A METHOD FOR PRODUCING GLYCOLS

摘要

This invention relates to a method for producing glycols. Such a method is particularly useful for preparing ethylene glycol from ethylene oxide and water. The method of this invention is a synergistic combination of the process of evaporation, absorption, and reaction, combined to enhance reactions of yields for reactions of epoxides with compounds containing hydroxy functional groups. Such method comprises making glycol in an evaporation column reactor as follows: (a) feeding a hydroxy compound into the reactor; (b) feeding an epoxide into the reactor such that the epoxide compound is contacted with hydroxyl compound in a reaction zone under conditions such that substantially all of the epoxide reacts to form a product comprising a glycol which is dissolved in liquid hydroxyl compound; (c) removing the mixture of liquid hydroxyl compound and dissolved glycol away from the reaction zone; and (d) heating the mixture of liquid hydroxyl compound and dissolved glycol such that at least some of the hydroxyl compound is evaporated away from the glycol; and (e) condensing and refluxing the evaporated hydroxyl compound and combining it with the hydroxyl compound of Step (a). In one aspect of the invention, the epoxide feed described in Step (b) enter the reactor through at least two distinct ports within the reactor. In another aspect of this invention, the method is synergistically conducted in at least two sequential evaporation columns which together form a multiple effect evaporation column reactor.