CN-116396149-B - Method for continuously preparing methylglyoxal based on glycerol gas-phase oxidation reaction

Abstract

The application relates to a method for continuously preparing methylglyoxal based on glycerol gas-phase oxidation reaction, which comprises the following steps of carrying out vaporization treatment on pure glycerol or glycerol solution to form raw material vapor, mixing the raw material vapor with gas containing O 2 to form mixed gas, and contacting the mixed gas with a supported nano gold catalyst to carry out selective oxidation reaction to generate methylglyoxal, wherein a carrier of the supported nano gold catalyst is metal oxide.

Inventors

• XU BAIQING
• WAN FANG
• You Kecheng

Assignees

• 清华大学

Dates

Publication Date

20260505

Application Date

20230327

Claims (10)

1. 1. A method for continuously preparing methylglyoxal based on a glycerol gas phase oxidation reaction, which is characterized by comprising the following steps: Vaporizing pure glycerol or glycerol solution to form raw material vapor; mixing the raw material vapor with a gas containing O 2 to form a mixed gas; and (3) contacting the mixed gas with a supported nano gold catalyst to perform a selective oxidation reaction to prepare the methylglyoxal, wherein a carrier of the supported nano gold catalyst is metal oxide, the temperature of the selective oxidation reaction is 260-280 ℃, the partial pressure of glycerin in the selective oxidation reaction is 0.5-1.7 kPa, and the molar ratio of O 2 to glycerin in the mixed gas is less than or equal to 2 and less than or equal to 60.
2. 2. The method for continuously preparing methylglyoxal based on vapor phase oxidation reaction of glycerin according to claim 1, wherein the solvent of glycerin solution includes one or more of water, N-dimethylformamide, and 1, 4-dioxane.
3. 3. The method for continuously preparing methylglyoxal based on the vapor phase oxidation reaction of glycerin according to claim 2, wherein the molar ratio of the solvent to glycerin in the glycerin solution is 0≤60.
4. 4. The method for continuously preparing methylglyoxal based on the vapor phase oxidation reaction of glycerin according to claim 1, wherein the molar ratio of O 2 to glycerin in the mixed gas is 8 to 53.
5. 5. The method for continuously preparing methylglyoxal based on the vapor phase oxidation reaction of glycerin according to claim 1, wherein the partial pressure of glycerin in the selective oxidation reaction is 0.5kpa to 0.8kpa.
6. 6. The method for continuously preparing methylglyoxal based on the vapor phase oxidation reaction of glycerin according to claim 1, wherein the space velocity of the selective oxidation reaction is 8000 ml.g cat -1 ·h -1 ~400000mL·g cat -1 ·h -1 .
7. 7. The method for continuously preparing methylglyoxal based on the vapor phase oxidation reaction of glycerin according to claim 1, wherein the space velocity of the selective oxidation reaction is 20000mL g cat -1 ·h -1 ~160000mL·g cat -1 ·h -1 .
8. 8. The method for continuously preparing methylglyoxal based on the vapor phase oxidation reaction of glycerin according to claim 1, wherein the nano gold in the supported nano gold catalyst is a metal simple substance or an alloy.
9. 9. The method for continuously preparing methylglyoxal based on the vapor phase oxidation reaction of glycerin according to claim 8, wherein the supported nano gold catalyst has a loading amount of 0.1wt.% or less and 16wt.% or less of Au.
10. 10. The method for continuously preparing methylglyoxal based on the vapor phase oxidation reaction of glycerin according to any one of claims 1 to 9, wherein the metal oxide includes one or more of ZrO 2 、TiO 2 、ZnO、NiO、Nb 2 O 5 、Co 3 O 4 and Al 2 O 3 .

