Utilization of coal gangue for preparing high‐silica porous materials with excellent ad/desorption performance on VOCs

Abstract

BACKGROUND: Coal gangue causes a series of environmental problems due to its low utilization rate and high amount of hoarding. However, the preparation of porous materials with coal gangue is an effective method of resource utilization. Mesoporous silica and meso-microporous ZSM-5 were prepared with alkali melting activation-acid leaching and hydrothermal synthesis, respectively. The orthogonal experiment was used to explore the optimal preparation conditions for mesoporous silica. Meso-microporous ZSM-5 were characterized with instruments. The adsorption and desorption performance of the porous material was explored by dynamic adsorption/desorption on volatile organic compounds (VOCs).RESULTS: The optimal preparation conditions for mesoporous silica are a roasting temperature of 800 °C, mass ratio of coal gangue to sodium carbonate of 1:0.6, and sulfuric acid leaching of 4 mol L −1 . The characterization results show that the molecular sieve has a superior specific surface and a certain amount of mesoporous pores due to the addition of the appropriate mesoporous template. The results of toluene dynamic adsorption experiments show that the meso-microporous ZSM-5 (ZSM-5-0.025PAC) has excellent adsorption and desorption performance (the adsorption capacity is up to 47.02 mg g −1 ), water resistance (the adsorption capacity decreased only 4.64%), and renewability (the adsorption and desorption efficiency is up to 95% and 97%).CONCLUSION: The porous materials prepared presented excellent VOCs ad/desorption performance, which has good industrial application prospects. The research provides a novel approach for the utilization of coal gangue.

Management of typical VOCs in air with adsorbents: status and challenges

“…Han et al 87 introduced a water-soluble polyacrylamide (PAM) hydrogel into the SAPO-34 synthesis system and prepared hierarchical SAPO-34 with both micropores and mesopores, whose catalytic life is prolonged by about three times with highly enhanced adsorption performance. Jiang et al 88 reported meso–microporous ZSM-5 by hydrothermal synthesis, and excellent adsorption and desorption performance (the adsorption capacity is up to 47.02 mg g −1 ), water resistance (the adsorption capacity decreased only 4.64%), and renewability (the adsorption and desorption efficiency are up to 95% and 97%, respectively) were achieved.…”

Fabrication and application of porous materials made from coal gangue: A review

“…Combined methods, including the alkali fusion–hydrothermal method, ultrasonic–hydrothermal method, and ball milling−hydrothermal method, which have better performance than traditional methods, have also been tested 54,124 . As shown in Table 3, the synthetized zeolite types include NaA, 53,120,123,125 NaX, 52,118,124,126,127 NaY, 119 SSZ‐13, 128 ZSM‐5, 129 magnetic zeolite, 54 and zeolite/activated carbon composites 120,130 …”

Study on the Influence of Particle Size Distribution on the Separation of Pyrite from Coal Gangue by Jigging

“…Coal gangue is a solid waste generated during coal mining [1], characterized by its low carbon content, which leads to a range of environmental issues due to its limited utilization and extensive accumulation [2][3][4]. Moreover, the presence of pyrite in coal gangue increases the risk of spontaneous combustion as sulfur easily oxidizes, further hindering comprehensive utilization [5,6].…”