Nitrogen-Containing Porous Carbon (image) Rice University Caption Particles of nitrogen-containing porous carbon are able to capture carbon dioxide from natural gas under pressure at a wellhead by polymerizing it, according to researchers at Rice University. When the pressure is released, the carbon dioxide returns to gaseous form. Credit Tour Group/Rice University Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.