Biodiesel is an alternative fuel that can be produced from a variety of lipid feedstocks. It has a number of perceived advantages over conventional petroleum diesel and as a result world production of biodiesel has increased dramatically since the turn of the century. Amongst its reported disadvantages is a widely observed increase in emissions of oxides of nitrogen, or NOx. Several explanations have been proposed for this phenomenon; in reality it is likely to be due to a combination of factors. The interplay of multiple factors affecting NOx emissions means that the increase in NOx when fuelling on biodiesel is not consistent or ubiquitous, but is instead dependent upon operating conditions and the specifics of the fuels being compared. The work documented in this thesis explores the nature and causes of the change in NOx emissions associated with biodiesel. The intention was that, by adjusting operating conditions, and using a wide range of fuels, doped with additives to achieve an even broader range of combustion characteristics, the impact of important variables would be made clearer, making it possible to reduce the problem to its lowest common denominators. In early experiments it was found that NOx emissions from biodiesel tended to be lower than those of petrodiesel under conditions where combustion was relatively highly premixed, but higher under more conventional diesel conditions where diffusion combustion constituted a larger proportion of heat release. The main experimental set revealed a definite increase in NOx emissions when fuelling on biodiesel, for a fixed start of combustion and equivalent degree of premixing. The addition of an oxygenate to petrodiesel elicited comparable NOx emissions to biodiesel, as a function of fuel-bound oxygen content; the data implies that the like-for-like biodiesel NOx increase may be a direct result of fuelbound oxygen. However, the like-for-like biodiesel NOx increase varies dependent upon operating conditions. In part, this may be related to higher apparent heat release rate (AHRR) through the diffusion burn phase when fuelling on biodiesel. This may result from the extended biodiesel injection duration. Across operating conditions, the extent to which smoke emissions when fuelling on petrodiesel exceeded those when fuelling on biodiesel was generally correlated with the magnitude of the biodiesel NOx increase; where the difference in smoke emissions was small, the biodiesel NOx increase was small, and where the difference in smoke emissions was more substantial, so was the difference in NOx emissions. This suggests a possible connection to changes in mixture stoichiometry. When differentiating between fuels, increased cetane number reduces NOx, and increased oxygen content increases NOx. Biodiesel does not necessarily have higher NOx emissions than petrodiesel: the biodiesel NOx increase exists where the difference in cetane number is insuffi cient to counteract the effects of fuel-bound oxygen content.

Un protocole d’altération de lubrifiants par NO2 en laboratoire a été développé pour étudier les effets de la nitroxydation sur les additifs et la base hydrocarbonée de lubrifiants moteur et comprendre leurs mécanismes d’altération. Des structures de produits d’altération et des voies de transformation ont pu être proposées ainsi que les facteurs contrôlant les cinétiques de dégradation des additifs. Les interactions entre les constituants de lubrifiants tant au niveau des cinétiques de dégradation que des structures des produits de dégradation ont ainsi été identifiées, notamment à partir d’un plan d’expériences. L’évolution des lubrifiants simulée en laboratoire n’est pas directement superposable à celle observée avec des essais moteur, un certain nombre de produits d’altération n’ayant pas été détectés en essais moteur. En revanche, les interactions contrôlant les cinétiques de dégradation des additifs sont proches dans les cas des expériences de laboratoire et des essais moteur. / An alteration laboratory protocol of lubricants by NO2 has been developed in order to investigate the effects of nitroxidation on base oil and additives from engine lubricants, and to understand the different mechanisms involved. The structure of alteration products and their transformation pathways have been proposed, as well as the factors that control the degradation kinetics of the additives. Interactions between lubricant constituents have been identified at the degradation kinetic level as well as the level of the alteration products formed, notably by means of an experimental design. The fate of lubricants in the laboratory experiments does not exactly match that observed in the case of engine tests, notably regarding the absence of formation of some degradation products. However, the interactions controlling the degradation kinetics of lubricant additives are close between laboratory experiments and engine tests.

