High-octane Gasoline Components Research Articles

MECHANISM OF CATALYTIC ISOMERIZATION–DISPROPORTIONATION PROCESSING OF STRAIGHT-RUN GASOLINE

The isomerization-disproportionation conversion of straight-run gasoline over the Co/HZSM/SO42--ZrO2 (SZ) composite catalytic system at atmospheric hydrogen pressure has been studied. Optimal process conditions (1800С; Н2/СН=3; WHSV = 2.5 h-1) was established, under which the conversion of С8+ hydrocarbons is 77.3%, and the sum of high-octane gasoline components С5–С6 alkanes increases from 11% to 61%. Тhe effect of C4-, C5–C6 products and H2O on this isomerization-disproportionation process have been studied. It is shown that, unlike the main C5–C6 products, side C4-products affect the stability of the process, and the catalyst is deactivated under the water's influence. Comparative studies of the conversion of a mixture of straight-run gasoline and C2H5OH showed that H2O vapor formed sites deactivate the centers located on the SZ. It has been established that the mechanism of isomerization-disproportionation conversion of straight-run gasoline with the participation of a composite catalytic system is realized through the conjugated interaction of red-ox centers contained on SZ with acid-base centers of Co/HZSM-5, responsible, respectively, for the formation of intermediate compounds [С4+C7] and their and their further hydro cleavage

Transformations of stable gas condensate hydrocarbons into high-octane gasoline components over ZSM-5 zeolite catalyst

The process of stable gas condensate zeoforming was implemented at the laboratory scale under the conditions of varying feedstock composition and technological parameters (temperature, pressure, feedstock flow rate). The directions of hydrocarbon transformations were established. The influence of technological parameters on the composition and properties of the obtained product was estimated. From the perspective of involving the obtained zeoforming product into production of motor gasoline, optimal technological parameters were determined (the temperature of 375 °C, the pressure of 2.5 MPa, the feedstock flow rate of 2 h−1), the most preferred feedstock was established (the feedstock, which contains high amount of naphthenes, which sufficiently influence aromatization reaction). The recipes for motor gasoline blending were developed using the zeoforming product as the major component for the production of different grades, such as RON-92, RON-95, RON-98, meeting the modern specifications.

Исследование технологии высокооктановых компонентов бензинов с улучшенными экологическими свойствами

Исследование технологии высокооктановых компонентов бензинов с улучшенными экологическими свойствами

Influence of UV-Activation of Modified Zeolite Catalysts on Their Physicochemical and Catalytic Properties in Their Process of Getting High-Octane Gasoline Components

The influence of UV-irradiation by an XeCl excimer lamp on the physicochemical and catalytic properties of MFI-type high-silica zeolites modified by cobalt tungsto- and molybdobismuthates in the process of getting high-octane gosoline components is studied. It is show that the concentration of acidic centers can be increased by 76%; the arene yield, by 4-13 wt%; and the octane number of the products, by 2-3 points as compared with starting zeolite if cobalt tungstobismuthate heteropoly compound (1 wt%) is used as the modifier and the material is activated by UV-irradiation for 24 min. It is established that UV-irradiation of modified zeolites increases the concentration of acidic centers and decreases the adsorption capacity and specific surface area.

Improvement of the Yield and Quality of Reformate by Combining Stepwise Reforming and Hydroisomerization

Three process flowsheets combining processes of catalytic reforming, interstage separation and reformate hydroisomerization were examined to improve the reformate yield of quality (minimized content of aromatic hydrocarbons including benzene). It was shown that the optimal version is the flowsheet including rectification of the intermediate reformate into three fractions (IBP 85 °C, 85–150 °C, and EBP 150 °C) that allowed, against the traditional catalytic fixed bed reforming, high-octane gasoline components with a lower benzene content (less than 1 wt %) to be produced at a noticeable increase in the reformate yield (4–5 wt %) and the octane number (up to 2 point RON). Effective catalysts were chosen for the stages of reforming and hydroisomerization; the catalysts were used for experimental modeling of the flowsheets of combined reforming and hydroisomerization under study. The results obtained supported the analytic estimation of the efficiency of the developed technology.

Thermodynamic analysis of a process for producing high-octane gasoline components from catalytic cracking gas

The results from a thermodynamic analysis of high-octane gasoline component production from catalytic cracking gases using zeolite catalyst OMNIKAT-210P modified with Ni, Co, Cr are presented. The equilibrium constants of the reactions assumed to occur in this process are calculated, along with the equilibrium yield of the reactions.

