Preparation and characterization of a porous silicate material using a CO2-storage material for CO2 adsorption

A porous silicon material (PSM) was successfully prepared by using a CO2-storage material (CO2SM) as raw material, in which Na2SiO3 was used as a silicon source and the CO2SM was used as an acid source. The effects of CO2SM dosage, particle size, post-treatment temperature, and post-treatment time on CO2 adsorption capability was systemically evaluated, and the optimum condition was confirmed by response surface experiments as follows: 10 g CO2SM dosage, 50 mL 0.5 M Na2SiO3, 40-160 mesh, the post-treatment temperature of 80 degrees C, and the post-treatment time of 36 h with the maximum adsorption capacity of 9.74 mg CO2/g adsorbent for 8% CO2/N-2 at 25 degrees C. Based the optimum condition, SiO32- extraction from coal gangue was used as the silicon source to prepare the PSM with the maximum adsorption capacity of 9.02 mg CO2/g adsorbent for 8% CO2/N-2 at 25 degrees C. Next, PSM was impregnated with ethanediamine (EDA), after that the CO2 adsorption capacity increased to 17.14 mg CO2/g adsorbent. In addition, the optimum PSM was characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, and N-2 adsorption desorption isotherms. Although the resulting materials showed a low adsorption capacity, its silicon source was inexpensive, which was of significance in the rational utilization of coal gangue. (C) 2017 Elsevier B.V. All rights reserved.