EP-4735412-A1 - REMOVAL OF ALDEHYDES IN ACETIC ACID PRODUCTION

Abstract

Processes for producing carboxylic acid are included herein. The processes include contacting methanol and carbon monoxide in the presence of a liquid reaction medium under carbonylation conditions sufficient to form a carbonylation product comprising acetic acid and acetaldehyde. At least a portion of the carbonylation product or a derivative thereof is contacted with a phyllosilicate clay-based adsorbent at adsorption conditions sufficient to selectively reduce a concentration of acetaldehyde present in the carbonylation product or a derivative thereof.

Inventors

• HALLINAN, NOEL, C.

Assignees

• LyondellBasell Acetyls, LLC

Dates

Publication Date

20260506

Application Date

20240626

Claims (20)

1. 1. A process for the production of acetic acid, the process comprising: reacting methanol and carbon monoxide in the presence of a carbonylation catalyst to form acetic acid in an acetic acid production reactor; flashing a reaction mixture discharged from the acetic acid production reactor into a vapor stream and a liquid stream, the vapor stream comprising acetic acid, water, methanol, methyl acetate, methyl iodide, and acetaldehyde; separating the vapor stream by distillation in a distillation column into: a product side stream comprising acetic acid and water; a bottoms stream; and an overhead stream comprising methyl iodide, water, methyl acetate, acetic acid, and acetaldehyde; condensing the overhead stream into: a light aqueous phase stream, comprising methyl iodide, acetaldehyde, water, methyl acetate, and acetic acid; and a heavy organic phase stream, comprising methyl iodide, acetaldehyde, water, methyl acetate, and acetic acid; and contacting an intermediate process stream with a phyllosilicate clay-based adsorbent at adsorption conditions sufficient to produce a treated intermediate process stream, wherein: the intermediate process stream comprises at least a portion of the light aqueous phase stream, at least a portion of the heavy organic phase stream, or a combination thereof, and has a first acetaldehyde content; the treated intermediate process stream has a second acetaldehyde content; and the second acetaldehyde content is less than the first acetaldehyde content.
2. 2. The process of claim 1, wherein the ratio of the first acetaldehyde content to the second acetaldehyde content is greater than or equal to 2.0.
3. 3. The process of claim 1, further comprising recycling the treated intermediate process stream to the acetic acid production reactor.
4. 4. The process of claim 1, wherein the phyllosilicate clay-based adsorbent comprises a kaolinite, a smectite, a vermiculite, an illite, a chlorite, or a combination thereof.
5. 5. The process of claim 4, wherein the smectite comprises a montmorillonite, beidellite, nantronite, saponite, hectorite, a bentonite, or a combination thereof.
6. 6. The process of claim 1. wherein the phyllosilicate clay-based adsorbent comprises interlayer cations, interlayer metal-oxide pillars, or a combination thereof.
7. 7. The process of claim 1, wherein the phyllosilicate clay-based adsorbent is acidified.
8. 8. The process of claim 1. wherein the phyllosilicate clay-based adsorbent has: a) a porosity as measured by an average pore volume in the range of from 0.1 to 1.4 cm 3 /g; b) a surface area in the range of from 50 m 2 /g to 800 m 2 /g; c) an average removal capability of greater than or equal to 0.3 g acetaldehyde/g of adsorbent; or d) a combination thereof.
9. 9. The process of claim 1 , wherein the phyllosilicate clay -based adsorbent is disposed on a fixed bed.
10. 10. The process of claim 9, wherein the phyllosilicate clay-based adsorbent is loaded in the fixed bed at a level sufficient to provide a loading in a range of from 1 g to 10 g phyllosilicate claybased adsorbent/g acetaldehyde to be adsorbed.
11. 11. The process of claim 1. wherein the adsorption conditions comprise an adsorption temperature in a range of from room temperature to 250°C.
12. 12. The process of claim 1, wherein the light aqueous phase stream comprises greater than 20 wt% water and the heavy organic phase stream comprises less than 1 wt% water.
13. 13. The process of claim 1 , wherein the phyllosilicate clay-based adsorbent is capable of undergoing regeneration.
14. 14. A method for removing acetaldehyde from an acetic acid system, comprising: providing from the acetic acid system a solution, comprising acetic acid, water, methyl acetate, methyl iodide, and acetaldehyde, wherein the acetaldehyde is present in a first concentration based on the total weight of the solution; and contacting the solution with a phyllosilicate clay-based adsorbent at adsorption conditions sufficient to produce a treated solution, wherein: the solution has a first acetaldehyde content; the treated solution has a second acetaldehyde content; and the second acetaldehyde content is less than the first acetaldehyde content.
15. 15. The method of claim 14. wherein the ratio of the first acetaldehyde content to the second acetaldehyde content is greater than or equal to 2.0.
16. 16. The method of claim 14, wherein the phyllosilicate clay -based adsorbent comprises a kaolinite, a smectite, a vermiculite, an illite, a chlorite, or a combination thereof.
17. 17. The method of claim 14, wherein the phyllosilicate clay-based adsorbent comprises interlayer cations, interlayer metal-oxide pillars, or a combination thereof.
18. 18. The method of claim 14, wherein the phyllosilicate clay -based adsorbent is acidified.
19. 19. The method of claim 14, wherein the phyllosilicate clay-based adsorbent has: a) a porosity as measured by an average pore volume in the range of from 0. 1 to 1.4 cm 3 /g; b) a surface area in the range of from 50 m 2 /g to 800 m 2 /g; c) an average removal capability of greater than or equal to 0.3 g acetaldehyde/g of adsorbent; or d) a combination thereof.
20. 20. The method of claim 14, wherein the adsorption conditions comprise an adsorption temperature in a range of from room temperature to 250°C.

