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EP-4736995-A1 - SEPARATION MEMBRANE, SEPARATION MEMBRANE LAYERED BODY, SEPARATION MODULE OR SEPARATION TOWER, HYDROGEN RECOVERY SYSTEM, AND HYDROGEN SEPARATION AND RECOVERY METHOD

EP4736995A1EP 4736995 A1EP4736995 A1EP 4736995A1EP-4736995-A1

Abstract

A separation membrane for separating hydrogen and a gas L, in which an activation energy Ep(S) (kJ/mol) of a permeance P(S) (mol/(m 2 ·s·Pa)) of hydrogen through the separation membrane derived within a range of a temperature Tam (°C) satisfying Formula (1-I) described below and an activation energy Ep(L) (kJ/mol) of a permeance P(L) (mol/(m 2 ·s·Pa)) of a gas L (provided that hydrogen is excluded) through the separation membrane derived within the same temperature range satisfy Formula (1-II) described below: 5 (°C) ≤ Tam (°C) ≤ 200 (°C) (1-I) [Ep(L)| < |Ep(S)| (1-II). There can be provided a separation membrane for separating and recovering hydrogen, a separation membrane laminated body, a separation module or separation tower, a hydrogen recovery system, and a method for separating and recovering hydrogen, which enable safe and highly efficient separation and recovery of hydrogen from a mixed gas composed of molecules having relatively close dynamic molecular diameters even when a supply pressure is relatively low, including separation and recovery of hydrogen from a hydrogen-oxygen mixed gas.

Inventors

  • HORIE, HIDEYOSHI
  • SATOU, KIMINORI
  • Ri, Morihiro
  • MIYAGI, HIDEKAZU
  • TAKEWAKI, TAKAHIKO
  • HORIUCHI, KAORU

Assignees

  • Mitsubishi Chemical Corporation

Dates

Publication Date
20260506
Application Date
20240628

Claims (20)

  1. A separation membrane in which an activation energy Ep(S) (kJ/mol) of a permeance P(S) (mol/(m 2 ·s·Pa)) of hydrogen through the separation membrane derived within a range of a temperature Tam (°C) satisfying Formula (1-I) described below and an activation energy Ep(L) (kJ/mol) of a permeance P(L) (mol/(m 2 ·s·Pa)) of a gas L (provided that L is at least one selected from the group consisting of carbon dioxide, argon, oxygen, nitrogen, and methane) through the separation membrane derived within the same temperature range satisfy Formula (1-II) described below: 5 ° C ≤ Tam ° C ≤ 200 ° C Ep L < Ep S
  2. The separation membrane according to claim 1, wherein Formula (1-III) described below is satisfied: P L < P S
  3. The separation membrane according to claim 1, wherein Formula (1-IV) described below is satisfied: 0 < Ep L < Ep S
  4. The separation membrane according to claim 1, wherein the separation membrane is an inorganic membrane.
  5. The separation membrane according to claim 1, wherein the separation membrane comprises a surface-modified zeolite membrane.
  6. A separation membrane laminated body comprising a separation membrane on a support, wherein the separation membrane is the separation membrane described in any one of claims 1 to 5, the support is tubular, and an inner diameter φi (mm) of the support satisfies Formula (1-VI) described below: 6 mm ≤ φi mm ≤ 16 mm
  7. A separation module or separation tower comprising a separation membrane, wherein the separation membrane is the separation membrane described in any one of claims 1 to 5, and a temperature Tos (°C) of the separation module or separation tower satisfies Formula (1-VII) described below: 45 ° C ≤ Tos ° C ≤ 200 ° C
  8. The separation module or separation tower according to claim 7, wherein a distance between an inner wall of the separation module or separation tower and the separation membrane closest to the inner wall is 0.1 cm or more and 50 cm or less.
  9. A separation module or separation tower comprising the separation membrane laminated body described in claim 6, wherein a temperature Tos (°C) of the separation module or separation tower satisfies Formula (1-VII) described below: 45 ° C ≤ Tos ° C ≤ 200 ° C
  10. The separation module or separation tower according to claim 7, further comprising at least one of a dehumidification mechanism, a warming mechanism, or a flame propagation suppression mechanism.
  11. A hydrogen recovery system comprising a separation membrane, wherein the separation membrane is the separation membrane described in any one of claims 1 to 5, and at least one temperature Tgm (°C) of a temperature of a mixed gas M to be separated and recovered in the hydrogen recovery system or a temperature of the separation membrane satisfies Formula (1-IX) described below: 45 ° C ≤ Tgm ° C ≤ 200 ° C
  12. A hydrogen recovery system comprising the separation membrane laminated body described in claim 6, wherein at least one temperature Tgm (°C) of a temperature of a mixed gas M to be separated and recovered in the hydrogen recovery system or a temperature of the separation membrane satisfies Formula (1-IX) described below: 45 ° C ≤ Tgm ° C ≤ 200 ° C
  13. The hydrogen recovery system according to claim 11, wherein the separation membrane is included in a separation module or separation tower, and a distance between an inner wall of the separation membrane module or separation tower and the separation membrane closest to the inner wall is 0.1 cm or more and 50 cm or less.
  14. The hydrogen recovery system according to claim 11, further comprising a pressurization mechanism for the mixed gas M to be supplied to the separation membrane.
  15. The hydrogen recovery system according to claim 11, further comprising at least one of a dehumidification mechanism, a warming mechanism, or a flame propagation suppression mechanism.
  16. The hydrogen recovery system according to claim 11, further comprising a decompression mechanism on a permeation side of the separation membrane.
  17. A method for separating and recovering hydrogen from a mixed gas M of hydrogen and a gas L1 by a separation membrane, the gas L1 having a larger dynamic molecular diameter than hydrogen, wherein the separation membrane is the separation membrane described in any one of claims 1 to 5, and at least one temperature Tgm (°C) of a temperature of the mixed gas M or a temperature of the separation membrane satisfies Formula (1-IX) described below: 45 ° C ≤ Tgm ° C ≤ 200 ° C
  18. The method for separating and recovering hydrogen according to claim 17, wherein a pressure F M (MPa (G)) of the mixed gas M to be supplied to the separation membrane satisfies Formula (1-XI) described below: 0.0 MPa G ≤ F M MPa G ≤ 0.2 MPa G
  19. The method for separating and recovering hydrogen according to claim 17, wherein a pressure on a permeation side of the separation membrane is set to a reduced pressure.
  20. The method for separating and recovering hydrogen according to claim 19, wherein the pressure on the permeation side of the separation membrane is -0.101 MPa (G) or more and - 0.065 MPa (G) or less.

