摘要 |
A method of making acid anhydrides from epoxide and carbon monoxide feedstocks is presented. In various aspects, the method includes steps of reacting the contents of a feed stream comprising an epoxide, a solvent, a carbonylation catalyst and carbon monoxide to produce a first carbonylation product stream comprising a beta-lactone, then reacting the contents of the first carbonylation product stream with additional carbon monoxide to produce a second carbonylation product stream comprising an acid anhydride, and separating at least a portion of the acid anhydride from the second carbonylation product stream to produce: i) an acid anhydride product stream comprising the separated portion of acid anhydride; and ii) a recycling stream comprising the carbonylation catalyst, and finally adding the recycling stream to the feed stream. |