Catalysts based on γ-Al2O3-supported sulfated zirconia for the isomerization of gasoline fractions

Supported Pt/SZ/Al2O3 catalysts prepared via the thermolysis of zirconium sulfate in support pores are studied. The content of the active component (sulfated zirconia) in the catalysts is 25–30 wt %, 2–2.5 times lower than in massive catalysts equivalent in their catalytic characteristics. Tests in the isomerization of n-hexane are performed. It is shown that the total yields of 2,2- and 2,3-dimethylbutanes (DMB) on the supported catalysts at temperatures of 140–160°C are 34–36 wt % at a stable C5+ catalyzate yield of 96–98 wt %, comparable to the results obtained on industrial isomerization catalysts based on sulfated zirconia. The results indicate that the supported Pt/SZ/Al2O3 catalysts can be used in the isomerization of C5-C6 fractions to synthesize environmentally friendly high-octane gasoline components.

Applying new kinetic and deactivation models in simulation of a novel thermally coupled reactor in continuous catalytic regenerative naphtha process

Naphtha reforming unit occupies a key position in refineries to obtain high octane gasoline and BTX (benzene, toluene, and xylene) components which are the basic substances of petrochemical industries. In this study, a novel thermally coupled reactor for continuous catalytic regenerative naphtha process has been proposed to boost the aromatics and hydrogen productions and to produce aniline as a valuable product. In this configuration, the naphtha reforming (endothermic reaction) and nitrobenzene hydrogenation (exothermic reaction) reactions are carried out simultaneously. According to complex kinetic of reforming process a new kinetic model including 32 pseudo components with 84 reactions is proposed. As well, a novel catalyst deactivation model considering acidic and metallic functions of catalyst is presented to predict the behavior of the reactions which subject to the catalyst deactivation. Mathematical modeling of coupled reactor is considered in two dimensions (radial and axial directions). In order to assess the performance of the new configuration, the modeling results of thermally coupled reactor (TCR) is compared with the obtained results of conventional reactor (CR). By employing coupled reactors, aromatics production rates is improved acceptably (about 92kmol/h in comparison with conventional system), and the amount of produced hydrogen is increased greatly (190kmol/h compared to CR).

NiMo supported acidic catalysts for heavy oil hydroprocessing

Large pore diameter Al 2O 3-SiO 2 acidic mixed oxide supports were prepared by using homogeneous co-precipitation method. The acidic properties of supports (oxide) and supported catalysts (sulfided) were chemically probed with cumene cracking (HCR) into propane and benzene at atmospheric pressure and 400 °C. NiMo supported hydroprocessing catalysts activities were also evaluated with heavy Maya crude oil. The use of acidic support is to optimize yield of high octane gasoline components, i.e. selective cracking of complex crude oil molecule. The supported fresh and spent catalysts were characterized by means of N 2 adsorption–desorption and SEM–EDX spectroscopic techniques. The results point out that deactivation takes place mainly at the entrance of pore due to coke deposition, while the depositions of vanadium and nickel sulfides mainly depend on the diameter of the pores. The results also indicated that the deactivation due to carbon deposition is carried out at initial hours of the crude oil processing. The large pore diameter catalyst contains higher amounts of deposited species, which are distributed proportionally along the extrudate radius, while for smaller pore diameter catalyst the deposition mainly occurs on the extrudate surface.

Kinetic Modeling of the Dimerization of Isobutene

The dimerization of isobutene (2-methylpropene) produces diisobutenes (2,4,4-trimethylpentenes) that can be used as high-octane gasoline components. The dimerization kinetics were studied in experiments carried out in a continuous stirred tank reactor at 60−120 °C with different feed concentrations. A commercial ion-exchange resin catalyst was used together with tert-butyl alcohol (2-methyl-2-propanol), which increases the selectivity for diisobutenes by reducing the activity of the sulfonic acid sites of the resin. Langmuir−Hinshelwood-type kinetic models were derived for the dimerization and trimerization reactions, and their parameters were estimated on the basis of the measured data. The only model to represent the data successfully was one where diisobutenes form using two active sites and triisobutenes via diisobutenes using three active sites. This type of model well describes the triisobutene formation rate and the observed maximum in the diisobutene rate. The apparent activation energy was 30 kJ/mol for dimerization.

