Adsorption of CO₂, CH₄, and N₂ on activated carbon now is considered as a promising approach for greenhouse gas capture and/or separation. The objective of this study was to determine whether the residual carbon in lignite coal liquefaction could be used as an inexpensive and effective replacement for activated carbon. The chemical structure and functional groups transformation of residual carbon were analyzed using Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR). The adsorption properties of CO₂, CH₄, and N₂ on the residual carbon were investigated at temperatures of 0°C, 10°C and 20°C up to a pressure of 100 kPa. The adsorption kinetics and thermodynamics were also discussed from the uptake curves with the isothermal model. The separation of CO₂/CH₄, CH₄/N₂, and CO₂/N₂ binary mixtures was determined using ideal adsorbed solution theory (IAST) model. At 0°C and 100 kPa, the simulated selectivities of CO₂/CH₄, CH₄/N₂, and CO₂/N₂ in 50/50 vol.% were 35, 11, and 38, respectively. Significant increased values than have previously been reported in the literature. The residual carbon from solvothermally treated lignite coal could be developed for greenhouse gas capture or biogas purification to achieve fuel grade quality.

现在认为活性炭上CO ₂，CH ₄和N _2的吸附是一种有前途的温室气体捕获和/或分离方法。这项研究的目的是确定褐煤煤液化中的残留碳是否可以用作活性炭的廉价有效替代品。残留碳的化学结构和官能团转化采用傅立叶变换红外光谱（FTIR）和核磁共振（NMR）进行了分析。研究了温度为0时CO ₂，CH ₄和N ₂在残留碳上的吸附性能。摄氏10度°C和20°C达到100 kPa的压力。还利用等温模型从吸收曲线讨论了吸附动力学和热力学。使用理想的吸附溶液理论（IAST）模型确定了CO ₂ / CH ₄，CH ₄ / N ₂和CO ₂ / N ₂二元混合物的分离。在0在50℃和100kPa下，CO ₂ / CH ₄，CH ₄ / N ₂和CO ₂ / N ₂在50/50体积％中的模拟选择性分别为35、11和38。与以前的文献报道相比，数值显着增加。溶剂热处理过的褐煤中的残留碳可用于温室气体捕集或沼气净化，以达到燃料级的质量。