Dehydration of water soluble monomers.

摘要

Water can be separated from aqueous solutions of organic chemicals miscible with carbon dioxide by a process which comprises the steps of:- a) contacting the aqueous solution with liquid carbon dioxide to form an extract phase of the organic chemical, carbon dioxide and some water, and a raffinate phase containing water; b) separating the extract phase from the raffinate phase; c) crystallizing by cooling and separating carbon dioxide hydrate from the extract phase; and d) evaporating the carbon dioxide. Optionally stages (c) and (d) can be reversed in time whereby a portion of the carbon dioxide is first evaporated prior to separation of the carbon dioxide hydrate. The process is applicable for example to the production of acrylic acid of high purity.