Basic intensity regulation of layered double oxide for CO2 adsorption process at medium temperature in coal gasification

Abstract

High purity hydrogen for integrated gasification combined cycle power generation (IGCC) can be produced by efficient adsorption of CO2 after water gas shift reaction in coal gasification. Based on adjustability of composition in layered double hydroxides (LDH) precursor, basicity intensity was modified and exhibited different adsorption capacity. Relationship among basic sites, CO2-bound modes, and adsorption capacity were established. Furthermore, by utilizing LDH anionic exchangeability, we introduced laurate ion into LDH interlamellar, and further mediated surface structure using methyl cellulose with long carbon chain. As-obtained Mg3Al-LDO-C12-MC effectively increased the number of medium/strong basic sites. Consequently, CO2-adsorption capacity at medium temperature of 300 °C was further increased to 0.85 mmol/g with the maximum rate of 0.37 mmol/g·min. This work develops a strategy to regulate basic site of adsorbents according to structural mechanism for CO2 elimination under medium temperature, and thus improve adsorption performance in industrial coal gasification process.