A dissertation submitted in compliance with the requirements for the Masters Degree in Technology in Biotechnology, Durban University of Technology, 2011. / Under environmental stress, most microalgae produce intracellular neutral lipids as a storage mechanism. In the biotechnology industry, these lipids are extracted and converted to microalgal biodiesel; however the extent of the stress is not measured for optimum lipid accumulation. In the series of studies undertaken, Pulse Amplitude Modulated (PAM) fluorometry was used to measure three types of physiological stress on Chlorella sp., a freshwater microalgal species. Biomass and lipid yields were also used as indicators of the induced stress conditions. Firstly, nutrient induced physiological stress and the subsequent synthesis of cellular neutral lipids was investigated. / M

M.Tech. (Chemical Engineering) / Please refer to full text to view abstract

The production of biodiesel from vegetable oils is not a new technology; it has been around since the 1950’s and both the research in terms of the different feedstock that can be used and the production of biodiesel has since been gaining momentum as there needs to be a new, sustainable and domestic alternative to petroleum fuels. These petroleum fuels pose enormous threats to the environment and therefore need to be replaced as they are mostly contributing to climate change and global warming not to mention the frequent price hikes which are crippling the South African economy. Biodiesel production using vegetable oils seems to be and is the future and a law has recently been passed which sanctions the production of biofuel locally.[1] South African fuel producers will instigate obligatory blending of fossil fuel with biofuel as the country moves to encourage investment in its biofuels sector. The production of biodiesel locally and the blending of biodiesel with other petroleum products will reduce the country’s dependence on imported fuel. The already established petrochemical companies like BP, Sasol and Engine are therefore mandated to purchase these biofuels if and when the biofuels meet the required South African National Standard (SANS) 1935 requirements. This is then where the challenge comes as most of these growing biofuel companies cannot afford to purchase testing equipment.The growing companiesthen discover upon completion of the biofuel manufacturing process that their product does not meet the required standard specification. The failure translates to a financial loss as the final product can possibly not be reworked. The aim of the project is then to assist these companies who are manufacturing biofuel, by providing them with in-house biofuel process methods which will allow for early detection, should there be a need to redo a step in the process and not wait until the completion of the production process. These in-house process-testing methods will range from pH determination, titration tests which will determine the soap content and the percentage free fatty acid content, water determination, density and visual testing. It is not cost-effective for these biodiesel manufacturers to send their samples for outsource testing as evidently the results obtained would be out of specification hence the need to provide these biodiesel manufacturers with in-house analytical testing techniques that will aid in monitoring of the biodiesel production.

Biodiesel from microalgae is a viable alternative for replacing the global demand for petro-diesel. High biomass and lipid production are key desirable characteristics needed in a species to be used for biodiesel production. It has been demonstrated in literature that the increase in salinity can increase the lipid content of microalgae, but lower the growth rate of a species. Therefore the effect that salinity has on the growth and lipid content of ten microalgal species, isolated from a warm temperate solar saltworks, was investigated. The microalgae were cultivated at a temperature of 22°C and at salinities ranging from 17 to 70 psu. It was found that growth and lipid production for all species were influenced to some degree by the salinity. Growth rates greater than 0.6 d-1 showed a decrease with higher salinity. Most (71 percent) of the growth rates that exceeded 0.6 per day were exhibited by cultures exposed to normal salinity (35 psu). This shift is a good indication that salinity inhibits/slows down growth and that the species in general prefer lower salinity conditions. Growth rates ranged from 0.17 ± 0.05 to 1.19 ± 0.17 d-1. Lipid content for the diatoms (2.78 ± 0.36 to 10.86 ± 4.59 percent DW) were lower than expected, whereas the lipid content for the green flagellates (3.10 ± 1.56 to 22.64 ± 1.19 percent DW) was on par with that reported in literature. To bring results into perspective a production model was developed to simulate a production scenario at the Swartkops Saltworks. Lipid and productivity results obtained in this study were used to estimate how much oil and biomass can be produced within the ponds of the Swartkops Saltworks. The model showed that although microalgae cultivation for biodiesel is technically feasible, at present it is not economically viable to do so.

