Modification of Activated Carbon Using Nitration Followed by Reduction for Carbon Dioxide Capture.

Activated carbon (AC) samples were modified using nitration followed by reduction to enhance their CO₂ adsorption capacities. Besides characterization of the samples, investigation of CO₂ capture performance was conducted by CO₂ isothermal adsorption, temperature-programmed (TP) CO₂ adsorption, cyclic CO₂ adsorption-desorption, and dynamic CO₂ adsorption tests. Almost all modified samples showed a rise in the amount of CO₂ adsorbed when the comparison is made in unit surface area. On the other hand, some of the samples displayed a capacity superior to that of the parent material when compared in mass unit, especially at elevated temperatures. Despite ~65% decrease in the surface area, TP-CO₂ adsorption of the best samples exhibited increases of ~10 and 70% in CO₂ capture capacity at 30 and 100 °C, respectively. [ABSTRACT FROM AUTHOR]