Description

REMOVAL OF ALDEHYDES IN ACETIC ACID PRODUCTION CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The application filed under the Patent Cooperation Treaty, which claims the benefit of priority to U.S. Provisional Patent Application No. 63/511,353 filed on June 30, 2023, which is incorporated herein by reference in its entirety. FIELD OF THE INVENTION [0002] This disclosure relates to the production of acetic acid. More particularly, the disclosure relates to removal of acetaldehyde in acetic acid production. BACKGROUND OF THE INVENTION [0003] In the current acetic acid production process, a reaction mixture is withdrawn from a reactor and is separated in a flash tank into a liquid fraction and a vapor fraction comprising acetic acid generated during the carbonylation reaction. The liquid fraction may be recycled to the carbonylation reactor, and the vapor fraction is passed to a separations unit, which by way of example may be a light-ends distillation column. The light-ends distillation column separates a crude acetic acid product from other components. The crude acetic acid product is passed to a drying column to remove water and then is subjected to further separations to recover acetic acid. [0004] One challenge facing the industry is the presence of aldehyde(s) in acetic acid production, which can be present in the feed and is also formed as an undesired byproduct of carbonylation reactions. Processes for removing aldehydes exist; however, there continues to be a need to improve upon, and provide alternatives to, current aldehyde removal processes. SUMMARY OF THE INVENTION [0005] The present disclosure relates to the production of acetic acid and related processes. In some embodiments, a process for the production of acetic acid comprises reacting methanol and carbon monoxide in the presence of a carbony lation catalyst to form acetic acid in an acetic acid production reactor. The process further comprises flashing a reaction mixture discharged from the acetic acid production reactor into a vapor stream and a liquid stream, wherein the vapor stream comprises acetic acid, water, methanol, methyl acetate, methyl iodide, and acetaldehyde. The vapor stream is separated by distillation in a distillation column into: a product side stream comprising acetic acid and water; a bottoms stream; and an overhead stream comprising methyl iodide, water, methyl acetate, acetic acid, and acetaldehyde. The overhead stream in condensed into: a light aqueous phase stream, comprising methyl iodide, acetaldehyde, w ater, methyl acetate, and acetic acid; and a heavy organic phase stream, comprising methyl iodide, acetaldehyde, water, methyl acetate, and acetic acid. An intermediate process stream is contacted with a phyllosilicate clay -based adsorbent at adsorption conditions sufficient to produce a treated intermediate process stream, wherein the intermediate process stream comprises at least a portion of the light aqueous phase stream, at least a portion of the heavy organic phase stream, or a combination thereof. The intermediate process stream has a first acetaldehyde content, the treated intermediate process stream has a second acetaldehyde content, and the second acetaldehyde content is less than the first acetaldehyde content. In some embodiments, the process further comprises recycling the treated intermediate process stream to the acetic acid production reactor. [0006] In some embodiments, a method for removing acetaldehy de from an acetic acid system, comprises providing from the acetic acid system a solution, comprising acetic acid, water, methyl acetate, methyl iodide, and acetaldehyde, wherein the acetaldehyde is present in a first concentration based on the total weight of the solution. The solution is contacted with a phyllosilicate clay-based adsorbent at adsorption conditions sufficient to produce a treated solution, wherein the solution has a first acetaldehyde content, the treated solution has a second acetaldehyde content, and the second acetaldehyde content is less than the first acetaldehyde content. [0007] The above paragraphs present a simplified summary of the presently disclosed subj ect matter in order to provide a basic understanding of some aspects thereof. The summary is not an exhaustive overview, nor is it intended to identify key or critical elements to delineate the scope of the subject matter claimed below. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description set forth below. BRIEF DESCRIPTION OF THE DRAWINGS [0008] The claimed subject matter may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and in which: [0009] FIG. 1 is a schematic of an exemplary acetic acid production system according to an embodiment of the invention; [0010] FIG. 2 shows overlaid graphs of FTIR absorbance for montmorillonite slurried with an H