CARBONYLATION PROCESS Russian patent published in 2003 - IPC

FIELD: industrial organic synthesis. SUBSTANCE: invention relates to carbonylation process in acetic acid production. Process is carried out by removing more high-molecular organic iodides, including hexyl iodide, from acetic acid prepared by carbonylation of methanol and/or its reactive derivative in presence of water in limited concentration, VIII-group precious metal (rhodium or iridium) as catalyst, methyl iodide as cocatalyst, and optionally catalyst promoter (metal-containing promoter, inorganic or organic iodide). Aqueous mixture containing acetic acid and at least one more high-molecular organic iodide is treated on distillation column or in column section. Water is separated as top fraction from dry acetic acid fraction, concentration of water on feed plate of column of column section being more than 8%, preferably 8-14%, and concentration of water in head of column of column section exceeding 70% and preferably being 70-85%. Process is conducted under gage pressure 10 to 100 bar at 100 to 300 C. EFFECT: increased purity of product. 11 cl, 2 ex