Process to produce an enriched composition through the use of a catalyst removal zone and an enrichment zone
View Patent ↗A process is provided for producing an enriched carboxylic acid compositions produced by contacting composition comprising a carboxylic acid with an enrichment feed in an enrichment zone to form an enriched carboxylic acid composition. This invention also relates to a process and the resulting compositions for removing catalyst from a carboxylic acid composition to produce a post catalyst removal composition.
1. A process to produce an enriched composition comprising terephthalic acid, said process comprising:
(a) subjecting a cooled carboxylic acid composition comprising terephthalic acid, and a wash feed to a catalyst removal zone in a terephthalic acid process to form a post catalyst removal composition, a wash liquor, and a catalyst rich liquor;
(b) contacting an enrichment feed with said post catalyst removal composition comprising terephthalic acid, to form said enriched composition; wherein said enrichment feed comprises at least one compound selected from the group consisting of isophthalic acid, phthalic acid, benzene-tricarboxylic acid isomers, hydroxybenzoic acid isomers, hydroxymethylbenzoic acid isomers, dicarboxybiphenyl isomers, dicarboxystilbene isomers, tricarboxybiphenyl isomers, tricarboxybenzophenone isomers, dicarboxybenzophenone isomers, dicarboxybenzil isomers, form-acet-hydroxybenzoic acid isomers, acet-hydroxymethylbenzoic acid isomers, and phthaldehyde isomers; wherein said enriched composition is enriched in at least one of said compounds relative to said post catalyst removal composition.
2. The process according to claim 1 wherein said cooled carboxylic acid composition is cooled to a temperature ranging from about 5° C. to about 195° C.
3. The process according to claim 1 wherein said cooled carboxylic acid composition is cooled to a temperature ranging from about 20° C. to about 195° C.
4. The process according to claim 3 wherein said wash feed is at a temperature ranging from about 20° C. to about 90° C.
5. The process according to claim 1 wherein said wash feed is at a temperature ranging from about 5° C. to about 195° C.
6. The process according to claim 1 wherein at least two of said compounds are enriched by at least 1000 ppmw.
7. A process to produce an enriched composition comprising terephthalic acid, said process comprising:
(a) oxidizing paraxylene in a primary oxidation zone to form a crude carboxylic acid composition comprising terephthalic acid;
(b) optionally subjecting said crude carboxylic acid composition to a liquid displacement zone to form a slurry composition;
(c) cooling and optionally enriching said slurry composition or said crude carboxylic acid composition in a cooling zone to form a cooled carboxylic acid composition;
(d) subjecting said cooled carboxylic acid composition, and a wash feed to a catalyst removal zone to form a post catalyst removal composition and a catalyst rich liquor;
(e) contacting said enrichment feed with said post catalyst removal composition comprising terephthalic acid, to form said enriched composition; wherein said enrichment feed comprises at least one compound selected from the group consisting of isophthalic acid, phthalic acid, benzene-tricarboxylic acid isomers, hydroxybenzoic acid isomers, hydroxymethylbenzoic acid isomers, dicarboxybiphenyl isomers, dicarboxystilbene isomers, tricarboxybiphenyl isomers, tricarboxybenzophenone isomers, dicarboxybenzophenone isomers, dicarboxybenzil isomers, form-acet-hydroxybenzoic acid isomers, acet-hydroxymethylbenzoic acid isomers, and phthaldehyde isomers; wherein said enriched composition is enriched in at least one of said compound relative to said post catalyst removal composition.
8. The process according to claim 7 wherein said primary oxidation zone comprises at least one oxidation reactor operated at a temperature from 110° C. to 200° C.
9. The process according to claim 7 wherein said catalyst removal zone has a wash ratio of about 0.2 to about 6.
10. The process according to claim 7 wherein said catalyst removal zone has a wash ratio of about 0.2 to about 2.
11. The process according to claim 7 wherein said catalyst removal zone has a wash ratio of about 0.5 to about 2.0.
12. The process according to claim 7 wherein said catalyst removal zone has a wash ratio of about 0.2 to about 1.0.
13. The process according to claim 7 wherein said cooled carboxylic acid composition is cooled to a temperature ranging from about 20° C. to about 90° C.
14. The process according to claim 7 wherein said cooled carboxylic acid composition is cooled to a temperature ranging from about 5° C. to about 195° C.
15. The process according to claim 13 wherein said cooled carboxylic acid composition is cooled to a temperature ranging from about 5° C. to about 195° C.
16. The process according to claim 7 wherein said wash feed is at a temperature ranging from about 20° C. to about 90° C.
17. The process according to claim 7 wherein said wash feed is at a temperature ranging from about 5° C. to about 195° C.
18. The process according to claim 7 wherein a liquid displacement zone is between the crystallization zone and cooling zone.
19. The process according to claim 1 wherein at least two of said compounds are enriched by at least 1000 ppmw.