Abstract: Provided herein is a process for the production and purification of acetic acid. In particular, this disclosure relates to improved processes for producing and purifying acetic acid by the carbonylation of methanol in the presence of a Group VIII metal carbonylation catalyst. The acetic acid production and purification process described herein controls the formation and mass composition of acetal impurities, such as 1,1-dimethoxyethane.

Abstract: A process for producing acetic acid is provided that is capable of lowering acetaldehyde mass composition in acetic acid. The process for producing acetic acid according to the present invention comprises at least one distillation step that satisfies the following operating conditions (i) temperature in a lower portion of the distillation column is not less than 40° C.; (ii) water mass composition in the lower stream is not less than 0.3 wt. %; or (iii) acetic acid mass composition in the lower stream on weight percentage basis is greater than the acetic acid mass composition in the first mixture; wherein the methanol mass composition in the first mixture is less than or equal to 2 wt. %.

Abstract: This process relates to controlling acetal formation when removing acetaldehyde from a methanol carbonylation process using an extractive distillation column. Acetals may be formed by a secondary reaction of acetaldehyde and an alcohol (such as methanol). The process controls the formations to prevent excess acetal accumulation in the lower stream from the extractive distillation column.

Abstract: A process for producing acetic acid that involves operating the flash vessel and first column at the lowest possible pressure for a given production rate is described. Low pressures are achieved by operating on a back pressure established by a vapor discharge from an absorbing system. This reduces the pressure differential to allow steady and efficient acetic acid production.

Abstract: Continuous acetic acid production with a process to remove and/or reduce permanganate reducing compounds (PRCs), including acetaldehyde. The process involves obtaining a stream comprising the PRCs and removing water from the stream through a dehydrating step, involving distillation, extraction, or phase separation. After removing water, an alkane may be combined to enhance the separation of PRCs from alkyl iodides.

Abstract: Processes for purifying acetic acid by distilling a process stream in a column in which acetic anhydride is formed in the lower portion of the column. The product stream withdrawn from the column comprises acetic acid, water at a concentration of no more than 0.2 wt. %, and acetic anhydride at a concentration of no more than 600 wppm. The process further comprises hydrating the acetic anhydride in the product stream to form a purified acetic acid product comprising acetic anhydride at a concentration of no more than 50 wppm.

Abstract: A process for producing acetic acid that involves operating the flash vessel and first column at the lowest possible pressure for a given production rate is described. Low pressures are achieved by operating on a back pressure established by a vapor discharge from an absorbing system. This reduces the pressure differential to allow steady and efficient acetic acid production.

Abstract: A process for producing acetic acid is disclosed in which the methyl iodide concentration is maintained in the vapor product stream formed in a flashing step. The methyl iodide concentration in the vapor product stream ranges from 24 to less than 36 wt. % methyl iodide, based on the weight of the vapor product stream. In addition, the acetaldehyde concentration is maintained within the range from 0.005 to 1 wt. % in the vapor product stream. The vapor product stream is distilled in a first column to obtain an acetic acid product stream comprising acetic acid and up to 300 wppm hydrogen iodide and/or from 0.1 to 6 wt. % methyl iodide and an overhead stream comprising methyl iodide, water and methyl acetate.

Abstract: A process for producing acetic acid that involves operating the flash vessel and first column at the lowest possible pressure for a given production rate is described. Low pressures are achieved by operating on a back pressure established by a vapor discharge from an absorbing system. This reduces the pressure differential to allow steady and efficient acetic acid production.

Abstract: A process for producing acetic acid is disclosed in which the methyl iodide concentration is maintained in the vapor product stream formed in a flashing step. The methyl iodide concentration in the vapor product stream ranges from 24 to less than 36 wt. % methyl iodide, based on the weight of the vapor product stream. In addition, the acetaldehyde concentration is maintained within the range from 0.005 to 1 wt. % in the vapor product stream. The vapor product stream is distilled in a first column to obtain an acetic acid product stream comprising acetic acid and up to 300 wppm hydrogen iodide and/or from 0.1 to 6 wt. % methyl iodide and an overhead stream comprising methyl iodide, water and methyl acetate.

