A process for the synthesis of PUFA-enriched triglycerides from high-acid crude fish oil

This paper reports a research interest, that aims to establish a feasible industrial process, for the enzymatic production of glycerides with highly concentrated n-3 polyunsaturated fatty acids (eicosapentaenoic acid and docosahexaenoic acid), from high-acid crude fish oils. The process covers enzymatic deacidification of crude fish oil, alkaline-based synthesis of polyunsaturated fatty acids ethyl esters, concentration of polyunsaturated fatty acids ethyl esters, and enzyme catalyzed synthesis of polyunsaturated fatty acids glycerides. Commercial available immobilized lipase, Novozym 435, was used as the catalyst. The synthesized glycerides contained 5.5% of eicosapentaenoic acid and 74.6% of docosahexaenoic acid, which was 1.21 and 2.71 times more than that in the original fish oil, respectively. The application of the designed process was successfully proved by a 100-fold scale-up reaction.     

Castor oil biodiesel production and optimization

Biodiesel is evolving to be one of the most employed biofuels for partial replacement of petroleum based diesel fuel, especially in recent years. The most widely used feedstocks for biodiesel production are vegetable oils. In this work, biodiesel production from castor oil has been synthesized by homogenous alkaline transesterification. The influence of catalyst concentration, methanol:oil molar ratio, reaction temperature and reaction time in the methyl ester content reached by castor oil transesterification have been evaluated. A yield of 95?wt% biodiesel was achieved at 1?wt% KOH, 60?°C, 9:1 methanol:oil ratio and 30?min reaction time. Transesterification at temperature 30?°C gave a yield compatibles with that obtained at 60?°C. The composition of the fatty acid methyl ester was determined by Gas Chromatography. The castor oil biodiesel produced was blended with different concentrations of petrodiesel to obtain B5, B10 and B20. The biodiesel properties and its blends were determined according to the standard test methods of analysis. The results showed that Castor oil biodiesel in the blends could lower the cloud point value, but simultaneously, increases the viscosity of the diesel–biodiesel blends. Thus, castor oil biodiesel with its very low cloud and pour points is suitable for using in extreme winter temperatures.     

固体酸催化大豆油与乙醇酯交换制备生物柴油

利用淀粉和对甲基苯磺酸合成了新型碳基固体酸催化剂,并将它应用于大豆油与乙醇的酯交换反应制备生物柴油。考察了反应时间、反应温度、醇油摩尔比、催化剂用量及使用次数等因素对生物柴油收率的影响。结果表明,新型碳基固体酸催化剂对大豆油与乙醇酯交换反应有很高的催化活性,易于分离,具有良好的稳定性。最佳反应条件为:醇油摩尔比为8∶1,催化剂质量分数为7.0%,反应时间8 h,反应温度为80℃,该条件下生物柴油的质量收率可达67.4%。     

Supercritical transesterification: Impact of different types of alcohol on biodiesel yield and LCA results

A series of experiments with transesterification of rapeseed oil in supercritical methanol and supercritical ethanol was carried out in a batch reactor at various reaction temperatures (250–350 °C), working pressure (8–12 MPa), reaction time (7, 15 and 30 min), and at a constant 42:1 alcohol to oil molar ratio. The effect of alcohol, temperature, pressure and reaction time on biodiesel yield was investigated using linear multiple regression models. In the observed range, temperature has the highest impact on yields, followed by reaction time and pressure. The relative importance of time and pressure in explaining yields is higher in the case of transesterification in supercritical ethanol. The results of environmental life cycle assessment have revealed that contrary to general belief the usage of ethanol instead of methanol cannot improve the sustainability and renewability of the transesterification process significantly.