In Vietnam, the research and application of biogas technology were given a considerable attention in past 30 years. There is several biogas plant models apply in the suburban and rural areas where most people’s life is based on animal husbandry. Each biogas plant model own strong points or weakness that adapt to detail circumstances. The biogas plants play a key role within the VACB farming system especially in the Mekong Delta where produce more than 50% of yearly national agriculture production. This paper gives a comprehensive overview on the popular biogas models in the Mekong Delta through its development history. Knowing on the presented biogas technology in the Mekong Delta will lead the biogas-related organizations or private on biogas development at this region. / Ở Việt Nam việc nghiên cứu và ứng dụng công nghệ khí sinh học đã được chú ý trong 30 năm gần đây. Một số mô hình khí sinh học đã và đang được lắp đặt tại các vùng ngoại ô và nông thôn là những nơi tập trung nhiều hộ dân chăn nuôi heo. Có nhiều mô hình khí sinh học đã được triển khai, trong đó mỗi mô hình đều có những điểm mạnh và điểm yếu đáp ứng theo từng yêu cầu cụ thể. Ở ĐBSCL nơi sản xuất trên 50% sản lượng nông nghiệp của cả nước, hầm ủ khí sinh học đóng một vai trò quan trọng trong mô hình canh tác VACB. Bài báo này trình bày chi tiết các kiểu hầm ủ khí sinh học phổ biến tại ĐBSCL tương ứng với từng thời điểm phát triển của công nghệ này. Sự hiểu biết về các kiểu hầm ủ khí sinh học hiện tại ở ĐBSCL sẽ giúp các tổ chức hoặc cá nhân có liên quan trong việc định hướng phát triển công nghệ khí sinh học cho toàn vùng.

The increase of petroleum cost as well as global warming and climate change result in investigation to discover new renewable energy resources. Bioenergy is one of the most important sources that is concerning the scientists and industrial sector. Although bioethanol had to be known as one of the most important renewable energy sources in order to reduce greenhouse gases and global warming, there is a limited number of publications reporting on them. In this review, a brief overview is offered about bioethanol production from algae. It can be given a deeper insight in dificulties and promising potential of bioethanol from algae. / Sự gia tăng giá nhiên liệu hóa thạch cùng với cảnh báo toàn cầu về biến đổi khí hậu hướng đến việc nghiên cứu tìm ra những nguồn năng lượng có thể tái tạo. Năng lượng sinh học là một trong những nguồn quan trọng được các nhà khoa học và doanh nghiệp quan tâm. Mặc dù ethanol sinh học đã được biết đến như là một trong những dạng năng lượng tái tạo quan trọng nhất để giảm thiểu các khí nhà kính và cảnh báo toàn cầu, nhưng chỉ có một số ít bài báo về nó. Trong bài tổng quan này, chúng tôi giới thiệu vắn tắt việc sản xuất ethanol sinh học từ tảo. Nó đưa ra cái nhìn sâu hơn về những khó khăn và tiềm năng hứa hẹn của sản xuất ethanol sinh học từ tảo.

Λόγω της αύξησης των τιμών του αργού πετρελαίου, τα τελευταία χρόνια η παραγωγή βιοντίζελ (biodiesel) έχει αποκτήσει μεγάλο ενδιαφέρον. Η χρήση των φυτικών ελαίων ως πρώτη ύλη στη βιομηχανία παραγωγής βιοντίζελ έχει πολλά μειονεκτήματα. Επομένως, το ενδιαφέρον των ερευνητών έχει στραφεί στη χρήση των SCO (ελαίων μονοκύτταρων οργανισμών), ως μία εναλλακτική πρώτη ύλη. Στην παρούσα διπλωματική εργασία, η βιομηχανική γλυκερόλη μετατράπηκε σε SCO από διάφορα στελέχη ελαιογόνων Ζυγομυκήτων, οι οποίοι καλλιεργήθηκαν υπό μη-ασηπτικές συνθήκες, χρησιμοποιώντας εκλεκτικά, περιοριστικά ως προς την πηγή αζώτου θρεπτικά μέσα καλλιέργειας, τα οποία ανέστειλαν τη βακτηριακή αύξηση. Όταν οι μύκητες Thamnidium elegans, Mortierella ramanniana, Mortierella isabellina, Zygorhynchus moelleri, Mucor sp. και Cunninghamella echinulatα καλλιεργήθηκαν σε pH6 υπό μη-ασηπτικές συνθήκες, ήταν ικανοί να παράγουν 1,2- 4,1 g/l βιομάζα και να συνθέτουν 17,5- 49,3% wt/wt λιπίδια επί της ξηρής τους βιομάζας. Τα επίπεδα