Characteristics of New Potassium-Based Sorbents Prepared with Nano-Titanium Oxide for Carbon Dioxide Capture

The CO(2) absorption and regeneration properties of novel regenerable potassium-based dry TiO(2) sorbents were measured in a fixed bed reactor at low temperature conditions (CO(2) absorption at 60 degrees C and regeneration at 200 degrees C). The K(2)CO(3)-based sorbent developed in this study showed excellent characteristics in regard to CO(2) absorption and regeneration. It satisfied the requirements of a sorbent: significant CO(2) capture capacity (85 mg CO(2)/g sorbent to 92 mg CO(2)/g sorbent) and fast and complete regeneration at a low temperature condition (1 atm, 150 degrees C). In particular, a K(2)CO(3)-based sorbent prepared (KTi(S-B)I30) by the impregnation of nano-size TiO(2) with K(2)CO(3) showed excellent characteristics in CO(2) absorption without pre-treatment with water vapor. This result was because of the effect of the textural property of the TiO(2) used as a support, which had a uniform pore size distribution in a very narrow range with a maximum of about 100 angstrom, unlike the K(2)CO(3)-based AC sorbent, which showed a very wide distribution ranging from 1 angstrom to 1000 angstrom. In addition, it had a relatively large surface area of about 45.4 m(2)/g. As a result, the CO(2) capture capacity of the sorbent was found to be affected by the pore size of the sorbent, as well as the surface area of the sorbent.