Patent ID: 6281385
Filing Date: 2001-08-28
Classification: B01J,C07C

Abstract:
A process for preparing acetic acid by gas-phase oxidation of saturated C.sub.4 -hydrocarbons and their mixtures with unsaturated C.sub.4 -hydrocarbons in a tube reactor comprising(1) providing in said tube reactor a coated catalyst comprising an inert nonporous support body having an outer surface and a catalytically active mixed oxide composition coating applied to the outer surface of the support body, said mixed oxide composition comprising(a) one or more oxides selected from the group consisting of titanium dioxide, zirconium dioxide, tin dioxide and aluminum oxide as component (a) andwherein the coated catalyst further comprises, as component (a), one or more oxides selected from the group consisting of the oxides of boron, silicon, hafnium, niobium, lanthanum and cerium in an amount of from 1 to 30% by weight, based on the total weight of the component (a),(b) from 0.1% to 1.5% by weight, based on the weight of the component (a) of vanadium pentoxide as component (b); and(2) reacting a gas mixture comprising oxygen or oxygen-containing gas, one or more C.sub.4 -hydrocarbons selected from the group consisting of a saturated C.sub.4 -hydrocarbon and a mixture of a saturated C.sub.4 -hydrocarbon with an unsaturated C.sub.4 -hydrocarbon and water vapor and having a C.sub.4 -hydrocarbon/air (oxygen) volume ratio of from 0.2/99.8 to 25/75 and a C.sub.4 -hydrocarbon/water vapor volume ratio of from 1/1 to 1/60 in contact with the coated catalyst at a temperature of from 100.degree. C. to 400.degree. C. and a gauge pressure of from 0.2 to 50 bar to produce the acetic acid.