Research On The Key Technologies Of Biodoesl Production From Soy Sauce Oil

Global energy shortage, environmental deterioration and heavy emissions of greenhouse gases caused that global warming was becoming increasingly worse, thus reducing the usage of fossil energy and developing new energy sources had become a global consensus, and clean energies such as wind, solar, geothermal and biomass energies had become the focus of research and development of all the countries in the world. Biodiesel was a kind of biomass energy, and the main component was fatty acid methyl ester, mainly prepared by animal and vegetable oils through ester exchange. Biodiesel burned more sufficiently than petroleum diesel, and could reduce78%CO2and90%absorbable particulate matter, friendly to the environment, being currently the research focus of all countries. This paper prepared biodiesel from soy sauce residue, which contained a large number of oils, and these oils can be extracted to be used for preparing biodiesel.Soy sauce residue was dried and crushed, and with petroleum ether (60～90℃) and80%vol alcohol mixture as the solvent, and oil extraction rate as the standard, the optimal extraction process of synthetic oil was determined by single factor and orthogonal test; three kinds of acidic ionic liquid were synthesized, with esterification rate and ester exchange rate as measure factors, acidic ionic liquid with optimal catalysis performance was selected; with esterification rate and ester exchange rate as measure factors, optimal oil esterification and transesterification process was determined by single factor and orthogonal test; composition and physicochemical properties of biodiesel sample prepared were analyzed with gas chromatographic method and the methods recommended by national standard; the results were as follows:Optimal oil extracting process from soy sauce residue was determined as: extraction rate can reach68.61%at temperature of65℃, extraction time of4h and liquid ratio of9, and the influencing factors were extraction time>temperature> liquid ratio. By GC-MC analysis, main ingredients of extracted crude oil were: hexadecanoic acid (9.71%), octadecadienoic acid (53.34%), octadecenoic acid (31.04%), octadecanoic acid (4.61%) and eicosanoic acid (0.56%). Through measuring, crude fibre content of drying soy sauce residue was7.8%, with fat content of23.6%, salt content of1.9and ash content of8.6%.Three kinds of acidic ion catalysts were prepared, which were1-methyl-3-(3-sulfonic acid propyl) imidazolium hydrogen sulfate ([HSO3-pmim]+[HSO4]-), N-methylimidazolium hydrogen sulfate ([Hmim]+[HS04]-),1-methyl-3-(3-sulfonic acid propyl) imidazole p-toluenesulfonate ([HSO3-pmim]+[PTSA]-), and at the same reaction condition, soy sauce residue oil was catalyzed to effect esterification transesterification reaction, and in three kinds of ionic liquids,[HSO3-pmim]+[HSO4]-had best catalytic performance, with very high stability, and with6recycles, esterification rate and ester exchange rate were all above90%, which was chose as the catalyst for biodiesel preparation.With acid ionic liquid [HSO3-pmim]+[HSO4]-as the catalyst, soy sauce residue oil was catalyzed to effect esterification and transesterification reactions, to determine the optimal esterification process:temperature of70℃, acidic ionic liquids:free fatty acid (mol/mol) of0.7, reaction time of90min, methanol:free fatty acid (mol/mol) of5:1, and the esterification rate was up to98.33%. In the influencing factors, the temperature had most and significant impacts on the esterification rate, followed by the reaction time, the amount of methanol and acidic ionic liquid dosage, which had no significant effect on the esterification rate. Optimal transesterification process was:temperature of70℃, reaction time of200min, acidic ionic liquid:total fatty acids (mol/mol) of0.20, methanol:total fatty acids (mol/mol) of7:1, and the ester exchange rate can reach to98.73%. In the influencing factors, the temperature had most and significant impacts on the esterification rate, followed by the reaction time, the amount of methanol and acidic ionic liquid dosage, which had no significant effect on esterification rate. In the case of8cycles using [HSO3-pmim]+[HSO4]-esterification rate and ester exchange rate were all above90%, and catalytic performance of [HSO3-pmim]+[HSO4]-was stability.With gas chromatography analysis, the main component of prepared biological diesel oil sample was fatty acid methyl ester, wherein the linoleic acid methyl ester of 53.43%, methyl oleate of31.09%, stearic acid methyl ester of4.65%and methyl palmitate of9.71%. All physical and chemical indicators met GB/T20828-2007standards, and some indicators had reached European EN14214standards, and of prepared biological diesel oil samples, cetane number, density, viscosity, oxidation stability and90%recovery temperature were similar to that of general biological diesel oil.