Thongthai Witoon and Metta Chareonpanich

pp. 403 - 407

Abstract

In the present study, porous silica synthesized using sodium silicate as a low-cost raw material was selected as a CO₂
sorbent. The effects of pore size and amount of silanol content on CO₂
 adsorption capacity were investigated. The physical
properties and surface chemistry (silanol content) of the porous silica products were characterized by means of N₂
-physisorption, Fourier transform infrared spectroscopy and thermogravimetric analysis technique. The pore size of the porous
silica materials did not affect the equilibrium CO₂
 capacity; however the porous silica with large pore size could enhance the
diffusion of CO₂
. The amount of silanol content was found to be a key factor for the CO₂
 adsorption capacity. A greater CO₂
adsorption capacity would be obtained with an increase of the silanol concentration on the surface of the porous silica
materials.