Waste rubber seeds as a renewable energy source: direct biodiesel production using a controlled crushing device

A multistep and high-cost biodiesel production could be simplified using the direct transesterification (DT) method.

Variability of Omega-3/6 Fatty Acid Obtained Through Extraction-Transesterification Processes from Phaeodactylum tricornutum

The effect of direct transesterification methods on the omega-3/6 composition of extracts from Phaeodactylum tricornutum was studied. The aim of this work was to identify an extraction method which allowed to obtain the most suitable profile of fatty acids in terms of its potential benefits to health, particularly if further used in the food industry. Seven methods using acids, alkalis, and heterogeneous-catalysts, (namely methods from 1 to 7, abbreviated as M1-M7) were performed to determine α-linolenic (ALA), linoleic (LA), docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids. The composition of fatty acids was in all cases characterized by the major abundance of palmitic (23.95–34.08%), palmitoleic (30.94–35.56%), oleic acids (3.00–7.41%), and EPA (0.5–6.45%). Unsaturated fatty acids extraction yield was higher with a two-step transesterification process (M6, 63.65%). The total fatty acid methyl ester content (FAME) obtained with acid-transesterification (M1) reached about 21% wt, and 60% w/w total lipids. ALA higher relative content (ALA/LA ratio) was obtained when a lipid pre-extraction step was performed prior to acid-catalysis (M4). The transesterification method based on alkali-catalyst (M3, KOH catalyst) led to obtain higher DHA relative contents (DHA/EPA ratio up to 0.11), although its FAME content was 3.75-fold lower than that obtained with acid-transesterification (M1). Overall, this study shows that direct transesterification with alkali-catalyst (M3) improves the determination of PUFA content from the diatom through a more efficient transesterification-based extraction process, and thus allow to assess the value of the biomass more accurately for application in the food industry.

Biodiesel Production Using Modified Direct Transesterification by Sequential Use of Acid-Base Catalysis and Performance Evaluation of Diesel Engine Using Various Blends

Biodiesel is a seemingly suitable alternative substitute for conventional fossil fuels to run a diesel engine. In the first part of the study, the production of biodiesel by modified direct transesterification (MDT) is reported. An enhancement in the biodiesel yield with a considerable reduction in reaction time with the MDT method was observed. The required duration for diesel and biodiesel blending was minimized including glycerol separation time from biodiesel in the MDT method. The development in the automotive sector mainly focuses on the design of an efficient, economical, and low emission greenhouse gas diesel engine. In the current experimental work Ceiba pentandra/Nigella sativa and diesel blends (CPB10 and NSB10) were used to run the diesel engine. A variety of approaches were implemented to improve the engine performance for these combinations of fuels. The fuel injector opening pressure (IOP) was set at 240 bar, the torriodal re-entrant combustion chamber (TRCC) having a six-hole injector with a 0.2 mm orifice diameter each, provided better brake thermal efficiency (BTE) with lower emissions compared with the hemispherical combustion chamber (HCC) and trapezoidal combustion chamber (TCC) for both CPB10 and NSB10. CPB10 showed better performance compared with NSB10. A maximum BTE of 29.1% and 28.6% were achieved with CPB10 and NSB10, respectively, at all optimized conditions. Diesel engine operation with CPB10 and NSB10 at 23° bTDC fuel injection timing, and 240 bar IOP with TRCC can yield better results, close to a diesel run engine at 23° bTDC fuel injection timing, and 205 bar IOP with HCC.

Obtaining Biodiesel by Direct Transesterification of Botryococcus braunii and Coccomyxa subellipsoidea

Biofuels have been obtained from vegetable oils, animal fats and recently from microorganisms such as algae, bacteria or yeasts that present a significant content of triacylglycerols through a transesterification reaction. Technical problems with biodiesel or agrodiesel (Term recently used, in this work we will use biodiesel), include oxidative stability, cold flow, and increased NOx emissions. The solution to these problems involves the use of additives on the one hand or modifying the fatty acid composition of the microorganisms alternatively, either through changes in the cultivation temperature, addition of nanomaterials, or through genetic modification, to obtain high-quality biofuels. In this work, two species of microalgae with high fatty acid content were obtained, Botryococcus braunii originating from Cuzco, Peru and Coccomyxa subellipsoidea C-169, from Marble Point, Antarctica, both were cultivated under optimal conditions and later direct transesterification was performed to obtaining biodiesel. The main objective was to develop an economical and viable process that allows it to compete with fossil fuels, based on obtaining biomass and the transesterification method. Here, direct transesterification was effective and allows to significantly reduce the problems associated with the increase in costs of obtaining biodiesel, because reduces critical steps, also the biodiesel thus obtained represents an advance in the development of high-quality biofuels, large-scale and inexpensive. Resumen. Los biocombustibles se han obtenido desde finales del siglo XIX a partir de aceites vegetales, grasas animales y recientemente a partir de microorganismos como algas, bacterias o levaduras que presentan un contenido significativo en triacilgliceroles mediante una reacción de transesterificación. Algunos de los problemas técnicos con el biodiésel o agrodiesel (término usado recientemente, en este trabajo usaremos biodiesel) son: estabilidad oxidativa, flujo en frío y aumento de emisiones de NOx. La solución a estos problemas incluye el uso de aditivos, por un lado, o modificar la composición de ácidos grasos de los microorganismos por otro, ya sea mediante cambios en la temperatura de cultivo, adición de nanomateriales, o mediante modificación genética, para obtener biocombustibles de alta calidad. En este trabajo se utilizaron dos especies de microalgas con gran contenido en ácidos grasos, Botryococcus braunii originaria de Cuzco, Perú y Coccomyxa subellipsoidea C-169, de Punta Mármol, Antártida, ambas fueron cultivadas en óptimas condiciones y posteriormente se realizó la transesterificación directa para obtener el biodiésel. El principal objetivo fue desarrollar un proceso económico y viable, que permita competir con los combustibles fósiles, a partir de la obtención de biomasa y el proceso de transesterificación. La transesterificación directa fue exitosa y permitió reducir significativamente los problemas asociados con el aumento de costos de obtención de biodiésel, ya que reduce pasos críticos del proceso, además el biodiésel así obtenido representa un avance en el desarrollo de biocombustibles de alta calidad, a gran escala y de bajo costo.

