Study On Oxidative Degradation Characteristics Of Three Biodiesels

The fossil energy crisis and the environmental pollution problems makes it become more and more urgent to study the alternative energy.Biodiesel is clean and renewable,and has received widespread attention from all over the world.But the biodiesel is easy to oxidize,that will increase viscosity,difficult to filter and generate many precipitates causing oil blockage,corrosion engine and other issues.So oxidation stability of biodiesel is one of the key points in the study of biodiesel.At present,the research on biodiesel at home and abroad mainly focuses on the development and influence of antioxidants,methods for assessing and improving oxidative stability.Few people studied the oxidative degradation of individual fatty acid methyl esters.The mechanism of oxidative degradation is still in the early stages.There are many researches that biomass fuel used in internal combustion engine.More attention to the change of conventional physical and chemical properties of engine oil and performance.But few studies on oxidative degradation characteristics of fatty acid methyl esters and changes of quality parameters caused by different degradation biodiesel.Therefore,in this paper,Rapeseed oil biodiesel,Soybean oil biodiesel and Jatropha oil biodiesel were subjects.The main research works are summarized as follows.Prepared from different origins of rapeseed oil biodiesel,soybean oil biodiesel,Jatropha oil biodiesel.GC-MS and FTIR were complementarily applied to analysis them.Different ratios of methyl oleate and methyl stearate were added into biodiesel samples respectively,then the effects of fatty acid methyl esters on the oxidative induction period and heat value were investigated.A study was carried out in order to get the oxidation degration reaction equation of Rapeseed oil biodiesel,Soybean oil biodiesel and Jatropha oil biodiesel.The biodiesel was oxidized by Rancimat method.GC-MS and FTIR were complementarily applied to identify fatty acid methyl esters after different oxidized time.At the same time,the relationship between oxidation time and heat value was studied.Get the kinetic parameters:reaction order,the rate constant and activation energy.The infrared spectrum changes at the characteristic peak 1740 cm-1.In addition,Jatropha oil biodiesel was analysised by TG-FTIR.The oretical parameter of C-H bond dissociation energies(BDEs)of methyl palmitate,methyl stearate,methyl oleate,methyl linoleate,methyl linolate were calculated using Gaussian 09.At the same time,the mechanism of oxidative degradation of biodiesel was preliminarily explained.