The synthesis of biodiesel from sunflower oil and methanol based on transesterification using the immobilized lipase from Thermomyces lanuginosus (Lipozyme TL-IM) has been investigated under silent conditions and under an ultrasound field. Ultrasound assisted process led to reduced processing time and requirement of lower enzyme dosage. We found for the first time that oil to methanol ratio of ...

The aim of this study was to increase the yield of biodiesel produced by Scenedesmus sp. through in situ transesterification by optimizing various process parameters. Based on the orthogonal matrix analysis for the acidic catalyst, the effects of the factors decreased in the order of reaction temperature (47.5%) > solvent quantity (26.7%) > reaction time (17.5%) > catalyst amount (8.3%). Based ...

due to the high price of virgin vegetable oils and the drawbacks of the homogeneous catalytic transesterification, in this work an economically profitable alternative process was proposed for biodiesel synthesis in which transesterification of the low-cost waste cooking oil (wco) with methanol in a heterogeneous system was done. alumina impregnated with sodium hydroxide was utilized as a solid ...

transesterification, one of the most effective methods for ester synthesis, is usually conducted under acid or basicconditions. although quite a few methods have been reported for transesterification, they are not general as far asp-ketoesters are concerned. some of these methods used toxic, expensive reagents and in relatives large amount. inthis research, transesterification reaction six type...

Introduction The possibility of using vegetable oils as fuel has been documented in the beginning of diesel engines. Biodiesel produced from waste oil by trans-esterification process can be used as a substitute for diesel in internal combustion engines [1]. Biodiesel can be produced by the transesterifcation of vegetable oils [2] such as soyabean oil, rapeseed oil, sunflower oil etc. [3]. Trans...

Introduction The fatty acid esters synthesis by transesterification of oils to produce biodiesel commonly involves methanol or ethanol as acyl acceptor. The transesterification of vegetable oils catalyzed by lipases is an alternative process for obtaining biodiesel. These biocatalysts working under mild conditions of temperature, allow for easy recovery of glycerol, synthesis of specific alkyl ...

Transesterification, one of the most effective methods for ester synthesis, is usually conducted under acid or basicconditions. Although quite a few methods have been reported for transesterification, they are not general as far asp-ketoesters are concerned. Some of these methods used toxic, expensive reagents and in relatives large amount. Inthis research, transesterification reaction six type...

Due to the high price of virgin vegetable oils and the drawbacks of the homogeneous catalytic transesterification, in this work an economically profitable alternative process was proposed for biodiesel synthesis in which transesterification of the low-cost waste cooking oil (WCO) with methanol in a heterogeneous system was done. Alumina impregnated with sodium hydroxide was utilized as a solid ...

The synthesis of four new peptidyl nucleosides is reported. The kinetic data obtained for the transesterification of 2'/3'-O-benzyloxycarbonyl-L-p-nitrophenylalanyl 5'-O-trityl ribonucleosides which contain different substituents at C position of the purine residue indicates for different mechanisms of the transesterification reaction. The peptidyl nucleosides with an amino group at C position ...

Biodiesel production is worthy of continued study and optimization of production procedures due to its environmentally beneficial attributes and its renewable nature. Heterogeneous transesterification is considered to be a green process. The process requires neither catalyst recovery nor aqueous treatment steps and very high yields of methyl esters can be obtained, close to the theoretical valu...