Thesis (M.S.)--University of Hawaii at Manoa, 2006. / Includes bibliographical references (leaves 69-72). / vii, 89 leaves, bound ill. 29 cm

Thesis (MScIng)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.

Submitted in fulfillment of the requirements for the Degree of Master of Technology: Chemical Engineering, Durban University of Technology, 2014. / Biodiesel is a renewable fuel that can be produced from animal fats, vegetable oils or recycled used cooking oil. From the 1970’s, biodiesel received increased focus as an alternative to crude oil and its component products. Among various processes used for biodiesel production, transesterification of glyceride and alcohol in the presence of a catalyst to produce ester (biodiesel) and glycerin remains the most common. In Africa, biodiesel is currently produced industrially in a number of ways via different methods. In South Africa, there are a number of biodiesel production plants that are continuous processes with feed samples from different sources. Reviewing the batch systems for developing economies, various observations were made. Some produced biodiesel using batch systems at room or day temperatures, another used different temperatures, some also used flat based buckets for their mixing and so on. This becomes difficult for local producers who desired to produce biodiesel on a very small scale for their farms or business. Hence, the study was aimed at evaluation batch biodiesel systems and to come up with a simplified approach for a producer in a developing economy or a local user. The objectives of this study were as follows; To evaluate biodiesel production options, and hence develop a simplified process that can be used to produce biodiesel in developing economies. The criteria for evaluation will include: ease of operation, non-specialist equipment, range of feedstock, product quality and product yield. To evaluate various factors that affect these criteria and make recommendations that will enable a local producer to remain within an optimum range Compare the produced biodiesel properties against general biodiesel and petroleum diesel ASTM standard range Recommend simplified equipment design for a local producer Perform economic evaluation to establish cost required both for equipment and raw materials for a local producer. After literature review on the existing processes, base catalyzed transesterification was selected. This is because of the simplicity as well as ease of operation. Experimental trials commenced using feeds from pure vegetable oil (PVO) and waste vegetable oil (WVO) to familiarize biodiesel production, as well as study the behavior of each having the research criteria in focus. Various variables that affect ease of operation, product quality, and yield were also investigated. These include temperature, type of catalyst (KOH or NaOH), type of alcohol (Methanol or Ethanol), concentration of catalyst, and purity of alcohol, and nature of feed (PVO or WVO). The effect of temperature was compared against product quality, yield, and ease of operation. Other variables were also compared against the same criteria. Treatment of WVO because of impurity and moisture contamination associated with such samples was also studied. The product was then tested using some ASTM procedures to compare biodiesel quality to acceptable standards. Efficient reaction time is paramount for a quality biodiesel. It was observed that biodiesel required between 25 and 30 minutes for a complete reaction. Lower temperatures clearly affected the quality of biodiesel produced. Best operating range was found to be between 55 oC – 75 oC is usually recommended for a transesterification reaction to obtain optimum yield and quality. The use of KOH compared to NaOH yields similar results even though NaOH is usually selected because of the reduced cost. The use of methanol compared to ethanol also yields similar results, even though methanol is usually preferred due to cost. Purity of available alcohol is vital as its reduction from 99.5 % to 75 % during experimental trials, yielded poor quality biodiesel. This is mainly due to moisture content that usually gives room for bacteria growth and corrosion of fuel lines in engines. As long as a titration test is carried out on the feed, the use of WVO is a good option. Varying catalyst concentrations from 0.5 % to 1.75 % were considered and the best regimes identified. This test will enable a producer from a growing economy to use the appropriate reagent, which will ensure the transesterification reaction is complete. After comparing appleseed and cone based design, the latter was selected as it will eliminate any difficulty that a local producer might encounter in making the biodiesel batch. In terms of costs, it was discovered that the major costs to a local producer will be the biodiesel mixer and fittings which will be fixed costs. Other variable costs are considered to be affordable, as the cost of waste vegetable oil is very low as well as other industrial reagent grade that will be required. In summary, batch biodiesel production for a local user or developing economy is a very feasible exercise. One needs to ensure that the recommendations regarding pre-treatment of feed oil, basic reaction criteria and other generic parameters are considered during production.

