Synthesis and characterization of porous carbon/mesoporous MCM-41 material from coal gasification fine slag and its CO2 adsorption performance

Coal gasification fine slag (FS) containing residual carbon (RC) and slag particles (SP) can serve as carbon and silica precursor to prepare porous materials. This study reports the high performance porous carbon/mesoporous silica from gasification fine slag for CO 2 capture. Herein, FS was treated by chemical activation followed by hydrothermal treatment to prepare porous carbon/mesoporous MCM-41. The resulting material exhibited a high surface area of 1309 m 2 /g and pore volume of 1.03 cm 3 /g. After hydrothermal treatment, the mesoporous silica exhibited well-ordered hexagonal arrays of mesoporous channels. The physiochemical properties of the mesoporous silica remained nearly unchanged with the variation of hydrothermal parameters in the presence of porous carbon. The porous carbon facilitated the adsorption of dissolved silica, which promoted a second nucleation step, leading to the formation of additional nanoparticles. Those interaction weakened the effect of reaction conditions on the interaction between the precursor silica and surfactant. The porous composite showed excellent CO 2 capture performance, with a breakthrough time of 75 min in the fixed bed and a CO 2 adsorption capacity of 3.016 mmol/g. The CO 2 adsorption kinetics of the composite were consistent with the Avrami kinetic models for porous composites. This work realized the utilization of full-component fine slag to synthesize porous carbon/mesoporous MCM-41 material which was suitable for CO 2 capture.