PETROBRAS; FINEP / Este trabalho apresenta o desenvolvimento de um modelo de simulação do processo de produção do biodiesel adequado à realidade brasileira, a qual possui os óleos de soja e algodão como principais matérias-primas. Estes óleos puros ou em misturas são modelados neste trabalho segundo uma expansão da composição em ácidos graxos de cada óleo vegetal, considerando triglicerídeos idealizados com cadeias laterais diferenciadas. Estes compostos são caracterizados na simulação a partir de propriedades fundamentais, como o ponto de ebulição, peso molecular, densidade e temperatura, pressão e volume críticos. Algumas delas possuem valores tabelados, enquanto outras foram estimadas pelo método de contribuição de grupos de Ambrose. O modelo é capaz de estimar propriedades do combustível final, tais como densidade, viscosidade e índice de iodo. Estes resultados foram verificados com dados experimentais obtidos da literatura. Além disso, dois fluxogramas do processo de produção do biodiesel foram modelados em estado estacionário, segundo os equipamentos responsáveis pela purificação e recuperação do biodiesel. No primeiro caso, propõe-se uma lavagem com água e uma coluna de destilação a vácuo. No segundo caso, tem-se um tanque horizontal, que representa um decantador, e novamente uma coluna de destilação a vácuo. Nos dois casos, os reagentes são bombeados para um reator contínuo, onde ocorre a conversão em biodiesel e glicerol. Esta conversão foi abordada de duas maneiras: usando uma conversão fixa em 95% e outra com a utilização de dados cinéticos da literatura capazes de descrever a conversão em função da concentração de reagentes e da temperatura da reação. Os resultados obtidos mostram o rendimento do processo em massa de biodiesel produzido para diferentes composições de matéria-prima. A partir destes resultados uma análise econômica preliminar é apresentada. Além disso, uma análise da integração energética é apresentada para o fluxograma de processo do segundo caso. Usando a análise "pinch", os níveis de utilidades são calculados e uma rede de trocadores de calor é proposta. / This work presents a simulation model for a biodiesel processing plant that fits the Brazilian case which utilizes soybean and cottonseed oils as major feedstocks. These pure oils or blends are modeled in this work according to a fatty acid expansion for each vegetable oil by considering abstract triglycerides with differentiated side chains. These components are characterized in the simulation by fundamental properties such as boiling point, molecular weight, density and critical temperature, pressure and volume. Some of them have reference values in the literature while others were estimated by Ambrose's group contribution method. In addition, two process flowcharts were modeled in steady state by using two different equipments for biodiesel downstream processing. In the first case, water washing and vacuum distillation columns are proposed. In the second case, there is a horizontal tank that represents a decantation unit followed by a vacuum distillation column. In both cases, reagents are fed to a continuous reactor where biodiesel plus glycerol conversion occurs. This conversion was modeled by using two different approaches. The first one considers a 95% fixed conversion while the second one uses kinetic data to describe the conversion as a function of reagents' concentration and temperature. The obtained results show the process efficiency for different feedstock compositions which are then used to accomplish a preliminary economic analysis. In addition, a process integration analysis is presented for the second process flowchart by using the pinch analysis. In this case, utility levels are calculated and a heat exchanger network is proposed.

