Conversion of vegetable oils on Pt/Al2O3/SAPO-11 to diesel and jet fuels containing aromatics (original) (raw)
Related papers
The production of high grade jet fuels from vegetable oils is an issue of special interest to refineries. The conversion process involved hydrotreating (i.e. hydrodeoxygenation and hydrodecarboxylation) of the oils followed by subsequent hydroisomerization. The paper focuses on hydrotreatment of vegetable oil, possible reaction mechanism and catalyst used for the process. Catalysts based on Nickel and Molybdenum supported on oxides is considered very active for the hydrotreating process then Platinum, Palladium and Ruthenium on zeolites. Change from noble metals to transition metals as the medium of catalyst for hydrotreatment of oil has also improved the overall process.
Diesel-like hydrocarbon production from hydroprocessing of relevant refining palm oil
Fuel Processing Technology, 2013
This paper demonstrates the initiated use of relevant refining palm oil for bio-hydrogenated diesel production. The conversions of crude palm oil (CPO) and its physical refining including degummed palm oil (DPO) and palm fatty acid distillate (PFAD) to diesel fuel by hydroprocessing were studied. The effects of operating parameters (i.e. reaction time, operating temperature, and pressure) and catalyst (i.e. Pd/C and NiMo/γ-Al 2 O 3) were examined in order to determine suitable operating condition for each feedstock. It was found that the hydroprocessing of CPO with Pd/C catalyst at 400°C, 40 bar, and reaction time of 3 h provides the highest diesel yield of 51%. When gum which contains phospholipid compounds is removed from CPO, namely DPO, the highest diesel yield of 70% can be obtained at a shorter reaction time (1 h). In the case of PFAD, which consists mainly of free fatty acids, a maximum diesel yield of 81% could be observed at milder conditions (375°C with the reaction time of 0.5 h). The main liquid products are n-pentadecane and n-heptadecane, having one carbon atom shorter than the corresponding fatty acids according to decarboxylation/decarbonylation pathways. Pd/C catalyst shows good catalytic activity for fatty acid feedstocks but becomes less promising for triglyceride feedstocks when compared to NiMo/γ-Al 2 O 3 .
Production of renewable diesel by hydroprocessing of soybean oil: Effect of catalysts
The effects of various supported catalysts on the hydroprocessing of soybean oil were studied. Several parameters were taken into account when evaluating the hydroprocessed products, including the conversion, selectivity (naphtha, kero/jet, and diesel), free-fatty acid content, oxygen removal, and saturation of double bonds. The hydroprocessing conversion order was found to be sulfided NiMo/c-Al 2 O 3 (92.9%) > 4.29 wt.% Pd/c-Al 2 O 3 (91.9%) > sulfided CoMo/c-Al 2 O 3 (78.9%) > 57.6 wt.% Ni/SiO 2 -Al 2 O 3 (60.8%) > 4.95 wt.% Pt/c-Al 2 O 3 (50.8%) > 3.06 wt.% Ru/Al 2 O 3 (39.7%) at a catalyst/oil weight ratio of 0.044. The most abundant composition in the liquid product was straight chain n-C 17 and n-C 15 alkanes when the Ni or Pd catalysts were used. Enhanced isomerization and cracking reaction activity on the CoMo catalyst may produce lighter and isomerized hydrocarbons. By combining gas-phase and liquid product analyses, decarboxylation was a dominant reaction pathway when the Pd catalyst was used, while hydrodeoxygenation was favored when the NiMo or CoMo catalyst was used.
