Dimethyl oxalate production method with byproduct (dimethyl carbonate)

Abstract

The invention provides a dimethyl oxalate production method with a byproduct (dimethyl carbonate). The method comprises the following steps: (a) introducing reaction materials containing CO and methyl nitrite into a coupling reactor, and carrying out reactions in the presence of a platinum family metal catalyst to obtain a gas phase material flow containing dimethyl oxalate and dimethyl carbonate; (b) introducing the gas phase material flow containing dimethyl oxalate and dimethyl carbonate into an ester separation tower to contact with a methanol material flow from the top of the ester separation tower and an extracting agent material flow containing oxalic acid from the middle of the ester separation tower in a countercurrent contact mode, obtaining crude methanol from the top of the ester separation tower, and obtaining a mixture containing dimethyl oxalate and dimethyl carbonate from the bottom of the ester separation tower; and (c) introducing the mixture into a dimethyl oxalate refining tower, obtaining a dimethyl carbonate product from the top of the dimethyl oxalate refining tower, and obtaining a dimethyl oxalate product from the bottom of the dimethyl oxalate refining tower; wherein the gas phase material flow containing dimethyl oxalate and dimethyl carbonate is not cooled after being introduced into the ester separation tower.

Description

technical field [0001] The present invention relates to a kind of production method of dimethyl oxalate, also relate to a kind of method of producing dimethyl oxalate and simultaneously by-product dimethyl carbonate. Background technique [0002] Dimethyl oxalate (DMO) is an important intermediate product, which can be hydrolyzed to produce oxalic acid, and can also be hydrogenated to produce ethylene glycol. It has important uses in the chemical industry. The synthetic route of dimethyl oxalate mainly contains two: the first route is to adopt methanol and oxalic acid esterification reaction to synthesize, and this route has the shortcoming that discharges waste water amount is big, and environmental pollution is serious; Another route is by carbon monoxide and suboxide Methyl nitrate is synthesized by coupling reaction under platinum group catalyst. Due to the rapid development of the coal chemical industry in recent years, the second route has attracted widespread attenti...

AI Technical Summary

Problems solved by technology

The problem of complex process and high energy consumption in the separation process of methanol and dimethyl carbonate has not been solved

[0016] In short, in the existing technology, for the separation method of dimethyl carbonate, whether it is pressure swing rectification or extractive distillation separation, there is a problem that the amount of methanol used is large, which leads to the separation of methanol and dimethyl carbonate The problem of complex process flow and high energy consumption

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