Development of novel nano/meso-porous materials for CO2 capture & separation

Abstract

This chapter presents a study in which amine-modified mesoporous silica molecular sieve SBA-15 is prepared as a “water-tolerant adsorbents,” which can adsorb CO2 in the presence of water vapor. Moreover, the study also examines the applicability for pressure (and/or temperature) swing adsorption (PTSA) process by CO2 adsorption–desorption measurement in a flow system. In this study, amine-modified mesoporous silica as novel adsorbent is prepared by blending various aminosilanes; i.e., (3-aminopropyl) triethoxysilane (APS), N-(2-aminoethyl)-3-aminopropyltriethoxysilane (AEAPS) and (3-trimethoxysilylpropyl)diethylenetriamine (TA), on mesoporous silica, SBA-15. This mixture is capable for CO2 capture and separation from flue gases. Pore walls of SEA-15 are modified uniformly with these aminosilanes, and relatively high surface area and uniform pore size are retained. Adsorption capacities of CO2 in the presence of water vapor are compared with that in the absence of water by a flow method. It was found that adsorption capacities of amine-modified SBA-15 under the wet condition are comparable to that under the dry condition. In particular, the adsorption capacity of TA anchored SBA-15 reaches 1.28 molkg-1 in presence of water vapor at 333 K. In addition, these adsorbents are completely regenerated by heating up to 423 K in the He flow.