A method for synthesizing dialkyl carbonate from biomass-based synthesis gas

Abstract

The invention belongs to synthesis methods of ester compounds in organic chemistry and particularly relates to a method for synthesizing diakyl carbonate from biomass-based synthesis gas. Biomass-based synthesis gas obtained from biomass-based agricultural and forestry residues used as initial materials is further catalyzed to form dimethyl ether, the obtained dimethyl ether is further catalyzed to form dimethyl carbonate, then, dimethyl carbonate is subjected to transesterification with monohydric alcohol or polyhydric alcohol, and diakyl carbonate is obtained. According to the method, diakylcarbonate is produced from the cheap agricultural and forestry residues used as raw materials, the production cost is saved, environmental pollution is reduced, and a new way is provided for industrial production of diakyl carbonate and efficient and comprehensive utilization of agricultural and forestry residues, and the method has significant economic and social benefits.

Description

technical field [0001] The invention relates to a method for preparing dialkyl carbonate, in particular to a method for synthesizing dialkyl carbonate from biomass-based synthesis gas. Background technique [0002] Dialkyl carbonate is a non-toxic chemical raw material, because its molecule contains -CO, -COOCH 3 and -CH 3 , has good reactivity, can react with a variety of alcohols, phenols, amines and esters, is a widely used organic compound and a good solvent, there are many types of dialkyl carbonate, some can be used as fuel, and some can be used As lubricating oil, some can be used as biodiesel, so it has high industrial application value and good market prospect. Among them, dimethyl carbonate is the most representative organic compound, and its synthesis methods mainly include phosgene synthesis, oxidative carbonylation, and transesterification. [0003] The traditional industrial production of dimethyl carbonate generally adopts the phosgene synthesis method, but...

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Problems solved by technology

[0003] The traditional industrial production of dimethyl carbonate generally adopts the phosgene synthesis method, but the synthesis can only maintain small-scale industrial production, and these preparation methods require phosgene, high operational safety requirements, and serious environmental pollution, so they are gradually replaced by the methanol oxidative carbonylation method replaced by

However, the methanol oxidative carbonylation method is divided into a liquid phase method and a gas phase method: in the reaction process of the liquid phase method, methanol is both a raw material and a solvent, and the oxygen concentration is always kept below the explosive limit in the reaction process. The catalyst is highly corrosive to the equipment, and the gas phase method requires a fixed-bed reactor. The disadvantage is that the catalyst activity is low

Imre Weisz once proposed to synthesize dimethyl carbonate by reacting dimethyl sulfate and sodium carbonate in a tank reactor, using chlorobenzene as a catalyst, and refluxing at 150-210°C for 6 hours to obtain dicarbonate with a yield of 44%. Methyl esters (WeiszI, Havelka F, Pellek Z, Dimethyl and diethyl carbonates, Hung Teljes, 1977, 14:221~226), but due to the low yield of this process, chlorobenzene and dimethyl sulfate are highly toxic, so the Law has not been further developed

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