Method for producing high-concentration alcohol
The present invention aims at providing a method for producing a high-concentration alcohol from a water-alcohol mixture, in which the overall process is efficient and the present invention relates to a production method of a high-concentration alcohol, including a water adsorption step of adsorbing water of a water-alcohol mixture on an adsorption column to obtain a first concentrated alcohol, a water desorption step of introducing an alcohol to obtain a hydrous alcohol, and a membrane separation step of introducing the hydrous alcohol into a membrane separation unit provided with a membrane composite containing zeolite having an SiO 2 /Al 2 O 3 molar ratio of 5 to 15 to obtain a second concentrated alcohol.
1. A method of producing a high-concentration alcohol which is methanol or ethanol, with an adsorption column and a membrane separation unit,
the method comprising:
(A) introducing a water-alcohol mixture into the adsorption column to adsorb water on the adsorption column and obtain a first concentrated alcohol,
(B) introducing the first concentrated alcohol obtained in (A) into the adsorption column to desorb the water adsorbed and obtain a hydrous alcohol, and
(C) after (B), introducing the hydrous alcohol into a membrane separation unit provided with a zeolite membrane composite containing zeolite having an SiO 2 /Al 2 O 3 molar ratio of 5 to 15 to obtain a second concentrated alcohol.
2. The method according to claim 1 , wherein the zeolite is zeolite having a framework density of 10.0 to 18.0 T/1000 Å.
3. The method according to claim 1 , wherein the zeolite is CHA-type zeolite.
4. The method according to claim 1 , wherein the water-alcohol mixture is a distillate obtained at the top of a rectification column before (A) and (B).
5. The method according to claim 1 , wherein a plurality of adsorption columns are present.
6. The method according to claim 1 , wherein the second concentrated alcohol obtained is reintroduced in an adsorption column in (A).
7. The method according to claim 1 , wherein the alcohol is ethanol and the water-alcohol mixture is obtained by alcohol fermentation with fermentative bacteria.
8. The method according to claim 1 , wherein the water-alcohol mixture further comprises an acid.
9. The method according to claim 1 , wherein the-membrane separation is performed by pervaporation.
10. The method according to claim 1 , wherein the membrane separation is performed by vapor permeation.