Description

Technical Field The present invention relates to a separation membrane that separates and recovers a desired component from a mixed gas containing a plurality of gas components, a separation membrane laminated body including the separation membrane, a separation module or separation tower equipped with the separation membrane, a hydrogen recovery system using the separation membrane, and a method for separating and recovering hydrogen. Background Art Active utilization of hydrogen as a next-generation energy source is expected, and various hydrogen production methods have been proposed. In particular, with regard to the production of so-called green hydrogen, there have been proposed a method of electrolyzing water using renewable energy such as sunlight, a method of simultaneously generating hydrogen and oxygen by total decomposition of water with a photocatalyst and separating and recovering hydrogen therefrom, and the like. In the case of electrolysis, oxygen and hydrogen will be obtained from positive and negative electrodes, but in practice, hydrogen and oxygen are mixed to some extent, and therefore, it is necessary to separate and recover hydrogen from the mixture. In the case of total decomposition of water by a photocatalyst, it is necessary to separate and recover hydrogen from a mixed gas having a stoichiometric composition, i.e., a ratio of hydrogen:oxygen = 2:1. A gas separation or concentration method has been proposed in which a mixed gas containing a plurality of gas components is brought into contact with a separation membrane, and a component having high permeability in the mixed gas is allowed to permeate the separation membrane to separate the component having high permeability from the mixed gas, or a component having low permeability is concentrated by allowing the component having high permeability to permeate the separation membrane from the mixed gas (e.g., see Patent Literature 1), and a porous support-zeolite membrane composite has been proposed as the separation membrane (e.g., see Patent Literatures 2 and 3). However, the mixed gas having a ratio of hydrogen:oxygen = 2:1 is also called hydrogen detonating gas, and once ignited, a detonation phenomenon in which a flame accompanied by a shock wave propagates at a speed exceeding the sound speed may occur, and it is necessary to consider sufficient safety in handling the mixed gas. For example, an explosion range and a detonation range of a hydrogen-oxygen mixed gas at ordinary pressure are described, and a hydrogen-oxygen mixed gas having a hydrogen concentration of from 3.9 vol% to 95.8 vol% is defined as being in the explosion range, and a hydrogen-oxygen mixed gas having a hydrogen concentration ranging from 15.5 vol% to 92.6 vol% is particularly defined as being in the detonation range (see Non-Patent Literature 1). From the above viewpoint, the generated hydrogen-oxygen mixed gas needs to be separated into hydrogen (or a hydrogen-rich gas having a composition equal to or higher than an appropriate composition) and oxygen (or an oxygen-rich gas having a composition equal to or higher than an appropriate composition) safely and highly efficiently. However, since the mixed gas is inherently difficult to handle and dynamic molecular diameters of hydrogen and oxygen are very close to each other, a technique of separating and recovering hydrogen from a hydrogen-oxygen mixed gas has not been sufficiently studied. For example, Non-Patent Literature 2 describes dynamic molecular diameters, and describes that hydrogen has a dynamic molecular diameter of 0.289 nm, oxygen has a dynamic molecular diameter of 0.346 nm, carbon dioxide has a dynamic molecular diameter of 0.330 nm, argon has a dynamic molecular diameter of 0.34 nm, nitrogen has a dynamic molecular diameter of 0.364 nm, and methane has a dynamic molecular diameter of 0.38 nm. It is hard to say that the separation and recovery techniques for such a mixed gas having dynamic molecular diameters close to each other have been sufficiently studied. Further, it is known that, when a desired component is separated from a mixed gas, the efficiency of the separation process is usually improved by pressurizing the supply side, but if the hydrogen-oxygen mixed gas is pressurized, its handling becomes more difficult and damage at the time of ignition becomes more serious. Therefore, a high-performance separation membrane is desired which can constitute a safe and highly efficient hydrogen-oxygen separation process at a low supply pressure of about tens of kPa (G) or less or at ordinary pressure. In the case of separating a mixed gas containing an additional component, for example, a hydrogen-methane mixed gas, in the case of separating a hydrogen-carbon dioxide mixed gas, or the like, further improvements in safety and efficiency of the technique of separating and recovering a desired molecule under a low supply pressure condition are desired. As a specific aspect, a separation process of