A method for catalyzing glycerol and carbon dioxide to synthesize glycerol carbonate

Abstract

The invention discloses a method for catalyzing glycerol and carbon dioxide to synthesize glycerol carbonate, comprising the following steps: adding a Cu-Mg-Al catalyst, glycerol, tetrahydrofuran and a solvent into a reactor, sealing the reactor, replacing the air in the reactor with N2 and CO2 in sequence, and after the replacement, introducing CO2 into the reactor for pressurization, and then heating to a reaction temperature for reaction to obtain glycerol carbonate; wherein: the chemical formula of the Cu-Mg-Al catalyst is Cu a Mg b Al c O m , m=a+b+1.5c, a:b:c=(0.5~1.5):(0.5~1.5):(0.5~1.5). In the method of the present invention, Cu-Mg-Al ternary oxide is used as a catalyst. The combination of the three oxides can provide effective catalytic active sites for glycerol and CO2. These active sites can reduce the activation energy required for converting glycerol into glycerol carbonate, thereby accelerating the reaction process and improving the conversion rate of glycerol.

Description

Technical Field

[0001] The invention specifically relates to a method for synthesizing glycerol carbonate by catalyzing glycerol and carbon dioxide. Background Art

[0002] As a common industrial by-product, the efficient use of glycerol not only helps solve the problem of resource waste, but also promotes the development of green chemistry. At the same time, as the main component of greenhouse gases, the effective conversion and fixation of carbon dioxide is of great significance for mitigating climate change. As an important organic chemical, glycerol carbonate has a wide range of applications in polymer production, textile manufacturing, medicine and cosmetics. Therefore, converting glycerol and carbon dioxide into glycerol carbonate not only realizes the reuse of resources, but also promotes the recycling of carbon, which has important economic and environmental value. However, the direct reaction process of glycerol and carbon dioxide to synthesize glycerol carbonate is limited by thermodynamics and usually needs to be carried out under relatively harsh conditions with low yields. For example, Vieville et al. first attempted to synthesize glycerol carbonate under supercritical CO2 conditions using zeolite and ion exchange resin as catalysts, but the glycerol conversion rate and carbonic acid selectivity were both low, and the glycerol carbonate yield was only 3.7% (Vieville C, Yoo JW, Pelet S, et al. Synthesis of glycerolcarbonate by direct carbonatation of glycerol in supercritical CO2in thepresence of zeolites and ion exchange resins[J]. Catal Lett, 1998, 56(4): 245−247). In order to improve the reaction efficiency and product yield, scientists have been continuously researching and exploring new catalytic systems and reaction conditions for the synthesis of glycerol carbonate from glycerol and carbon dioxide. For example, Aresta et al. used methanol as solvent and 13X zeolite as dehydrating agent to catalyze the synthesis of glycerol carbonate from glycerol and CO2 under the catalytic action of nBu2SnO. The conversion rate of glycerol and the selectivity of glycerol carbonate were improved, and the yield of glycerol carbonate was increased to 32% (ARESTA M, DIBENEDETTO A, NOCITOF, et al. A study on the carboxylation of glycerol to glycerol carbonate with carbon dioxide: the role of the catalyst, solvent and reaction conditions [J]. J Mol Catal A: Chem, 2006, 257). However, the yield of 32% is still low. In summary, based on current research, the conversion rate of glycerol and the selectivity of glycerol carbonate in the method of catalyzing the synthesis of glycerol carbonate from glycerol and CO2 are both low. Summary of the invention

[0003] The purpose of the present invention is to provide a method for synthesizing glycerol carbonate by catalyzing glycerol and carbon dioxide with high glycerol conversion rate and good glycerol carbonate selectivity.

[0004] The present invention provides a method for catalyzing glycerol and carbon dioxide to synthesize glycerol carbonate, which adopts the following technical scheme: A method for catalyzing glycerol and carbon dioxide to synthesize glycerol carbonate comprises the following steps: Cu-Mg-Al catalyst, glycerol, tetrahydrofuran and solvent are added to a reactor, and after the reactor is sealed, the air in the reactor is replaced with N2 and CO2 in turn. After the replacement is completed, CO2 is introduced into the reactor for pressurization, and then heated to the reaction temperature for reaction to obtain glycerol carbonate; wherein: the chemical formula of the Cu-Mg-Al catalyst is Cu a Mg b Al c O m , m=a+b+1.5c, a:b:c=(0.5~1.5):(0.5~1.5):(0.5~1.5); The synthetic route is as follows: .

