Study On The Epoxidation Of Plant Oil-Based Feedstocks And Their Cyclic Carbonates

Carbon dioxide is not only a global-warming gas, but also a potential inexpensive and abundant C1 building block. The fixation of CO2 under relative mild condition has the important economic and academic significance. After epoxidation, plant oils, a renewable resource, can couple with CO2 to produce plant oil-base cyclic carbonate. In this paper, we mainly studied on the epoxidation of soybean oil(SBO) and the synthesis of carbonated soybean oil(CSBO).Firstly, high concentration hydrogen peroxide solution was applied into epoxidation of soybean oil to solve the long existing problem in the traditional process reaction, such as long reaction cycle, producing a large amount of wastewater and acid water, low production rate and low quality of product. Study had found that the higher concentration of hydrogen peroxide, the faster reaction rate, the lower iodine value will get, and decoloring effect was better. Using 70% concentration of H2O2, we got the best reaction time was 3~4 h, reaction temperature was at 60 ℃, dosage of formic acid was 6% of the soybean oil dosage. And then, we got the product that the epoxy value was 6.23%, the iodine value was 2.1 g I2/100 g, chromaticity(Pt-Co) ≤ 90, which conformed to the quality of industry standards of epoxy soybean oil. In addition, the study had found that using high concentration of hydrogen peroxide can heat to the reaction temperature in a short period of time without using other heat, which making the epoxidation reaction possible under no heat condition. After process improvement, the final epoxy value was 6.05%, iodine value was 2.9 g I2/100 g, chromaticity(Pt- Co) ≤100. In the reation the energy conservation and emissions reduction is remarkable, which had a good potential in market application.Secondly, 4 kinds of Salen-Al were synthesized, and characterized by FT-IR, UV, 1H-NMR, 13C-NMR and MS. And then selected high catalytic active catalyst in 4 kinds of Salen-Al and 6 kinds of quaternary ammonium salt, at last L3 and CTAB was selected, form a binary catalyst system. Study had found that the best reaction temperature was 120 ℃, pressure was 2 MPa, Salen-Al: CTAB = 1:1. After 8 h,the yield was as high as 76.8%. Compared to the one-component catalytic, the reaction conversion rate of the binary catalyst system was obvious increased. In addition, the mechanism of binary catalyst system was discussed.Finally, the binary catalyst system of Salen-Al/CTAB was grafted onto the graphene oxide, and we synthesized a heterogeneous catalyst Salen-Al-CTAB-GO successfully. So that making a homogeneous catalyst into a heterogeneous catalyst, to solve the problem of homogeneous catalyst, such as the difficult of recycling. The catalyst was characterized by FT-IR, RS, TEM. Meanwhile, the reaction temperature, reaction pressure and the amount of catalyst was studied, and got the best reaction condition as follows: the catalyst 0.8 g, reaction temperature 130 ℃, reaction pressure 2 MPa, after 8 h, the yield was 42.1%. In addition, the performance of catalyst recycle was studied, and found the catalytic activity was still good after using 6 times.