NOVELTY - Removing hydrocarbon impurity from acetic acid production method involves reacting methanol and carbon monoxide in presence of carbonylation catalyst, catalyst stabilizer, methyl iodide and acetate, and water to form acetic acid stream having hydrocarbon impurity followed by distilling heavy organic phase into the iodide vapor stream and bottom stream of the acid, acetate, iodide and impurity; extracting bottom stream with water/acetic acid solution/methanol solution to form organic phase comprising impurity and aqueous phase and recycling aqueous phase to carbonylation.    USE - For removing a hydrocarbon impurity (selected from alkanes, alkenes and/or aromatics) from an acetic acid production process; and separating methyl iodide and hydrocarbon comprising alkanes, alkenes and/or aromatics, preferably 3-12C alkane (claimed).    ADVANTAGE - The method efficiently removes hydrocarbon impurity (i.e. over 50% of the hydrocarbon impurity) from the acetic acid production process.    DETAILED DESCRIPTION - Removing a hydrocarbon impurity from an acetic acid production process, involves:    (A) reacting methanol and carbon monoxide in presence of carbonylation catalyst, catalyst stabilizer, methyl iodide, water and methyl acetate to produce an acetic acid stream containing hydrocarbon impurity;    (B) flashing at least a portion of the acetic acid stream into a vapor stream comprising acetic acid, water, methanol, methyl acetate, methyl iodide and the hydrocarbon impurity, and a liquid stream comprising the catalyst and the catalyst stabilizer;    (C) separating the vapor stream by distillation into a product stream comprising acetic acid and a minor amount of water, and an overhead stream comprising methyl iodide, water, methyl acetate, acetic acid and the hydrocarbon impurity;    (D) condensing and separating the overhead stream into a light, aqueous phase comprising water, acetic acid, and methyl acetate, and a heavy, organic phase comprising methyl iodide, acetic acid, methyl acetate, and the hydrocarbon impurity;    (E) distilling at least a portion of the heavy, organic phase into a vapor stream comprising the majority of methyl iodide and a bottoms stream comprising the majority of acetic acid, methyl acetate, methyl iodide, and the hydrocarbon impurity;    (F) extracting the bottoms stream with water, an acetic acid aqueous solution, or with a methanol aqueous solution, and forming an organic phase comprising the majority of the hydrocarbon impurity and an aqueous phase comprising the majority of water, acetic acid, methyl iodide and optional methanol; and    (G) recycling the aqueous phase to the carbonylation reaction of the step (A).    An INDEPENDENT CLAIM is included for separating methyl iodide and hydrocarbon, involving extracting a mixture of methyl iodide and hydrocarbon with an extracting solution selected from water, acetic acid aqueous solution, and methanol aqueous solution; and forming an organic phase comprising the hydrocarbon and an aqueous phase comprising methyl iodide.