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CN-121974896-A - Ionic liquid catalyzed CO2Process for preparing soybean oil-based cyclic carbonates

CN121974896ACN 121974896 ACN121974896 ACN 121974896ACN-121974896-A

Abstract

The invention discloses a method for preparing soybean oil-based cyclic carbonate by catalyzing CO 2 with ionic liquid, which comprises the following steps of mixing epoxidized soybean oil with the ionic liquid in a closed environment, discharging air in the closed environment, then filling CO 2 into the closed environment, regulating the air 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. The preparation method provided by the invention has the advantages that the reaction temperature and the CO 2 pressure are low, the reaction time is short, the reaction condition is mild, the ionic liquid shown in the structural formula is used for catalyzing CO 2 to prepare the soybean oil-based cyclic carbonate, the conversion rate and the selectivity of the epoxidized soybean oil are good, the yield of the obtained soybean oil-based cyclic carbonate is 40% -60%, the conversion rate, the selectivity and the yield are good, and the ionic liquid has good recycling property and can be reused.

Inventors

  • ZHANG CHAOQUN
  • ZENG HONG

Assignees

  • 华南农业大学

Dates

Publication Date
20260505
Application Date
20260407

Claims (10)

  1. 1. The method for preparing soybean oil-based cyclic carbonate by catalyzing CO 2 with ionic liquid is characterized by comprising the following steps: Mixing the epoxidized soybean oil and the ionic liquid in a closed environment, discharging air in the closed environment, then filling CO 2 into the closed environment, regulating the air 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 product; the structural formula of the ionic liquid is as follows: 、 、 、 、 、 、 Or (b) 。
  2. 2. The method for preparing soybean oil-based cyclic carbonate by using ionic liquid to catalyze CO 2 according to claim 1, wherein the molar amount of the ionic liquid is 5% of the molar amount of epoxy groups in the epoxidized soybean oil.
  3. 3. The method for preparing soybean oil-based cyclic carbonate by catalyzing CO 2 with ionic liquid according to claim 1, wherein the method for exhausting air in the closed environment is to introduce CO 2 to 5 times into the closed environment.
  4. 4. The method for preparing soybean oil-based cyclic carbonate by catalyzing CO 2 with ionic liquid according to claim 1, wherein the temperature is 120 ℃, the stirring speed is 400 rpm, and the reaction time is 12 hours.
  5. 5. The method for preparing soybean oil-based cyclic carbonate by catalyzing CO 2 with an ionic liquid according to claim 1, wherein the gas pressure of CO 2 is adjusted to 2.0. 2.0 MPa.
  6. 6. The method for preparing soybean oil-based cyclic carbonate by using ionic liquid to catalyze CO 2 according to claim 1, wherein the purification method is that the crude product obtained after the reaction is dissolved in ethyl acetate, the organic phase is dried, then the organic phase is subjected to suction filtration and rotary evaporation, and finally the obtained product is dried at 80 ℃.
  7. 7. The method for preparing soybean oil-based cyclic carbonate by using ionic liquid catalyzed CO 2 according to claim 6, wherein the method for drying the organic phase is to add anhydrous magnesium sulfate to the organic phase.
  8. 8. The method for preparing soybean oil-based cyclic carbonate by catalyzing CO 2 with an ionic liquid according to claim 1 is characterized in that the ionic liquid is prepared by dissolving 1, 3-tetramethyl guanidine or 1, 8-diazabicyclo [5.4.0] undec-7-ene in water to obtain a mixture, adding amino acid into the mixture under the condition of ice water bath, adding hydrogen halide into the mixture under the condition of avoiding light, and then reacting 16 h under the condition of 100 ℃ in nitrogen atmosphere, wherein the amino acid is histidine or lysine, and the hydrogen halide is HI or HBr.
  9. 9. The method for preparing soybean oil-based cyclic carbonate by using ionic liquid to catalyze CO 2 according to claim 8, wherein when the amino acid is histidine, the molar ratio of 1, 3-tetramethylguanidine or 1, 8-diazabicyclo [5.4.0] undec-7-ene to the amino acid is 3:1; When the amino acid is lysine, the molar ratio of 1, 3-tetramethylguanidine or 1, 8-diazabicyclo [5.4.0] undec-7-ene to the amino acid is 2:1.
  10. 10. The method for preparing soybean oil-based cyclic carbonate by using ionic liquid catalyzed CO 2 according to claim 8, wherein the molar ratio of 1, 3-tetramethylguanidine or 1, 8-diazabisspiro to hydrogen halide is (40-60): 20-35.

