| abstract |
PROBLEM TO BE SOLVED: To provide a method and an apparatus for producing a saturated carboxylic acid having 1 to 4 C atoms, which provide a high acid yield and thereby produce a by-product as a high-value substance. Offer. SOLUTION: The reaction outlet gas is partially recirculated in the reaction gas circulation, and when the acid concentration in the content recirculated by the separation step is reduced, 100 to 400 ° C. The reaction temperature, at a pressure of 1.2 * 10 5 Pa~51 * 10 5 Pa, saturated or unsaturated C 4 - hydrocarbons and mixtures thereof, in the presence of an oxygen-containing gas and steam, the presence of at least one catalyst Below, by gas phase oxidation, C A saturated carboxylic acid having 1 to 4 atoms is prepared, in which case the crude acid is separated from the reaction outlet gas by countercurrent washing. A high selectivity is obtained, the required energy consumption is reduced, and a high passive safety with respect to the risk of explosion arises, so that the whole process implementation can be easily formed. |