A new carbide slag （CS） seriflux utilization was proposed. The flue gas from a coal-fired plant was first bubbled into CS seriflux for CO2 capture. The obtained carbonated carbide slag seriflux （CCSS） was dried and utilized as a CO2 sorbent in the calcium looping cycles. The CO2 capture behavior of the dried CCSS and the raw CS was investigated in a dual fixed-bed reactor and a thermo- gravimetric analyzer. The effects of carbonation time, calcination temperature and carbonation temperature on CO2 capture performance of CCSS in the multiple carbonation/ calcination cycles were studied. The results show that the CO2 capture capacity of CCSS was higher than that of CS. Calcined at 950 ℃, CCSS shows better carbonation reactivity than CS, which benefits CO2 capture under severe calcination conditions. In the range of 700 to 725℃ for the carbonation, CCSS shows the optimal CO2 capture performance. The calcined CCSS shows better porous microstructure than the calcined CS. The calcined CCSS exhibits a larger surface area and pore volume in the cycles, which favors a higher CO2 capture capacity in the multiple cycles.
A kind of industrial solid waste, i.e., carbide slag, was used as CaO precursor to synthesize CO2 sorbent. The highly reactive synthetic sorbent was prepared from carbide slag, aluminum nitrate hydrate and glycerol water solution by the combustion synthesis method. The results show that the synthetic sorbent exhibits a much higher CO2 capture capacity compared with carbide slag. The CO2 capture capacity and the carbonation conversion of the synthetic sorbent are 0. 38 g/g and 0. 70 after 50 cycles, which are 1.8 and 2. 1 times those of carbide slag. The average carbonation conversion and the CO2 capture efficiency of the synthetic sorbent are higher than those of carbide slag with the same sorbent flow ratios. The required sorbent flow ratios are lower for synthetic sorbent to achieve the same CO2 capture efficiency compared with carbide slag. With the same sorbent flow ratio and CO2 capture efficiency, the energy requirement in calciner for the synthetic sorbent is less than that for carbide slag.