PETROBRAS; FINEP / Este trabalho apresenta o desenvolvimento de um modelo de simulação do processo de produção do biodiesel adequado à realidade brasileira, a qual possui os óleos de soja e algodão como principais matérias-primas. Estes óleos puros ou em misturas são modelados neste trabalho segundo uma expansão da composição em ácidos graxos de cada óleo vegetal, considerando triglicerídeos idealizados com cadeias laterais diferenciadas. Estes compostos são caracterizados na simulação a partir de propriedades fundamentais, como o ponto de ebulição, peso molecular, densidade e temperatura, pressão e volume críticos. Algumas delas possuem valores tabelados, enquanto outras foram estimadas pelo método de contribuição de grupos de Ambrose. O modelo é capaz de estimar propriedades do combustível final, tais como densidade, viscosidade e índice de iodo. Estes resultados foram verificados com dados experimentais obtidos da literatura. Além disso, dois fluxogramas do processo de produção do biodiesel foram modelados em estado estacionário, segundo os equipamentos responsáveis pela purificação e recuperação do biodiesel. No primeiro caso, propõe-se uma lavagem com água e uma coluna de destilação a vácuo. No segundo caso, tem-se um tanque horizontal, que representa um decantador, e novamente uma coluna de destilação a vácuo. Nos dois casos, os reagentes são bombeados para um reator contínuo, onde ocorre a conversão em biodiesel e glicerol. Esta conversão foi abordada de duas maneiras: usando uma conversão fixa em 95% e outra com a utilização de dados cinéticos da literatura capazes de descrever a conversão em função da concentração de reagentes e da temperatura da reação. Os resultados obtidos mostram o rendimento do processo em massa de biodiesel produzido para diferentes composições de matéria-prima. A partir destes resultados uma análise econômica preliminar é apresentada. Além disso, uma análise da integração energética é apresentada para o fluxograma de processo do segundo caso. Usando a análise "pinch", os níveis de utilidades são calculados e uma rede de trocadores de calor é proposta. / This work presents a simulation model for a biodiesel processing plant that fits the Brazilian case which utilizes soybean and cottonseed oils as major feedstocks. These pure oils or blends are modeled in this work according to a fatty acid expansion for each vegetable oil by considering abstract triglycerides with differentiated side chains. These components are characterized in the simulation by fundamental properties such as boiling point, molecular weight, density and critical temperature, pressure and volume. Some of them have reference values in the literature while others were estimated by Ambrose's group contribution method. In addition, two process flowcharts were modeled in steady state by using two different equipments for biodiesel downstream processing. In the first case, water washing and vacuum distillation columns are proposed. In the second case, there is a horizontal tank that represents a decantation unit followed by a vacuum distillation column. In both cases, reagents are fed to a continuous reactor where biodiesel plus glycerol conversion occurs. This conversion was modeled by using two different approaches. The first one considers a 95% fixed conversion while the second one uses kinetic data to describe the conversion as a function of reagents' concentration and temperature. The obtained results show the process efficiency for different feedstock compositions which are then used to accomplish a preliminary economic analysis. In addition, a process integration analysis is presented for the second process flowchart by using the pinch analysis. In this case, utility levels are calculated and a heat exchanger network is proposed.