[0005] Preferably, the preparation method of the Cu-Mg-Al catalyst comprises the following steps: adding copper salt, magnesium salt, aluminum salt and urea into water to dissolve, and then performing a hydrothermal reaction; after the reaction is completed, filtering the reaction liquid, washing and drying the filter cake to obtain a solid; and sintering the solid in an oxygen-containing atmosphere to obtain a Cu-Mg-Al catalyst.

[0006] Preferably, the copper salt, magnesium salt and aluminum salt are water-soluble salts of copper, magnesium and aluminum, respectively, and more preferably nitrates, sulfates and chlorides; the copper salt, magnesium salt and aluminum salt are added according to the molar ratio of copper, magnesium and aluminum of (0.5~1.5):(0.5~1.5):(0.5~1.5).

[0007] Preferably, the ratio of the molar number of the urea to the total molar number of copper, magnesium and aluminum in the copper salt, magnesium salt and aluminum salt is (4-9):1.

[0008] Preferably, the hydrothermal reaction temperature is 110-130° C., and the hydrothermal reaction time is 18-36 h.

[0009] Preferably, the oxygen-containing atmosphere is an air atmosphere or an oxygen atmosphere; the sintering temperature is 500-600° C., the sintering time is 4-6 hours, and the sintering heating rate is 9-11° C. / min.

[0010] Preferably, the mass ratio of the Cu-Mg-Al catalyst to glycerol is (0.5-1.5):(1-2); the mass ratio of the Cu-Mg-Al catalyst to tetrahydrofuran is (0.5-1.5):(3-6).

[0011] Preferably, the solvent is N,N-dimethylformamide, and the volume ratio of glycerol to the solvent is (1-2):(9-11).

[0012] Preferably, the reaction temperature is 120-130° C. and the reaction time is 3-4 h.

[0013] Preferably, the pressurization is to a pressure of 2-4 MPa.

[0014] The above one or more technical solutions of the present invention can achieve at least one of the following beneficial effects: The method of the present invention adopts Cu-Mg-Al ternary oxide as a catalyst. The combination of the three oxides can provide effective catalytic active sites for glycerol and CO2. These active sites can reduce the activation energy required for converting glycerol into glycerol carbonate, thereby accelerating the reaction process and improving the conversion rate of glycerol. Tetrahydrofuran is further added as a dehydrating agent in the method of the present invention, which can continuously remove the generated water from the reaction system, thereby promoting the reaction equilibrium to move in the direction of generating glycerol carbonate, thereby improving the selectivity of glycerol carbonate. In addition, tetrahydrofuran and the Cu-Mg-Al catalyst also have a synergistic effect, which can significantly improve the conversion rate of glycerol and the selectivity of glycerol carbonate. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The graphs are the change curves of the conversion rate of glycerol and the selectivity of glycerol carbonate at different reaction temperatures in Examples 1 and Examples 6 to 8.

[0016] Figure 2 The graphs are the change curves of the conversion rate of glycerol and the selectivity of glycerol carbonate at different reaction times in Example 1 and Examples 9 to 11.

[0017] Figure 3 The graph is a change curve of the conversion rate of glycerol and the selectivity of glycerol carbonate under different reaction pressures in Example 1 and Examples 12 to 14. DETAILED DESCRIPTION

[0018] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively and meticulously below in conjunction with the accompanying drawings and preferred embodiments of the present invention, but the protection scope of the present invention is not limited to the following specific embodiments. Unless otherwise defined, all the professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention. Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0019] As mentioned above, the present invention provides a method for catalyzing glycerol and carbon dioxide to synthesize glycerol carbonate, which adopts the following technical scheme: A method for catalyzing glycerol and carbon dioxide to synthesize glycerol carbonate comprises the following steps: Cu-Mg-Al catalyst, glycerol, tetrahydrofuran and solvent are added to a reactor, and after the reactor is sealed, the air in the reactor is replaced with N2 and CO2 in turn. After the replacement is completed, CO2 is introduced into the reactor for pressurization, and then heated to the reaction temperature for reaction to obtain glycerol carbonate; wherein: the chemical formula of the Cu-Mg-Al catalyst is Cu a Mg b Al c O m , m=a+b+1.5c, a:b:c=(0.5~1.5):(0.5~1.5):(0.5~1.5).

