Efficient Carbon Dioxide Capture Of Sepiolite Adsorbent Modified By Aminosilane

In this work,sepiolite（SEP）adsorbent carrier for industrial use was pretreated with hydrochloric acid,and then four different doses of APTS,APTES,AEAPTS and TRI were used as grafting agents for the pretreated sepiolite to prepare P-SEP adsorbents with different aminosilane grafting functions.Firstly,four different grafting agents（APTS,APTES,AEAPTS,TRI）were used to study the effects of different modification methods on carbon dioxide adsorption capacity,carbon dioxide adsorption isotherm and recycling performance.The results of orthogonal experiment showed that:the modification temperature was 85℃,the reaction time was 20 h,the grafting ratio was 30%,APTS and AEAPTS grafting agent were selected when the adsorption temperature was 30℃,and the orthogonal influence factor was the highest.The optimum grafting ratio of sepiolite grafted APTS and AEAPTS with other solid amine adsorbents,carbon dioxide adsorption capacity,adsorption temperature variation trend,thermal stability and recycling performance were compared and analyzed.The results of APTA and AEAPTS loading and adsorption temperature experiments showed that when the concentration of ATPS was 30 wt%（30%-APTS-P-SEP）,the adsorption capacity of carbon dioxide per gram of adsorbent was1.33 mmol at 30℃;and when the grafting ratio of AEAPTS was 0.3 g（0.3 g AEAPTS-P-SEP）,the carbon dioxide adsorption capacity of the adsorbent was 1.43mmol/g at 30℃,and the regeneration ability was good and stable.The adsorbent samples were characterized by N₂adsorption/desorption,TEM,X-ray diffraction,Fourier transform infrared spectroscopy and thermogravimetric analysis.The increased surface area and pore volume of SEP can effectively immobilize APTS in its channel.The comprehensive results show that although the adsorption capacities of0.3 g AEAPTS-P-SEP and 30%-APTS-P-SEP are not very outstanding,the cyclic adsorption stability and thermal stability of APTS and AEAPTS are better than those of the same type of solid amine adsorbents,and their comprehensive performance are better than those of the same type of adsorbents.Therefore,APTS and AEAPTS grafted functional P-SEP（30%-APTS-P-SEP and 0.3 g AEAPTS-P-SEP）can be used as a kind of promising carbon dioxide capture materials after combustion.