The Need

Improved separation of by-product carbon dioxide from nitrogen in power plants and industrial exhaust systems would considerably decrease greenhouse gas emissions. The current method of separation that is most often used in industry is amine absorption, however this method is costly, has a large carbon footprint, and is not environmentally friendly due to problems associated with handling large amounts of hazardous chemicals necessary for the separation. CO₂/N₂ separation with membranes is promising as an alternative approach, but the best membrane technologies currently available suffer from too low of permeance and selectivity to be industrially feasible. As a result of these problems, there is a need for an improved membrane for CO₂/N₂ separation with higher permeance and selectivity than what is currently available.

The Technology

Researchers at The Ohio State University, led by Dr. W.S. Winston Ho, have developed a membrane capable of CO₂/N₂ separation with high permeance and selectivity. The technology achieves this result through active transport. This membrane shows a CO₂ permeance greater than 2900 GPU and a CO₂/N₂ selectivity greater than 85 at a flue gas temperature of 87°C. Experts say that a permeance of at least 1000 GPU and selectivity of at least 70 would be necessary for economic operation of a CO₂/N₂ separation membrane in industry. This novel membrane overcomes the deficiencies of amine absorption and the deficiencies of currently available membrane separation technologies.

Commercial Applications

• Oil and gas production and processing
• Power plant operation

Benefits/Advantages

• Lower operating cost and more environmentally friendly than separation by amine absorption
• High permeance and selectivity
• Operates effectively at high temperature
• Easy to operate