysts, preventing it from agglomeration.

Interest and investment in biofuel production is growing in response to political and economic drivers associated with concerns over fossil fuel depletion; the need for energy security; greenhouse gas emission reduction demands; and the perceived potential for biofuel production to contribute to rural development and poverty alleviation. Despite this, empirical data on the impacts of biofuel crops are limited and their potential role in enabling livelihood diversification activities in sub-Saharan Africa is under-explored. Addressing this gap, this research takes an integrated case study approach to assess the impacts of different Jatropha curcas cultivation models on rural livelihoods across a range of study sites in Malawi. The research develops and adopts an integrated research methodology that combines the Sustainable Livelihoods Framework (SLF) with the diffusion of innovation model, using participatory and conventional social science research methods to achieve a multi-scale analysis spanning from local to national levels. Findings show that the overall approach to cultivation (from planting method, through production and processing to marketing) is more important in providing a livelihood contribution than the model of cultivation used. When Jatropha is promoted as a boundary fence, the crop and its by-products (such as seedcake fertiliser) can contribute to all 5 livelihood asset groups (natural, physical, financial, human and social capitals): directly or indirectly through financial capital substitution. However, a complex set of factors are involved in farmers' adoption decisions, .which intimately link the livelihood context, communication channels and the characteristics of the innovation itself. This results in varying numbers of households cultivating the crop in the case study villages. In addition, constraints identified at the local to national level mean livelihood benefits are yet to be fully realised. Communication amongst the diverse range of stakeholders involved in Jatropha cultivation in Malawi is characterised by isolated networks, individuals and groups at the local to sub- national level. At the national level, the private sector dominates policy dialogue. Moreover, relevant legislation and policy is absent, hindering the development of the sector. Policy recommendations and action points for actors are presented in order to address these constraints. At the national level, it is recommended that the government of Malawi should prioritise rural development as a policy goal for the future of national biofuel production and take steps to develop a coherent biofuels policy which is fully integrated into national development policies. At local to sub-national levels, stakeholder communications must be improved in order to facilitate knowledge management and governance of the sector, and investments must be made in the extension services network.

This thesis presents a feasibility study on the conversion of biomass-derived pyrolysis oils to hydrogen gas via the advanced steam reforming processes of chemical looping reforming (CLR) and sorption enhanced steam reforming (SESR). According to thermodynamic equilibrium, the optimum conditions of steam reforming of model pyrolysis oils compounds were around 600°C and molar steam to carbon ratio (S/C) of 3, to save raising excess steam in the process. Palm empty fruit bunches (PEFB) pyrolysis oil and pine pyrolysis oil were investigated as renewable feedstock for H2 production. The experiments were carried out in a down-flow packed bed micro reactor using commercial Ni catalyst at 1 atm. The SIC of 1.89 (moist fuel) was found to provide the best operating conditions for steam reforming of both pyrolysis oils. In the SESR experiments, dolomite was mixed in the reactor bed to capture C02 produced from the steam reforming of pyrolysis oils. High sorption enhancement effects were demonstrated in particular for pine oil. Short CLR experiments were performed tor both oils using the same Ni catalyst acting as oxygen transfer material. The oils were able to reduce the catalyst close to 90% despite high O-content, and undergo CLR. The feasibility of steam reforming of aqueous fraction of pyrolysis oils was performed with co-reforming of ethanol using two catalysts: 'A' with a NiO loading of 18 wt% on α-alumina, and 'B' with 25 wt% NiO on γ-alumina. The aqueous phase was derived from water phase separation of the pine oil at a 1: 10 oil :water mass ratio. Both catalysts demonstrated high fuel conversion and H2 yield for S/C ratios between 2.4 and 4.8. Chemical looping reforming performed at S/C of 3.66 resulted in almost 90% reduction of catalyst A and around 20% reduction of catalyst B whilst maintaining nearly complete fuel conversion.

An small-scale CHP system has been proposed coupling a single-staged gasification unit with a suitably matched energy recovery device, utilising biomass pellets. Biomass pelletisation is an established industry in Northern Europe however there is no standardisation governing the quality of the pellets produced. The first objective investigated the pressure pelletisation of switchgrass for five types of material preparation. The effects of pelletisation pressure and temperature on the quality of pellets were evaluated in terms of density, strength and durability.