The chiyoda/uop acetica™ process: A novel acetic acid technology

Recently, Chiyoda and UOP have introduced a novel heterogeneous methanol carbonylation process, called the Acetica process, for the production of acetic acid. The technology, which is based on a heterogeneous rhodium (Rh) catalyst, offers several distinct advantages over existing homogeneous processes. Immobilization enables increased catalyst concentration in the reaction mixture, which is directly proportional to acetic acid production rate, without the addition of an alkali iodide salt promoter. The heterogeneous catalyst also results in reduced by-product formation because of the lower water concentrations present in the process. The Acetica process uses a bubble-column reactor because of its excellent gas-liquid contacting and because it minimizes catalyst attrition. Because the reactor has no moving impeller, a mechanical seal is not required, thus simplifying high-pressure operation and enabling the use of low-purity CO. The technology offers an iodide-removal system if the product is to be used for vinyl acetate monomer (VAM) production. Expected product yields are greater than 99% and 92% of theoretical values based on methanol and CO consumption, respectively.