Pilot-scale production of mesoporous silica-based adsorbent for CO2 capture

Abstract

This study presents a pilot-scale spray drying system designed to manufacture spherical mesoporous silica particles (MSP) that is capable of producing up to 100g per hour. The MSP fabricated via a nozzle pressure of 4kg/cm2 and a drying temperature of 200°C possess a high specific area of 1012m2/g, a narrow pore size distribution with an average pore diameter of 2.4nm, and large pore volume of 0.81cm3/g. They were further modified with a tetraethylenepentamine (TEPA-MSP) to enhance CO2 adsorption selectivity from gas streams. The adsorption capacity of 15% CO2 on TEPA-MSP was significantly influenced by adsorption temperature and water vapor of air streams, and reached a maximum of 87.05mg/g (1.98mmol/g) at 60°C and 129.19mg/g (2.94mmol/g) at a water vapor of 6.98%. The adsorption capacities and the physicochemical properties of TEPA-MSP were preserved through 20 cycles of adsorption–desorption operation. A comparative study revealed that the TEPA-MSP had better adsorption performance of 15% CO2 than the TEPA-modified granular activated carbon and zeolite. These results suggest that the TEPA-MSP can be stably employed in the prolonged cyclic CO2 adsorption and that they possess good potential for CO2 capture from flue gas.