Online upgrading of bio-oil with alkali-treated HZSM-5 zeolites

HZSM-5 zeolite was treated by sodium hydroxide solution, and then characterized by XRD, SEM, BET and Py-FTIR, respectively. Physical and chemical properties and composition analysis was applied to the organic phase of bio-oils. Thermogravimetric analysis was performed on three deactivated catalysts after using for 120 min and the peak area of char was calculated. The results show that the alkali-treated HZSM-5 catalyst retains typical MFI topology structure and forms a certain number of mesoporous. At the same time, the bio-oil organic phase made with modified HZSM-5 (after 1 h treatment) achieves a higher yield rate and better physical properties. The content of hydrocarbons increases significantly to 37.67% mainly with the increase of mononuclear aromatics. In addition, modified HZSM-5 catalyst (after 1 h treatment) has a better effect on the removal of acid, aldehyde and ketone contained in the bio-oil organic phase, which improves stability of the bio-oil with calorific value of 35.32 MJ/kg. The amount of coke in the HZSM-5 zeolite after 1 h alkali treatment obviously decreases.