ANHYDROUS CARBONYLATION FOR PRODUCTION OF ACETIC ACID

摘要

PROBLEM TO BE SOLVED: To provide an improved method for producing acetic acid by minimizing the concentration of water contained in a reactor. SOLUTION: This method for producing acetic acid comprises reacting methanol and/dimethyl ether with a gaseous reactant containing carbon monoxide and <9 mol.% of hydrogen in the presence of at least one noble metal of the group VIII in the periodic table as a catalyst, a halogen compound as an auxiliary catalyst and an iodine salt as a catalyst stabilizer. Therein, the methanol and/or dimethyl ether and the gaseous reactant are supplied into a carbonylation reactor, and a liquid reaction composition containing the following components (i) to (vi) is maintained in the reactor. (i): methyl acetate in an amount of 1-35 wt.%, (ii): acetic anhydride in an amount of <=8 wt.%, (iii): a halogen compound in an amount of 3-20 wt.%, (iv): a group VIII noble metal catalyst in an amount of 1-2, 000 ppm, (v) : an iodide salt in an amount sufficient to give 0.5-20 wt.% of iodide ion of the formula: I<-> , and (vi): the remainder of the composition.