Coal gasification fine slag (FS), classified as an industrial solid waste, is composed of residual carbon (RC) and slag particles (SP). The simultaneous utilization of RC and SP to prepare hierarchical porous composite (HTC) could realize the value-added utilization of FS. The role of SP in FS on HTC preparation is extremely vital and worthy of study. In this paper, FS was successfully used to synthesize HTCs for CO 2 adsorption. Orthogonal experiment was conducted to study the effect of SP on the properties of the synthesized HTCs. The changes of impregnation conditions could be effective for developing pore structure of HTCs and the surface area increased by 226 m 2 /g. Furthermore, the role of SP in FS on HTCs preparation was analyzed. After chemical activation, there was generation of many new pores in SP that the surface area and pore volume could reach 302 m 2 /g and 0.271 cm 3 /g. Besides, the leached metallic elements in the process of KOH impregnation could affect the mesopore development. The HTCs also proved to be attractive for CO 2 capture. The highest CO 2 adsorption capacity of 2.35 mmol/g at 25 °C was achieved with 5-PH-FSHCT sample. It also exhibited good selectivity of CO 2 over N 2 of 9.5. Furthermore, the sample had not only fast adsorption kinetics that it reached saturation levels in about 1.5 min, but also excellent regeneration efficiency 97% after ten cycles. All results suggest that FS has a great potential to be reused as a high performance adsorbent for practical and industrial CO 2 adsorption applications.
Zekai Miao,Xinran Han,Hao Ge,Rui Wu,Congchao Zhang,Hai Zhu,Shengping Wang
Coal gasification fine slag (FS), as a by-product of coal gasification process, contains residual carbon (RC) and slag particles (SP). The two components can be used as raw materials to prepare porous materials. Whereas, during simultaneous utilization of RC and SP, their synergistic mechanism remains unclear. The research on the mechanism is beneficial for synthesis of the high performance CO 2 adsorbent. Herein, FS was treated by chemical activation followed by hydrothermal treatment to prepare porous composite material (FS-25-HA-HT) which had high surface area of 2194 m 2 /g and pore volume of 2.095 cm 3 /g. After chemical activation, the SP could be completely dissolved in alkali solution within around 20 min. The adsorption of porous carbon in alkali solution and strong electrostatic attraction from oxygen groups with the Si, Al-containing groups led to the increase of the concentration of Si (9825 ppm) and Al (2986 ppm) in subnatant during hydrothermal treatment. Thus, the aluminosilicate could deposit on the surface of porous carbon and pile up to form new crystal layer, which could increase the surface area and the CO 2 adsorption capacity. The adsorbent met both high uptake (5.32 mmol/g at 0 °C) and fast adsorption kinetics (adsorption equilibrium time of 3 min.). The clarification of synergism during simultaneous utilization of RC and SP offers new routes to prepare high performance adsorbent.
危险品化学品经营许可证（带存储）