Abstract: The present invention relates to an improved process for producing an organic carboxylic acid having (n+1) carbon atoms by reacting an alcohol having n carbon atoms with carbon monoxide in the presence of a rhodium catalyst system. More particularly, the present invention relates to carbonylation of alcohol such as methanol catalyzed by a rhodium system to produce acetic acid. The characteristic of the present invention is the addition of a catalyst stabilizer in the reaction medium to avoid or to alleviate the precipitation of the catalyst in the liquid phase. The catalyst as used herein is a an inorganic salt of alkaline metal having the following formula (A): XnMm  (A) X=Li+, Na+, K+; M=CO3−2, HCO3−, PO4−3, HPO4−2, H2PO4−, SO4−2, HSO4−, C2O4−2, HC2O4−, B(C6Y5)4−1; Y=H, F or CF3.

Abstract: The present invention relates to an improved process for producing an organic carboxylic acid having (n+1) carbon atoms by reacting an alcohol having n carbon atoms with carbon monoxide in the presence of a rhodium catalyst system. More particularly, the present invention relates to carbonylation of alcohol such as methanol catalyzed by a rhodium system to produce acetic acid. The characteristic of the present invention is the addition of a catalyst stabilizer in the reaction medium to avoid or to alleviate the precipitation of the catalyst in the liquid phase. The catalyst stabilizer as used herein is a pyridine derivative having substituent(s) of such as (CH2)mCOOR or (CH2)mSO3R (R═H or hydrocarbons; m=0-6).