σύνθεσης της βιομάζας ήταν ~50% χαμηλότερα από εκείνα που επιτεύχθηκαν όταν οι Ζυγομύκητες καλλιεργήθηκαν υπό ασηπτικές συνθήκες. Διάφορες αντι-βακτηριακές ουσίες (αιθέρια έλαια, αντιβιοτικά) χρησιμοποιήθηκαν ώστε να επιτευχθεί υψηλότερη συσσώρευση βιομάζας και λιπιδίων από τους Ζυγομύκητες. Σε pH5, ο μύκητας M. ramanniana παρήγαγε 4,4 g/l βιομάζα που περιείχε 22% wt/wt λιπίδια, ενώ ο μύκητας T. elegans παρήγαγε 3,4 g/l βιομάζα που περιείχε 45% wt/wt λιπίδια επί της ξηρής τους βιομάζας. Όταν προστέθηκε στο μέσο καλλιέργειας αιθέριο έλαιο θυμαριού, 4,8 g/l βιομάζα συντέθηκαν από το μύκητα Τ. elegans που περιείχαν 42,6% wt/wt λιπίδια. Επιπλέον, όταν προστέθηκαν στο μέσο καλλιέργειας αντιβιοτικά και αιθέριο έλαιο, ο μύκητας T. elegans ήταν ικανός να παράγει 7,9 g/l βιομάζα που περιείχε 31,5 % wt/wt λιπίδια. Τα αποτελέσματα έδειξαν ότι αν και ο πληθυσμός των βακτηρίων ανέστειλε την αύξηση των μυκήτων, η συσσώρευση των λιπιδίων δεν επηρεάστηκε από την παρουσία των βακτηρίων στο μέσο καλλιέργειας, συγκρινόμενα με αποτελέσματα πειραμάτων που πραγματοποιήθηκαν υπό ασηπτικές συνθήκες (control). Ως εκ τούτου, αναπτύχθηκε μια διεργασία δύο σταδίων στις κωνικές φιάλες και στο βιοαντιδραστήρα, κατά την οποία η αύξηση του μύκητα πραγματοποιήθηκε υπό ασηπτικές συνθήκες (1ο στάδιο) και ακολούθησε η συσσώρευση των λιπιδίων που πραγματοποιήθηκε υπό μη-ασηπτικές συνθήκες (2ο στάδιο). Στο 2ο στάδιο, προστέθηκε στο θρεπτικό μέσο καλλιέργειας αιθέριο έλαιο θυμαριού ως αντι- βακτηριακή ουσία. Από αυτή τη διεργασία, υψηλές ποσότητες λιπιδίων συσσωρεύτηκαν μέσα στο μυκήλιο του μύκητα, με απόδοση που έφτασε περίπου 13% wt/wt μικροβιακού ελαίου ανά καταναλωθείσα γλυκερόλη. / Biodiesel production has gained much interest during last years as an alternative fuel source, which arises from the escalating prices of petroleum fuels. The use of plant oils as feedstock for the biodiesel manufacture has many drawbacks, thus the interest has turned to single cell oil (SCO) as an alternative. In this thesis, raw glycerol was converted into SCO by oleaginous Zygomycetes, cultivated under non-aseptic conditions, using selective nitrogen limited media that inhibit the bacterial growth. Thamnidium elegans, Mortierella ramanniana, Mortierella isabellina, Zygorhynchus moelleri, Mucor sp. and Cunninghamella echinulata, cultivated at pH6 under non-aseptic conditions, were able to produce 1.2- 4.1 g/l of biomass and synthesized 17.5- 49.3 % wt/wt of lipids in their biomass. These accumulation levels in biomass were ~50% lower compared to those achieved when Zygomycetes grown under aseptic conditions. Various anti-bacterial compounds, including essential oils and antibiotics were used in order to achieve a higher biomass and lipid accumulation. At pH5, M. ramanniana produced 4.4 g/l biomass containing 22% wt/wt lipids in their biomass, while T. elegans produced 3.4 g/l biomass containing 45% wt/wt of lipids. When thyme essential oil was added into the growth medium, T. elegans produced 4.8 g/l biomass containing 42.6% wt/wt lipids. Furthermore, with the addition of antibiotics together with essential oil into the medium, the production of SCO was further improved with T. elegans being able to produce 7.9 g/l of biomass containing 31.5% wt/wt lipids. The obtained data showed that although bacterial populations inhibited the fungal growth, lipid accumulation remained unaffected by the presence of bacteria in the growth medium compared to control experiments (conducted under aseptic conditions). Therefore, a two-stage process was developed in both flasks and bioreactor, in which growth was performed under aseptic conditions (1st stage) followed by lipid accumulation performed under non-aseptic conditions (2nd stage) in the presence of thyme essential oil as an antibacterial agent. Large amounts of lipids were accumulated inside the mycelia, yielding around 13% wt/wt of oil per glycerol consumed.

