392871 Novel Porous Carbon Adsorbents for CO2 Capture from Flue Gas and Natural Gas Upgrade

Tuesday, November 18, 2014: 2:10 PM
International 1 (Marriott Marquis Atlanta)
Jun Wang1, Zheling Zeng2, Jiangfeng Yang1,3, Rajamani Krishna4 and Shuguang Deng1, (1)Chemical Engineering Department, New Mexico State University, Las Cruces, NM, (2)State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China, (3)Research Institute of Special Chemicals, Taiyuan University of Technology, Taiyuan, China, (4)Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, Netherlands

A few N-functionalized porous carbon adsorbents were synthesized and characterized for capturing carbon dioxide from flue gas and separating carbon dioxide from natural gas. The hydroquinone and quinone functional groups were grafted into a hierarchical porous carbon framework via Friedel-Crafts reaction for selective capture and removal of carbon dioxide from flue gases and natural gas. Adsorption isotherms of CO2, CH4, and N2 were measured at 1 atm and three different temperatures, and used for predicting the carbon adsorbents’ separation capability by using the Ideal Adsorbed Solution Theory (IAST).  At 298 K and 1 atm, the highest CO2/N2 selectivity value of 26.5 is obtained on the hydroquinone-grafted carbon (OAC-1), which is significant improvement (158.7%) of the pristine porous carbon (OAC-0), and the highest CO2/CH4 selectivity value of 4.6 is obtained on the quinone-grafted carbon (OAC-2), 28.4% better than the pristine porous carbon. The CO2 adsorption capacity on the modified activated carbon was increased from 3.02 mmol g-1 to 3.46 mmol g-1 at 298 K and 1 atm, although the specific surface area was reduced after modification. In addition, transient breakthrough simulations for CO2/CH4/N2 binary mixtures were conducted to demonstrate the good separation performance in a fixed bed adsorber.  The heats of adsorption of carbon adsorbents are lower than other adsorbents, suggesting a low regeneration energy requirement. Overall the new porous carbon adsorbents developed in this work look very promising for flue gas treatment and natural gas upgrading.

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