Published December 2007
In regions where bio-derived ethanol is not readily available, ethyl acetate is produced from ethylene via acetaldehyde (Tischchenko reaction) or via ethanol by ethylene hydration and esterification with acetic acid. To eliminate the need for acetaldehyde or ethanol intermediates, BP Chemicals and Showa Denko independently developed technologies that produce ethyl acetate by direct addition of ethylene and acetic acid.
BP Chemical’s technology is trademarked as Avada (for Advanced Acetates by Direct Addition) and is based on the vapor-phase reaction of ethylene and acetic acid in the presence of a heteropolyacid (HPA). In 2001, BP Chemicals successfully brought on stream a 220,000 t/yr ethyl acetate plant in Hull, UK, using the Avada technology. BP claims that the Avada process is more energy efficient and environmentally friendly than other routes to ethyl acetate. Showa Denko developed a similar version of the direct addition process that is currently in operation by Showa Esterindo at Merak, Indonesia. The plant came on stream in 1999 and has a capacity of 70,000 t/yr of ethyl acetate.
In this review, we present a technical and economic evaluation of the direct addition process, based on the production of 220 million lb/yr (100,000 t/yr) of ethyl acetate at a U.S. Gulf Coast location. Our analysis indicates that the investment and production costs of the direct addition process are significantly higher than those for conventional esterification of acetic acid and bio-derived ethanol. We conclude that the direct addition process can be competitive only in geographic areas where ethylene is readily available from steam cracking and bio-derived ethanol is expensive to produce or import.