Novel Catalysts Development for Production of Jet Fuel Range Hydrocarbons from Vegetable Oils (2021)

Production of jet fuel range hydrocarbons via processing of oleic acid has proved to be a\nviable alternative to the conventional ways of producing jet fuel range hydrocarbons. In this study,\nthe collaborative influence of Fe on the Cu/SiO2-Al2O3 catalysts of 5–15 wt. % Cu loadings was\nestablished by changing the contents of Fe in the range of 1–5 wt. % on the optimized 13 wt. %Cu\ncatalyst supported on SiO2-Al2O3. The highest yield (59.5%) and selectivity (73.6%) jet fuel range\nhydrocarbons were obtained from the evaluation of the Fe(3)-Cu(13)/SiO2-Al2O3 catalyst at 300\n°C and 2.07 MPa H2 pressure, which can be attributed to its desirable textural properties, mild\nBronsted acid sites confirmed pyridine FTIR analysis, high metal dispersion revealed from CO\nchemisorption analysis and TPR analysis.\nIn the second phase of this research work, the collaborative effects of 1 wt.% Ti, 1 wt.%\nZr, and 0.5-2 wt.% Sn on the promising bimetallic catalyst (Fe(3)-Cu(13)/SiO2-Al2O3) were also\nestablished through in depth characterization and evaluation to produce jet fuel range\nhydrocarbons via hydroprocessing of oleic acid. Hydroprocessing of oleic acid over 1 wt. % Sn\npromoted Fe(3)-Cu(13)/SiO2-Al2O3 catalyst at 320°C, 2.1 MPa H2 pressure and 8 h, resulted in\nthe highest selectivity (76.8 %) and yield (71.7 %) of jet fuel range hydrocarbons. The promising\nperformance of the catalyst is attributed to its high metal dispersion (revealed from its smallest\ncrystallite size of 5.1 nm and its weakest metal-support interaction), desirable textural properties\n(revealed from its largest surface area of 571 m2\n/g and highest pore volume of 0.65 cm3\n/g).\nMaximization of selectivity of jet fuel range hydrocarbons and oleic acid conversion with\nthe best combination of the process parameters involved and evaluation of thermodynamic and\nkinetic activation parameters is the focus of phase 3 of this research work. Reduced quadratic jet\nfuel range hydrocarbons selectivity model and reduced cubic oleic acid conversion model of high\nsignificance levels and high correlation coefficient were developed. Reaction temperature of 339.5\noC, 6.2 wt.% catalyst concentration, 1.6 MPa H2 pressure and 8.0 h reaction time were the optimum\nprocess parameters that can maximize selectivity of jet fuel range hydrocarbons and oleic acid\nconversion at 82.2% and 98.2 %, respectively. This process was found to be endothermic,\nirreversible and non-spontaneous with 45.8kJ/mol activation enthalpy of reaction, -0.25kJ/mol\nentropy of reaction and the reaction’s Gibb’s free energy of 198.8kJ/mol at 340 oC. The minimum\nenergy required for the reaction to take place was evaluated to be 50.7kJ/mol.\n\niv\n\nProduction of aviation biofuel that will be competitive with the conventional jet fuel\nderived from crude oil in terms of its cost effectiveness has been the subject of research in recent\nyears. In the phase 4 of this research work, technoeconomic analysis of greenseed canola derived\njet fuel range hydrocarbons were carried out using a SuperPro design software. 79200 MT/year of\noleic acid (model compound of greenseed canola oil) was hydroprocessed with 1.6 MPa of\nhydrogen over a 1 wt. % Sn promoted trimetallic catalyst to produce 59345 MT/year jet fuel range\nhydrocarbons of 99.5 wt. % purity. Economic evaluation of the production process revealed net\nannual profit of 1.25 million dollars, respectively, with 38.46 % return on investment and 2.6 years\npayback time.\nIn conclusion, a novel 1 wt. % Sn promoted on Fe(3)-Cu(13)/SiO2-Al2O3 catalyst was\nestablished to be effective and profitable for production of jet fuel range hydrocarbons after\noptimization of catalysts of different supports, loadings of Sn, Fe and Cu, process parameters and\neconomic evaluation.