Στην παρούσα διδακτορική διατριβή μελετήθηκε η συνδυασμένη παραγωγή υδρογόνου και μεθανίου από την ενεργειακή καλλιέργεια του γλυκού σόργου. Το γλυκό σόργο είναι ένα μονοετές ενεργειακό φυτό, μεγάλης φωτοσυνθετικής ικανότητας, πλούσιο σε υδατάνθρακες, το οποίο θεωρείται ιδανικό για την παραγωγή βιοκαυσίμων. Η παραγωγή του υδρογόνου από τα σάκχαρα του σόργου, πραγματοποιήθηκε μέσω της ενδογενούς βακτηριακής καλλιέργειας του φυτού, γεγονός που καθιστά τη διεργασία όχι μόνο τεχνικά αλλά και οικονομικά ελκυστική. Σε πρώτο στάδιο, μελετήθηκε η επίδραση των λειτουργικών συνθηκών στη ζυμωτική παραγωγή του υδρογόνου από τα διαλυτά σάκχαρα του γλυκού σόργου, μέσω μικτής μικροβιακής καλλιέργειας, σε συνεχή μεσόφιλο, βιοαντιδραστήρα. Στη συνέχεια, η πλούσια σε οργανικό φορτίο απορροή του ζυμωτικού υδρογονοπαραγωγού βιοαντιδραστήρα, υπέστη περαιτέρω επεξεργασία σε συνεχή μεσόφιλο αναερόβιο χωνευτήρα, με ταυτόχρονη παραγωγή μεθανίου. Το μοντέλο ADM1 (Anaerobic Digestion Model No 1), χρησιμοποιήθηκε για τη μαθηματική προσομοίωση και των δύο βιοδιεργασιών. Η δομή του μοντέλου τροποποιήθηκε προκειμένου να βελτιωθούν οι προβλέψεις για τη διεργασία παραγωγής υδρογόνου. Τέλος, πραγματοποιήθηκε οικονομική αποτίμηση της βιωσιμότητας της συνολικής διεργασίας παραγωγής υδρογόνου και μεθανίου, από το γλυκό σόργο. Η παραγωγή βιοκαυσίμων, με τον τρόπο που έχει σχεδιαστεί, αποδείχτηκε οικονομικά μη συμφέρουσα, αλλά με κάποιες βελτιώσεις πιθανό να αποτελέσει ανταγωνιστική τεχνολογία, στο κοντινό μέλλον. / In the present study we investigated the hydrogen and methane production from sweet sorghum biomass. Sweet sorghum is an annual plant, characterized by high photosynthetic efficiency. Sweet sorghum biomass is rich in readily fermentable sugars and thus it can be considered as an excellent raw material for biofuels generation. It is the first time that this plant is used for the production of hydrogen, although ethanol and methane are among the best-known microbial products produced from sweet sorghum. Τhe fermentative production of hydrogen was achieved using an indigenous mixed microbial culture. The present study concerns the fermentative production of hydrogen from the sugars contained in sorghum extract. The process took place in a mesophilic continuous stirred tank type bioreactor, by an indigenous mixed microbial culture and it was studied at various conditions. Τhe subsequent anaerobic treatment of the effluent of the fermentative hydrogenogenic reactor with the simultaneous production of methane was investigated in a continuous stirred tank type reactor operated at three hydraulic retention times. The recently developed anaerobic model ADM1 was used to simulate the anaerobic digestion process and the fermentative hydrogen production process. However the structure of the model was modified, in order to improve the predictions for biohydrogen production. Finally, technoeconomic analysis was performed to determine the potential economic viability of the process. Biohydrogen and methane production from sweet sorghum biomass was not economic feasible; therefore improvement of the process design is necessary.

