Patent ID: 9446363
Filing Date: 2016-09-20
CPC Classification: B01D,B01J,C07C,Y02P

Claim Text:
1. An apparatus for producing acetic acid comprising: (a) a reactor for carbonylating methanol or its reactive derivatives, the reactor containing a catalyst selected from rhodium catalysts, iridium catalysts and mixtures thereof, and a methyl iodide promoter in an acetic acid reaction mixture; (b) a feed system for providing carbon monoxide and methanol or its reactive derivatives to the reactor; (c) a flash system configured to receive a stream of the reaction mixture and separate it into (i) at least a first liquid recycle stream, and (ii) a crude process stream containing acetic acid; (d) a first distillation column coupled to the flash system, the first distillation column being adapted to separate low boiling components including methyl iodide from the crude process stream, and generate a purified process stream, the first distillation column and optionally the reactor and flash system also operating to generate a vent gas stream comprising volatile organic components including methyl iodide; (e) an absorber tower adapted for receiving the vent gas stream and removing methyl iodide therefrom with a first or a second scrubber solvent, the first and second scrubber solvents being different solvents, the absorber tower also being coupled to a first scrubber solvent source and a second scrubber solvent source which are capable of supplying the different first and second scrubber solvents; and (f) a switching system for alternatively providing the first or the second scrubber solvents to the absorber tower from either the first scrubber solvent source or the second scrubber solvent source; wherein the apparatus is configured such that the first and second scrubber solvents are supplied to the top of the absorber tower only.