Technology and device for synthesizing dimethyl carbonate

Abstract

A technology for synthesizing dimethyl carbonate adopts a two-tower continuous reaction, and comprises the following steps: a raw material liquid methanol is fed from the upper part of a gas and liquid distributor of a first reactor, flows out of the gas and liquid distributor and enters the reaction section of a reactor, a raw material gas CO is introduced to the first reactor from the bottom ofthe reaction section of the reactor, O2 is divided into 2-5 passages, O2 in the 2-5 passages except one is distributed in the reaction section of the reactor, a reaction is continuously carried out under the action of a catalyst in the reaction section to generate dimethyl carbonate, a formed mixed liquid A flows into the water separation section of the first reactor, methanol and dimethyl carbonate in the mixed A go through a bottom hydrophobic membrane and continuously downwards flow into a tower bottom to form a mixed liquid B, water permeates a surrounding hydrophilic membrane, and then iscollected and discharged, the mixed liquid B in the bottom of the first reactor enters a second reactor, a crude product is extracted from the bottom of the second reactor, and non-condensable gasesCO, O2 and CO2 obtained after the reactions in the first reactor and the second reactor are discharged from the top of the reactors. The technology has the advantages of simple process, high methanolconversion rate and low energy consumption.

Description

technical field [0001] The invention belongs to a synthesis process and device of dimethyl carbonate Background technique [0002] Dimethyl carbonate (DMC) is an environmentally friendly chemical. It is a colorless transparent liquid at room temperature, miscible with most organic solvents such as alcohols, ketones, esters and ethers, and hardly soluble in water. It has the characteristics of high oxygen content, low vapor pressure, easy volatility and low toxicity. Dimethyl carbonate molecules contain carbonyl and methyl groups, which can replace phosgene as carbonylation reagents, methyl halides and dimethyl sulfate as methylation reagents, and freon and chloroform as solvents. It can be used as an oil additive instead of methyl tert-butyl ether (MTBE), and has broad application prospects. [0003] Since Enichem successfully developed the DMC process in liquid phase oxidative carbonylation of methanol in 1983, the synthesis of DMC by oxidative carbonylation has become a ...

AI Technical Summary

Problems solved by technology

This technique has the following disadvantages: 1) the gas-liquid mixing discharge consumes a lot of energy; 2) the water generated by the reaction stays in the reactor, causing the DMC hydrolysis reaction to be serious; 3) the DMC content is lower than 40% in the crude product. Azeotropic or pressure swing distillation refining DMC process consumes a lot of energy

Images