Thesis (MScEng (Process Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Development of analytical methods to characterise biodiesel has become central to the overall success of the marketing of biodiesel fuel. In this regard, different bodies including the American Society for Testing and Materials (ASTM) and the European normalization (EN) have come up with various methods to determine important biodiesel parameters such as total glycerol, methanol and the fatty acid methyl esters (FAMEs), etc. Various studies have been conducted on the parameters mentioned above using a variety of instrumentation and sample preparations. The best methods reported are those that have been adopted by both the ASTM and EN standards. The purpose of this study was to develop alternative analytical methods to both the recommended ASTM and EN methods and, in some cases, to make modifications to both standards (ASTM D 6571 and EN 14214) and methods to determine total and bound glycerol, the ester content and also methanol content in biodiesel. Moreover, water washing after transesterification and the effect this practice has on biodiesel cold flow properties such as kinematic viscosity, cloud and pour point and density were evaluated. The possibility of using the iodine value to predict the feedstock source of an unknown biodiesel was also investigated. Six different vegetable oil samples were transesterified with methanol and used for this study. The six samples used were palm, crown, sunflower, waste vegetable oil (wvo), peanut and rapeseed biodiesel. Quantitative results indicated that the use of programmable temperature volatilisation (PTV) for total glycerol did not produce the required repeatability of between 1-4% relative standard deviation(RSD) for total glycerol analyses in biodiesel with precision of 25%, 86%, 25% and 56% for free glycerol (FG), monoglycerides (MG), diglycerides (DG), and triglycerides (TG) respectively. The standard requires a relative standard of between 1-4% As an alternative to the method using gas chromatography, normal phase high performance chromatography (HPLC) with binary gradient elution was used to determine the bound glycerol content. This method proved accurate and repeatable with RSD % of 0.33, 1.12, and 1.2 for TG, DG and MG respectively. Following the EN14103 protocol (European standard ester determination), the Zebron ZBWAX column which is comparable to the specification recommended by EN14103 but afforded the determination of ester content from the esters of myristic acid (C14:0) to behenic acid (C22:0) with reproducibility with RSD % of 6.81, 1.91, 7.27, 0.64, 1.18, 1.55, 6.03, 1.96, and 5.21 for methyl esters of myristic, palmitic, stearic, oleic, linoleic, linolenic, arachidoic, gadoleic and behenic acid respectively. Solid phase micro extraction (SPME) using GC-MS was developed as an alternative to both the EN14110 and ASTM D93 protocols for determining the methanol content in biodiesel. For this method, polyethylene glycol fibre (PEG) was used together with a deuterated methanol internal standard and a DB-FFAP (60m×0.25um×0.25um) column. Less volume of sample was required as compared to the EN14214 method. This method was found to be sensitive, accurate and repeatable with a RSD % of 4.82. The Iodine number of biodiesel decrease compared to their corresponding feed stock and therefore predicting the feed stock of an unknown biodiesel was going to be difficult .Results from this study indicated that it is not possible to predict the feed stock source of an unknown biodiesel from its iodine value. The effect of water washing after phase separation on biodiesel cold flow properties such as kinematic viscosity, density, cloud and pour point depended on the type of biodiesel produced. We observed that water washing after transesterification caused an increase in all the cold flow properties of sunflower biodiesel, whereas only the densities and kinematic viscosities increased in the case of palm and waste vegetable oil biodiesel. The cloud and pour point of the latter two diesel samples remained unchanged after water washing. Thus, the effect of water washing on biodiesel cold flow depended on the type of biodiesel. Blending a highly saturated biodiesel (fewer numbers of double bonds) with a less saturated biodiesel (higher number of double bonds) resulted in an improvement of both the pour and cloud points of the resultant biodiesel blend. / AFRIKAANSE OPSOMMING: Die ontwikkeling van analitiese metodes om biodiesel te karakteriseer word tans as ‘n kernmaatstaf gesien om biodiesel suksesvol te bemark. Hiervoor het verskeie liggame wat die Amerikaanse Vereniging vir Toetsing van Materiale (AVTM) en die Europese Normalisering (EN) insluit met verskeie standaard analitiese metodes vorendag gekom om belangrike biodiesel parameters soos bv. totale gliserol, metanol en vetsuur metielesters te meet. Om hierdie parameters te bepaal is van ‘n wye verskeidenheid