Chemical looping combustion of sewage sludge with oxygen carrier of cement-modified hematite

Chemical looping combustion (CLC) for sewage sludge has a relatively low efficiency using hematite as oxygen carrier. The experiments on improving the reactivity of hematite with cement modified for CLC of sewage sludge in a 1kW_th continuous CLC unit were carried out. Compared to hematite oxygen carrier, the concentrations of unconverted combustible gas rapidly decrease when the cement-hematite is used. Moreover, both carbon conversion and combustion efficiency increase when the cement is added. Although some ash particles deposit on the surface of oxygen carrier and a part of Fe₂O₃ is reduced to FeO, there are no defluidization and sintering problems.