Description

Method for preparing soybean oil-based cyclic carbonate by catalyzing CO 2 with ionic liquid Technical Field The invention belongs to the technical field of cyclic carbonates, and particularly relates to a method for preparing soybean oil-based cyclic carbonate by catalyzing CO 2 with ionic liquid. 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 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, the gas pressure and the time are in a milder state at the same time, and severe reaction conditions are generally required to ensure that a higher yield is obtained. 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. The ionic liquid (AAIL) is a salt substance which is liquid at room temperature or near room temperature and is completely composed of cations and anions, and can be used as a catalyst for synthesizing cyclic carbonate by catalyzing CO 2 by cyclopropane. However, due to the weak nucleophilicity of the carboxyl anion of AAIL itself, it is necessary to raise the temperature to provide sufficient energy, even in combination with the use of a halide salt as a cocatalyst. In addition, the prior art lacks a method for preparing soybean oil-based cyclic carbonate by using the ionic liquid as CO 2, so that Epoxidized Soybean Oil (ESO) is needed to be used as a raw material, and a method for preparing the soybean oil-based cyclic carbonate by catalyzing CO 2 by using the ionic liquid is developed. 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, solve the technical problems that an ionic liquid needs a cocatalyst and is difficult to be used for preparing soybean oil-based cyclic carbonate by catalyzing CO 2 by the ionic liquid, and provide a method for preparing the soybean oil-based cyclic carbonate by catalyzing CO 2 by the ionic liquid. According to a first aspect of the present invention, there is provided a process for preparing soybean oil based cyclic carbonates from ionic liquid catalyzed CO 2, comprising the steps of: Mixing the epoxidized soybean oil and the ionic liquid in a closed environment, discharging air in the closed environment, then filling CO 2 into the closed environment, regulating the air 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 product; the structural formula of the ionic liquid is as follows: 、、、、、、 Or (b) 。 The preparation method provided by the invention has the advantages of low reaction temperature, low CO 2 air pressure, short reaction time and mild reaction conditions. The invention discovers that the ionic liquid with the structural formula can catalyze CO 2 to prepare the soybean oil-based cyclic carbonate, the conversion rate of the epoxidized soybean oil in the preparation process is 53-68%, the selectivity is 76-90%, and the yield of the soybean oil-based cyclic carbonate is 40-60%. Preferably, the ionic liquid has the structural formula: . When the ionic liquid catalyzes CO 2 to prepare soybean oil-based cyclic carbonate, 65.2% of CSO conversion rate, 88.5% of selectivity and 57.7% of comprehensive yield are realized. In some embodiments, the temperature is 120 ℃. The soybean oil-based cyclic carbonate is prepared at the reaction temperature, and the yield can reach 72.2%. In some embodiments, the molar amount of ionic liquid is 5% of the molar amount of epoxy groups in the epoxidized soybean oil. In some embodiments, the rotational speed of the agitation is 400 rpm. In some embodiments, the reaction takes 12 hours. At this reaction time, the yield of soybean oil-based cyclic carbonate was highest. In some embodiments, the gas pressure of CO 2 is adjusted to 2.0 MPa. In some embodiments, the purification is performed by dissolving the crude product obtained after the reaction in an organic solvent to obtain an organic phase, drying the organic phase, then suction filtering an