Mechanism Of Br?nsted Acidic Ionic Liquid Catalyzed Transesterification Of Camelina Oil And Waste Cooking Oil To Produce Biodiesel

Due to the rapid increase of the world population and the acceleration of modern industrial processes,human demand for fossil fuels is increasing,leading to the depletion of fossil fuels and excessive emissions of CO2.Biodiesel preparation is a process for preparing short-chain lipids by transesterification of short-chain alcohols under acidic or basic conditions using edible oils,non-edible oils,animal fats and microalgae oils as raw materials.Edible oils such as soybean oil and com oil are recognized as the first generation biodiesel raw materials.However,the use of first-generation biodiesel feedstocks can cause food shortages and food and land disputes.Therefore,the preparation of biodiesel from the second generation of biodiesel raw materials such as camelina oil and waste oil can effectively avoid food shortage and food safety.An ionic liquid refers to an organic salt that exhibits a liquid state below 100?.Due to their customizability,non-flammability,thermal stability,low volatility and recyclability,ionic liquids are widely used in cellulose dissolution,acid/base catalysis and other fields.1-butyl-3-methylimidazolium hydrogensulfate([Bmim][HSO4]),1-butyl-3-methylimidazolium hydrogen phosphate([Bmim]2[HPO4])and 1-butyl-The 3-methylimidazolium phosphate dihydrogenate ion([Bmim][H2PO4])is a short chain Br?nsted acidic ionic liquid.It can dissociate H+during the reaction and act as an acidic catalyst.Therefore,this paper intends to catalyze the transesterification of canola seed oil with methanol by[Bmim][HSO4],and catalyze the transesterification of waste oil with methanol with[Bmim]2[HPO4],[Bmim][H2PO4]as catalyst.The reaction produces biodiesel.The effects of alcohol-oil molar ratio,reaction time,reaction temperature and catalyst dosage on biodiesel production were discussed in detail.It mainly includes the following parts:1.[Bmim][HSO4]catalyzes the transesterification of camelina oil with methanol.The composition of Chinese cabbage seed biodiesel was characterized by infrared spectroscopy and gas chromatography-mass spectrometry.The main components were saturated fatty acid esters(C16:0,C18:0),monounsaturated fatty acid esters and polyunsaturated.Fatty acid ester(C18:2,C18:3).The effects of reaction temperature of 50-200?,reaction time 20-100 min,n methanol:n kale seed oil at 10-40,n[Bmim[HSO4]:n camelina Oil on biodiesel production were studied.The results showed that the transesterification of canola seed oil with methanol reached equilibrium at 100? for 40 min,n methanol:n camelina oil Was 20,n[Bmim][HSO4]:n camelina oil Was 3.In addition,[Bmim][HSO4]has good thermal stability and can be reused 4 times,and the biodiesel yield is 91.6%.2.[Bmim]2[HPO4],[Bmiml[H2pO4]and[Bmim][HSO4]catalyze the transesterification of methanol with waste oil.The obtained biodiesel products were characterized by infrared spectroscopy and gas chromatography-mass spectrometry.The reaction temperature was 150-225?.the reaction time was 30-180 min,and the molar ratio of methanol to waste oil was 10-50.The effect of[Bmini]2[HPO4]content on 3-11 wt%on biodiesel yield.The conversion results were compared with 1-butyl-3-methylimidazolium phosphate dihydrogen salt([Bmim][H2PO4])and conventional catalyst concentrated sulfuric acid catalyzed transesterification conversion.The results showed that[Bmim]2[HPO4]catalyzed the transesterification of the waste oil with methanol at 175,150 min,the molar ratio of alcohol to oil was 20,the catalyst content was 5 wt%,the reaction reached equilibrium,and the biodiesel yield reached the maximum 95.6%.[Bmim][H2PO4]catalyzed the transesterification of the waste oil with methanol at 175?,150 min,the molar ratio of alcohol to oil was 20,the catalyst content was 9 wt%,the reaction reached equilibrium,and the biodiesel yield reached a maximum of 92.5%.In addition,the thermal stability of[Bmim]2[HPO4],[Bmim][H2PO4]was very good,and the yield of biodiesel was still 89.1%and 88.9%after repeated use four times.From the conversion effect,[Bmim]2[HPO4]has the highest conversion rate and is similar to the traditional acid catalyst concentrated sulfuric acid.The conversion rate of[Bmim][H2PO4]is also much higher than that of[Bmim][HSO4].And the main component of the obtained bio-produced oil is saturated fatty acid,which can greatly improve the combustion heat of biodiesel.In terms of reeycling,[Bmim]2[HPO4]and[Bmim][H2PO4]have good repeatability,and there is no significant decrease in biodiesel yield after 4 repetitions of the experiment,indicating ionic liquid.Has good thermal and chemical stability.It is also easier to separate on the separation than the conventional acid catalyst concentrated sulfuric acid,and only needs to be allowed to stand in the separatory funnel.