Evaluation and optimisation of direct transesterification methods for the assessment of lipid accumulation in oleaginous filamentous fungi

Background Oleaginous filamentous fungi can accumulate large amount of cellular lipids and potentially serve as a major source of oleochemicals for food, feed, chemical, pharmaceutical, and transport industries. Transesterification of microbial oils is an essential step in microbial lipid production at both laboratory and industrial scale. Direct transesterification can considerably reduce costs, increase sample throughput and improve lipid yields (in particular fatty acid methyl esters, FAMEs). There is a need for the assessment of the direct transesterification methods on a biomass of filamentous fungi due to their unique properties, specifically resilient cell wall and wide range of lipid content and composition. In this study we have evaluated and optimised three common direct transesterification methods and assessed their suitability for processing of fungal biomass. Results The methods, based on hydrochloric acid (Lewis method), sulphuric acid (Wahlen method), and acetyl chloride (Lepage method), were evaluated on six different strains of Mucoromycota fungi by using different internal standards for gas chromatography measurements. Moreover, Fourier transform infrared (FTIR) spectroscopy was used for the detection of residual lipids in the biomass after the transesterification reaction/extraction, while transesterification efficiency was evaluated by nuclear magnetic resonance spectroscopy. The results show that the majority of lipids, in particular triglycerides, were extracted for all methods, though several methods had substandard transesterification yields. Lewis method, optimised with respect to solvent to co-solvent ratio and reaction time, as well as Lepage method, offer precise estimate of FAME-based lipids in fungal biomass. Conclusions The results show that Lepage and Lewis methods are suitable for lipid analysis of oleaginous filamentous fungi. The significant difference in lipid yields results, obtained by optimised and standard Lewis methods, indicates that some of the previously reported lipid yields for oleaginous filamentous fungi must be corrected upwards. The study demonstrates value of biomass monitoring by FTIR, importance of optimal solvent to co-solvent ratio, as well as careful selection and implementation of internal standards for gas chromatography.

Direct Transesterification for Biodiesel Production and Testing the Engine for Performance and Emissions Run on Biodiesel-Diesel-Nano Blends

In the current research, the biodiesel was prepared from feedstocks of Neem oil and Karanja oil employing a single step direct transesterification method using acid-base catalysts simultaneously. The fuel properties of both Neem and Karanja biodiesel along with different biodiesel-diesel blends were studied and compared. Biodiesel produced from Neem oil was found better in terms of kinematic viscosity, calorific value and cloud point for all its blends with diesel compared to Karanja biodiesel-diesel blends. Experiments were conducted to study the effects of addition of graphene nano particles on fuel properties of biodiesel-diesel blends. The B20 biodiesel-diesel blend was selected, which was blended with graphene nano particles in different proportions (35, 70, 105 ppm) to get different stable and symmetric B20-nano blends. The fuel properties except kinematic viscosity were further improved with higher dosages of nano particles with the biodiesel-diesel blend. The performance and emissions tests were conducted on 4-stroke variable compression ratio diesel engine. Higher concentrated B20-nano blends of Neem (NOME20GO105) and Karanja (KOME20GO105) resulted in 31 and 30.9% of brake thermal efficiency, respectively, compared with diesel of 32.5%. The brake-specific fuel consumption (BSFC) was reduced by 10 and 11% for NOME20GO105 and KOME20GO105, respectively, compared to their respective B20 blends. Similarly, carbon monoxide (CO) was reduced significantly by 27 and 29% for NOME20GO105 and KOME20GO105, respectively.

Enhanced fatty acid methyl esters recovery through a simple and rapid direct transesterification of freshly harvested biomass of Chlorella vulgaris and Messastrum gracile

Conventional microalgae oil extraction applies physicochemical destruction of dry cell biomass prior to transesterification process to produce fatty acid methyl esters (FAMEs). This report presents a simple and rapid direct transesterification (DT) method for FAMEs production and fatty acid profiling of microalgae using freshly harvested biomass. Results revealed that the FAMEs recovered from Chlorella vulgaris were 50.1 and 68.3 mg with conventional oil-extraction-transesterification (OET) and DT method, respectively. While for Messastrum gracile, the FAMEs recovered, were 49.9 and 76.3 mg, respectively with OET and DT methods. This demonstrated that the DT method increased FAMEs recovery by 36.4% and 53.0% from C. vulgaris and M. gracile, respectively, as compared to OET method. Additionally, the DT method recovered a significantly higher amount of palmitic (C16:0) and stearic (C18:0) acids from both species, which indicated the important role of these fatty acids in the membranes of cells and organelles. The DT method performed very well using a small volume (5 mL) of fresh biomass coupled with a shorter reaction time (~ 15 min), thus making real-time monitoring of FAMEs and fatty acid accumulation in microalgae culture feasible.