Abstract: Processes for purifying acetic acid by distilling a process stream in a column in which acetic anhydride is formed in the lower portion of the column. The product stream withdrawn from the column comprises acetic acid, water at a concentration of no more than 0.2 wt. %, and acetic anhydride at a concentration of no more than 600 wppm. The process further comprises hydrating the acetic anhydride in the product stream to form a purified acetic acid product comprising acetic anhydride at a concentration of no more than 50 wppm.

Abstract: A process for producing acetic acid is disclosed in which the methyl iodide concentration is maintained in the vapor product stream formed in a flashing step. The methyl iodide concentration in the vapor product stream ranges from 24 to less than 36 wt. % methyl iodide, based on the weight of the vapor product stream. In addition, the acetaldehyde concentration is maintained within the range from 0.005 to 1 wt. % in the vapor product stream. The vapor product stream is distilled in a first column to obtain an acetic acid product stream comprising acetic acid and up to 300 wppm hydrogen iodide and/or from 0.1 to 6 wt. % methyl iodide and an overhead stream comprising methyl iodide, water and methyl acetate.

Abstract: Processes for purifying acetic acid by distilling a process stream in a column in which acetic anhydride is formed in the lower portion of the column. The product stream withdrawn from the column comprises acetic acid, water at a concentration of no more than 0.2 wt. %, and acetic anhydride at a concentration of no more than 600 wppm. The process further comprises hydrating the acetic anhydride in the product stream to form a purified acetic acid product comprising acetic anhydride at a concentration of no more than 50 wppm.

Abstract: A process for producing acetic acid that involves operating the flash vessel and first column at the lowest possible pressure for a given production rate is described. Low pressures are achieved by operating on a back pressure established by a vapor discharge from an absorbing system. This reduces the pressure differential to allow steady and efficient acetic acid production.

Abstract: A process for producing acetic acid is disclosed in which the recycle ratio of the mass flow of the light liquid phase recycled to the reactor to the mass flow of the aqueous recycle stream recycled to the reactor is less than or equal to 2.

Abstract: A process for producing acetic acid is disclosed in which the recycle ratio of the mass flow of the light liquid phase recycled to the reactor to the mass flow of the aqueous recycle stream recycled to the reactor is less than or equal to 2.

Abstract: Processes for purifying acetic acid by distilling a process stream in a column in which acetic anhydride is formed in the lower portion of the column. The product stream withdrawn from the column comprises acetic acid, water at a concentration of no more than 0.2 wt. %, and acetic anhydride at a concentration of no more than 600 wppm. The process further comprises hydrating the acetic anhydride in the product stream to form a purified acetic acid product comprising acetic anhydride at a concentration of no more than 50 wppm.

Abstract: A process for producing acetic acid is disclosed in which the methyl iodide concentration is maintained in the vapor product stream formed in a flashing step. The methyl iodide concentration in the vapor product stream ranges from 24 to less than 36 wt. % methyl iodide, based on the weight of the vapor product stream. In addition, the acetaldehyde concentration is maintained within the range from 0.005 to 1 wt. % in the vapor product stream. The vapor product stream is distilled in a first column to obtain an acetic acid product stream comprising acetic acid and up to 300 wppm hydrogen iodide and/or from 0.1 to 6 wt. % methyl iodide and an overhead stream comprising methyl iodide, water and methyl acetate.

Abstract: Processes for purifying acetic acid by distilling a process stream in a column in which acetic anhydride is formed in the lower portion of the column. The product stream withdrawn from the column comprises acetic acid, water at a concentration of no more than 0.2 wt. %, and acetic anhydride at a concentration of no more than 600 wppm. The process further comprises hydrating the acetic anhydride in the product stream to form a purified acetic acid product comprising acetic anhydride at a concentration of no more than 50 wppm.

Abstract: A process for producing acetic acid is disclosed in which the methyl iodide concentration is maintained in the vapor product stream formed in a flashing step. The methyl iodide concentration in the vapor product stream ranges from 24 to less than 36 wt. % methyl iodide, based on the weight of the vapor product stream. In addition, the acetaldehyde concentration is maintained within the range from 0.005 to 1 wt. % in the vapor product stream. The vapor product stream is distilled in a first column to obtain an acetic acid product stream comprising acetic acid and up to 300 wppm hydrogen iodide and/or from 0.1 to 6 wt. % methyl iodide and an overhead stream comprising methyl iodide, water and methyl acetate.