Low-cost preferential different amine grafted silica spheres adsorbents for DAC CO_(2)removal

DAC CO_(2)capture is gaining wide attention as one of the most difficult carbon approaches to tackle climate change.In this work,different pore-size silica spheres were grafted using different amine groups such as APTES,APTMS,and Diamine.Herein,all samples based on the wet and dry grafting method were used for CO_(2)adsorption isotherm at room temperature and pressure(298 K and 1 bar).The sample based on the wet grafting(Silica-APTES-W)sample shows the highest CO_(2)uptake 1.67 mmol/g.Also,the adsorption isotherm of the Silica-APTES-W sample was showed a high capacity of CO_(2)1.2 mmol/g at 25℃,which describes the strong physical interaction between CO_(2)and amine.The isosteric adsorption of Silica-APTES-W also confirmed that the physical adsorption was dominant because of low adsorption heat ranging from 23 to 37 k J/mol.Also,the fixed bed experiment was conducted with 2000 ppm CO_(2)that obtains the optimal working capacity 4.5 m L/g with the lowest regeneration temperature 90℃.It was shown that Silica-APTES-W sample was superior performance for DAC CO_(2)capture in practical applications.