In situ hydro-deoxygenation onto nickel-doped HZSM-5 zeolite catalyst for upgrading pyrolytic oil

Global energy demand has drastically increased due to urbanization and industrialization; thus, developing alternative renewable energy sources is urgently required. In the present work, upgrading the pyrolytic oil (PO) derived from fresh palm fruit was performed by the catalytic in situ hydrodeoxygenation (in situ HDO) process. Preparation of nickel-doped HZSM-5 zeolite (SiO2/Al2O3 = 40) was achieved by incipient wetness impregnation techniques using different weight percents of nickel dopant into HZSM-5. Nickel-doped HZSM-5 zeolite (Ni-HZSM-5) was further subjected to chemical reduction for 5 h in the oxygen-free environment (10% H2 and 90% N2) at 550 degrees C. The structural properties showed a potential reduction of NiO-HZSM-5 to Ni-HZSM-5, enhancing the catalytic potential. The morphological characterizations showed spherical-shaped Ni agglomerated onto HZSM-5. Acidity and oxygen contents in the pyrolytic oil were achieved by catalyst-aided HDO process at 220 degrees C for 6 h using methanol as a hydrogen donor. The catalytically upgraded pyrolytic oil (UPO) was analyzed for density, HHV, CHNO, and TGA. The best upgrading oil was distilled following ASTM D86 to separate gasoline, kerosene, and diesel. The acidity, density, HHV, and viscosity were measured before and after the upgradation processes. The results showed the potential impact of Ni with 10% doped on HZSM-5 on HDO reaction and illustrated the lowest oxygen content in upgraded pyrolytic oil products. Considerable decrease in viscosity and density level indicated that in situ HDO not only reduced oxygen content but also cracked pyrolytic oil to small molecules. The distilled product of upgrading oil was higher than pyrolytic oil by approximately 15% in volume. The viscosity, density, and HHV were under standard specifications of kerosene and diesel, except for acidity. However, the acidity was reduced by over 60% compared with raw material.

Automated summary

This study focuses on the upgrading of pyrolytic oil derived from fresh palm fruit using the catalytic in situ hydrodeoxygenation (in situ HDO) process. Nickel-doped HZSM-5 zeolite (Ni-HZSM-5) was prepared and shown to enhance the catalytic potential. The in situ HDO process successfully reduced the oxygen content and cracked the pyrolytic oil into smaller molecules, resulting in an upgraded oil that meets the specifications of kerosene and diesel fuels.