Treatment of alcohol compositions
View Patent ↗Process for reducing the water and carboxylic acid content of an alcohol composition containing at least one alcohol having one to four carbon atoms, water and at least one carboxylic acid having from one to four carbon atoms by contacting the alcohol composition with a desiccant bed containing at least one porous inorganic oxide material at elevated temperature. At least one of the porous inorganic oxide material(s) contains Brønsted acid sites and/or neutralized Brønsted acid sites.
1. A process for reducing the water and carboxylic acid content of an alcohol composition comprising at least one alcohol having one to four carbon atoms, water and at least one carboxylic acid having from one to four carbon atoms, said process comprising contacting the alcohol composition with a desiccant bed comprising at least one porous inorganic oxide material at elevated temperature, wherein at least one of the porous inorganic oxide material(s) contains Brønsted acid sites and/or neutralised Brønsted acid sites.
2. A process according to claim 1 , wherein the desiccant bed comprises an admixture of a desiccant material and a porous inorganic oxide material containing Brønsted acid sites and/or neutralised Brønsted acid sites, wherein said porous inorganic oxide material containing Brønsted acid sites and/or neutralised Brønsted acid sites is different to the desiccant material.
3. A process according to claim 1 , wherein the desiccant bed consists of one or more porous inorganic oxide materials containing Brønsted acid sites and/or neutralised Brønsted acid sites and functions as a desiccant.
4. A process according to claim 1 , wherein the desiccant bed comprises molecular sieve 3A, molecular sieve 4A and mixtures thereof.
5. A process according to claim 1 , wherein the porous inorganic oxide material is at least partially in the form of the alkali metal salt.
6. A process according to claim 1 , wherein the porous inorganic oxide material is at least partially in the protonated form.
7. A process according to claim 1 , wherein the alcohol composition comprises ethanol.
8. A process according to claim 1 , wherein the alcohol composition comprises acetic acid.
9. A process according to claim 7 , wherein the alcohol composition comprises acetic acid.
10. A process according to claim 1 , wherein the alcohol composition comprises at least one butanol.
11. A process according to claim 1 , wherein the alcohol composition comprises butyric acid.
12. A process according to claim 1 , wherein the alcohol composition is in the vapour phase when it is contacted with the desiccant bed.
13. A process according to claim 1 , wherein the contacting of the alcohol composition with the desiccant bed is performed at a temperature in the range of from 70° C. to 250° C.
14. A process according to claim 13 , wherein the contacting of the alcohol composition with the desiccant bed is performed at a temperature in the range of from 120 C to 210 C.
15. A process according to claim 14 , wherein the contacting of the alcohol composition with the desiccant bed is performed at a temperature in the range of from 140 C to 190° C.
16. A process according claim 1 , wherein the contacting of the alcohol composition with the desiccant bed is performed at a pressure in the range of from 0.15 MPa to 5 MPa.
17. A process according to claim 1 , wherein the concentration of water in the alcohol composition is in the range of from 1to 10 vol %.
18. A process according to claim 1 , wherein the concentration of carboxylic acid in the alcohol composition is in the range of from 25 ppmw to 1 wt %.
19. A process for reducing the acetic acid content of an ethanol composition comprising ethanol, water and acetic acid, said process comprising contacting the ethanol composition with a desiccant bed comprising at least one porous inorganic oxide material at elevated temperature, wherein at least one of the porous inorganic oxide material(s) contains Brønsted acid sites and/or neutralised Brønsted acid sites.
20. A process according to claim 19 , wherein the desiccant bed consists of a porous inorganic oxide material selected from molecular sieve 3A, molecular sieve 4A and mixtures thereof.