Dehydration method and dehydration apparatus providing increased water permeation

Patent metadata

Field	Value
Publication number	US-12138598-B2
Application number	US-201916704091-A
Country	US
Kind code	B2
Filing date	Dec 5, 2019
Priority date	Jun 7, 2017
Publication date	Nov 12, 2024
Grant date	Nov 12, 2024

Abstract

A dehydration method is a dehydration method for selectively separating water from a mixture that contains water, and the method includes a step of supplying the mixture to a supply side space of a separation membrane, and a step of making a pressure difference between the supply side space and a permeation side space of the separation membrane. The separation membrane includes a first zeolite membrane that faces the permeation side space and is constituted by a first zeolite and a second zeolite membrane that faces the supply side space and is adjacent to the first zeolite membrane. The second zeolite membrane is constituted by a second zeolite that has the same framework structure as framework of the first zeolite and has a lower Si/Al atom ratio than a Si/Al atom ratio of the first zeolite.

First claim

The invention claimed is:

1. A dehydration apparatus comprising:
a separation vessel including a separation membrane that selectively separates water from a mixture containing water, and a housing portion that is sectioned by the separation membrane into a supply side space to which the mixture is supplied and a permeation side space to which water permeated through the separation membrane flows out; and
a pressure changing apparatus configured to increase the pressure in the supply side space and/or reduce the pressure in the permeation side space, wherein
the separation membrane includes a first zeolite membrane that faces the permeation side space, and a second zeolite membrane that faces the supply side space and is adjacent to the first zeolite membrane,
a first zeolite that constitutes the first zeolite membrane contains at least a silicon atom and an oxygen atom, and
a second zeolite that constitutes the second zeolite membrane has a framework structure that is the same as a framework structure of the first zeolite, the second zeolite has a lower Si/Al atom ratio than a Si/Al atom ratio of the first zeolite, and the second zeolite contains at least a silicon atom, an aluminum atom, an oxygen atom, and at least one type of atom selected from the group consisting of alkali metals, alkaline earth metals, and hydrogen;
wherein the framework structure of the first zeolite and the second zeolite is MFI.

2. The dehydration apparatus according to claim 1 , wherein
the first zeolite is a high-silica zeolite, and
the second zeolite is a low-silica zeolite.

3. A dehydration method for selectively separating water from a mixture that contains water, using the dehydration apparatus according to claim 1 , the method comprising:
a step of supplying the mixture to a supply side space of the separation membrane; and
a step of making a pressure difference between the supply side space and a permeation side space of the separation membrane, wherein
the separation membrane includes:
a first zeolite membrane configured to face the permeation side space and is constituted by a first zeolite; and
a second zeolite membrane configured to face the supply side space and is adjacent to the first zeolite membrane, and
the second zeolite membrane is constituted by a second zeolite that has a same framework structure as framework of the first zeolite and has a lower Si/Al atom ratio than a Si/Al atom ratio of the first zeolite.

4. The dehydration method according to claim 3 , wherein
the first zeolite is a high-silica zeolite, and
the second zeolite is a low-silica zeolite.

5. The dehydration method according to claim 3 , wherein
the framework structure of the first zeolite and the second zeolite is any one of MFI, DDR, MEL, BEA, or CHA.

6. The dehydration method according to claim 3 , wherein
the framework structure of the first zeolite and the second zeolite is MFI or MEL.

Assignees

• Ngk Insulators Ltd

Inventors

• Noda Kenichi
• Miyahara Makoto
• Shimizu Katsuya
• Hagio Takeshi

Classifications

• C02F2101/30

  Organic compounds · CPC title

• C02F1/448

  by pervaporation · CPC title

• B01D61/362

  Pervaporation · CPC title

• B01D67/0051

  by controlled crystallisation, e,.g. hydrothermal growth · CPC title

• B01D63/066

  with a porous block having membrane coated passages · CPC title