Catalytic fast Co-Pyrolysis of sewage sludge−sawdust using mixed metal oxides modified with ZSM-5 catalysts on dual-catalysts for product upgrading

Catalytic fast co-pyrolysis of sewage sludge and sawdust was performed using Py/GC-MS for pyrolytic product upgrades. Metal oxides (NiO and MoO₃) and ZSM-5 catalysts had been introduced into single catalytic pyrolysis. The combination of NiO + MoO₃ in mixed metal oxides (MMOs) was modified with ZSM-5 under a dual-catalyst with different catalytic layouts. In the pyrolysis process, the metal oxides specifically promoted the formation of phenols, ketones, and furans. ZSM-5 was proven to be more effective in producing aromatic hydrocarbons and phenols and in reducing the oxygenated compounds. The combination of MMOs with ZSM-5 effectively improved product distribution by increasing the production of aromatics and phenols. MMOs promoted the aromatics selectivity of undesirable PAHs (70.5%), however, the addition of ZSM-5 to MMOs appeared to reduce and inhibit the formation of PAHs by 0.85%. The highest yield of aromatics was obtained by the layout of the ZSM-5/MMO dual catalysts layout which was 21.6%. Dual catalysts of MMOs and ZSM-5 in separated layout created promising effects in further increasing the production of aromatic hydrocarbons and phenols compared to the mixture of MMOs modified ZSM-5.