Toray Industries, Inc., announced that it has innovated a carbon dioxide (CO2) separation membrane with a dual all-carbon structure. This comprises a hollow fiber porous carbon fiber as a support and a thin carbon membrane separation layer on the surface.
The membrane offers superb CO2 separation performance and high durability. It is more suitable than conventional inorganic separation membranes for making facilities more compact. Toray will step up R&D to deploy this separation membrane in social infrastructure.
CO2 separation technology is vital to using CO2 to help materialize a circular carbon economy. This technology commonly employs absorption- and adsorption-based facilities. The issue with such setups, however, is that they consume too much energy. This situation fueled worldwide research into energy-efficient membrane separation techniques.
Separation layers with pores smaller than one nanometer offer better gas permeability because they are thinner, but the lower pressure resistance necessitates combining with a support layer. Regular inorganic support layers are hard and brittle, and the diameters cannot be reduced, preventing dense module packing and miniaturization.
Toray created a porous carbon fiber with a continuous pore structure in 2019. This fiber can provide a support layer for gas separation membranes that offer excellent gas permeability and chemical and heat resistance by creating a hollow fiber.
The company’s new CO2 separation membrane employs a thin, hollow-fiber porous carbon fiber with a diameter of less than 300 micrometers as a support layer. On the surface is a uniform carbon film separation layer just a few micrometers thick.
With the support and separation layers independent, this separation membrane delivers excellent CO2 separation and durability. The membrane is flexible and incredibly thin, enabling continuous production just like with regular fibers. The high density packing enables module miniaturization. CO2 permeability can be five times greater than that of conventional inorganic CO2 separation membrane modules with the same volume.
One prospective use for Toray’s new separation membrane is natural gas and biogas purification. It could also serve in hydrogen production and purification, exhaust gas CO2 separation, and other gas separation applications by taking advantage of the selectivity of functional layers according to the gases to be separated.
Toray will draw on the innovation hub capabilities of the R&D Innovation Center for the Future at the Shiga Plant, where the company started out in 1926, to pursue strategic open innovation by engaging with academic institutions and key partners from diverse fields and commercializing more advanced gas separation membranes.
The company looks to help the world balance greenhouse gas emissions and absorption in line with the Toray Group Sustainability Vision and Toray Vision 2030 by leveraging its innovative technologies and advanced materials.
In keeping with its corporate philosophy of “contributing to society through the creation of new value with innovative ideas, technologies and products,” Toray will keep helping to resolve environmental, resources, and energy issues and continue to pursue R&D to achieve carbon neutrality.