Potassium-Based Regenerable Solid Sorbents for CO2 Capture

摘要

The potassium-based sorbents were prepared by impregnation with potassium carbonate (30 wt.% K2CO3 ) onto supports such as activated carbon (AC), Al2O3, CsNaX, SiO2 , MgO, CaO, and TiO2. CO2 capture capacities and regeneration properties of those sorbents were measured in a fixed bed reactor at various temperature conditions (CO2 absorption at 60 Oc and regeneration at 200 Oc). The KTiI30 sorbent developed in this work showed excellent CO2 capture capacity of 92.9 mg CO2/g sorbent, which was 97% of the theoretical value, in the presence of 9 vol.% H2O without pre- treatment, unlike KACI30. In addition, it was possible to regenerate the spent sorbent even within a low temperature range between 130 and 150 Oc, unlike KAlI30 and KMgI30. The regeneration temperature of the KTiI30 sorbent was lower than that of KAlI30 and KMgI30 due to the formation of the KHCO3 crystal structure only, which was easily converted to the K2CO3 phase at low temperature, after CO2 absorption.