Process for preparing dimethyl carbonate by reacting methanol, carbon monoxide and oxygen

Abstract

The invention discloses a synthesizing method of dimethyl carbonate through oxidizing and oxonating liquid phase of carbinol in the chemical technological domain, which comprises the following steps: adopting ion liquid as solvent and metal copper salt as catalyst; setting the weight rate of carbinol and ion liquid at 1: 4-10: 1 and the rate of catalyst and carbinol at 1: 100-1: 10; reacting under 80-180 Deg C; setting the initial total pressure of CO and O2 at 0.5-6.0Mpa with the molar rate of CO and O2 at 100: 1-2: 1 for 1-6h; realizing the synthesizing reaction to form dimethyl carbonate with single-course transmission rate at 10-20% and object product selectivity not less than 95%.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and in particular relates to a method for preparing dimethyl carbonate through liquid-phase oxidative carbonylation reaction of methanol, carbon monoxide and oxygen. Background technique [0002] Dimethyl carbonate (DMC) is a high value-added organic chemical raw material, which can replace highly toxic phosgene and dimethyl sulfate as carbonylation reagents, methylation reagents, etc. to manufacture many valuable chemical products. Used in the synthesis of high-performance resins, pharmaceuticals, and pesticide intermediates; it can replace various toxic solvents as solvents for paints and paints; because of its high oxygen content, it can replace methyl tert-butyl ether (MTBE) as a gasoline additive It also has a very broad application prospect. The preparation methods of dimethyl carbonate include phosgene method, methanol oxidative carbonylation method (including liquid phase metho...

AI Technical Summary

Problems solved by technology

However, due to the poor solubility of CuCl in the reaction system, a high concentration of CuCl must be used in the Enichem process to obtain a sufficient reaction rate; at the same time, CuCl is highly corrosive to the reaction equipment, and glass or enamel lining must be added to the inner wall of the reactor, etc. Anti-corrosion materials; in addition, the process has problems such as catalysts, reactants, and products that are difficult to separate

Chinese patent CN1197792A (1998) uses CuCl as the main catalyst, magnesium chloride, calcium chloride, etc. as auxiliary agents to prepare a composite catalyst modified by alkaline earth metal salts, which improves the solubility of cuprous chloride in the reaction solution to a certain extent. Improved catalytic activity, but did not solve the problem of corrosion of equipment, nor did it solve the problem of difficult separation of catalysts, reactants and products

Chinese patent CN1333086A (2002) has announced to take CuCl as main catalyst, and the composite catalyst that nitrogen-containing heterocyclic compound or macromolecule complex forms, has further improved the dissolubility of cuprous chloride in reaction solution, has improved The activity and selectivity of the catalyst, and the corrosion of the reaction system to the equipment have been reduced, but the problem of difficult separation of the catalyst, the reactant and the product has not been solved