[0020] Cu-Mg-Al ternary oxide can provide effective catalytic active sites for glycerol and CO2; these active sites can reduce the activation energy required for the conversion of glycerol into glycerol carbonate, thereby accelerating the reaction process and improving the conversion rate of glycerol. The Cu-Mg-Al catalyst has a certain alkalinity that can promote the effective contact and reaction between glycerol molecules and carbon dioxide, thereby improving the conversion rate of glycerol and the selectivity of glycerol carbonate. Tetrahydrofuran has high permeability and solubility and can effectively penetrate into glycerol molecules. In the present invention, tetrahydrofuran is used as a dehydrating agent, which can continuously remove the generated water from the reaction system, thereby promoting the reaction equilibrium to move in the direction of generating glycerol carbonate, thereby improving the conversion rate of glycerol and the selectivity of glycerol carbonate. Compared with other dehydrating agents, tetrahydrofuran has a certain synergistic effect with Cu-Mg-Al ternary oxide, which can further improve the catalytic effect of the Cu-Mg-Al ternary oxide catalyst.

[0021] Preferably, the preparation method of the Cu-Mg-Al catalyst comprises the following steps: dissolving copper salt, magnesium salt, aluminum salt and urea in water, carrying out a hydrothermal reaction, filtering the reaction liquid after the reaction is completed, washing and drying the filter cake to obtain a solid, and sintering the solid in an oxygen-containing atmosphere to obtain a Cu-Mg-Al catalyst.

[0022] Preferably, the copper salt, magnesium salt and aluminum salt are water-soluble salts of copper, magnesium and aluminum, respectively, and more preferably nitrates, sulfates and chlorides; the copper salt, magnesium salt and aluminum salt are added according to the molar ratio of copper, magnesium and aluminum of (0.5~1.5):(0.5~1.5):(0.5~1.5).

[0023] Preferably, the ratio of the molar number of the urea to the total molar number of copper, magnesium and aluminum in the copper salt, magnesium salt and aluminum salt is (4-9):1.

[0024] Preferably, the hydrothermal reaction temperature is 110-130° C., and the hydrothermal reaction time is 18-36 h.

[0025] Preferably, the oxygen-containing atmosphere is an air atmosphere or an oxygen atmosphere; the sintering temperature is 500-600° C., the sintering time is 4-6 hours, and the sintering heating rate is 8-12° C. / min.

[0026] Preferably, the mass ratio of the Cu-Mg-Al catalyst to glycerol is (0.5-1.5):(1-2); the mass ratio of the Cu-Mg-Al catalyst to tetrahydrofuran is (0.5-1.5):(3-6).

[0027] Preferably, the solvent is N,N-dimethylformamide, and the volume ratio of glycerol to the solvent is (1-2):(9-11).

[0028] Preferably, the reaction temperature is 120-130° C. and the reaction time is 3-4 h.

[0029] Preferably, the pressurization is to a pressure of 2-4 MPa.

[0030] In the present invention, the reaction temperature is preferably 120-130°C. When the reaction temperature is low, the glycerol conversion rate and the selectivity of glycerol carbonate are both low; as the reaction temperature increases, the glycerol conversion rate and the selectivity of glycerol carbonate both increase. However, when the reaction temperature exceeds 120°C, the glycerol conversion rate does not increase significantly, but the selectivity of the product glycerol carbonate decreases.

[0031] In the present invention, the reaction time is preferably 3 to 4 hours. When the reaction time is too short, the glycerol conversion rate is low and the glycerol carbonate selectivity is also low. As the reaction time increases, the glycerol conversion rate and the glycerol carbonate selectivity both show a significant increasing trend. However, when the reaction time exceeds 3 hours, the glycerol conversion rate and the glycerol carbonate selectivity are not significantly improved.

