Study On Preparation Of Biodiesel From Oilstock

At present, the cost problem of material is the key factor that restricts the development of biodisel line. So seeking one kind of cheap material is one of the direction to study, too. Oilstock will meet the need to synthesize biodiesel because of its sleazy price and broad source. Oilstock is a by-product from the vegetable oil refining. Its main useful components are phosphatide and neutral oil. The content of total fatty acid reaches 40%～60%, which can be exploited as an material of producting biodiesel.In this study, the production of biodiesel from oilstock has been investigated. The production cost can be saved and a new way for utilizing the byproduct of edible oil factory has been developed.In this research, main manufacturing technique based traditional fatty acid manufacturing technique has been improved and a technological line of producting biodiesel from oilstock were developed. On the basis of mechanism study of spliting fat, a new hydrolytic catalyst was prepared and it has been successfully applied to process of producting fatty acids from oilstocks. For its low cost and high catalyst efficiency, high-efficiency catalyst can be widely used as appropriate hydrolytic catalyst in producing fatty acid from oilstock or soapstock.The fatty acid prepared from oilstock by the new high-efficiency catalyst can be converted to fatty acid methyl esters using acid catalyst. Through orthogonal experiment the optimal experiment the conditions of esterification were obtained. The main conclusions of the experiments were as follows:(1) The process of fatty acid production was optimized by orthogonal experiments with ratio of hydrolysis as the index. The optimal conditions were: the amount of catalys was 3%,the amount of sulfurie acid was 6%, the amount of water was 75%, and reaction time was 4h at 110℃, under which the acid value was 183.96mgKOH/g.(2) The optimal conditions of the first methyl esterification through the optimization of single factor and orthogonal experiments with ratio of esterification as the index were: the reaction temperature was 65℃, the amount of sulfuric acid as eatalyst was 2.5%, the amount of methanol was 100%, and the reaction time was 3.5h, under which the ratio of esterification was 97.84%.The crue fatty acid methyl esters prepared by one-step acid catalyst esterification method must be purified to meet the specifications for biodiesel. In this research, the purify process and the performance index of the biodiesel were investigated. The crude methyl ester can be purified and unified by vacuum distillation. The acid value of biodiesel is too high and can be reduced by Na2SiO3 refining. All biodiesel prepared in the redearch can nearly meet the biodiesel specifications of china.In this research, qualitative analysis of biodiesel by gas chromatography (GC) was developed.By means of GC, main components of biodiesel were methyl palmitate(C16:0), methyl stearate(C18:0), methyl oleate(C18:1), methyl linoleate (C18:2), methyl linolenate(C18:3), methyl eicosenoic(C20:1), methyl erucate (C22:1).The total contents of methyl ester reach more than 98%.