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CN-121974897-A - Preparation method of soybean oil-based cyclic carbonate

CN121974897ACN 121974897 ACN121974897 ACN 121974897ACN-121974897-A

Abstract

The invention discloses a preparation method of soybean oil-based cyclic carbonate, which comprises the following steps of mixing epoxidized soybean oil and a catalyst in a closed environment, discharging air in the closed environment, then filling CO 2 into the closed environment, regulating the pressure of CO 2 to 1.0-2.0-MPa, then reacting for 10-12 hours at the temperature of 100-120 ℃ under the stirring condition, and purifying to obtain the soybean oil-based cyclic carbonate, wherein the catalyst consists of tetrabutylammonium bromide and triethanolamine borate, and the molar ratio of the tetrabutylammonium bromide to the triethanolamine borate is (1-4): 1. The catalyst is composed of tetrabutylammonium bromide and triethanolamine borate, is used for preparing the soybean oil-based cyclic carbonate by the reaction of epoxidized soybean oil and CO 2 , improves the yield of the soybean oil-based cyclic carbonate, reduces the production cost, and has the advantages of lower reaction temperature, lower CO 2 air pressure, less reaction time and mild reaction conditions.

Inventors

  • ZHANG CHAOQUN
  • ZENG HONG

Assignees

  • 华南农业大学

Dates

Publication Date
20260505
Application Date
20260407

Claims (10)

  1. 1. The preparation method of the soybean oil-based cyclic carbonate is characterized by comprising the following steps of: Mixing the epoxidized soybean oil and the catalyst in a closed environment, discharging air in the closed environment, then filling CO 2 into the closed environment, regulating the pressure of CO 2 to 1.0-2.0-MPa, then reacting for 10-12 hours at the temperature of 100-120 ℃ under the stirring condition, and purifying to obtain the soybean oil; the catalyst consists of tetrabutyl ammonium bromide and triethanolamine borate, and the molar ratio of the tetrabutyl ammonium bromide to the triethanolamine borate is (1-4): 1.
  2. 2. The method for producing soybean oil-based cyclic carbonate according to claim 1, wherein the molar ratio of tetrabutylammonium bromide to triethanolamine borate is 2:1.
  3. 3. The method for preparing soybean oil-based cyclic carbonate according to claim 1 or 2, wherein the molar amount of tetrabutylammonium bromide is 4% -6% of the molar amount of epoxy groups in epoxidized soybean oil, and the molar amount of triethanolamine borate is 1.25% -5% of the molar amount of epoxy groups in epoxidized soybean oil.
  4. 4. The method for producing soybean oil-based cyclic carbonate according to claim 1, wherein the air in the closed environment is discharged by introducing CO 2 times to the closed environment.
  5. 5. The method for producing soybean oil-based cyclic carbonate according to claim 1, wherein the temperature is 120 ℃.
  6. 6. The method for producing soybean oil-based cyclic carbonate according to claim 1, wherein the stirring speed is 400 rpm.
  7. 7. The method for producing soybean oil-based cyclic carbonate according to claim 1, wherein the reaction time is 12 hours.
  8. 8. The method for producing soybean oil-based cyclic carbonate according to claim 1, wherein the pressure of CO 2 is adjusted to 2.0 MPa.
  9. 9. The method for preparing soybean oil-based cyclic carbonate according to claim 1, wherein the purification method comprises dissolving the crude product obtained after the reaction in an organic solvent to obtain an organic phase, washing and drying the organic phase, then subjecting the organic phase to suction filtration and rotary evaporation, and finally drying the obtained product at 80 ℃.
  10. 10. The method for producing soybean oil-based cyclic carbonate according to claim 9, wherein the organic solvent is ethyl acetate; The washing method comprises washing the organic phase with saturated saline for 8-10 times; The organic phase was dried by adding anhydrous magnesium sulfate to the organic phase.

