Study On Methyl Esterification Of Waste Frying Oils

At present, the transesterification reaction of triglyceride which are the leading components of vegetable oil or animal fat with methanol using NaOH or KOH as a homogeneous catalyst is conducted to produce methyl fatty acid ester as biodiesel. Although this process is a mature technology, there are some disadvantages including Saponification during the reaction which leads to the difficulty in separation of the production and wastewater from the washing of the production to remove the base catalyst. These problems could be avoided by using the heterogeneous solid catalysts for the production of biodiesel.From the diagrams of GC/MS, we discovered that the components of the productions catalysed by cation resin catalyst had the same retention time and the same form of peaks as the components of the production catalysed by NaOH. The cases had also occurred in simplex gas chromatography(GC) which was used to calculate theconversion rate of methyl fatty acid ester by peak areas. Through GC/MS, the precisecomponents of the production could also be acquired. The four most important components were methyl oleate (C₁₇H₃₃COOCH₃),methyl linoleate (C₁₇H₃₁COOCH₃), methyl stearate (C₁₇H₃₅COOCH₃), methyl hexadecanoate (C₁₅H₃₁ COOCH₃)The commercial macroporous cross-link resins were tested as heterogeneous-catalysts to catalyze transesterification of soybean oil with methanol. We found that NKC-9 had a good catalytic effect.Orthogonal experiments were taken out in order to the optimizing Experiments of the esterification of the pretreated soybean oil. The order of influences for the effect of esterification was the reaction temperature, the reaction time , the amount of the catalyzer and the ratio of mellow to oil. Using the soybean oil as raw material, in the condition of the ratio of oil to mellow (w/v)of 1:0.8, the reaction temperature of 70℃and the reaction time of 4h, the production after decompress distillation was analyzed by GC, and the content of polymethyl methaerylate was about 94.4%.In connection with the above basis,the paper focuses on the transesterification reaction kinetics through the experiment and concludes some outcomes. According to calculations showed soybean oil and methanol synthesis of fatty acid methyl ester activation energy of 10.5KJ/mol.NKC-9 resin was used for used frying oil methyl ester of the process. We also got a better catalytic effect. The catalytic activity of regeneration resin reduced little.