# US 11,110,403 B2 · Method for producing separation membrane using MFI-type zeolite (silicalite)

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- Number: US 11,110,403 B2
- Document ID: US11110403B2
- Status: Granted
- Kind: B2
- Application number: 16/312,096
- Filed: 2017-06-13
- Published: 2019-05-30
- Granted: 2021-09-07
- Earliest claimed: 2016-06-21
- Assignees: Hitachi Zosen Corporation
- Applicants: Hitachi Zosen Corporation
- Inventors: Kazuhiro Yano; Masaya Itakura; Kentaro Shinoya; Satoshi Imasaka
- Web page: https://patentgrep.com/patent/US11110403B2

## CPC

- B01D 69/108: {Inorganic support material}
- B01D 53/228: {characterised by specific membranes}
- B01D 67/0051: {by controlled crystallisation, e,.g. hydrothermal growth}
- B01D 69/106: {Membranes in the pores of a support, e.g. polymerized in the pores or voids}
- B01D 69/12: Composite membranes; Ultra-thin membranes
- B01D 71/0213: {Silicon}
- B01D 71/0281: {Zeolites}
- C01B 37/02: Crystalline silica-polymorphs, e.g. silicalites {dealuminated aluminosilicate zeolites}
- C04B 41/85: with inorganic materials
- B01D 2323/24: Use of template or surface directing agents [SDA]
- B01D 2325/20: Specific permeability or cut-off range
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE

## Abstract

Provided is a method for producing a separation membrane including a silicalite membrane without using NaOH or the like that causes an increase in cost with respect to equipment, facilities, and process time. The method for producing a separation membrane is a method for producing a separation membrane including a porous support and a silicalite membrane that is formed on the support and has an MFI-type zeolite crystal structure, and is characterized in that the method includes a step of producing a seed crystal, a step of attaching the seed crystal onto the porous support, a step of producing a membrane synthesis raw material composition containing SiO2, an organic template, and H2O, and a step of immersing the porous support having the seed crystal attached thereto in the membrane synthesis raw material composition and performing hydrothermal synthesis, and the composition ratio of the membrane synthesis raw material composition is as follows: SiO2:organic template:H2O=1:(0.05 to 0.15):(50 to 120).

## Claims

### Claim 1

A method for producing a separation membrane which includes a porous support and a silicalite membrane that is formed on the support and has an MFI-type zeolite crystal structure, the method comprising:
a step of producing a seed crystal;
a step of attaching the seed crystal onto the porous support;
a step of producing a membrane synthesis raw material composition containing SiO2, an organic template containing a hydroxy group, and H2O; and
a step of immersing the porous support having the seed crystal attached thereto in the membrane synthesis raw material composition and performing hydrothermal synthesis,
wherein the composition ratio of the membrane synthesis raw material composition is as follows: SiO2:organic template:H2O=1:(0.05 to 0.15):(50 to 120),
wherein a main component of the porous support is alumina;
wherein one end portion or both end portions in the longitudinal direction of the porous support is adhered to a dense ceramic material by a bonding agent, the ceramic material containing alumina in an amount of 50 wt % or more; and
wherein the bonding agent is composed of a ceramix oxide, the ceramic oxide containing, as essential components, (i) 17 to 48 wt % of SiO2, (ii) 2 to 8 wt % of Al2O3, (iii) 24 to 60 wt % of BaO, and (iv) 0.5 to 5 wt % of ZnO, an amount of the essential components with respect to a total weight of the ceramic oxide being from 80 to 84.5 wt %, the ceramic oxide also containing at least one of La2O3, CaO, or SrO, an amount of the at least one of La2O3, CaO, or SrO with respect to the total weight of the ceramic oxide being from 11.7 to 15.8 wt %.

### Claim 2 (depends on 1)

The method for producing a separation membrane according to claim 1, characterized in that the organic template containing a hydroxy group is TPAOH (tetra-n-propylammonium hydroxide).

### Claim 3 (depends on 1)

The method for producing a separation membrane according to claim 1, characterized in that the average particle diameter dseed of the seed crystal and the surface layer portion average pore diameter dsupport of the porous support have a relationship represented by the following formula (1):
1.5<(dsupport/dseed)<3.25. [Formula 1]

### Claim 4 (depends on 1)

The method for producing a separation membrane according to claim 1, characterized in that the porous support is composed of a ceramic material, and the average pore diameter of the porous support becomes smaller from the inside of the porous support toward the surface layer portion of the porous support having the silicalite membrane formed thereon.