Thesis (Master of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, 2019. / The biodiesel industry produces large volumes of biodiesel wastewater (BDWW) during the purification of crude biodiesel. This wastewater is characterised by high concentrations of chemical oxygen demand (COD), biological oxygen demand (BOD), total suspended solids (TSS), and fats, oils and greases (FOG) which in turn defines BDWW as a highly polluted effluent. The low nitrogen and phosphorous content of BDWW creates an unfavourable environment for the growth of microorganisms, thereby making it difficult to degrade naturally. Biodiesel companies discharge untreated non-compliant wastewater directly to the municipal sewer system. Treatment prior to discharge is a necessity since the disposal of untreated BDWW may raise serious environmental concerns (i.e. disturbance of biological ecosystems) resulting in penalties liable by non-compliant companies due to the implementation of the waste discharge charge system (WDCS) which is regulated by the industrial waste discharge standard limits in South Africa (SA). This study aimed to combine the advantages of the conventional anaerobic baffled reactor (ABR) system with microbial fuel cell (MFC) technology resulting in an innovative technology used to treat high strength industrial BDWW at ambient conditions. Many studies have reported effective treatment of BDWW, however to date literature implementing an ABR equipped with MFC technology has not been reported. The main objectives of the study were to determine which parameters do not meet the industrial wastewater discharge standard limits, whether pH and carbon:nitrogen:phosphorous (C:N:P) ratio adjustments will suffice prior to treatment with the ABR-MFC, the maximum power density (PD) as well as to determine the treatment efficiency of the ABR-MFC.

Rapidly increasing concerns about energy security coupled with detrimental environmental impacts posed by the dependence on fossil fuels, and an urgent need for rural development in Africa are key drivers for the search for fuel alternatives. The international effort into the development of criteria and indicators for sustainable bioenergy production clearly recognizes that bioenergy production must not be at the expense of biodiversity and food security. Owing to its multi-purpose capabilities i.e. its ability to rehabilitate eroded lands, drought resistance as well as its biophysical and maintenance requirements, Jatropha was selected as a potential candidate for the production of biodiesel. Jatropha is not new to the people of Tanzania, the study area of the project. Research has shown that, its associated social, environmental and economic benefits are crucial to economic development of the country. At present, all of Tanzania’s petroleum based products are imported; about 90% of the energy consumed is derived from biomass; road, rail and electricity networks are underdeveloped. Environmental degradation is also a concern in the country. The aim of the study was to identify three optimal locations for large scale Jatropha cultivation for biodiesel production in Tanzania’s semi arid regions. Geographical Information Systems was used to overlay several remotely sensed data from previous research namely semi arid regions delineations, agro-ecological sub-zones that had Jatropha potential as well as the administrative zones of Tanzania. The unavailable and/unsuitable areas were verified against literature and this enabled the areas that were under cultivation, were housing biodiversity or were generally constrained to be filtered out from the study area. The three largest, available and potentially suitable areas that the study identified for large scale Jatropha cultivation occupied about 7.6 million hectares. Assuming an optimal seed yield and an oil content of 35%, these areas are capable of producing about 14.4 million litres of Jatropha oil per annum. Targeting a SADC fuel import substitution of 10%, these 14.4 million litres of Jatropha oil that the three areas will meet about 83% of the country’s energy needs. Owing to the state of electricity generation in Tanzania, these three areas are able to generate about six percent of electricity and this can contribute to some extend to the country energy needs. From the analysis it was clear to note that the production of biodiesel for blending or for electricity generation is going to be economically viable from the three selected regions. The available and suitable areas that were not consolidated within the three selected regions can be used for small scale Jatropha cultivation and their produce can be fed to large scale commercial oil production or they can use the biodiesel to produce their own electricity. Jatropha will have to be irrigated to enhance a viable economic yield; infrastructure will need to be constructed to areas that are not served by roads and railway lines. All of this bodes well for enhancing rural development. The government has already had the foresight to establish the National Biofuels Task Force which will need to monitor investors to ensure no enforced human displacement and/or exploitation in areas where the large scale farms are to be established. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2009.

