Method of manufacturing methanol

摘要

A method of manufacturing methanol comprising reacting hydrocarbons with water vapor in a reformer (30) to produce a synthesis gas containing hydrogen, carbon monoxide and carbon dioxide, recovering carbon dioxide from combustion exhaust gas which has been discharged from the reformer (30) by a carbon dioxide recovery apparatus (90) provided with a carbon dioxide absorption tower and with a carbon dioxide-absorbing solution regenerating tower, feeding the carbon dioxide thus recovered to the upstream side and/or the downstream side of the reformer (30), allowing reaction of the synthesis gas to take place over a catalyst to produce a reaction product, recovering liquid crude methanol from the reaction product, distilling the liquid crude methanol in a distillation apparatus (80) provided with a pressure distillation tower and with an atmospheric distillation tower to separate it into refined methanol and waste water containing low boiling point organic compounds and high boiling point organic compounds. Bottom liquid in a topping tower of the distillation apparatus (80) is heated and introduced into the pressure distillation tower in the distillation step, and the heat of distilled liquid discharged from the top of the pressure distillation tower is utilized as a heat source for the carbon dioxide-absorbing solution regenerating tower (93) and as a heat source for the atmospheric distillation tower.