Patent attributes
The invention relates to a process for the preparation of alkanediol, which process involves (a) contacting alkylene oxide with carbon dioxide in the presence of catalyst to obtain a first liquid reaction mixture containing cyclic carbonate, (b) optionally removing carbon dioxide and/or alkylene oxide, (c) increasing the pressure of the liquid reaction mixture obtained in step (a) and/or (b), (d) contacting the pressurized first reaction mixture obtained in step (c) with water in the presence of catalyst to obtain a second reaction mixture containing alkanediol and carbon dioxide, (e) separating the second reaction mixture into a liquid effluent and a gaseous effluent containing carbon dioxide, and (f) recycling at least part of the gaseous effluent containing carbon dioxide to step (a),in which process the pressure in step (d) is higher than the pressure in step (a).
