Synthesizing and Characterizing a Mesoporous Silica Adsorbent for Post-Combustion CO2 Capture in a Fixed-Bed System

MCM-41, a mesoporous silica with a high surface area and hexagonal structure, was synthesized, and commercial nano-silicon dioxide (SiO2) was used as a solid adsorbed in post-combustion CO2 capture. The CO2 adsorption experiments were conducted in a fixed-bed adsorption system using 5-15 vol.% CO2/N-2 at a flow rate of 100 mL/min at varying temperatures (20-80 degrees C) and atmospheric pressure. Analyses (X-ray diffraction, nitrogen adsorption-desorption isotherms, Fourier-transform infrared spectroscopy, and transmission electron microscopy (TEM)) revealed that the synthesized MCM-41 has mesoporous characteristics: a high surface area and large pore volumes. The CO2 adsorption capacity of MCM-41 and commercial nano-SiO2 increased considerably with increasing CO2 concentration and temperature, peaking at 60 degrees C. Below 60 degrees C, dynamics rather than thermodynamics governed the adsorption. Increasing the temperature from 60 to 80 degrees C decreased the adsorption capacity, and the reaction became thermodynamically dominant. Additionally, compared with commercial nano-SiO2, the MCM-41 sorbent demonstrated superior regenerability and thermal stability.

Automated summary

In this study, MCM-41, a mesoporous silica with high surface area and large pore volumes, was successfully synthesized and used for post-combustion CO2 capture. The results showed that the CO2 adsorption capacity of MCM-41 and commercial nano-SiO2 increased with increasing CO2 concentration and temperature, reaching a peak at 60 degrees C. Additionally, MCM-41 sorbent demonstrated superior regenerability and thermal stability compared to commercial nano-SiO2.