Attrition and cyclic CO2 Capture of CaO Pellets with Aluminates under Pressurized Carbonation

摘要

Recent attempts to improve the attrition resistance and CO2 uptake of Ca-based sorbent by making pellets with aluminates have succeeded in enhancing their effectiveness. The effects of parameters on sorbent attrition were investigated.Batch experiments were also conducted in a fluidized bed at optimal reaction conditions from previous studies (Carbonation: 0.5MPa and 700℃ in 15% CO2/air balance for 15min;Calcination: 0.lMPa and 950℃ in air for 10 min). The pore structure characteristics (BET,BJH) were measured as a supplement to the attrition and reaction studies.Results showed that the mechanical property of the pellets with the particle size of 1.0-1.43mm were greatly enhanced,especially for the pellet made from CaO-0.5% CLS.A slow decay in CO2 capture capacity of the sorbents was observed after making pellets during the first few cycles.It was attributed to attrition of sorbents and the exposure of inner core of the CaO sorbents,which are in favor of CO2 capture. The pore structure showed that its BJH pore volume and BET surface area did not change much,which benefits CO2 uptake of the sorbents during the cycling.