Optimization of catalytic hydrodeoxygenation of oleic acid into biofuel using fluoroplatinum oxalate zeolite supported catalyst

Optimization of hydrodeoxygenation (HDO) of oleic acid (OA) into paraffinic biofuel using zeolite supported fluoroplatinum oxalate (FPtOx/Zeol) catalyst is reported in this study. FPtOx/Zeol was synthesized via incorporation of HF modified oxalic acid (OxA) functionalized K2PtCl4 into zeolite A support. FPtOx/Zeol was characterized and the results showed highly dispersed tetrahedral and octahedral Pt species which are effective for sequential hydrogenation of the unsaturated OA bond and the HDO of OA, respectively. Furthermore, there was increase in Si/Al ratio of FPtOx/Zeol leading to loss of crystallinity due to dealumination of the extra framework and framework alumina as a result of acid attacks and calcination, respectively. FPtOx/Zeol activity was tested on the HDO of OA in a semi-batch reactor and the process parameters were optimized using validated quadratic models. The optimum conditions were 364 °C, 18 bar and 27.8 mg FPtOx/Zeol loading under reaction time of 58 min to produce 28.39% iso-C18H38 and 68.93% n-C18H38. The presence of the isomerized product was due to the combine effect of fluoride ion and oxalic acid functionalization on the catalyst. FPtOx/Zeol reusability studies showed consistency after three consecutive runs. These results are promising for further research toward commercialization of biofuel production.