O 2,3-butanodiol (2,3-BDO) é um composto com potencial de uso em diferentes segmentos industriais, podendo ser obtido por síntese química tradicional ou via processos fermentativos a partir de diferentes fontes de carbono. Entre suas aplicações potenciais, destaca-se a utilização como precursor na indústria de polímeros, matéria-prima na produção de solventes, agente anticongelante, combustível líquido ou aditivo de combustíveis. A síntese de 2,3-BDO pela fermentação do glicerol subproduto da indústria de biodiesel por bactérias anaeróbias facultativas é particularmente atrativa, considerando-se a grande disponibilidade desta matéria-prima e a possibilidade de integração de processos e produtos no conceito de biorrefinaria. Entretanto, o uso do glicerol subproduto para este fim, deve ser ainda cuidadosamente avaliado, considerando a significativa quantidade de impurezas nele contidas. Neste trabalho, avaliou-se a utilização do glicerol subproduto em meio mineral, para o crescimento celular e produção de estereoisômeros de 2,3-BDO e acetoína por Klebsiella oxytoca ATCC 8724 e Enterobacter aerogenes ATCC 13048. Os resultados foram comparados com os alcançados om o uso de glicerol puro e glicose, em ensaios em regime descontínuo alimentado com concentração inicial de substrato (S0) de 80 g/L, em meio mineral padrão (PC), frequência dos agitadores de 700 rpm e fluxo específico de ar de 0,50 volumes de ar por volume de meio por minuto (vvm). Na sequência, foram realizados ensaios fermentativos com E. aerogenes com glicerol subproduto e diferentes meios de cultivo relatados na literatura, com S0 = 40 g/L, variação da frequência dos agitadores (650 a 750 rpm) e do fluxo específico de ar (0,50 a 0,87 vvm). Para a otimização do meio de cultivo, realizou-se um planejamento experimental do tipo Box-Behnken Design-3k, com a avaliação de três variáveis independentes - (NH4)2SO4, (NH4)2HPO4 e MgSO4.7H2O -, em três níveis. A avaliação cinética do cultivo de E. aerogenes no meio definido foi realizada em regime descontínuo em comparação ao uso do meio mineral padrão (PC). As metodologias analíticas utilizadas no decorrer da pesquisa foram validadas. Como resultados, nos cultivos com E. aerogenes em regime descontínuo alimentado, empregando-se glicerol puro e subproduto como substratos, rendimentos (ρ) da ordem de 82 e 84%, respectivamente, foram atingidos, sendo superiores ao obtido com glicose (71%). Nos ensaios conduzidos com diferentes formulações de meios de cultivos, a produção de biomassa foi favorecida na primeira etapa da fermentação com o uso do meio MD4, sendo cerca de 38% superior em relação ao meio mineral padrão (PC). Nos ensaios de otimização, E. aerogenes foi capaz de adaptar-se frente às diferentes concentrações dos sais presentes no meio contendo glicerol subproduto. Visando maximizar os resultados em termos de produção específica em relação à biomassa (YP/X), fator de conversão de substrato em produtos (YP/S) e concentração final de produtos (Pf), a partir dos resultados da otimização, sugere-se a utilização de um meio de cultivo definido contendo (g/L): glicerol, 80; (NH4)2SO4, 7,71; (NH4)2HPO4, 3,15; MgSO4.7H2O, 0,6; KOH, 0,45. Considerando o conjunto de características dos métodos cromatográficos e espectrofotométricos utilizados, ambos são adequados para aplicação nesta pesquisa, fornecendo resultados confiáveis das fermentações. De forma geral, os resultados alcançados indicam a aplicabilidade do glicerol subproduto como substrato para a produção fermentativa de 2,3-BDO e acetoína pelas bactérias anaeróbias facultativas Klebsiella oxytoca ATCC 8724 e Enterobacter aerogenes ATCC 13048. Além disso, também foi demonstrado que a produção de 2,3-BDO pode ser conduzida com E. aerogenes a partir de glicerol subproduto, empregando-se meios simplificados em comparação ao padrão descrito na literatura, significando um ganho econômico para esta fermentação. