METHOD OF SYNTHESIS OF ACETIC ACID Russian patent published in 2003 - IPC

FIELD: organic chemistry, chemical technology. SUBSTANCE: invention relates to acetic acid preparing. Methanol and/or its reactive derivative interacts with carbon monoxide in liquid reaction medium in the carbonylation reactor. Liquid reactive mixture comprises precious metal of VIII group of periodic system as carbonylation catalyst, methyl iodide as co-catalyst taken in the concentration at least 2 wt.% and, optionally, promoter and water taken at least in the limited concentration, methyl acetate in the concentration at least 8 wt.% and acetic acid to be produced. Liquid reaction mixture is removed from the carbonylation reactor and fed to at least one the separation zone by a single equilibrium evaporation with addition of heat or without heat addition. Vapor fraction containing water, acetic acid, methyl acetate and methyl iodide is prepared and liquid fraction containing precious metal of VIII group of periodic system and, optionally, one promoter is prepared also. Liquid fraction is recovered into the carbonylation reactor. Vapor fraction is added on fractionating column of light distillates. Technological flow containing acetic acid is removed from fractionating column of light distillates. From the fractionating column head vapor fraction containing methyl acetate, methyl iodide, water and acetic acid is removed and condensed. Condensed vapor fraction is fed in device for decantation where this fraction is separated for upper (aqueous) and bottom (organic) layer. All or part of upper (aqueous) layer is recovered in fractionating column as phlegm and bottom (organic) layer is recovered into reactor. Capacity for separation for upper (aqueous) and bottom (organic) layer in the decantation device is maintained due to acetic acid concentration in the condensed vapor fraction equal to 8 wt.% or less. EFFECT: improved technology of process. 9 cl, 2 dwg, 1 ex