Abstract: Process for the production of acetic acid by (a) introducing methanol, methyl acetate, dimethyl ether and/or methyl iodide and carbon monoxide into a first reaction zone containing a liquid reaction composition comprising a carbonylation catalyst, optionally a carbonylation catalyst promoter, methyl iodide, methyl acetate, acetic acid and water, (b) withdrawing at least a portion of the liquid reaction composition together with dissolved and/or entrained carbon monoxide and other gases from the first reaction zone, (c) passing at least a portion of the withdrawn liquid reaction composition to a second reaction zone, wherein at least a portion of the dissolved and/or entrained carbon monoxide is consumed, (d) passing at least a portion of the liquid reaction composition from the second reaction zone into a flash separation zone to form a vapor fraction, which comprises acetic acid, methyl iodide, methyl acetate and low pressure off-gas, comprising carbon monoxide; and a liquid fraction, which comprises carbony

Abstract: A process for the production of acetic acid comprising: introducing methanol and/or a reactive derivative thereof and carbon monoxide into a first reaction zone containing a liquid reaction composition comprising a carbonylation catalyst, optionally a carbonylation catalyst promoter, methyl iodide, methyl acetate, acetic acid and water; withdrawing at least a portion of the liquid reaction composition together with dissolved and/or entrained carbon monoxide from the first reaction zone; passing at least a portion of the withdrawn liquid reaction composition to a second reaction zone; passing at least a portion of the liquid reaction composition from the second reaction zone into a flash separation zone; wherein the temperature of the liquid reaction composition withdrawn from the first reaction zone is in the range of 170 to 195° C.; and the temperature of the liquid reaction composition passed from the second reaction zone to the flash separation zone is at least 8° C.