An 11 Blockheizkraftwerken (BHKW) ohne Oxidationskatalysator und an 10 BHKW mit Oxidationskatalysator in Sachsen und Thüringen wurden die Einflussfaktoren auf die Formaldehydemissionen untersucht. Geprüft wurden insbesondere die Motorbetriebsparameter wie z.B. Zylindertemperaturen, Verbrennungsluftverhältnis, die Biogaszusammensetzung und die Biogasfeuchte. Im Ergebnis konnte kein bzw. nur ein geringer Einfluss der untersuchten Parameter auf die Formaldehydbildung festgestellt werden. Ebenfalls ließ sich bei den meisten der untersuchten Anlagen kein Einfluss von Wartungstätigkeiten sowie Ersatzteil- und Betriebsstoffwechseln auf die Formaldehydemissionen feststellen. Sollte der Gesetzgeber künftig einen niedrigeren Formaldehydgrenzwert vorschreiben, werden zusätzliche Technologien zur Biogasaufbereitung z.B. mit Aktivkohlefilter und zur Abgasnachbehandlung z.B. mit Oxidationskatalysator oder Thermoreaktor notwendig. Diese müssen aber noch hinsichtlich ihrer Standzeiten untersucht und optimiert werden.

To mitigate the problems of depleting and soaring price of fossil fuels, the production and use of renewable energy have been vigorously promoted. In Europe, the role of biologically-derived fuels and in particular biodiesel is gradually increasing in prominent. Rapeseed biodiesel is the most widely produced in Europe. As a consequence, enormous amount of by-products from production processes are being generated. Current strategies for managing these by-products (mainly rapeseed meal and crude glycerol) seem not to be economically sustainable. More efficient utilisation could add more value to the production chain which in turn would raise the competitiveness of biodiesel compared to petro-diesel. The aim of the project reported in this thesis was to study the feasibility of producing a value added product, polyhydroxybutyrate (PHB), from by-products generated from rapeseed biodiesel production processes as well as to investigate the effects of methanol, a major impurity in crude glycerol, on growth of Cupriavidus necator, a PHB-producing micro-organism.The preliminary study of C. necator growth in crude glycerol based media revealed that optimum concentration of crude glycerol was in a range 15-25 g/L. It was also found that slight changes in the carbon to nitrogen ratio of the feedstock did not significantly affect the growth while methanol at concentrations beyond 10 g/L did. A model based on a saturation equation was developed and used to successfully predict the inhibition of growth by methanol. From the developed model, mechanisms of the inhibition were proposed. The model could also be used to predict satisfactorily growth or productivity rates in other systems containing short-chain alcohols. The growth in solutions derived from rapeseed meal (designated as hydrolysate) via solid-state fermentation by Aspergillus oryzae followed by hydrolysis of the fermented solids was also studied. The biomass production was found to increase as a function of initial free amino nitrogen (FAN) concentration presented in the hydrolysate. However, at higher initial FAN concentrations, a lower conversion of nitrogen to biomass was observed. PHB production was studied using a feedstock which was a mixture of the hydrolysate and crude glycerol. Total biomass concentration reached 28.8 g/L at 120 h with 86% PHB content. PHB productivity and PHB yield on glycerol were 0.21 g/L•h and 0.32 g/g respectively. These results were comparable with those obtained when pure glycerol and synthetic crude glycerol were used, suggesting that, technically, the use of the generic rapeseed- and crude glycerol-based feedstock to produce PHB is feasible.Overall, the feasibility of producing PHB from rapeseed biodiesel by-products has been demonstrated. The satisfactory result leads to the more important outlook that the generic feedstock derived from rapeseed biodiesel by-products has the potential to be used to produce a wide range of products depending on the micro-organism used. Further development of this process to improve nutrient production efficiency as well as product yields and subsequent integration of the process into the biodiesel production process could well be an important contribution in the development of a sustainable biodiesel industry.

