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Biodiesel, fatty acid methyl ester produced by the transesterification of vegetable oil with methanol, is a promising alternative to petroleum-based diesel fuel. In the present study, the methanolysis of high free fatty acid (FFA) Jatropha curcas oil in a transesterification reaction using K2CO3 /CaO solid base catalyst was studied. The various reaction parameters in the transesterification reaction were also discussed. The catalyst was characterized by means of Fourier transform infrared, X-ray diffraction, temperature programmed desorption of CO2 , scanning electron microscopy, particle size analyzer, true density, and surface area analyzer. The optimum conversion of jatropha oil was 92% when the transesterification reaction was carried out at 70 °C with 10:1 molar ratio of methanol to oil at reaction time of 3 h and catalyst amount of 6 wt%. The efficiency of catalysts in the methanolysis of jatropha oil was also investigated. [ABSTRACT FROM AUTHOR]

Metal hydroxides and alkoxides are popular base catalysts for production of fatty acid methyl esters (FAME). Hydroxides dissolved in alcohols produce water. Some of that water reacts with triacylglycerols (TAGs) to produce free fatty acids instead of desired FAME, thus decreasing the yield of the transesterification reaction. Metal alkoxides are expensive, their production is hazardous and energy intensive, therefore, less expensive safer and more efficient catalysts for transesterification are desirable. Glycerol derived non-toxic alkoxide base catalysts were synthesized by heating KOH solution (50 wt%) and glycerol at three different mole ratios (KOH: glycerol, denoted KGly, at 1:1, 2:1, and 3:1) under four different vacuum pressures. Transesterification reactions were conducted. The reaction rate and yield of FAME synthesis from TAG achieved by catalyst prepared at 3:1 mole ratio of KOH: glycerol achieved superior or similar FAME yield to conventional potassium methoxide catalyst under same reaction conditions. At 120 s after adding catalyst, the reactions achieved satisfactory yield (74.3-78.9%) which was similar to that of KOCH3 catalyst (77.9%). The reactivity of catalyst at initial stage of the reaction was in the following order: KGly (1:1)3

Structured lipids have been synthesized using different medium chain fatty acids based on the reaction with long chain triglyceride viz. moringa oil, in the presence of supercritical C02. Effect of different operating parameters related to supercritical C02 approach on the product yields has been studied also establishing the effect of type of biocatalyst (using two forms of commercial lipases as Novozym 435 and Lipozyme RM). It was observed that 100 bar pressure at 50 °C temperature with 300 rpm speed, molar ratio of 4:1 (medium chain fatty acids: long chain triglycerides), reaction time as 5h and Novozym 435 as the catalyst were the best conditions giving 63.2% yield which was much higher as compared to the conventional approach where only 28.2% yield was obtained. After acidolysis, the residual unreacted triglycerides were extracted using hexane and allowed to react again with free corresponding medium fatty acids under same reaction conditions. After complete reaction with medium fatty acids, product obtained was structured lipids with medium chain fatty acids at 1,3 position and long chain fatty acid at 2-position. The enzyme reusability studies confirmed that enzyme was efficient up to 15 cycles providing a cost effective proposition. Overall, it was established that structured lipids possessing significant nutritional benefits could be effectively synthesised using green intensified approach based on supercritical C02. [ABSTRACT FROM AUTHOR]