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES / 2,3-butanediol (2,3-BDO) is a compound with potential to be used in different industrial segments, that can be obtained by traditional chemical synthesis or via fermentative processes from different carbon sources. Among its potential applications, it is included the use as chemical building blocks in polymer industries, raw material for the production of solvents, antifreeze agent, liquid fuel or fuel additive. The synthesis of 2,3-BDO by the fermentation of glycerol by-product of the biodiesel industry by facultative anaerobic bacteria is particularly attractive considering the high availability of this substrate and the possibility of integrating processes and products into the concept of biorefinery. However, the use of the by-product glycerol for this purpose is still to be carefully assessed considering the significant amount of impurities it contains. In this work, the use of by-product glycerol in mineral medium for the cell growth and the production of stereoisomers of 2,3-BDO and acetoin by Klebsiella oxytoca ATCC 8724 and Enterobacter aerogenes ATCC 13048 was evaluated. The results were compared with those obtained with the use of pure glycerol and glucose, in fed-batch cultivations with initial substrate concentration (S0) of 80 g.L-1, standard mineral medium (PC), impeller speed of 700 rpm, and air flow rate of 0.50 volumes of air per volume of medium per minute (vvm). In order, cultivations with E. aerogenes with by-product glycerol and different culture media reported in the literature, with S0 = 40 g.L-1, variation of the impeller speed (650 to 750 rpm) and the specific air flow rate (0.50 to 0.87 vvm), were carried out. For the optimization of the culture medium, an experimental Box-Behnken Design -3k was performed, with the evaluation of three independent variables – (NH4)2SO4, (NH4)2HPO4 and MgSO4.7H2O –, at three levels. The kinetic evaluation of the cultivation of E. aerogenes in the defined medium was performed in batch fermentations in comparison to the use of the standard mineral medium (PC). The analytical methodologies used during the research were validated. As results, in fed-batch cultivations with E. aerogenes, using pure glycerol and by-product as substrates, yields (ρ) of the order of 82 and 84%, respectively, were reached, higher than that obtained with glucose (71%). In the trials conducted with different formulations of culture media, biomass production was favored in the first fermentation stage using the MD4 medium, about 38% higher than the standard mineral medium (PC). In the optimization experiments, E. aerogenes was able to adapt to the different concentrations of the salts present in the medium containing by-product glycerol. In order to maximize the results in terms of specific production factorin relation to biomass (YP/X), product from substrate conversion factor (YP/S) and final product concentration (Pf), from the optimization results, it is suggested the use of a defined medium containing (g.L-1): glycerol, 80; (NH4)2SO4, 7.71; (NH4)2HPO4, 3.15; MgSO4.7H2O, 0.6, KOH, 0.45. Considering the set of characteristics of the chromatographic and spectrophotometric methods used, both are suitable for application in this research, providing reliable results of the fermentations. In general, the results indicate the applicability of by-product glycerol as a substrate for the fermentative production of 2,3-BDO and acetoin by the facultative anaerobic bacteria Klebsiella oxytoca ATCC 8724 and Enterobacter aerogenes ATCC 13048. In addition, it has also been demonstrated that the production of 2,3-BDO can be conducted by E. aerogenes from by-product glycerol, using simplified media in comparison to the standard one described in the literature, which would positively reflect in the costs for this fermentation.