Description

Preparation method of soybean oil-based cyclic carbonate Technical Field The invention belongs to the technical field of cyclic carbonates, and particularly relates to a preparation method of soybean oil-based cyclic carbonate. Background Vegetable oil-based cyclic carbonates are key raw materials for the preparation of NIPU, and are prepared by converting epoxidized vegetable oil and CO 2 into cyclic carbonates. At present, the epoxy vegetable oil has longer fatty acid chain and larger steric hindrance of active groups in the structure, so that the epoxy vegetable oil in the catalytic chain has harsh cycloaddition reaction conditions, and the high-yield vegetable oil-based cyclic carbonate is difficult to synthesize. In the synthesis process, in order to ensure high yield, the reaction gas pressure reaches more than 10 bar, and the reaction time is not less than 16 h. Not only are these conditions difficult to meet at the same time mild conditions, but they also tend to result in lower yields of cyclic carbonates. In the actual catalytic cycloaddition reaction, it is difficult to achieve that the reaction temperature, pressure and time are all in a milder state, and one of them is usually sacrificed to ensure higher yield. For example, it may be necessary to extend the reaction time to 70 h for carrying out the reaction under normal pressure conditions, or to shorten the reaction time to 16 h for using supercritical CO 2 pressure. Therefore, there is a need to develop a process for preparing soybean oil-based cyclic carbonates with high yields using Epoxidized Soybean Oil (ESO) as a raw material. Disclosure of Invention The invention aims to solve the problems of harsh reaction conditions and low yield in the process of converting epoxidized soybean oil and CO 2 into cyclic carbonate, and provides a preparation method of soybean oil-based cyclic carbonate. According to an aspect of the present invention, there is provided a method for preparing soybean oil-based cyclic carbonate, comprising the steps of: Mixing the epoxidized soybean oil and the catalyst in a closed environment, discharging air in the closed environment, then filling CO 2 into the closed environment, regulating the pressure of CO 2 to 1.0-2.0-MPa, then reacting for 10-12 hours at the temperature of 100-120 ℃ under the stirring condition, and purifying to obtain the soybean oil; the catalyst consists of tetrabutylammonium bromide and triethanolamine borate, and the molar ratio of the tetrabutylammonium bromide to the triethanolamine borate is (1-4): 1. The invention discovers that tetrabutylammonium bromide is used as a main catalyst, triethanolamine borate is used as a cocatalyst, and the combination of the tetrabutylammonium bromide and the triethanolamine borate is used as a binary homogeneous catalyst, compared with the tetrabutylammonium bromide which is used as a catalyst, the activation energy of chemical reaction is obviously reduced, and the efficient generation of soybean oil-based cyclic carbonate is further accelerated. Specifically, the activation energy of tetrabutylammonium bromide in combination with triethanolamine borate was reduced to 57.16 kJ/mol, corresponding to a pre-finger factor of 1.79×10 5. The combination of the two can improve the conversion rate and the selectivity of the epoxidized soybean oil in the reaction process of the epoxidized soybean oil and the CO 2, so as to improve the yield of the soybean oil-based cyclic carbonate. Meanwhile, the preparation method of the invention adopts lower reaction temperature and CO 2 pressure, and can obtain the soybean oil-based cyclic carbonate with high yield in less reaction time. In the process, they not only play the role of catalyst to promote the reaction, but also play the role of solvent, thereby providing a proper medium environment for the reaction. The triethanolamine borate used in the invention has excellent fat solubility, can be fully fused with the substrate epoxidized soybean oil, and is favorable for improving the rate of cycloaddition reaction. In some embodiments, the molar ratio of tetrabutylammonium bromide to triethanolamine borate is 2:1. The invention discovers that when the molar ratio of tetrabutylammonium bromide to triethanolamine borate is 2:1 in the binary homogeneous catalyst, the yield of the soybean oil-based cyclic carbonate obtained by the reaction at 100 ℃ is 44.4 percent, which is far higher than the yield of the soybean oil-based cyclic carbonate obtained by the molar ratio of 1:1 or 4:1. In some embodiments, the temperature is 120 ℃. In some embodiments, the molar amount of tetrabutylammonium bromide is 4% to 6% of the molar amount of epoxide groups in the epoxidized soybean oil and the molar amount of triethanolamine borate is 1.25% to 5% of the molar amount of epoxide groups in the epoxidized soybean oil. Preferably, the molar amount of tetrabutylammonium bromide is 5% of the molar amount of epoxy groups in epoxidized soybean oil