Lipase-Catalysed In Situ Transesterification of Waste Rapeseed Oil to Produce Diesel-Biodiesel Blends

Abstract

Rapeseed oil of high acidity, an agricultural industry by-product unsuitable for food, was used as an inexpensive raw material for the production of biodiesel fuel. The use of rapeseed oil that is unsuitable for food and lipase as a catalyst makes the biodiesel production process environmentally friendly. Simultaneous oil extraction and in situ transesterification using diesel as an extraction solvent was investigated to obtain a diesel-biodiesel blend. The diesel and rapeseed oil blend ratio was 9:1 (w/w). The enzymatic production of biodiesel from rapeseed oil with high acidity and methanol using eleven different lipases as biocatalysts was studied. The most effective biocatalyst, lipase—Lipozyme TL IM (Thermomyces lanuginosus), which is suitable for in situ transesterification—was selected, and the conversion of rapeseed oil into fatty acid methyl ester was evaluated. The influence of the amount of methanol and lipase, the reaction temperature and the reaction time were investigated to achieve the highest degree of transesterification. The optimal reaction conditions, when the methanol to oil molar ratio was 5:1, were found to be a reaction time of 5 h, a reaction temperature of 25 °C and a lipase (Lipozyme TL IM) concentration of 5% (based on oil weight). Under these optimal conditions, 99.90% (w/w) of the rapeseed oil was extracted from the seed and transesterified. The degree of transesterification obtained was 98.76% (w/w). Additionally, the glyceride content in the biodiesel fuel was investigated and met the requirements perfectly.

Statistical Optimization of Biodiesel Production from Salmon Oil via Enzymatic Transesterification: Investigation of the Effects of Various Operational Parameters

“…In recent years, biocatalytic transesterification, which is catalyzed by lipases, has been intensively studied for biodiesel production [5,[7][8][9]. As lipases catalyze the reaction through interactions with the molecules at specific sites, the conversion efficiency and product purity are high, with little need for downstream processing.…”

Improved Synthesis of α-Glycerol Monolaurate Using Lipozyme TL IM

“…Accordingly, the selection of a catalyst from Lipozyme TL IM is an excellent alternative to replace K 2 CO 3 and Na 2 CO 3 in the synthesis reaction of α-Glycerol Monolaurate. Some literature showed that Lipozyme TL IM has excellent catalytic activity in a transesterification reaction between a fatty acid ester and an alcohol to produce new fatty acid esters 23,24) . In addition, it is a cheap and commercial lipase from Novozym and also has an active site formed by Ser-His-Asp residues 21,23) .…”

“…The increase in reaction temperature at 40℃ caused a decrease in product yield to 75.6％ and down to 56.4％ at a temperature of 50℃. Each substrate has a different binding response on the active site since the optimum temperature in the reaction with the Lipozym TL IM catalyst was different 24) . The reaction temperature is inversely proportional to the yield of 1,2-acetonide-3-lauryl glycerol but not significantly at 40, 45, and 50℃.…”

Current State and Perspectives on Transesterification of Triglycerides for Biodiesel Production

“…In situ transesterification involves one step of direct extraction and transesterification, in which alcohol acts as solvent extraction and transesterification reagent. In situ transesterification, commonly termed reactive extraction has the advantages of reducing the processing time and the amount of solvent [263][264][265]. In addition, it is environmentally benign since hazardous air pollutants, such as hexane, can be avoided [266].…”