Catalytic Upgrading of “Off-Spec” Aromatic-Rich Oils from the NSC Process
Energy & Fuels, 1999
The aromatic oil, which is a byproduct of the processes of naphtha steam cracking (NSC), was hydrocracked with Mo-, Co-, and Mo-Co-loaded zeolite catalysts. Experiments were performed at a temperature range of 375-450°C. The initial hydrogen pressure was 10 MPa, and the reaction time was 90 min. The main fraction of the reaction product, the liquid portion, was investigated from a hydrogenation and cracking point of view. The loading of the metal oxide on zeolite increased the cracking and hydrogenation performance of the catalysts. Molybdenum had a good hydrogenation effect, whereas cobalt had a good cracking effect. Comparing the hydrogenation and cracking performance of one-metal-loaded catalysts to those of two-metalloaded catalysts, the cracking effect of two-metal catalysts was much more than one-metal catalysts. However, the hydrogenation performance of one-metal and two-metal catalysts were approximately equal to each other. The activated catalysts were also used in experiments. The activation of unloaded zeolite catalysts was more effective on the cracking performance of the catalyst. The liquid fractions of the reaction products were also separated into aliphatic, aromatic, and polar fractions by liquid absorption chromatography. The results showed that the type of the catalyst was not effective on the distribution of aliphatic, aromatic, and polar fractions. It was observed that a portion of the aliphatic compounds converted to aromatics at temperatures higher than 425°C. At the end of this study, a valuable liquid product to be burnt, such as fuel oil, was obtained from aromatic oil.
Renewable & Sustainable Energy Reviews, 2017
Growing demand for fossil fuels and related environmental issues have directed global attention towards development of alternative fuels from renewable sources. In this regard, biodiesel synthesized from vegetable oils and animal fats has shown potential as alternative to diesel fuel owing to its comparable fuel properties and combustion characteristics. However, higher oxygen content in biodiesel has raised some technical issues for its long term utilization in engines. Subsequently, the second generation liquid hydrocarbon fuels are being developed via catalytic deoxygenation of fatty acids present in vegetable oils. Presently, the research focus is on the pathways for catalytic deoxygenation like hydrodeoxygenation, decarboxylation, and decarbonylation. In hydrodeoxygenation, use of hydrogen gas and sulfided metal catalysts ensure higher conversion of vegetable oil into hydrocarbon fuel compared to the other two pathways. On the contrary, decarboxylation and decarbonylation are mostly hydrogen-free processes ensuring economical production of hydrocarbon fuel from vegetable oils. Hence, the techno-economical issues related to deoxygenation process need to be addressed for its commercial viability. Further, key operating parameters like nature of catalysts and supports, catalyst amount, reaction temperature, reaction atmosphere, hydrogen partial pressure, feed type, feed rate, type of solvent, H 2 / fatty acid molar ratio etc. are reported to have substantial influence on the hydrocarbon yield and selectivity. This review paper expounds a comparative assessment on the various deoxygenation pathways with their reaction mechanisms to opt for the suitable pathway for conversion of vegetable oils into hydrocarbon fuels based on yield and selectivity of the desired product, ease of use, economy etc. It also explicates the influence of various operating parameters to obtain optimum hydrocarbon conversion and selectivity during catalytic deoxygenation of vegetable oils and related feedstock.
Alternative Non-Food-Based Diesel Fuels and Base Oils
Industrial & Engineering Chemistry Research, 2018
The importance of aliphatic fuel and base oil blending components produced on non-petroleum basis is increasing. Therefore, the possibility to produce these environmental friendly products in new catalytic ways was studied. High molecular weight Fischer-Tropsch wax synthetized from lignocellulose-based synthesis gas, waste fatty acids and different triglycerides were converted to diesel fuels and base oils over NiMoP/Al 2 O 3 and Pt/SAPO-11 catalysts. The optimal operating parameters of high-quality products were determined. The
Diesel-like fuel obtained by pyrolysis of vegetable oils
Journal of Analytical and Applied Pyrolysis, 2004
The pyrolysis reactions of soybean, palm tree, and castor oils were studied. The pyrolytic products were analyzed by CG-FID, CG-MS, and FTIR, showing the formation of olefins, paraffins, carboxylic acids, and aldehydes. The adequate choice of distillation temperature (DT) ranges made it possible to isolate fuels with physical-chemical properties comparable to those specified for petroleum based fuels. The catalytic upgrading of the soybean pyrolytic fuel over HZSM-5 zeolite at 400 • C was also studied and has shown a partial deoxygenation of the pyrolytic products.
Studies on Usage of Straight Vegetable oils as fuel for diesel engines
The increasing industrialization and motorization of the world has led to a steep rise in the demand of fossil fuel and associated environmental issues. Fossil fuels are obtained from limited reserves and will run out eventually. Therefore renewable and environmental-friendly energy substitutes such as bio fuels as well as fuel efficiency improving methods are required.