Two-step supercritical dimethyl carbonate method for biodiesel production from Jatropha curcas oil

Abstract

This study reports on a novel two-step process for biodiesel production consisting of hydrolysis of oils in sub-critical water and subsequent supercritical dimethyl carbonate esterification. This process found to occur optimally at the sub-critical water treatment (270 degrees Celsius/27 MPa) for 25 min followed by a subsequent supercritical dimethyl carbonate treatment (300 degrees Celsius/9 MPa) for 15 min to achieve a comparably high yield of fatty acid methyl esters, at more than 97 wt%. In addition, the fatty acid methyl esters being produced satisfied the international standard specifications for use as biodiesel fuel. This new process for biodiesel production offers milder reaction condition (lower temperature and lower pressure), non-acidic, non-catalytic and applicable to feedstock with high amount of free fatty acids such as crude Jatropha curcas oil.

Biofuel that Keeps Glycerol as Monoglyceride by 1,3-Selective Ethanolysis with Pig Pancreatic Lipase Covalently Immobilized on AlPO4 Support

“…Novel methodologies to prepare esters from lipids using different acyl acceptors which directly afford alternative co-products are currently under development [13,[20][21][22]. The transesterification reaction of triglycerides with dimethyl carbonate (DMC) [23][24][25][26][27], methyl acetate [28][29][30][31][32] or ethyl acetate [33,34] can generate a mixture of three FAME or FAEE molecules and one of glycerol carbonate (GC) or glycerol triacetate (triacetin). These mixtures including glycerol derivative molecules have relevant physical properties to be employed as novel biofuels [35,36].…”

“…As in the two methods described before [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36], the already patented Ecodiesel-100 [37][38][39] obtained through the 1,3-selective partial ethanolysis of the triglycerides with PPL, is a mixture of two parts of FAEE and one part of MG, that integrates the glycerol as a soluble derivative product (MG) in the diesel fuel, but unlike these methods, no specific reagent (such as dimethyl carbonate or methyl acetate) more expensive than methanol (or ethanol) are used. This strategy is based on obtaining an incomplete alcoholysis by application of 1,3-selective lipases, so that the glycerol remains in the form of monoglyceride which avoids the production of glycerol as a by-product, reducing the environmental impact of the process.…”

Optimization of catalyst-free production of biodiesel from Ceiba pentandra (kapok) oil with high free fatty acid contents

“…hydrolysis of fatty acid esters using sub/supercritical water, followed by supercritical methyl/ethyl esterification of fatty acids into methyl/ ethyl esters. For example, Minami and Saka [15], Kusdiana and Saka [16], and Ilham and Saka [17] firstly treated triglycerides in oils/fats in subcritical water for the hydrolysis reaction to produce fatty acids and these fatty acids are further converted to methyl esters through supercritical esterification. They reported that by applying two-step process above, the reaction can be conducted at more convenient conditions and the backward reaction between glycerol and fatty acid methyl ester can be suppressed.…”

Supercritical fluid technology in biodiesel production

“…Another solution to apply the two-step method is to use dimethyl carbonate, named the "Saka and Ilham Process" [72]. The hydrolysis conditions are 270°C and 27 MPa, and are followed in a second step by the esterification of FAs to FAME in SCDMC at 300°C and 9 MPa.…”