Amine-Containing Membranes Incorporated with Carbon Nanotubes or CO2 Separation
A novel amine-containing membrane incorporated with carbon nanotubes for CO2/N2 separation with a vacuum pulled on the permeate side
CO2 concentration in the atmosphere has surpassed 400 ppm in the past decade. The combustion of fossil fuels is a major contributor to the large amount of CO2 emission, and membrane technologies have been suggested as a promising approach to capture CO2 from large stationary sources (e.g., flue gases from coal-fired and natural gas-fired power plants), followed by compression and geological sequestration. Multiple research efforts were dedicated to design membrane processes that can capture 90% CO2 from the power plant flue gases with a CO2 purity of at least 95%. Although various membrane materials have been developed to decrease the CO2 capture cost based on different membrane processes, the membrane performances, in terms of CO2 permeance and CO2/N2 selectivity, were seldom measured under the vacuum operation mode.
Reseachers at the Ohio State University, led by W.S. Winston Ho, have developed a novel amine-containing membrane incorporated with carbon nanotubes for CO2/N2 separation with a vacuum pulled on the permeate side. In the selective layer of the membrane, amine-containing polymers are used to form the polymer matrix whereas amino acid salts are employed as mobile carriers to facilitate the transport of CO2. Untreated and functionalized carbon nanotubes are incorporated in the amine-containing polymers, respectively, as rigid inorganic fillers. The invention demonstrated that pristine, acid treated, and amino-functionalized carbon nanotubes can all serve to reduce the penetration of the selective layer into the nanoporous substrate under vacuum.