Description

Method for continuously preparing methylglyoxal based on glycerol gas-phase oxidation reaction Technical Field The application relates to the technical field of catalytic conversion and utilization of biomass resources, in particular to a method for continuously preparing methylglyoxal based on a glycerol gas-phase oxidation reaction. Background The methylglyoxal is an important organic chemical intermediate, is mainly used for synthesizing cimetidine serving as a gastric drug and furanone serving as a flavor enhancer, can also be used for synthesizing medicines with the effects of relieving pain, resisting cancer, resisting hypertension, sterilizing, resisting viruses and the like, and chemicals such as pesticides, antioxidants, fiber treating agents and the like, so that the methylglyoxal has wide application in the fields of medicines, foods, cosmetics, pesticides, rubber, textiles and the like. In industrial production, 1, 2-propylene glycol is often used as a raw material, electrolytic silver is used as a catalyst, for example, the domestic public patent CN1240203A and the like, and the reaction is required to be carried out at a higher reaction temperature (450-650 ℃) because the activity of the electrolytic silver is low at a low temperature, and the catalyst is more easily deactivated due to sintering at a high temperature. In addition, 1, 2-propanediol is derived from propylene, so that the production of methylglyoxal is severely dependent on non-renewable fossil energy, and the production cost of methylglyoxal will rise gradually with the decrease of fossil energy reserves. Disclosure of Invention Against the background, it is necessary to provide a method for continuously preparing methylglyoxal based on biomass conversion utilization and glycerol gas phase oxidation reaction, aiming at the problems of high reaction temperature in methylglyoxal production and excessive dependence on fossil energy. A method for continuously preparing methylglyoxal based on a glycerol gas phase oxidation reaction, which is characterized by comprising the following steps: Vaporizing pure glycerol or glycerol solution to form raw material vapor; mixing the raw material vapor with a gas containing O 2 to form a mixed gas; And (3) contacting the mixed gas with a supported nano gold catalyst to perform a selective oxidation reaction to prepare the methylglyoxal, wherein the carrier of the supported nano gold catalyst is a metal oxide. In some of these embodiments, the solvent of the glycerol solution comprises one or more of water, N-dimethylformamide, and 1, 4-dioxane, and preferably the solvent is water. In some of these embodiments, the glycerol solution has a molar ratio of 0≤solvent to glycerol of 60. In some of these embodiments, the O 2 -containing gas is pure O 2 or air. In some embodiments, the molar ratio of 0.2≤O 2 to glycerol in the mixed gas is equal to or less than 60. In some embodiments, the partial pressure of glycerol in the selective oxidation reaction is 0.5kPa to 10.0kPa, and preferably, the partial pressure of glycerol in the selective oxidation reaction is 0.8kPa to 5.1kPa. In some of these embodiments, the space velocity of the selective oxidation reaction is 8000mL g cat-1·h-1～400000mL·gcat-1·h-1, preferably 20000mL g cat-1·h-1～160000mL·gcat-1·h-1. In some embodiments, the temperature of the selective oxidation reaction is 210-320 ℃, preferably 230-280 ℃. In some embodiments, the nano-gold in the supported nano-gold catalyst is a simple metal or an alloy. In some embodiments, the supported nanogold catalyst has a loading of 0.1wt.% or less of Au of 16wt.%. In some of these embodiments, the metal oxide comprises one or more of ZrO 2、TiO2、ZnO、NiO、Nb2O5、Co3O4 and Al 2O3, preferably the metal oxide is one or more of ZrO 2、TiO2 and ZnO. In the method for continuously preparing methylglyoxal based on the glycerol gas-phase oxidation reaction, the vaporized glycerol is selectively oxidized on the nano gold catalyst loaded by the metal oxide to generate methylglyoxal. The reaction can be carried out at a lower temperature, the reaction condition is mild, the reaction raw material glycerol is derived from renewable biomass resources, and the method is low in cost and easy to obtain, and is a green and economical method for preparing methylglyoxal. Detailed Description In order that the application may be understood more fully, the application will be described with reference to the following examples. This application may be embodied in many different forms and is not limited to the embodiments described herein. The terminology used in the description of the application herein is for the purpose of describing embodiments only and is not intended to be limiting of the application. The application provides a method for continuously preparing methylglyoxal based on a glycerol gas-phase oxidation reaction, which comprises the following steps of carrying out vaporization treatment on pure glycerol or a glycer