Novel technique route of coal gasification with Co ₂ capture using Cao sorbents via three-stage interconnected fluidized beds

To modify the temperature mismatch between coal gasification and CO ₂ capture in one gasifer, a novel technique route of coal gasification with CO ₂ capture via three-stage interconnected fluidized beds (ICFB) was proposed. The three-stage ICFB consisted of a gasifier, an adsorber, and a calcinator, which separated the coal gasification, CO ₂ capture, and sorbents regeneration. Also, it could keep the three processes performing at the rational reaction temperatures. A process simulation was constructed on the basis of the chemical and phase equilibrium method using Aspen Plus, and the effects of the adsorption temperature and the steam/coal ratio on adsorption products composition, CO ₂ capture efficiency, H ₂ yield, and carbon conversion ratio were investigated. The results indicate the adsorption temperature range 600-630 °C and the steam/coal mass ratio range 2.1-2.7 are the possible optimal reaction conditions. The modified process shows an optimal coal gasification with increasing H ₂ concentration of 32.60% and capturing CO ₂ efficiency of 85.17%, compared with the coal gasification with CO ₂ capture in one gasifier.