Abstract:
The sulfur content of pyrite in coal is high, and it is directly used for coal chemical looping combustion, and its migration is complicated, causing many adverse effects, which needs to be paid attention to. Select Liuzhi Coal (LZ) in Guizhou Province, deash it by pickling and remove pyrite sulfur directionally, then add quantitative pyrite model compound as fuel (LZ-DP+FeS
2), self-made CuFeMnO
4 composite oxygen carrier, In the double-temperature tube furnace, the transfer of oxygen, the evolution of sulfur and the interaction between the two reacted at different temperatures were systematically studied. The results show that the doping of Mn effectively enhances the reduction of Fe
3+ in CuFeMnO
4, the transfer of oxygen and its reactivity; When LZ-DP+FeS
2 coal is pyrolyzed alone, pyrite sulfur evolves complexly and produces different gaseous sulfur components such as H
2S, SO
2, COS and CS
2, but when a certain amount of CuFeMnO
4 is added, it decomposes and releases O
2 successively and transfers the lattice oxygen in it, so that all kinds of gaseous sulfur are fully oxidized at high temperature to form more SO
2. Multiple cycle experiments show that CuFeMnO
4 has enhanced directional sulfur fixation ability while maintaining good regenerative ability, and has great application potential in coal chemical looping combustion.