Effects of moisture content and CaO on municipal solid waste pyrolysis in a fixed bed reactor

• Three single MSW components were respectively pyrolyzed in a fixed bed reactor.
• Moisture reduces H2 but improves tar in bamboo and paper pulp pyrolysis without CaO.
• Moisture improves H2 but reduces tar in PE pyrolysis without CaO.
• CaO promotes H2 and reduces tar in all three single MSW components pyrolysis.

Experiments of municipal solid waste (MSW) pyrolysis were carried out in a self-design fixed bed reactor. Polyethylene (PE), paper pulp and bamboo (chopsticks) were adopted to represent three major components in MSW in the experiments. The effects of moisture content (0, 50% and 66.7%) and CaO (0, 2 g and 4 g) on product composition and lower heating value (LHV) of syngas were investigated. The temperature was set at 900 °C and each MSW sample was 4 g in each test. The results indicated that increasing moisture content led to lower H2 concentration but higher tar yield in paper pulp and bamboo pyrolysis, but the influence was converse in PE pyrolysis; the addition of CaO promoted H2 production but reduced tar yield; the maximum LHV of syngas was achieved at zero moisture content in bamboo and paper pulp pyrolysis, while that was achieved at 66.7% moisture content in PE pyrolysis.