[0032] In the present invention, the reaction pressure is preferably 2-4 Mpa. When the reaction pressure is too low, the conversion rate of glycerol is low and the selectivity of the product glycerol carbonate is not high. As the reaction pressure increases, the conversion rate of glycerol and the selectivity of the product glycerol carbonate increase significantly. However, when the reaction pressure exceeds 3 Mpa, the conversion rate of glycerol and the selectivity of the product glycerol carbonate are reduced.

[0033] Example 1 Step 1: CuMgAlO 3.5 Preparation of catalyst: 0.03 mol Cu(NO3)2·3H2O, 0.03 mol Mg(NO3)2·6H2O, 0.03 mol Al(NO3)3·9H2O and 0.6 mol urea were added into 500 mL deionized water, stirred and dissolved, and then hydrothermally reacted at 120°C for 24 h. After the reaction was completed, the reaction solution was filtered, and the filter cake was washed and vacuum dried at 60°C overnight to obtain a solid; the solid was placed in a sintering furnace, heated to 550°C at 10°C / min in an air atmosphere, and sintered for 5 h to obtain CuMgAlO 3.5 catalyst.

[0034] Step 2: Preparation of glycerol carbonate: Add 1 mL of glycerol, 10 mL of N,N-dimethylformamide, 0.5 g of CuMgAlO 3.5 Catalyst and 3.5g tetrahydrofuran; then seal the autoclave and cool it in an ice-water bath, then replace the air in the autoclave with N2 and CO2 in turn, after replacing 3 times each, fill with CO2 and pressurize to 3MPa, then heat to 120℃ under stirring conditions for reaction 3h; after the reaction, cool the autoclave naturally to room temperature, and after exhausting the residual gas in the autoclave, the reaction liquid contains glycerol carbonate.

[0035] The reaction liquid in step 2 was collected by a needle filter for gas chromatography detection. The detection results are shown in Table 1.

[0036] Comparative Example 1 The preparation method is basically the same as that of Example 1, except that the catalyst prepared in step 1 is different. In this comparative example, CuMgO2 is used as the catalyst.

[0037] The specific preparation method of CuMgO2 catalyst is as follows: take 0.03 mol Cu(NO3)2·3H2O, 0.03 mol Mg(NO3)2·6H2O and 0.6 mol urea, dissolve in 500 mL deionized water, stir to dissolve, hydrothermally react at 120°C for 24 hours, filter the reaction solution, wash the filter cake and vacuum dry it at 60°C overnight to obtain a solid; place the solid in a sintering furnace, heat to 550°C at 10°C / min under air atmosphere, and sinter for 5 hours to obtain a CuMgO2 catalyst.

[0038] Comparative Example 2 The method is basically the same as that in Example 1, except that the catalyst prepared in step 1 is different. The catalyst in this comparative example is CuAlO 2.5 .

[0039] CuAlO 2.5 The specific preparation method of the catalyst is as follows: 0.03 mol Cu(NO3)2·3H2O, 0.03 mol Al(NO3)3·9H2O and 0.6 mol urea are dissolved in 500 mL of deionized water, stirred and dissolved, and then hydrothermally reacted at 120°C for 24 h, the reaction solution is filtered, the filter cake is washed and vacuum dried at 60°C overnight to obtain a solid; the solid is placed in a sintering furnace, heated to 550°C at 10°C / min in an air atmosphere, and sintered for 5 h to obtain CuAlO 2.5 catalyst.

[0040] Comparative Example 3 The method is substantially the same as that of Example 1, except that in step 2, an equal amount of acetonitrile is used instead of tetrahydrofuran.

[0041] Comparative Example 4 The preparation method is basically the same as that of Example 1, except that in step 2, an equal amount of 2-cyanopyridine is used instead of tetrahydrofuran.

[0042] Example 2 The preparation method is basically the same as that in Example 1, except that in step 2, the amount of tetrahydrofuran added is 2 g.

[0043] Example 3 The preparation method is basically the same as that in Example 1, except that in step 2, the amount of tetrahydrofuran added is 5 g.

