Treatment of alcohol compositions

Patent metadata

Field	Value
Publication number	US-2016326076-A1
Application number	US-201415107674-A
Country	US
Kind code	A1
Filing date	Dec 19, 2014
Priority date	Dec 24, 2013
Publication date	Nov 10, 2016
Grant date	—

Abstract

There is provided a process for reducing the water and carboxylic acid content of an alcohol composition comprising at least one alcohol having from one to four carbon atoms, water and at least one carboxylic acid having from one to four carbon atoms, wherein said process comprises: (a) forming a vapour phase alcohol composition A and a liquid phase alcohol composition B from the alcohol composition; (b) separating a second vapour phase alcohol composition C and an aqueous phase D from the liquid phase alcohol composition B in a distillation column, wherein the aqueous phase D contains the majority of the carboxylic acid that was present in the liquid phase alcohol composition B; (c) passing the vapour phase alcohol composition A to a drying unit comprising a desiccant, (d) passing the vapour phase alcohol composition C to a drying unit comprising a desiccant; and (e) recovering an alcohol composition from the drying unit of step (c) and the drying unit of step (d); wherein the recovered alcohol composition of step (c) has a reduced water and carboxylic acid content.

First claim

1 - 20 . (canceled)

21 . A process for reducing the water and carboxylic acid content of an alcohol composition comprising at least one alcohol having from one to four carbon atoms, water and at least one carboxylic acid having from one to four carbon atoms, wherein said process comprises:
(a) forming a vapour phase alcohol composition A and a liquid phase alcohol composition B from the alcohol composition; (b) separating a second vapour phase alcohol composition C and an aqueous phase D from the liquid phase alcohol composition B in a distillation column, wherein the aqueous phase D contains the majority of the carboxylic acid that was present in the liquid phase alcohol composition B; (c) passing the vapour phase alcohol composition A to a drying unit comprising a desiccant; (d) passing the vapour phase alcohol composition C to a drying unit comprising a desiccant; and (e) recovering an alcohol composition from the drying unit of step (c) and the drying unit of step (d); wherein the recovered alcohol composition of step (e) has a reduced water and carboxylic acid content.

22 . A process as claimed in claim 21 , wherein the vapour phase alcohol composition A and the liquid phase alcohol composition B are formed by vaporisation of the alcohol composition.

23 . A process as claimed in claim 21 , wherein the vapour phase alcohol composition A and liquid phase alcohol composition B are formed by pre-dividing the alcohol composition into a first portion and a second portion, passing the first portion to a vaporisation unit so that substantially all of the first portion is vaporised in the vaporisation unit to form the vapour phase alcohol composition A, and passing the second portion to the distillation column as the liquid phase alcohol composition B.

24 . A process as claimed in claim 21 , wherein the vapour phase alcohol composition A and liquid phase alcohol composition B are formed by pre-dividing the alcohol composition into a first portion and a second portion, passing the first portion to a vaporisation unit so that the first portion is divided in the vaporisation unit into the vapour phase alcohol composition A and a third portion, and passing the second portion and the third portion to the distillation column as the liquid phase alcohol composition B.

25 . A process as claimed in claim 21 , wherein the vaporisation step does not result in a significant difference in the concentration of water present in the vapour phase alcohol composition A and the liquid phase alcohol composition B.

26 . A process as claimed in claim 21 , wherein the vapour phase alcohol composition A and the vapour phase alcohol composition C are passed to the same drying unit comprising a desiccant.

27 . A process as claimed in claim 26 , wherein the vapour phase alcohol composition A and the vapour phase alcohol composition C are combined prior to being passed to the drying unit comprising a desiccant.

28 . A process as claimed in claim 21 , wherein the alcohol composition comprises ethanol.

29 . A process as claimed in claim 21 , wherein the alcohol composition comprises acetic acid.

30 . A process as claimed in claim 21 , wherein the alcohol composition comprises at least one butanol.

