Process for preparing acetic acid by gas-phase oxidation of saturated C4-hydrocarbons and their mixtures with unsaturated C4-hydrocarbons

摘要

A process for preparing acetic acid by gas-phase oxidation of saturated C4-hydrocarbons and their mixtures with unsaturated C4-hydrocarbons in a tube reactor using a coated catalyst comprising an inert nonporous support body and a catalytically active mixed oxide composition comprising (a) one or more oxides selected from the group consisting of titanium dioxide, zirconium dioxide, tin dioxide and aluminum oxide and (b) from 0.1% to 1.5% by weight, based on the weight of the component (a) and per m2/g of specific surface area of the component (a), of vanadium pentoxide applied to the outer surface of the support body, wherein a gas mixture comprising oxygen or oxygen-containing gas, one or more C4-hydrocarbons and water vapor and having a C4-hydrocarbon/air (oxygen) volume ratio of from 0.2/99.8 to 25/75 and a C4-hydrocarbon/water vapor volume ratio of from 1/1 to 1/60 is reacted over the coated catalyst at a temperature of from 100° C. to 400° C. and a gauge pressure of from 0.2 to 50 bar.