Coal gasification fine slag (FS) is an inevitable by-product in the gasification process. The preparation of activated carbons (ACs) can realize the value-added utilization of FS. In this work, FS with about 70 % ash yield was prepared to ACs through KOH activation and then used to CO₂ capture. The residual carbon (RC) obtained from acid-treatment of FS was also to fabricate ACs. The ACs had interconnected macropores and micro-mesopores structure. The ACs were characterized using adsorption of nitrogen, SEM, TEM, Raman spectra, XRD, and TG. The optimized FS-based AC had a specific surface area of 1187 m²/g and a pore volume of 0.89 cm³/g. Furthermore, at the same ash yield, the surface area of FS-based ACs was larger than that of RC-based ACs. Experimental evidence presented that abundant metallic elements were leached using the impregnation method to mix KOH and raw material. Additionally, they could react with the carbon matrix and catalyzed the activation reactions to promote the development of pore structure. The ACs showed well CO₂ adsorption performance. FS2−800-60 exhibited a high CO₂ capture of 4.01 and 2.53 mmol/g at 0 and 25 °C. Additionally, the ACs showed a high adsorption rate that CO₂ adsorption uptake almost reached constant values within two minutes. All these results illustrate that ACs prepared from FS could be high efficiency and cost-effective adsorbent for CO₂ capture.

煤气化细渣（FS）是气化过程中不可避免的副产物。活性炭的制备可以实现FS的增值利用。在这项工作中，通过KOH活化将具有约70％灰分产率的FS制备为AC，然后用于CO ₂捕集。通过FS的酸处理获得的残余碳（RC）也用于制造AC。AC具有相互连接的大孔和微中孔结构。使用氮气，SEM，TEM，拉曼光谱，XRD和TG表征AC。优化的基于FS的AC具有1187m ² / g的比表面积和0.89cm ³的孔体积/G。此外，在相同的灰分产率下，基于FS的AC的表面积大于基于RC的AC的表面积。实验证据表明，使用浸渍法将丰富的金属元素浸出以混合KOH和原料。另外，它们可以与碳基质反应并催化活化反应以促进孔结构的发展。AC显示出良好的CO ₂吸附性能。FS2-800-60在0和25°C下显示出4.01和2.53 mmol / g的高CO ₂捕集率。另外，AC显示出高的吸附速率，使得CO ₂吸附吸收在两分钟内几乎达到恒定值。所有这些结果表明，由FS制备的AC可能是高效且经济高效的CO吸附剂_2次捕获。