Preparation and CO₂ Adsorption Properties of Porous Particles Based on Alkaline Solid Wastes

Abstract

Goaf filling is an effective method of preventing goaf disasters in mines. If the filling material can mineralize and absorb a large amount of CO 2 , then the goaf will provide a huge amount of space for carbon storage, which will help to achieve carbon peaking and carbon neutrality. The purpose of this article is to prepare a kind of porous particle with high porosity and a large specific surface area that can be used to fill the mined-out area and adsorb a large amount of CO 2 by using the mineralized solid waste as the aggregate. Taking the compressive strength and CO 2 adsorption capacity as the objective function, a chemical foaming method and an orthogonal experiment were used to determine the optimal ratio of porous particles. The results showed that when the masses of carbide slag, oleic acid, cetyltrimethylammonium bromide, sodium hypochlorite, and water were 19.5, 0.3, 0.07, 1.35, and 15 g, respectively, the pore sizes of the prepared porous particles had a gradient distribution, i.e., micropores, mesopores, and macropores accounted for 18.75, 80.93, and 0.32%, respectively. In addition, the compressive strength reached 79.4 N, and the static CO 2 adsorption capacity was 117.43 cm 3 /g. The superimposed calculation of the adsorption capacity and mineralization capacity showed that 1 ton of solid waste can theoretically store approximately 0.66 ton of CO 2 . The pseudo-first-order kinetic model can well fit the adsorption process of an adsorbent for CO 2 , which proves that the adsorption process of adsorbent for CO 2 is a physical adsorption mechanism. The porous particles prepared based on solid waste are harmless and simple in the preparation process. They can fill the underground space of mines after adsorbing CO 2 and realize the integration of solid waste utilization, carbon storage, and underground space disaster management, with significant social, economic, and ecological benefits.

One-Step Synthesis of 3D Pore-Structured Adsorbent by Cross-Linked PEI and Graphene Oxide Sheets and Its Application in CO2 Adsorption

“…The q a of GO-PEI­(1800,1) was compared with that of graphene-based adsorbents commonly found in the literature (Table ). Under the same CO 2 partial pressure conditions, GO-PEI­(1800,1) exhibited a greater q a (2.18 mmol/g) compared to TEPA grafted carboxy-activated graphene oxide (1.2 mmol/g), which is almost double. It should be noted that most adsorption experiments in the literature were performed with pure CO 2 at 1 bar or higher pressure.…”

“…In recent decades 3D graphene-based materials have emerged as a response to preserve the large surface area of 2D graphene and obtain tunable pore size and large pore volume. The high specific surface area, porous structure, and highly tunable surface functional groups of 3D graphene oxide (GO) based materials endow the material with the potential to be an excellent adsorbent. − Since adsorption technology is a promising capture technology for the greenhouse gas CO 2 , researcher have conducted continuous studies on CO 2 adsorbents, − but have not been able to find commercially applicable adsorbents so far. With the emergence of 3D graphene-based materials, people began to apply this material to the preparation of CO 2 adsorbent, and gradually carried out research on the CO 2 adsorption performance of this adsorbent.…”