Process for the production of acetic acid

• Main Authors: HENNIGAN SEAN ANTHONY, BREEDEN CLIVE RICHARD, FROOM SIMON FREDERICK THOMAS, SMITH STEPHEN JAMES
• Format: Patent
• Language: English
• Published: 09.10.2012
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; CHEMISTRY; METALLURGY; ORGANIC CHEMISTRY

Process for the production of acetic acid by (a) introducing methanol, methyl acetate, dimethyl ether and/or methyl iodide and carbon monoxide into a first reaction zone containing a liquid reaction composition comprising a carbonylation catalyst, optionally a carbonylation catalyst promoter, methyl iodide, methyl acetate, acetic acid and water, (b) withdrawing at least a portion of the liquid reaction composition together with dissolved and/or entrained carbon monoxide and other gases from the first reaction zone, (c) passing at least a portion of the withdrawn liquid reaction composition to a second reaction zone, wherein at least a portion of the dissolved and/or entrained carbon monoxide is consumed, (d) passing at least a portion of the liquid reaction composition from the second reaction zone into a flash separation zone to form a vapor fraction, which comprises acetic acid, methyl iodide, methyl acetate and low pressure off-gas, comprising carbon monoxide; and a liquid fraction, which comprises carbonylation catalyst and optional carbonylation catalyst promoter, and (e) passing the vapor fraction from the flash separation zone to one or more distillation zones to recover acetic acid product. The temperature of the liquid reaction composition withdrawn from the first reaction zone is in the range of 170 to 195° C.; and the temperature of the liquid reaction composition passed from the second reaction zone to the flash separation zone is at least 8° C. greater than the temperature of the liquid reaction composition withdrawn from the first reaction zone.