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Blended Rubbery Polymer for Gas Separation
NETL Ref No.  
23N-05
Patent Status

U.S. Patent Pending

Main Visual
Figure 1: Gas separation properties of NETL’s blended rubbery polymer membrane (green dot).
Main Visual Caption

Figure 1: Gas separation properties of NETL’s blended rubbery polymer membrane (green dot).

Introduction

NETL researchers have developed a method for creating advanced polymer membranes to efficiently separate CO2 from nitrogen (N2), addressing key challenges in current gas separation technologies. These membranes combine excellent CO2 permeability, selectivity and stability, even in humid conditions, making them ideal for industrial applications such as CO2 capture from flue gas. The membranes are fabricated as thin films or bulk materials and perform long-term without degradation. This innovation improves gas separation efficiency and has potential applications in the medical and environmental fields.

The Technology

Overview

Industrial processes that require efficient CO₂/N₂ separation often depend on polymeric membranes that can provide high permeability and selectivity, yet these materials frequently encounter issues with mechanical integrity, poor aging resistance or susceptibility to plasticization under varying conditions. Conventional solutions that provide permeability can lack robustness, exhibiting diminished performance when exposed to humidity or prolonged use and making them unsuitable for large-scale applications. Complex fabrication steps and difficulties in achieving thin, defect-free films that do not degrade in the presence of water vapor or fluctuating temperatures further complicate efforts, underscoring the need for more robust, adaptable solutions to develop high-performance membrane materials.

NETL’s invention is a rubbery blend polymer membrane that resists aging and humidity, and exceeds Robeson’s 2008 upper bound for CO2/N2 separation. By exhibiting high CO2 permeance (up to 4,500 GPU), moderate CO2/N2 selectivity (40) and long-term stability, this NETL innovation can efficiently separate CO2 from flue gas in power plants and industrial facilities, providing a more stable and cost-effective alternative to traditional amine-based capture systems. The invention’s high molecular weight facilitates thin-film coating, enabling defect-free membranes as thin as 120 nm. Potential applications include use for CO2 capture, natural gas sweetening, membrane reactors, hygiene products and drug delivery systems.

Benefits

Advantages
  • High CO2 permeability and selectivity
  • Superior CO2 transport properties
  • Robust, stable and humidity resistant, with few limitations on reaction conditions
  • Versatile for fabrication as thin films or bulk materials suitable for industrial-scale deployment
  • Optimal performance across multiple gas separation scenarios and over a wide temperature range
  • Cost-effective, long-term performance, reducing replacement costs

Applications

Uses
  • CO2 capture and separation
    • Natural gas fueled post-combustion flue gas
    • Blast furnace waste gas
    • Cement plants waste gas
    • Biomass gas
  • CO2/Methane (CH4) separation
  • CO2 membrane reactors
  • CO2 enrichment
  • Manufacturing
    • Steel and cement
    • Environmental
    • Hygiene and medical products
Date Posted: 
Date Posted
July 01, 2025

 

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