31 . A process as claimed in claim 21 , wherein the alcohol composition comprises butyric acid.

32 . A process as claimed in claim 21 , wherein the alcohol composition has a water concentration in the range of from 0.05 wt % to 10 wt %.

33 . A process as claimed in claim 21 , wherein the alcohol composition has a carboxylic acid concentration in the range of 500 ppmw to 5 wt %.

34 . A process as claimed in claim 21 , further comprising using a portion of the alcohol composition having a reduced water and carboxylic acid content recovered in step (e) to regenerate the drying unit of step (c) and/or step (d), and optionally passing a portion of the resulting stream comprising alcohol and water to the distillation column.

35 . A system for reducing the water and carboxylic acid content of an alcohol composition comprising at least one alcohol having from one to four carbon atoms, water and at least one carboxylic acid having from one to four carbon atoms, wherein said system comprises:
(a) means to form a vapour phase alcohol composition A and a liquid phase alcohol composition B from the alcohol composition; (b) a distillation column configured to separate a second vapour phase alcohol composition C and an aqueous phase D from the liquid phase alcohol composition B, wherein the aqueous phase D contains the majority of the carboxylic acid that was present in the liquid phase alcohol composition; (c) a drying unit comprising a desiccant through which the vapour phase alcohol composition A is passed; and (d) a drying unit comprising a desiccant through which the vapour phase alcohol composition C is passed.

36 . A system as claimed in claim 35 , wherein the means to form the vapour phase alcohol composition A and the liquid phase alcohol composition B comprises a vaporisation unit configured to vaporise part of the alcohol composition to form the vapour phase alcohol composition A and the liquid phase alcohol composition B.

37 . A system as claimed in claim 35 , wherein the means form the vapour phase alcohol composition A and the liquid phase alcohol composition B comprises means to pre-divide the alcohol composition into a first portion and a second portion, and a vaporisation unit configured to vaporise substantially all of the first portion.

38 . A system as claimed in claim 35 , wherein the means to form into the vapour phase alcohol composition A and the liquid phase alcohol composition B comprises means to pre-divide the alcohol composition into a first portion and a second portion, and a vaporisation unit configured to vaporise part of the first portion to form the vapour phase alcohol composition A and a third portion, the second portion and the third portion together forming the liquid phase alcohol composition B.

39 . A system as claimed in claim 35 , wherein the drying unit through which the vapour phase alcohol composition C is passed is the same drying unit as the drying unit through which the vapour phase alcohol composition A is passed.

40 . A method of preparing a fuel alcohol composition from an alcohol composition comprising at least one alcohol having from one to four carbon atoms, water and at least one carboxylic acid having from one to four carbon atoms, wherein said method involves:
(a) determining the concentration of water and carboxylic acid present in the alcohol composition; (b) if the alcohol composition comprises a concentration of water which is greater than the azeotropic concentration for the alcohol composition, passing the entire alcohol composition to a distillation column of step (c) as a liquid phase alcohol composition B;
if the alcohol composition comprises a concentration of water which is equal to or lower than the azeotropic concentration for the alcohol composition, and the carboxylic acid concentration is equal to or lower than the maximum desired concentration of carboxylic acid in the fuel alcohol composition, vaporising the entire alcohol composition to form a vapour phase alcohol composition A; or
if the alcohol composition comprises a concentration of water which is equal to or lower than the azeotropic concentration for the alcohol composition, and the carboxylic acid concentration is greater than the maximum desired concentration of carboxylic acid in the fuel alcoh

Assignees

• Bp Plc

Inventors

• Bough Matthew

Classifications

• C10L1/02

  essentially based on components consisting of carbon, hydrogen, and oxygen only · CPC title

• C07C29/80 Primary

  by distillation · CPC title

• B01D53/261

  by adsorption · CPC title

• C07C37/76

  by steam distillation · CPC title

• B01D3/002

  by continuous methods · CPC title