La substitution des composés carbonés d'origine fossile par des matières premières renouvelables représente un enjeu majeur et stratégique pour l'environnement, l'économie, et la santé publique. Nous nous sommes particulièrement intéressés au cas des dérivés du phénol, largement utilisés dans le domaine des matériaux synthétiques (résines, plastiques). Des travaux antérieurs ont démontré le potentiel des monomères de flavanols, sous-unités constitutives des chaines polymériques des tanins condensés comme substituts aux phénols issus de la pétrochimie, tels que le bisphénol A, l'objectif du présent travail a été de contribuer au développement d'une voie industrielle d'accès à de tels composés par dépolymérisation des tanins condensés (proanthocyanidines), une ressource végétale abondante mais actuellement peu exploitée pour ce type d'applications. Cette dépolymérisation peut être obtenue par rupture de la liaison interflavanique en milieu acide et piégeage des carbocations formés par un réactif nucléophile. Différentes stratégies et conditions ont été étudiées pour mieux comprendre le rôle de l'acide, du nucléophile, du solvant et l'impact de la température sur la réaction de dépolymérisation. Les stratégies sélectionnées, menées sur un dimère B2 pur servant de modèle et sur un extrait industriel de tanins de pépins de raisins blancs issus de marcs à l'échelle du gramme, ont été comparées en termes de rendement, de cinétique, de stabilité des produits, et de facilité de mise en œuvre et de traitement dans la perspective d'une production à plus grande échelle respectant au mieux les objectifs du développement durable et les contraintes de l'industrialisation. / The substitution of fossil carbon by renewable raw materials is a major strategic challenge for the environment, economy and public health. Our thesis focuses on the utilisation of phenol derivatives, which are widely used in the field of synthetic materials (resins, plastics). Previous studies have demonstrated the potential of plant flavanol monomers as substitutes for petrochemical phenols such as bisphenol A. The objective of this work was to contribute to the development of an industrial access to such compounds by depolymerization of condensed tannins (proanthocyanidins), an abundant plant resource currently untapped for such applications. Depolymerization can be performed by breaking the interflavan bonds in acidic medium and scavenging the released carbocations by a nucleophilic reagent. Various strategies and conditions were studied and compared to better understand the role of the acid, the nucleophile and the solvent and temperature in the depolymerisation reaction. The selected strategies, applied on a pure B2 dimer used as a model and an industrial seed tannins extract from white grape pomace at the gram scale, were compared in terms of performance, kinetics, product stability, ease of implementation and work-up in the context of a larger scale production complying with the objectives of sustainable development and the constraints of industrialization.

The thesis presents an experimental investigation of combustion performance and emissions of waste cooking oil (WCO) based biodiesel. To evaluate the comparative performance of biodiesel and diesel, combustions tests were conducted using Continuous Combustion rig (CCR) and Land Rover VM diesel engine. Firstly, physical properties of WCO biodiesel and diesel samples were measured in the laboratory. Elemental analysis of WCO biodiesel showed that there are differences between the functional groups in diesel and biodiesel which lead to major differences in the combustion characteristics of the two fuel types. It was found that biodiesel had 10% lower carbon content, almost no sulphur content for biodiesel and up to 12% more oxygen content compared with diesel. This explains the lower caloric value for WCO biodiesel (up to l8 %) compared with diesel. However, higher oxygen content and double bounds in WCO biodiesel increase its susceptibility to oxidation. The CCR test results showed an increase in combustion gas temperature with the increases in biodiesel blend ratio in diesel. This was due to a faster reaction rate for biodiesel than that of diesel leading to a faster brakeage of the hydrocarbon chain to release more heat. The engine tests were performed to measure the torque and emissions for different engine speeds and loads. In general a decrease in engine torque with up to 9% for biodiesel was observed, which was due to the lower calorific value of biodiesel compared with that of diesel. The brake specific fuel consumption (BSFC) increased as the biodiesel blend ratio in diesel increases due a greater mass of fuel being injected at a given injection pressure, compared with diesel. Using WCO blends ratio up to 75% in diesel showed a reduction in exhaust emission compared with diesel, however, at the cost of increased fuel consumption. A common conclusion can be drawn in favour of the WCO biodiesel as being a greener alternative to petro-diesel when used in blend with diesel. However, due to large variations in the biomass used for biodiesel production could lead to variations in physical and chemical properties between biodiesel produced from different biomass. Therefore more stringent standards need to be imposed for biodiesel quality in order to diminish the effect of variation in physicochemical properties on engine performance and emissions. The future work in developing standard test procedures for establishing fuel properties and limits/targets would be beneficial in using a large amount of waste cooking oil in the production of biodiesel, thus contributing to reduction in CO2 and waste minimisation.