Thesis (MScEng (Process Engineering))--University of Stellenbosch, 2007. / Biodiesel, a fatty acid alkyl ester, derived from the transesterfication of vegetable oil, is considered a renewable fuel that can be used as a replacement for fossil diesel. The urgency for biofuel production in South Africa is motivated by the vulnerability of crude oil prices, high unemployment, climate change concerns and the need for the growing economy to use its resources in a sustainable manner. The technical feasibility of biodiesel production has been proven and this study investigates its preliminary economic feasibility in South Africa by looking at the market, financial and agricultural feasibility of commercial biodiesel production. / ENGLISH ABSTRACT: Biodiesel, a fatty acid alkyl ester, derived from the transesterfication of vegetable oil, is considered a renewable fuel that can be used as a replacement for fossil diesel. The urgency for biofuel production in South Africa is motivated by the vulnerability of crude oil prices,high unemployment, climate change concerns and the need for the growing economy to use its resources in a sustainable manner. The technical feasibility of biodiesel production has been proven and this study investigates its preliminary economic feasibility in South Africa by looking at the market, financial and agricultural feasibility of commercial biodiesel production. The market feasibility. The potential market size for biodiesel in South Africa is about 1 billion litres if it is to replace 10% of its diesel consumption by 2010. However, governmental legislation and policies are needed to create a predictable and growing market for biodiesel in South Africa. These policies or regulations could be in the form of subsidising feedstock for biodiesel production, subsidising the biodiesel itself, using government purchasing power, mandatory blending legislation, tax incentives or price compensation agreements. The financial feasibility. Calculations to asses the financial feasibility of commercial biodiesel production are based on a 2500 kg/h (22.5 million litres/annum) containerized plant. This size is based on findings of Amigun & von Blottnitz (2005) that the optimum biodiesel plant size in South Africa ranges between 1500 and 3000 kg/h. Two types of plants were considered, namely a seed extraction biodiesel production (SEBP) plant using locally produced oilseeds as feedstock and a crude oil biodiesel production (COBP) plant using imported crude vegetable oil as feedstock. The capital investment for a SEBP plant ranges between R110 and R145 million while a COBP plant would require a capital investment of about R45 to R50 million. These amounts include a working capital of about R35 million due to money that is fixed in a 3 month stock supply.Feedstock and raw material contribute to about 80% of the manufacturing cost while transport costs are the second biggest contributor. These results point to the fact that the plant location is very important in order to minimize production costs. Thus, commercial biodiesel production should not be centralized, but should rather happen through greater number of relatively small plants located in oilseed producing regions. (South Africa would require about 46 plants each producing 2500 kg/h to produce 10% of its diesel by 2010). The sensitivity analyses showed that the manufacturing costs of a SEBP plant are very sensitive to changes in oilseed and oilcake prices while the manufacturing costs of a COBP plant are very sensitive to a change in crude vegetable oil price. The fluctuating nature of the agricultural commodity prices makes biodiesel manufacturing costs predictable. Soybean biodiesel costs are the most sensitive to price changes while sunflower biodiesel costs are the least affected. An increase in glycerol price would decrease the manufacturing costs of biodiesel by about 12 cents/litre for every R1000/ton increase in price. Glycerol prices are currently too low to consider in the calculations due to a global oversupply as a result of biodiesel production. The break even price of biodiesel is calculated by adding R1.01/litre fuel tax to the manufacturing cost, which means that biodiesel produced from oilseeds (except canola) will not be able to compete with the current price of fossil diesel (30 August 2006) without subsidies or legislation. The agricultural feasibility. Producing 10% of South Africa’s diesel using oilseeds would require a major production increase.Biodiesel production will also increase the local oilcake supply which means South Africa will change from being a net-importer of oilcake (730 thousand tons/year) to a net-exporter of oilcake (1.7 million tons/year). Land availability for such a production increase is not a problem which means that the agricultural resources and potential market are available to produce and absorb 10% of the