Acetic Acid by Low Pressure Carbonylation of Methanol with a Supported Rhodium Catalyst

Acetic acid is produced commercially by low pressure carbonylation of methanol in the presence of a homogeneous rhodium catalyst and the promoter methyl iodide. Recently, Reilly Industries, Inc. applied for patents on using a hererogeneous rhodium catalyst supported on polyvinylpyridines for the same carbonylation. The resulting supported rhodium catalyst process reportedly can have a space-time yield that is 350-530% of the space-time uield of the homogeneous rhodium catalyst process, i.e., 7.0-8.0 mol/liter/hr versus 1.5-2.0 mol/liter/hr.

This new technology has the potential for modest improvement if further process development does not uncover adverse situations not addressed in this preliminary evaluation.