The effect of torrefaction and ZSM-5 catalyst for hydrocarbon rich bio-oil production from co-pyrolysis of cellulose and low density polyethylene via microwave-assisted heating

Highlights: • Bio-oil with 54.94% of hydrocarbons was obtained during catalytic co-pyrolysis of MTC and LDPE. • Selectivity to aromatic hydrocarbons was apparently enhanced in the acquired bio-oils. • A remarkable synergistic effect was observed for catalytic MTC co-pyrolysis. • The promotion of thermal degradation and remarkable lower activation energy were obtained. This study aims to investigate the effect of microwave torrefaction and ZSM-5 catalyst for hydrocarbon rich bio-oil production from microwave co-pyrolysis of cellulose and low density polyethylene (LDPE). FTIR analysis displayed remarkable reductions of active hydroxyl and ether groups in microwave torrefied cellulose (MTC), demonstrating that cellulose was less stable than MTC. GC/MS analysis indicated that the hydrocarbons content was ranged from 18.36% to 54.94% in the obtained bio-oils under different conditions, and the maximum hydrocarbons content (54.94%) which also contained the highest aromatic hydrocarbons (19.49%) was obtained from MTC catalytic co-pyrolysis. Microwave-assisted Thermogravimetric analyzer (MW-TGA) analysis showed that MTC catalytic co-pyrolysis apparently shifted the major thermal degradation to a lower temperature area, an evident synergistic effect was observed during MTC catalytic co-pyrolysis. Kinetics study revealed that the activation energy was significantly reduced from 97.87 kJ/mol to 63.86 kJ/mol for co-pyrolysis and MTC catalytic co-pyrolysis, respectively.