Patent ID: 7902397
Filing Date: 2011-03-08
Classification: C07C

Abstract:
1. A carbonylation process for producing acetic acid comprising: (a) carbonylating methanol or its reactive derivatives in the presence of water, a catalyst selected from rhodium catalysts, iridium catalysts and mixtures thereof, and a methyl iodide promoter to form an acetic acid reaction mixture in a reactor; (b) providing a portion of the acetic acid reaction mixture to a flash vessel wherein the acetic acid mixture is separated into a liquid recycle stream and a first crude product stream; (c) recycling the liquid recycle stream back to the reactor and feeding the first crude product stream to a light ends column; (d) distilling the first crude product stream to remove low boiling components to produce purified first product stream and a liquid residue stream, wherein the liquid residue stream comprises acetic acid; (e) vaporizing a portion of the liquid residue stream to produce a second product stream from the liquid residue stream and a residual liquid residue stream; (f) recycling the residual liquid residue stream back into the reactor and feeding the second product stream forward in the process for further purification to produce acetic acid.