Method for preparing ethylene glycol

Abstract

The invention relates to a method for producing glycol, which mainly solves the problem that catalysts in the prior art are poor in stability and short in regeneration period. By adopting a technical proposal of taking oxalate as raw material, taking polar or nonpolar solvent as thinner and allowing the raw material to be in contact with and react with a copper-bearing catalyst so as to form glycol-containing effluent at a temperature between 120 and 300 DEG C, at a weight space velocity between 0.01 and 10 hours, with the hydrogen / ester molar ratio of 5-300:1, under the reaction pressure between 0.1 and 10.0 MPa, under the condition that the mass fraction of the oxalate is between 0.1 and 100 percent, the method solves the problem well, and can be used in the industrial production of glycol.

Description

technical field

[0001] The invention relates to a method for producing ethylene glycol, in particular to a method for producing ethylene glycol by catalytic hydrogenation of dimethyl oxalate or diethyl oxalate. Background technique

[0002] Ethylene glycol (EG) is an important organic chemical raw material, mainly used in the production of polyester fiber, antifreeze, unsaturated polyester resin, lubricant, plasticizer, nonionic surfactant and explosives, etc. It can be used in industries such as paint, photographic developer, brake fluid and ink, as a solvent and medium for ammonium perborate, and for the production of special solvents such as glycol ether, etc., and has a wide range of uses.

[0003] At present, large-scale ethylene glycol production at home and abroad adopts the process route of direct hydration or pressurized hydration. This process is to prepare a mixed aqueous solution of ethylene oxide and water at a ratio of 1:20 to 22 (molar ratio) in a fixed bed. ...

Examples

Embodiment 1

[0015] Weigh 80 grams of a silicon oxide carrier with a specific surface area of ​​200 square meters per gram, according to 18% Cu+0.2% Cu 2 O / SiO 2 Content configuration solution, the steps are as follows: select copper nitrate, make an impregnation solution according to the Cu load, immerse the silicon oxide carrier in the solution for 20 hours, dry it in vacuum at room temperature for 8 hours to obtain a solid, and then bake it at 500 ° C After 4 hours, 4 grams of the prepared catalyst were loaded into a tubular reactor with a diameter of 18 mm, and the temperature was increased with hydrogen for reduction to obtain a copper-containing catalyst.

[0016] Using dimethyl oxalate as raw material and methanol as solvent, at a reaction temperature of 220°C and a weight space velocity of 0.5 hours -1 , the hydrogen / ester molar ratio is 80: 1, the reaction pressure is 2.8MPa, and the mass percentage of dimethyl oxalate is under the condition of 10%, the mixture of raw material an...

Embodiment 2

[0018] According to each step and condition of embodiment 1, only the composition of catalyst is 20%Cu+4%Cu 2 O / SiO 2 , using methanol as a solvent, dimethyl oxalate as a raw material, at a reaction temperature of 270°C, and a weight space velocity of 8 hours -1 , the hydrogen / ester molar ratio is 80: 1, the reaction pressure is 1.5MPa, and the mass percentage of dimethyl oxalate is under the condition of 35%, the conversion rate of dimethyl oxalate is 100%, the selectivity of ethylene glycol was 81%.

Embodiment 3

[0020] According to each step and condition of embodiment 1, only the composition of catalyst is 15%Cu+10%Cr+1%Cu 2 O / SiO 2 , using ethanol as a solvent, diethyl oxalate as a raw material, at a reaction temperature of 180°C, and a weight space velocity of 0.3 hours -1 , the hydrogen / ester molar ratio is 60: 1, the reaction pressure is 0.8MPa, and the mass percentage of diethyl oxalate is under the condition of 80%, the conversion rate of diethyl oxalate is 99%, the selectivity of ethylene glycol was 89%.

technical field

[0001] The invention relates to a method for producing ethylene glycol, in particular to a method for producing ethylene glycol by catalytic hydrogenation of dimethyl oxalate or diethyl oxalate. Background technique

[0002] Ethylene glycol (EG) is an important organic chemical raw material, mainly used in the production of polyester fiber, antifreeze, unsaturated polyester resin, lubricant, plasticizer, nonionic surfactant and explosives, etc. It can be used in industries such as paint, photographic developer, brake fluid and ink, as a solvent and medium for ammonium perborate, and for the production of special solvents such as glycol ether, etc., and has a wide range of uses.

[0003] At present, large-scale ethylene glycol production at home and abroad adopts the process route of direct hydration or pressurized hydration. This process is to prepare a mixed aqueous solution of ethylene oxide and water at a ratio of 1:20 to 22 (molar ratio) in a fixed bed. ...

Examples

Embodiment 1

[0015] Weigh 80 grams of a silicon oxide carrier with a specific surface area of ​​200 square meters per gram, according to 18% Cu+0.2% Cu 2 O / SiO 2 Content configuration solution, the steps are as follows: select copper nitrate, make an impregnation solution according to the Cu load, immerse the silicon oxide carrier in the solution for 20 hours, dry it in vacuum at room temperature for 8 hours to obtain a solid, and then bake it at 500 ° C After 4 hours, 4 grams of the prepared catalyst were loaded into a tubular reactor with a diameter of 18 mm, and the temperature was increased with hydrogen for reduction to obtain a copper-containing catalyst.

[0016] Using dimethyl oxalate as raw material and methanol as solvent, at a reaction temperature of 220°C and a weight space velocity of 0.5 hours -1 , the hydrogen / ester molar ratio is 80: 1, the reaction pressure is 2.8MPa, and the mass percentage of dimethyl oxalate is under the condition of 10%, the mixture of raw material an...

Embodiment 2

[0018] According to each step and condition of embodiment 1, only the composition of catalyst is 20%Cu+4%Cu 2 O / SiO 2 , using methanol as a solvent, dimethyl oxalate as a raw material, at a reaction temperature of 270°C, and a weight space velocity of 8 hours -1 , the hydrogen / ester molar ratio is 80: 1, the reaction pressure is 1.5MPa, and the mass percentage of dimethyl oxalate is under the condition of 35%, the conversion rate of dimethyl oxalate is 100%, the selectivity of ethylene glycol was 81%.

Embodiment 3

[0020] According to each step and condition of embodiment 1, only the composition of catalyst is 15%Cu+10%Cr+1%Cu 2 O / SiO 2 , using ethanol as a solvent, diethyl oxalate as a raw material, at a reaction temperature of 180°C, and a weight space velocity of 0.3 hours -1 , the hydrogen / ester molar ratio is 60: 1, the reaction pressure is 0.8MPa, and the mass percentage of diethyl oxalate is under the condition of 80%, the conversion rate of diethyl oxalate is 99%, the selectivity of ethylene glycol was 89%.