Synthesis of Acetic Acid by Catalytic Oxidation of Butenes (Part 1)

The probability of acetic acid synthesis from n-butenes and isobutene was studied with V2O5-binary catalysts. As a second component, following atoms were added to V2O5 in the form of oxide or metal; Rh, B, Cr, Nb, Zn, Pd, Ta, Zr, Si, Ni, Ge, Fe, Ca, Pt, W, Li, Cd, As, Co, Te, Mg, Mn, Mo, Cu, Ag, P, Ba, Ti, Sn, Al, and Sb.In the presence of water, n-butenes and isobutene were oxidized to acetic acid with more than 40% selectivity based on the carbon atom at about 100% conversion of each butene with air containing 3% of butene over V-Cr(3/7), V-Rh(8/2), V-B(5/5) and V-Nb(5/5) catalysts at 270∼310°C.Acetaldehyde, acetone, formaldehyde, maleic acid, formic acid, propionic acid, acrylic acid and citoraconic acid were obtained in low yields from n-butenes.On the other hand, from isobutene methacrylic acid and isobutylic acid were formed in addition to above by-products in low yields.As to the reaction path, acetic acid was considered to be formed via hydration of butenes to form an alcoholic intermediate1)), followed by oxydehydrogenation on the catalyst which had some different active sites to induce other reactions at the same time.