PROCESS FOR THE PREPARATION OF AN ALKANEDIOL AND A DIALKYL CARBONATE

摘要

An alkanediol and a dialkyl carbonate are prepared in a process comprising: (a) reacting an alkylene carbonate and an alkanol feedstock into a reaction zone under transesterification conditions to obtain a product mixture of dialkyl carbonate, unconverted alkanol, the alkanediol, and unconverted alkylene carbonate; (b) separating dialkyl carbonate and unconverted alkanol from the product mixture to obtain a bottom product stream containing alkanediol and unconverted alkylene carbonate; (c) recovering the dialkyl carbonate; and (d) separating alkanediol from the bottom product stream to leave a recycle stream comprising unconverted alkylene carbonate, wherein the recycle stream comprising unconverted alkylene carbonate is split in at least two portions, and at least one portion is recycled to the reaction zone and another portion is subjected to hydrolysis to yield alkanediol and carbon dioxide.