countries diesel in the form of biodiesel. However, at the moment the commercial production of biodiesel does not seem financially feasible without any government imposed legislation or subsidies. / AFRIKAANSE OPSOMMING: Biodiesel, ‘n hernubare brandstof wat uit groente olie vervaardig word, is ‘n moontlike plaasvervanger vir petroleum diesel. Biodiesel vervaardiging in Suid Afrika word aangespoor deur hoë kru olie pryse, hoë werkloosheid syfers, toenemende bewustheid van klimaatveranderings en druk op ‘n groeiende ekonomie om sy bronne volhoubaar te gebruik. Die vervaardiging van biodiesel is relatief maklik en hierdie studie is ‘n voorlopige ondersoek in die ekonomiese lewensvatbaarheid van komersiële biodiesel produksie in Suid Afrika deur te kyk na die mark, finansiële en landbou lewensvatbaarheid daarvan. Die mark lewensvatbaarheid. Die potensiële grote vir ‘n biodiesel mark in Suid Afrika is omtrent 1 miljard liter indien dit 10% van sy petroleum diesel teen 2010 wil vervang, maar wetgewing sal nodig wees om ‘n voorspelbare en groeiende mark te skep. Hierdie wetgewing kan in die vorm van subsidies vir boere of biodiesel produsente wees, gebruik maak van regerings koopkrag, verpligtende inmeng maatreëls, belasting voordele of prys vergoeding ooreenkomste. Die finansiële lewensvatbaarheid. Berekeninge om die finansiële lewensvatbaarheid te bepaal is op ‘n 2500 kg/uur (22.5 miljard liter/jaar) gedoen. Hierdie aanleg grote is gebaseer op inligting verkry deur Amigun & von Blottnitz (2005) wat sê dat die optimale grote biodiesel aanleg in Suid Afrika tussen 1500 en 3000 kg/uur is. Daar is na twee tipe aanlegte gekyk, naamlik na ‘n saad ekstraksie biodiesel vervaardigings (SEBP) aanleg wat plaaslike oliesade as voer materiaal gebruik en ‘n kru olie biodiesel vervaardigings (COBP) aanleg wat ingevoerde groente olie as voer materiaal gebruik. 'n SEBP aanleg het ‘n kapitale belegging van tussen R100 en R145 miljoen nodig terwyl ‘n COBP aanleg slegs tussen R45 en R50 miljoen nodig het. Hierdie bydrae sluit werkende kapitaal van omtrent R35 miljoen in wat vas is in 3 maande se voer materiaal kostes. Die onderstaande tabel wys die vervaardigings kostes vir albei tipe aanlegte en verskillende voer materiale. Omtrent 80% van die kostes is voer materiaal terwyl vervoerkostes die tweede hoogste bydraer is. Hierdie resultaat wys na die feit dat die aanleg ligging ‘n baie belangrike rol speel om vervaardigins kostes te minimeer. Dus word die stelling gemaak dat kommersiële biodiesel vervaardiging nie in ‘n paar sentrale aanlegte moet plaasvind nie, maar eerder in ‘n klomp verspreide relatief kleiner aanlegte moet plaasvind. Hierdie kleiner aanlegte sal in die oliesaad produserende streke versprei moet wees. (Suid Afrika sal omtrent 46 aanlegte nodig hê wat elk 2500 kg/uur produseer om 10% van sy diesel teen 2010 te kan vervaardig). Die sensitiwiteits analise het gewys dat die kostes van ‘n SEBP aanleg baie sensitief vir veranderings in oliesaad en oliekoek pryse is. Die kostes van ‘n COBP aanleg is baie sensitief vir veranderinge in groente olie pryse. Wisselvallige landbou pryse maak die kostes van biodiesel baie wisselvallig en onvoorspelbaar. Sojaboon biodiesel kostes is die sensitiefste vir prys veranderings terwyl sonneblom saad die minste geaffekteer word deur sulke prys veranderings. Vir elke R1000/ton wat die glyserol prys styg sal die vervaardigings kostes van biodiesel met 12 sent/liter daal. Die glyserol prys is op die oomblik te laag om in ag te neem weens ‘n oormaat glyserol in die wêreld mark as gevolg van biodiesel produksie. Die gelykbreek prys van biodiesel word uitgewerk deur R1.01/liter brandstof belasting by die vervaardigings kostes by te tel. Op die oomblik (30 Augustus 2006) kan biodiesel van oliesade (behalwe kanola) nie met die petroleum diesel prys meeding nie sonder enige subsidies of wetgewing. Die landbou lewensvatbaarheid. Die landbou implikasies om 10% van die land se diesel uit oliesade te vervaardig word in die onderstaande tabel uiteengesit. Hierdie resultate is gebaseer op die feit dat al drie oliesade gebruik word vir biodiesel vervaardiging en dat die oppervlak verhouding van die drie oliesade konstant bly soos die produksie vermeerder. Biodiesel vervaardiging sal ook die plaaslike oliekoek produksie vermeerder sodat Suid Afrika sal verander van ‘n netto-invoerder (730 duisend ton/jaar) tot ‘n netto-uitvoerder (1.7 miljoen ton/jaar) van oliekoek. Land beskikbaarheid vir so ‘n vermeerderde produksie is nie ‘n probleem nie wat beteken dat Suid Afrika wel die landbou bronne en potensiële mark het om 10% van sy diesel te vervaardig en te absorbeer in die vorm van biodiesel. Uit `n finansiële oogpunt lyk dit egter asof die kommersiële vervaardiging van biodiesel in Suid Afrika nie lewensvatbaar sal wees, sonder enige wetgewings of subsidies, nie. / Centre for Renewable and Sustainable Energy Studies