[0044] Table 1 From the data in Table 1, it can be seen that in Example 1, CuMgAlO 3.5 The ternary oxide catalyst is compared with CuMgO2 in Comparative Example 1 and CuAlO in Comparative Example 2. 2.5 The conversion rate of glycerol and the selectivity of glycerol carbonate were significantly improved over the binary oxide catalyst, indicating that CuMgAlO 3.5 Ternary oxide catalysts can better catalyze glycerol to produce glycerol carbonate.

[0045] Comparative Examples 3 and 4 respectively used acetonitrile and 2-cyanopyridine as dehydrating agents. From the results, the conversion rate of glycerol and the selectivity of glycerol carbonate were significantly reduced compared with those in Example 1, indicating that when the catalyst is CuMgAlO3.5 When tetrahydrofuran is used as a dehydrating agent, the effect is optimal.

[0046] In Examples 2 and 3, the amount of tetrahydrofuran, a dehydrating agent, is changed, and the conversion rate of glycerol and the selectivity of glycerol carbonate fluctuate to a certain extent, but the overall comprehensive performance is maintained at a good level.

[0047] Example 4 The method is basically the same as that in Example 1, except that the catalyst in step 1 is CuMg 0.5 Al2O 4.5 , the specific preparation method is as follows: CuMg 0.5 Al2O 4.5 Preparation of catalyst: 0.03 mol CuSO4·5H2O, 0.015 mol MgSO4, 0.03 mol Al2(SO4)3 and 0.5 mol urea were added into 500 mL deionized water, stirred and dissolved, and then hydrothermally reacted at 110°C for 36 h. After the reaction, the reaction solution was filtered, and the filter cake was washed and vacuum dried at 60°C overnight to obtain a solid. The solid was placed in a sintering furnace, heated to 500°C at 8°C / min in an air atmosphere, and sintered for 6 h to obtain CuMg 0.5 Al2O 4.5 catalyst.

[0048] Example 5 The method is basically the same as that in Example 1, except that the catalyst in step 1 is Cu2Mg2AlO 4.5 , the specific preparation method is as follows: Cu2Mg2AlO 4.5 Preparation of catalyst: 0.06 mol CuCl2, 0.06 mol MgCl2, 0.03 mol AlCl3 and 0.9 mol urea were added into 500 mL deionized water, stirred and dissolved, and then hydrothermally reacted at 130°C for 18 h. The reaction solution was filtered, and the filter cake was washed and vacuum dried at 60°C overnight to obtain a solid. The solid was placed in a sintering furnace, heated to 600°C at 12°C / min in an air atmosphere, and sintered for 4 h to obtain Cu2Mg2AlO 4.5 catalyst.

[0049] The reaction liquids in step 2 of Examples 4 and 5 were collected by needle filters for gas chromatography detection. The detection results can be seen in Table 2.

[0050] Table 2 It can be seen from the data in Table 2 that when the ratio of each oxide in the three-way catalyst changes, the conversion rate of glycerol and the selectivity of glycerol carbonate will also fluctuate to a certain extent, but the overall effect is maintained at a good level.

[0051] Embodiment 6-8 Examples 6 to 8 are substantially the same as Example 1, except that the reaction temperature in step 2 is different. The specific reaction temperature and test results can be seen in Figure 1 and Table 3.

[0052] Table 3 from Figure 1 It can be seen from the data in Table 3 that when the reaction temperature is lower than 110°C, the conversion rate of glycerol and the selectivity of glycerol carbonate are not high. When the temperature reaches 120°C, the conversion rate of glycerol and the selectivity of glycerol carbonate are significantly improved. However, when the temperature reaches 130°C, compared with the reaction temperature of 120°C, the conversion rate of glycerol is improved, but the improvement is not much, the selectivity of glycerol carbonate is significantly reduced, and the overall yield of glycerol carbonate decreases.

[0053] Embodiments 9 to 11 Examples 9 to 11 are basically the same as Example 1, except that the reaction time in step 2 is different. The specific reaction time and test results can be seen in Figure 2 and Table 4.

[0054] Table 4 from Figure 2 It can be seen from the data in Table 4 that when the reaction time is less than 2 h, the conversion rate of glycerol and the selectivity of glycerol carbonate are not high. With the extension of the reaction time, the conversion rate of glycerol and the selectivity of glycerol carbonate will be significantly improved. When the reaction time exceeds 3 h, with the extension of the reaction time, the conversion rate of glycerol and the selectivity of glycerol carbonate will not be significantly improved.

