Study On The Technology Of Branched Chain Of Natural Oils And Fats

In this paper, the technology of branched chain of natural oils and fats were carried out by epoxidation and ring-opening. The epoxidation of oil and isomerization etherification reaction with solid acid catalyst were studied. Specifically, the epoxidation of oil catalyzed by D002-H resin, the preparation, characterization and its catalystic activities of ring-opening catalyst was investigated.D002-H resin was applied to the synthesis of the epoxidized soybean oil(ESO) which was used as a feedstock for the preparation of branched chain fatty acid ester. In single factor experiments, the optimum reaction conditions were obtained as follows, reaction time was 6h, reaction temperature was 55 ℃, the amount of formic acid dosage was 20 wt% of soybean oil mass, the amount of hydrogen peroxide dosage was 150 wt% of soybean oil mass, the amount of D002-H resin catalyst was 12 wt% of soybean oil mass. And the epoxy value of final product was 6.18%, Iodine Value decreased to 1.5 gI2/100 g.A series of modified catalysts were synthesized by loading different concentrations of sulfuric acid, nitric acid and hydrochloric acid on montmorillonite(MMT). The activties of catalysts were investigated by the ring-opening reaction of epoxidized soybean oil using isooctanol as the probe reaction, the optimum modified conditions of the immobilized catalysts were carried out at concentration of sulfuric acid of 0.25 mol/L, liquid-solid ratio of 12 mL/g at 50℃ for 24 h. The structure of catalyst was characterized by FT-IR, BET, XRD, NH3-TPD, TGA. The XRD revealed that the interlayer spacing of modified MMT with different degrees of expanded and the internal crystalline structure substantially unchanged. The BET revealed that the pore size distribution of the modified MMT was more uniform, and the specific surface area and pore diameter were significantly increase. The results of NH3-TPD indicated that the strong acid sites of the modified MMT catalysts were significantly improved. The results of TGA indicated that the thermodynamic stability of the modified MMT catalysts were significantly improved.The branched fatty acid esters were prepared by using the modified MMT as epoxy ring-opening catalyst and ESO as raw material. The technological conditions were optimized by single factor and orthogonal experiment. The open-loop yield was 98.46% under the conditions of the modified MMT catalyst dosage 6%(based on ESO), alcohol/epoxy bond molar ratio of 3:1 and temperature at 100 ℃ for 9 h. The modified MMT has high catalytic activity, the immobilized catalysts showed better catalytic performance than concentrated sulfuric acid and sodium. The raw materials of epoxy soybean oil and branched chain fatty acid esters were identified by FT-IR, MS, TGA and 1H NMR. The thermal stability, viscosity temperature performance and low temperature flow property of the branched chain fatty acid esters were significantly increased. The epoxy value of the branched fatty acid esters was 0.05%, Acid Value was 1.12 mg KOH/g, decompose temperature increased to 190 ℃, Viscosity Index was 123, Pour Point was-12 ℃.The branched fatty acid methyl esters were prepared by using the modified MMT as ring-opening catalyst and epoxidized fatty acid methyl ester as raw material. The technological conditions were optimized by single factor and orthogonal experiment. The open-loop yield reached 99.56% under the conditions of the modified MMT catalyst dosage 5%(based on the epoxidized fatty acid methyl esters), alcohol/epoxy bond molar ratio of 3:1 and temperature at 90 ℃ for 10 h. The open-loop conversion rate could reach 95.73% after the modified MMT reused 5 times, its showed good stability. The branched fatty acid methyl esters were identified by FT-IR, MS, TGA and 1H NMR. The branched chain fatty acid methyl esters epoxy value decreased to 0.02%, Acid Value was 1.14 mg KOH/g. Viscosity Index was 169, Pour Point was-21 ℃, Flash Point was 230 ℃.