Patent ID: 10759730

Abstract:
Provided is an acetic acid production method that enables, in a scrubbing system, efficient separation and obtaining of methyl iodide and an absorbing solvent; restrainment of corrosion of the interior of a distillation column; efficient separation between and recovery of hydrogen iodide and methyl iodide; or sufficient recovery of hydrogen iodide. The acetic acid production method according to the present invention includes a first absorption step and a second absorption step. In the first absorption step, an offgas is brought into contact with a first absorbent to allow the first absorbent to absorb an iodine compound from the offgas, to give a first gas, where the first absorbent includes at least one of C2 or higher alcohols, esters of C3 or higher carboxylic acids, esters between carboxylic acids and C2 or higher alcohols, ethers, ketones, water, and basic aqueous solutions. In the second absorption step, the first gas is brought into contact with a second absorbent to allow the second absorbent to absorb an iodine compound from the first gas, where the second absorbent includes at least one of C2 or higher alcohols, esters of C3 or higher carboxylic acids, ethers, esters between carboxylic acids and C2 or higher alcohols, ketones, water, basic aqueous solutions, and acetic acid and differs in composition from the first absorbent.