[0055] Embodiments 12 to 14 Examples 12 to 14 are basically the same as Example 1, except that the pressure of CO2 pressurization in step 2 is different. The specific pressurization pressure and test results can be seen in Figure 3 and Table 5.

[0056] Table 5 It can be seen from the data in Table 5 that when the pressurization pressure is less than 2 MPa, the conversion rate of glycerol and the selectivity of glycerol carbonate are not high. With the increase of the pressurization pressure, the conversion rate of glycerol and the selectivity of glycerol carbonate will be significantly improved. However, when the pressurization pressure exceeds 3 MPa, the conversion rate of glycerol and the selectivity of glycerol carbonate will decrease.

[0057] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for catalyzing glycerol and carbon dioxide to synthesize glycerol carbonate, characterized in that: The following steps are involved: Cu-Mg-Al catalyst, glycerol, tetrahydrofuran and solvent are added to a reactor, and after the reactor is sealed, the air in the reactor is replaced with N2 and CO2 in turn. After the replacement is completed, CO2 is introduced into the reactor for pressurization, and then heated to the reaction temperature for reaction to obtain glycerol carbonate; wherein: the chemical formula of the Cu-Mg-Al catalyst is Cu a Mg b Al c O m , m=a+b+1.5c, a:b:c=(0.5~1.5):(0.5~1.5):(0.5~1.5).

2. The method for catalyzing glycerol and carbon dioxide to synthesize glycerol carbonate according to claim 1, characterized in that: The preparation method of the Cu-Mg-Al catalyst comprises the following steps: adding copper salt, magnesium salt, aluminum salt and urea into water to dissolve them, and then performing a hydrothermal reaction; after the reaction is completed, filtering the reaction liquid, washing and drying the filter cake to obtain a solid; and sintering the solid in an oxygen-containing atmosphere to obtain the Cu-Mg-Al catalyst.

3. The method for synthesizing glycerol carbonate by catalyzing glycerol and carbon dioxide according to claim 2, characterized in that: The copper salt, magnesium salt and aluminum salt are water-soluble salts of copper, magnesium and aluminum respectively; the copper salt, magnesium salt and aluminum salt are added according to the molar ratio of copper, magnesium and aluminum of (0.5~1.5):(0.5~1.5):(0.5~1.5).

4. The method for catalyzing glycerol and carbon dioxide to synthesize glycerol carbonate according to claim 2, characterized in that: The ratio of the molar number of the urea to the total molar number of copper, magnesium and aluminum in the copper salt, magnesium salt and aluminum salt is (4-9):

1.

5. The method for catalyzing glycerol and carbon dioxide to synthesize glycerol carbonate according to claim 2, characterized in that: The hydrothermal reaction temperature is 110-130° C., and the hydrothermal reaction time is 18-36 hours.

6. The method for catalyzing glycerol and carbon dioxide to synthesize glycerol carbonate according to claim 2, characterized in that: The oxygen-containing atmosphere is an air atmosphere or an oxygen atmosphere; the sintering temperature is 500-600° C., the sintering time is 4-6 hours, and the sintering heating rate is 9-11° C. / min.

7. The method for catalyzing glycerol and carbon dioxide to synthesize glycerol carbonate according to claim 1, characterized in that: The mass ratio of the Cu-Mg-Al catalyst to glycerol is (0.5-1.5):(1-2); the solvent is N,N-dimethylformamide, and the volume ratio of glycerol to the solvent is (1-2):(9-11).

8. The method for catalyzing glycerol and carbon dioxide to synthesize glycerol carbonate according to claim 1 or 6, characterized in that: The mass ratio of Cu-Mg-Al catalyst to tetrahydrofuran is (0.5~1.5):(3~6).

9. The method for catalyzing glycerol and carbon dioxide to synthesize glycerol carbonate according to claim 1, characterized in that: The reaction temperature is 120~130℃ and the reaction time is 3~4h.

10. The method for catalyzing glycerol and carbon dioxide to synthesize glycerol carbonate according to claim 1, characterized in that: Pressurize to a pressure of 2~4Mpa.

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