toetse met verskillende instrumente en monsterbereidings gebruik gemaak. Die beste metodes is deur beide die AVTM en EN aanvaar. Die doel van hierdie studie was om metodes te ontwikkel wat as alternatiewe kan dien tot die wat deur die AVTM en EN voorsgeskryf is. In sommige gevalle is aanpassings tot beide die standaarde (AVTM en EN) en metodes aangebring om die totale en gebonde gliserol-, esteren metanolinhoud te bepaal. Verder is die effek van ‘n water wasstap na transesterifikasie op biodiesel se kouevloei eienskappe gevalueer wat eienskappe soos kinematiese viskositeit, vertroebelingspunt, gietingspunt en digtheid insluit. Die moontlike gebruik van die Jodiumpunt om die bron van die voerstof van ‘n onbekende diesel te bepaal is ook ondersoek. In hierdie studie is ses verskillende oliemonsters van plantaardige oorsprong gebruik wat d.m.v. metanol getransesterifiseer is. Hierdie monsters het palm-, kroon-, sonneblom-, afvalplant-, grondboontjie- en raapsaadolie ingelsuit. Tydens die studie is programmeerbare temperatuur vervlugtiging (PTV) vergelyk met inkolom inspuiting soos deur AVTM D6584/EN14214 vir totale gliserol analise voorgeskryf. Kwantitatiewe resultate het getoon dat die PTV metode nie die verlangde akkuraatheid van ‘n relatiewe standaardafwyking (RS) van 1-4% vir beide vrye en gebonde gliserol kon handhaaf nie. Die akkuraatheid was in die omgewing van 25%, 86%, 25% en 56% vir vrye gliserol (VG), monogliseriede (MG), digliseriede (DG) en trigliseriede (TG), onderskeidelik. Normale fase hoë werkverrigting vloeistofchromatografie met ‘n binêre elueeringsgradiënt is as alternatief tot gaschromatografie (GC) ondersoek om die gebonde gliserolinhoud te bepaal. Al was die GC metode meer sensitief, het die vloeistofchromatografie metode ‘n hoë graad van akuraatheid en herhaalbaarheid getoon met RS% waardes van 0.33, 1.12 en 1.2 wat vir TG, DG en MG, onderskeidelik, verkry is. ‘n Zebron ZB-WAX kolom is vir die EN14103 protokol gebruik. Behalwe vir ‘n groter lengte kon hierdie kolom met spesifikasies soos deur EN14103 voorgeskryf vergelyk word. Met die gebruik van hierdie kolom kon die esterinhoud van miristiensuur (C14:0) tot behensuur (C14:0) bepaal word. ‘n Hoë graad van herhaalbaarheid met RS% waardes van 6.81, 1.91, 7.27, 0.64, 1.18, 1.55, 6.03, 1.96 en 5.21 vir die metielesters van miristien-, palmitien-, stearien-, oleïn-, linoleïn-, linoleen-, aragidoon-, gadoleïen- en behensuur is onderskeidelik verkry. Om die metanolinhoud van die biodiesel te bepaal is soliede fase mikroekstraksie (SFME) m.b.v. gaschromatografie-massaspektrometrie (GC-MS) as alternatiewe tot EN14110 en AVTM D93 ontwikkel. In hierdie metode is daar van poliëtileenglikolvesels (PEG) en gedeutereerde metanol saam met ‘n DB-FFAP kolom (60 mm x 0.25 mm x 0.25 mm) gebruik gemaak. Hierdie metode het ‘n kleiner monstervolume as die EN14214 metode benodig en was sensitief, akkuraat en hehaalbaar wat tot ‘n RS% waarde van 4.82 gelei het. Op grond van die Jodiumwaarde van biodiesel en hul ooreenstemmende voerstowwe het hierdie studie bevind dat die Jodiumwaarde nie gebruik kan word om die voerstof van ‘n onbekende diesel kan voorspel nie. Die effek van ‘n water wasstap na faseskeiding op verskeie kouevloei eienskappe soos kinematiese viskositeit, vertroebelingspunt, gietingspunt en digtheid het van die tipe diesel afgehang. Dit is bevind dat ‘n water wasstap na transesterifikasie ‘n toename in al die kouevloeieienskappe van sonneblomdiesel tot gevolg gehad het. In teenstelling hiermee het slegs die kinematiese viskositeit en digtheid van palm- en afvalplantdiesel vermeerder terwyl hul vertroebelings- en gietingspunte onveranderd gebly het. Die hipotese dat ‘n water wasstap na transesterifikasie tot swak kouevloei eienskappe lei is dus as onwaar bevind aangesien hierdie eienskappe deur die tipe biodiesel bepaal word. Deur ‘n hoogs versadigde biodiesel (lae aantal dubbelbindings) met ‘n minder versadigde biodiesel (hoë aantal dubbelbindings) te vermeng het tot ‘n verbetering van beide die vertroebelings- en gietingspunte gelei. / Centre for Renewable and Sustainable Energy Studies

