Preparation of K-N co-doped commercial cylindrical carbon via the coal partial steam gasification for CO2 adsorption

Abstract

The formed activated carbon is a promosing carbon based absorbent for CO2 adsorption in fossil energy industrial process. In this paper, the preparation method of commercial formed activated carbon and the partial steam gasification of coal via the addition of K2CO3 and melamine were combined to prepare cylindrical activated carbon with high abrasive resistance and well-developed pore structure. The CO2 adsorption capacity and mechanism of the prepared carbons were also explored. The results showed that the steam gasification reactivity of coal was enhanced by the addition of K2CO3 and melamine. The prepared cylindrical carbons had the abrasive resistance higher than 95% and their specific surface area reached 1451 m2/g after K was added to coal. Nearly 70% of microporous proportion was obtained for the cylindrial carbons from the N doped and K-N co-doped coals as 1.3 times as that from undoped carbon. Both the CO2 chemisorption and physical adsorption were improved by the K/N doping. It was concluded that the N species content and narrow micropore volume (<1 nm) showed the more important role on CO2 total and physical adsorption capacity respectively. Good cyclic stability of CO2 adsorption was also observed for the doped cylindrical carbons.