Catalyst used for synthesizing diethyl carbonate from urea and ethanol, preparation method and application thereof

Abstract

The invention relates to a catalyst used for synthesizing diethyl carbonate from urea and ethanol. The catalyst is a solid alkaline catalyst and is prepared through a precipitation method or a coprecipitation method. A preparation method includes following steps: preparing an aqueous solution from soluble metal salt of alkaline-earth metals, transition metals and other metals; adding dropwisely a certain amount of a precipitating agent with a pH value being adjusted to between 8-12 to obtain a precursor; drying the precursor at 50-150 DEG C for 2-24 hours; and then calcining the precursor at 200-1000 DEG C for 2-10 hours. The catalyst is simple in preparation, is high in activity, is environmental-friendly, is easy to separate and recycle and is good in stability.

Description

[0001] technology field, [0002] The invention relates to a catalyst and its preparation method and application, in particular to a solid base catalyst for synthesizing diethyl carbonate from urea and ethanol, its preparation method and application. technical background [0003] Diethyl carbonate, referred to as DEC, contains carbonyl, ethoxy, and ethyl groups in the molecule, which have good reactivity. A series of important organic chemical products are derived from the reaction. DEC itself is a low-toxic substance, which will slowly hydrolyze when released into the environment to generate ethanol and carbon dioxide, and will not pollute the environment. Therefore, it is an environmentally friendly chemical. It is used in solvents, electrolytes, organic synthesis, pharmaceuticals and engineering plastics, etc. Fields are widely used. The oxygen content of 40.6% of diethyl carbonate is much higher than that of methyl tert-butyl ether (MTBE) (18.2%). As an oxygen-containing...

AI Technical Summary

Problems solved by technology

However, there are more or less deficiencies in economy and technology: the phosgene method, the raw material phosgene is highly toxic, and the by-product hydrochloric acid corrodes the equipment, causing serious environmental pollution; the oxidative carbonylation method of ethanol, CO is poisonous, and the reaction material is flammable Explosive; transesterification method, high cost of raw material DMC, poor selectivity

Zhao Xinqiang et al. (NO.CN101659616A) used oxides or composite oxides such as lead and zinc to catalyze the alcoholysis of urea to synthesize DEC. The highest yield of DEC was 20%. The catalyst used was highly toxic and easily lost, which was not conducive to industrial application.