吸附法是碳捕集的主要途径之一。氨基功能化多孔材料作为重要的CO2吸附剂,通常以价格高昂的介孔分子筛为载体,这极大地限制了吸附法的规模化应用。因此,降低载体成本对于碳捕集有着重要的现实意义。使用盐酸处理煤气化细渣(FS)制得酸浸渣材料(AFS),进一步嫁接3-氨丙基三乙氧基硅烷(APTES)制备氨基功能化CO2吸附材料(AFS-A-x)。利用热重分析(TG-DTG)、傅立叶变换红外光谱分析(FTIR)和低温N2吸脱附等方法对样品进行表征,利用高压气体吸脱附仪(PCTPro)考察FS,AFS和AFS-A-x的CO2吸附性能,建立等温吸附模型,并计算等量吸附热。结果表明:相较于FS,AFS的硅羟基含量更高,孔隙结构更丰富,更适合做嫁接原材料。在60℃,0.1MPa的吸附条件下,AFS-A-3材料的CO2吸附量较AFS材料的CO2吸附量提高了19.6%,达到0.61mmol/g,在30℃~70℃的温度范围内,AFS-A-3的吸附性能随温度上升而下降;相同条件下,在低压段(0MPa~0.015MPa)AFS-A-3的吸附能力明显高于AFS的吸附能力,说明AFS-A-3在低CO2分压条件下有更高的应用潜力;经过十次吸脱附循环后,AFS-A-3在60℃,0.1MPa条件下对CO2的吸附量下降了5%;AFS和AFS-A-3的等温吸附曲线可用Langmuir模型较好描述。相比于AFS,嫁接改性的AFS-A-3对CO2的等量吸附热明显增加,据此推断吸附类型由物理吸附主导转变为物理吸附与化学吸附共同作用。

Adsorption is one of the main methods for carbon capture. Solid amino-func- tionalized adsorbents are important CO adsorbents, typically using expensive mesoporous mole- cular sieves as the carrier, which greatly limits the scalability of adsorption methods. Therefore, reducing carrier cost has important practical significance for CO capture. In this study, acid leac- hing residue (AFS) was prepared by treating coal gasification fine slag (FS) with hydrochloric acid and was further grafted with 3-aminopropyl triethoxysilane (APTES) to create an ammonia functionalized CO adsorption material (AFS-A-x). The samples were characterized using ther- mogravimetric analysis (TG-DTG), Fourier transform infrared spectroscopy (FTIR) and N ad- sorption-desorption at low temperatures. The CO adsorption properties of FS, AFS and AFS-A- x were investigated by high pressure gas adsorption-desorption instrument (PCTPro). The ad- sorption isothermal model was established, and the equivalent adsorption heat was calculated. The results show that compared with FS, AFS has higher silica hydroxyl content and more abun- dant pore structure, which was more suitable for grafting. Under the adsorption condition of ℃ and 0.1 MPa, compares to AFS ,the CO adsorption capacity of AFS-A-3 is increased by 19.6% to 0.61 mmol/g. Within the temperature range of ℃ ℃, the adsorption perform- ance of AFS-A-3 decreases with the increasing temperature. Under the same conditions, the ad- sorption capacity of AFS-A-3 in the low-pressure section (0 MPa 0.015 MPa) is significantly higher than that of AFS, suggesting that AFS-A-3 has higher application potential under condi- tions of low CO partial pressure. After ten cycles of adsorption and desorption, the CO adsorp- tion capacity of AFS-A-3 decreases by 5% at ℃ and 0.10 MPa. The isothermal adsorption curves of AFS and AFS-A-3 could be well described by the Langmuir model. Compared with AFS, the graft-modified AFS-A-3 has a significant increase in the equivalent adsorption heat of CO . This suggests a shift in the adsorption type from being predominantly physical adsorption to a combination of both physical and chemical adsorption.