Regeneration of the HZSM-5 zeolite deactivated in the upgrading of bio-oil via non-thermal plasma injection (NTPI) technology

•Regenerate the coked HZSM-5 zeolite via non-thermal plasma injection (NTPI).•Optimal regeneration temperature using NTPI technology is around 250 °C.•Coke can be decomposed into COx by reacting with the active substances.•It is feasible to apply NTPI to the field of zeolite-based catalyst regeneration.

The main objective of the present work was applying a new method to regenerate the coked HZSM-5 zeolite on a laboratory scale. The non-thermal plasma injection (NTPI) technology, which can overcome the disadvantages of conventional regeneration methods, had been applied to regenerate HZSM-5 zeolite deactivated in the upgrading of biomass pyrolysis vapors. Experiments were carried out at different temperatures using self-designed setup to investigate the regeneration effect with O2 as the discharge gas. The optimal regeneration temperature was around 250 °C and the regeneration process can be finished in a shorter time. Characterizations of the HZSM-5 zeolite before and after regeneration were profoundly performed by SEM, TG, BET method, Pyr-FT-IR and XRD. The coke can be removed completely and the activity of the coked HZSM-5 zeolite can be recovered quickly. The coke deposited on the HZSM-5 zeolite can be effectively decomposed into CO and CO2 by reacting with the active substances which were generated through the discharge reactions of NTP generator. It is promising to apply this technology to the field of zeolite-based catalyst regeneration and realize its industrial applications in the near future.