Production of Bio-jet fuel from palm fatty acid distillate over Bi-Functional CoPd/HZSM-12 catalysts

Abstract

Jet fuel is one of the major products from a petroleum refinery, its combustion emissions contribute to global warming. Therefore, bio-jet fuel is introduced to solve this problem. Palm fatty acid distillate (PFAD) is an interesting feedstock for bio-jet fuel production via three reactions including deoxygenation, hydrocracking, and isomerization. In this study, the monometallic (Co and Pd) and bimetallic (CoPd and NiPd) supported on HZSM-12 zeolite with various metal loadings and bimetallic CoPd with various zeolite supports (HZSM-12, HZSM-5, and HY) were investigated in a continuous flow trickle bed reactor. The presence of bimetallic CoPd on HZSM-12 zeolite support enhanced the deoxygenation activity and acidity for bio-jet fuel production. Moreover, 10Co1Pd/HZSM-12 exhibited high stability due to its low coke formation. 10Ni1Pd/HZSM-12 catalyst showed high deoxygenation reaction but low hydrocracking thus it produced a high amount of biodiesel. The 10Co1Pd/HZSM-5 catalyst had high acidity which excessively cracked, resulting in a low quantity of bio-jet fuel, while the 10Co1Pd/HY catalyst had a big 3-dimensional pore size that caused a low selectivity to bio-jet fuel production and high coke formation. Furthermore, the optimal condition for bio-jet fuel production over 10Co1Pd/HZSM-12 catalyst was found at 350 °C, 30 bar, LHSV of 1.5 h⁻¹, and H₂/feed molar ratio of 8, giving 55 % bio-jet fuel yield.