Study on preparation of refined oil by upgrading of pyrolytic vapors using Zn-P/HZSM-5 zeolite

Abstract

Zn and P were selected to modify HZSM-5 for further improving the production and fuel quality of refined bio-oil. Analysis methods including XRD, SEM EDS, ICP-AES and BET were applied to characterize the modified HZSM-5. The influence of physical and chemical properties of refined bio-oil, chemical composition of aqueous phase and the anti-coking ability of the modified HZSM-5 with loading of Zn and P were studied. The results show that the framework of modified HZSM-5 was not influenced by modification of Zn and P distributing uniformly on the surface of HZSM-5. The BET of modified HZSM-5 decreases when loading mass of Zn increases. When Zn loading mass is 3% the physicochemical properties of refined bio-oil are as follows: oxygen content is 10.67%, high calorific value is 36.76 MJ/kg, and pH value is 5.85. Meanwhile, the relative content of acids, alcohol and ether, aldehyde and ketone in aqueous phase decreases significantly. Aromatic compounds and aromatic hydrocarbon increase significantly with the relevant amount of 91.93% and 74.63%, respectively. The anti-coking ability of modified HZSM-5 is enhanced with P loading, which improves the stability of HZSM-5. Zn loading promotes the formation of carbenium ion and hydrogen transfer, which improves the aromatization performance of HZSM-5.