METHOD FOR PREPARING ACETIC ACID AND/OR METHYL ACETATE AND METHOD FOR IMPROVING STABILITY AND/OR PREVENTION OF DEACTIVATION OF CATALYST IN PREPARING ACETIC ACID AND/OR METHYL ACETATE Russian patent published in 2004 - IPC

FIELD: organic chemistry, chemical technology, catalysts.

SUBSTANCE: invention relate to a method for preparing acetic acid and/or methyl acetate in liquid phase in the presence of carbon monoxide and catalytic system and to a method for enhancing stability and working life of catalyst used. On the first step under conditions of methanol carbonylation the isomerization reaction of methyl formate is carried out to yield acetic acid and/or methyl acetate. Catalytic system comprises at least one halogenated promoter and at least one iridium-base catalytic compound. On the second step named as step of instantaneous evaporation partial evaporation of reaction medium prepared on the first step is carried out in a separator. The total content of formic acid and methyl formate in non-evaporated liquid phase removing from separator is maintained at the level 1 wt.-% but preferably at the level from 1 to 50 wt.-%, and more preferably at the level from 1 to 30 wt.-% with respect to this liquid fraction. Invention provides preparing acetic acid and/or methyl acetate in the enhanced stability of catalytic system being even at low values of water content and extremely low values of carbon monoxide pressure in reaction zone. Invention provides enhancing stability and activity of catalytic system due to prevention of its deactivation in the reaction zone.

EFFECT: improved preparing method.

22 cl, 3 tbl, 11 ex