US 12151217 B1Patent grantUnited States

Supported Membrane for Industrial Gas Separation

Official patent title

Gas separation membrane

Arabic title: غشاء لفصل الغازات

Invention

Problem

Industrial gas separation can be energy intensive, while polymer membranes often face a trade-off between permeability and selectivity and may be sensitive to chemical degradation. Polyimides are stable, but imparting selective adsorption without sacrificing transport remains difficult.

Why it matters

Membrane-based separation can offer a simpler, potentially lower-energy route for purifying gas mixtures than solvent regeneration or cryogenic distillation. New membrane chemistries must still be validated for actual separation performance.

Approach

The disclosure forms an alternating polyimide from 4,4′-diselanediyldianiline and ethylenediaminetetraacetic dianhydride, casts a porous membrane layer on a ceramic substrate, and uses the membrane to permeate one gas preferentially from a mixture.

Who may benefit

Potential beneficiaries include industrial-gas and natural-gas processors, membrane-material manufacturers, chemical-separation companies, and researchers developing carbon-capture or hydrogen-purification technologies.

Potential value

The technology provides a distinct selenium-containing polyimide chemistry, a reproducible staged casting process, and a porous ceramic-supported membrane format intended for separating mixtures that may contain H2, N2, CH4, CO, CO2, and H2S.

Background

Industrial gas purification supports product quality and environmental control, but common approaches have drawbacks. Sorbent systems require regeneration, and cryogenic distillation is energy intensive and best suited to certain concentrated feeds. Membranes can operate with simpler equipment, yet polymeric materials must balance permeability, selectivity, chemical stability, and processability. Polyimides offer useful thermal and chemical stability, although selective gas adsorption can be difficult to introduce without reducing transport. The patent addresses this materials problem through a diselenide-containing polyimide membrane on a ceramic support.

Technology overview

Equimolar diselenediyldianiline and ethylenediaminetetraacetic dianhydride are reacted through a poly(amic acid) intermediate and imidized at 170–200 °C. The resulting polymer is dissolved to form a 10–30 wt.% casting solution, deposited on a silica or other ceramic substrate, and progressively heated at three temperature stages. A working example describes polymer synthesis and casting a 20 wt.% solution on glass; claims then cover contacting the membrane with a multi-gas feed to form an enriched permeate.

Potential applications

Potential removal of CO2 or H2S from mixed-gas streams.
Hydrogen separation and purification research.
Methane, nitrogen, or carbon-monoxide membrane-separation studies.
Ceramic-supported polymer membranes for industrial gas processing.

Evidence-supported advantages

Introduces a defined diselenide-containing alternating polyimide chemistry.
Uses a porous polymer layer supported on a ceramic substrate.
Provides specified polymerization, casting, and staged-heating conditions.
Includes a documented working example for polymer and membrane fabrication.

Development stage

A working example describes polymer synthesis and membrane fabrication; gas-separation performance and commercialization were not established.

Commercial opportunity

The membrane chemistry may be licensed to gas-separation material or module developers for performance evaluation. Commercial viability depends on measured permeability and selectivity, mixed-gas durability, contaminant resistance, membrane area scale-up, module integration, and operating economics. Long-term plasticization and aging behavior would also need assessment.

Patent classifications

WIPO IPC

B01D71/64Separation
B01D53/22Separation

CPC

B01D53/228Separation
B01D67/0011Separation
B01D67/0013Separation
B01D71/64Separation
C08G73/1057Macromolecular compounds obtained otherwise than by reactions involving only carbon-to-carbon unsaturated bonds
C08G73/1078Macromolecular compounds obtained otherwise than by reactions involving only carbon-to-carbon unsaturated bonds
C08G73/1085Macromolecular compounds obtained otherwise than by reactions involving only carbon-to-carbon unsaturated bonds
C08J5/18Working-up; general compounding processes; after-treatment of macromolecular compounds
B01D2053/221Separation
B01D2323/081Separation
C08J2379/08Working-up; general compounding processes; after-treatment of macromolecular compounds

Inventors

First inventorTarek Ahmed Yousef
InventorSaad Shaaban

Keywords

polyimide membrane
diselenide polymer
gas separation
ceramic support
CO2
H2S
hydrogen purification
membrane casting

Patent document and drawings

The patent publication is mapped to this record. Patent drawings remain within that publication; no separately cleared public media package has been supplied.