Thesis (MBA)--Stellenbosch University, 2011. / The purpose of the study is to investigate the feasibility and sustainability of producing biodiesel from Jatropha, which contains oil in its seeds by using the Rainbow Biotech economic intervention or also known as the Distributed Food and Fuel Plantation (DFFP) model. The DFFP model is an effective mechanism for producing food and fuel in conjunction with each other, without the biodiesel production influencing the production of food in an adverse way. This is very important, as food security is a high priority for Africa, in order to address the problem of hunger and poverty. Biodiesel produced from Jatropha is an eco-friendly and sustainable alternative to fossil fuel diesel, as it is a carbon neutral fuel. Jatropha cultivation will also create much needed employment in the rural areas of Africa, which has the highest need for socio-economic development on the continent. Jatropha also has the ability to grow on marginal soils and wastelands. Africa has vast open spaces on which Jatropha, as a biodiesel source, can be cultivated without infringing on food production areas. The energy return of the whole production cycle of Jatropha biodiesel is nevertheless a source of much debate. Most stakeholders felt that the energy return is negative. No agreement has yet been reached about whether the energy content of the by-products from biodiesel must be included in the integrated energy balance equation. In order to make biodiesel from Jatropha a sustainable alternative for small farmers in the Southern African Development Community (SADC), government and regional policies will have to support it by promoting it actively. This will generate interest from global biodiesel investors who will then be willing to invest in projects based on the DFFP model of economic development. The DFFP model offers investors economic returns on investment of between 29 and 33 per cent and payback periods of less than four years. It is a very attractive economic development instrument, as it will ensure equitable and sustainable economic and rural expansion in SADC. Ultimately, this model has the potential to create a better life for all the inhabitants on the African continent. Rainbow Biotech (the DFFP model), as an economic development mechanism, will therefore indeed be the next big thing for the SADC in the future.

Thesis (MBA (Business Management))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: Through the continual pursuit to reduce wastage through converting unmarketable by-products into a form that can be sold or used, it was established that an opportunity was available to refine poor-quality fish oil into a fuel source for internal use by a company. By commissioning a biodiesel refinery at the pelagic fish-processing facility of Pioneer Fishing (Pty) Ltd, it will be possible to refine the fish oil into biodiesel and easily distribute the fuel to the fishing vessels or the trucks used for the catching and transportation of pelagic fish. South African legislation is promoting small-scale biodiesel plants by reducing the taxes and levies payable on biodiesel sold by those refineries. The aim of this research report is to provide Pioneer Fishing (Pty) Ltd with a business plan to motivate the commissioning of a small-scale biodiesel plant to process the waste fish oil into a useable energy source to fuel the fishing vessels and trucks. / AFRIKAANSE OPSOMMING: Die voortdurende strewe na minder vermorsing deur onbemarkbare neweprodukte in ʼn verhandelbare of bruikbare vorm om te sit, het die geleentheid uitgewys om visolie van ʼn swak gehalte tot ʼn brandstof vir interne gebruik deur ‟n maatskappy te raffineer. Deur ʼn biodieselraffinadery by die diepseevisverwerkingsfasiliteit van Pioneer Fishing (Edms) Bpk in gebruik te neem, sal die afvalvisolie van dié aanleg tot biodiesel geraffineer kan word. Die biodiesel sal betreklik maklik beskikbaar gestel kan word aan die vaartuie en die vragmotors wat vir die vangs en vervoer van die diepseevis gebruik word. Heersende Suid-Afrikaanse wetgewing moedig juis kleinskaalse biodieselaanlegte aan deur ʼn korting toe te staan op die belasting en heffings op die biodiesel van sodanige raffinaderye. Hierdie navorsingsverslag het ten doel om Pioneer Fishing (Edms) Bpk van ʼn sakeplan te voorsien ter motivering van die ingebruikneming van ʼn kleinskaalse biodieselaanleg om die afvalvisolie tot ʼn bruikbare energiebron te verwerk waarmee die visvaartuie en -vragmotors aangedryf kan word.

published_or_final_version / abstract / Mechanical Engineering / Doctoral / Doctor of Philosophy