Synthesis of mesoporous silica from bottom ash and its application for CO_2 sorption

摘要

A supernatant solution of silicate species extracted from bottom ash in a power plant was used to prepare a mesoporous silica by the synthesis protocol of SBA-15. XRD, N, adsorption-desorption, and TEM confirmed a disordered mesopore structure. The pore volume and average pore size of the product were significantly larger than SBA-15 prepared using pure chemicals, and complementary textural mesoporosity was detected. When the mesoporous silica was tested for carbon dioxide sorption after polyethyleneimine (PEI) impregnation, substantially higher CO_2 sorption capacity (169 mg CO_2/g-sorbent) was achieved than that of PEI-impregnated pure SBA-15 under the same test conditions. High CO_2 sorption capacity was maintained when the gas composition was changed to 15% CO_2, and the hybrid material exhibited satisfactory performances during the 10 recycle runs.