New CO2 Sorbent Synthesized with Nanoporous TiO(OH)2 and K2CO3

Abstract

The objective of this study is to develop a new cost-effective CO2 sorbent, K2CO3/TiO(OH)2 or KTi, with inexpensive and widely available K2CO3 and nanoporous TiO(OH)2 as supporting material. The performance of KTi CO2 capture was evaluated using a fixed-bed tubular reactor under different experimental conditions, including sorption temperature, flow rate, and moisture concentration of flue gas. Use of TiO(OH)2 as a support for K2CO3 leads to a significant increase of CO2 sorption capacity per unit of K2CO3 by about 37 times. The optimal K2CO3 loading on TiO(OH)2 is 30 wt %. The highest sorption capacity achieved with KTi is 1.69 mmol of CO2/g of KTi, whereas the theoretical sorption capacity of KTi with the prepared TiO(OH)2 could be as high as 3.32 mmol of CO2/g of KTi. The enthalpy change of the KTi-based CO2 sorption is −28.51 kcal/mol. Moreover, KTi is regenerable and stable. Therefore, KTi is a promising CO2 sorbent.