REMOVING HYDROCARBON IMPURITIES FROM ACETIC ACID PRODUCTION INTERMEDIATE PRODUCT Russian patent published in 2014 - IPC C07C51/12 C07C51/48 C07C53/08 C07C51/44 

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of removing hydrocarbon impurities from an intermediate product of production of acetic acid, which includes extracting the intermediate product with a hydrocarbon extracting agent to form a light phase containing the hydrocarbon impurity and the extracting agent, and a heavy phase containing acetic acid, where the intermediate product contains methyl iodide, acetic acid, methyl acetate and the hydrocarbon impurity. The invention also relates to a method of producing acetic acid, which includes a) reacting methanol and carbon monoxide in the presence of a carbonylation catalyst, a catalyst stabiliser, methyl iodide, water and methyl acetate to obtain an acetic acid stream containing a hydrocarbon impurity; b) dividing, by flash evaporation, the acetic acid stream into a vapour stream containing acetic acid, water, methanol, methyl acetate, methyl iodide and the hydrocarbon impurity, and a liquid stream containing the catalyst and the catalyst stabiliser; c) dividing the vapour stream from step b) by distillation into a product stream containing acetic acid and water, and an overhead product containing methyl iodide, water, methyl acetate, acetic acid and the hydrocarbon impurity; d) condensing the overhead product from step c) to form a light aqueous phase containing water and acetic acid, methyl acetate and a heavy organic phase containing methyl iodide, acetic acid, water and the hydrocarbon impurity; e) distilling the heavy organic phase from step d) into a vapour stream containing methyl iodide, and a lower stream containing acetic acid, methyl iodide, water and the hydrocarbon impurity; and f) extracting the lower stream from step e) with a hydrocarbon extracting agent and forming a light phase containing the hydrocarbon impurity and the extracting agent, and a heavy phase containing methyl iodide, water and acetic acid.

EFFECT: improved method of removing hydrocarbon impurities from an acetic acid production intermediate product.

13 cl, 6 ex