Catalytic cracking of gas oils in electromagnetic fields: reactor design and performance

The application of dielectric heat transfer in the catalytic cracking and hydrocracking of gas oils has been investigated. A three-phase spouted-bed catalytic reactor has been designed and operated using dielectric radio frequency (RF) heating. The electromagnetic power was transferred to the reactor by a 27.12 MHz RF generator acting through two capacitor plates. In this technique, heat is generated to the catalyst held in the electromagnetic field and thermal energy dissipated to the surroundings of the catalyst volume preventing carbon formation by eliminating secondary reactions. Energy transfer from the RF filed to the reaction was solely dependent on the dielectric properties of solids in the reactor, effectively the catalyst or transient carbon. Three zeolitic catalysts have been tested. These catalysts were 13X, 5A and Ammonium Y Zeolite. Two different gas oils have been used as feedstocks for the experiments. Saudi Light Vacuum Gas Oil (SALVGO) supplied by Saudi Aramco Oil and North Sea Light Gas Oil (BPLGO) supplied by BP Oil. A comparative study of the two gas oils cracked over 13X zeolitic catalyst has been presented. The analysis of the feedstocks have shown that SALVGO contains hydrocarbons in the range C 11–C 30 with average molecular weight of 294, while BPLGO contains hydrocarbons in the range C 11–C 25 with average molecular weight of 243. The analysis of cracked products have shown a production of lower olefins such as propene and butene with hydrogen sulphide from SALVGO at a conversion of 87% and aromatics such as benzene and toluene from BPLGO at a conversion of 72%. The successful use of zeolitic catalyst in producing lower olefins and aromatics with an RF dielectric reactor suggests exploring this type of reactor for objectives such as the production of reformulated gasoline, in which butene is used as feedstock for production of high-octane gasoline components such as MTBE and alkylate.

Studies on supported triflic acid in alkylation

A thermally stable solid acid catalyst has been prepared by treating amorphous silica gel with trifluoromethanesulphonic (triflic) acid (TFA) at 150°C in a closed glass vessel. A solvent such as 1,1,2-trichloro-2,2,1-trifluoro-ethane (Freon 113) can be conveniently used to dissolve TFA. The obtained material is an active catalyst in the alkylation of isobutane with n-butenes to yield high-octane gasoline components. In the reaction it behaves like a truly solid catalyst not leaching TFA in the solution for about 24 h. The catalyst characterisation has been performed by 1H- and 19F-NMR and IR spectroscopy.

Impact of Unleaded Gasoline in Reducing Emissions in Saudi Arabia

Saudi Arabia is dealing progressively with tighter restrictions on refined product qualities. Efforts are ongoing within the country concerning the phase-out of lead in motor gasoline and the reduction of sulfur in diesel as well. The removal of lead is the main characteristic of environmental friendly gasoline. The detrimental health effects of using leaded gasoline are many, and lead exposure can cause kidney failure, brain dysfunction, behavioral problems, and neurological impairment. Saudi Arabia is moving towards using unleaded gasoline, and efforts are being put forward by research organizations to produce lead-free gasoline in the Kingdom. A high severity fluid catalytic cracking process is being developed for converting vacuum gas oil into high-octane gasoline components. This process requires high temperature and pressure and low contact time as compared to the conventional FCC process.

Utilization of Bach Ho Associated Gas Condensate in Vietnam for Isomerate Gasoline.

Petro Vietnam has already completed the construction of a pipeline to bring gas from Bach Ho oil field to Vung Tau, and the associated gas, approximately 1500MMm3/yr, has been transported through this pipeline to onshore.It will take more time until its full utilization is realized. The associated gas contains condensate as a heavier component and its more effective utilization is expected to raise the economic value of the gas. It mainly contains C5-C7 paraffin and RON is estimated to be less than 70, and the production of aromatics for petrochemicals and that of high-octane isomerate gasoline components would be recommended. Isomerate gasoline is environmentally acceptable for Vietnam because it can eliminate the leaded gasoline now being used. Technical studies are being carried out on isomerization processes, plant design and construction cost estimation. The total investment cost of a 5000BPD isomerization plant is around 2000MM yen. Economics studies are also conducted, and its feasible commercial operation is likely (ROI>24.1%, after tax, base case).

98/03604 Production of high octane gasoline components by hydroprocessing of coal-derived aromatic hydrocarbons

98/03604 Production of high octane gasoline components by hydroprocessing of coal-derived aromatic hydrocarbons

Thermodynamic probability of the conversion of multiring aromatics to isoparaffins and cycloparaffins

Thermodynamic properties were shown to provide a good estimation for product selectivity, thereby reducing the number of screening tests with respect to reaction temperature. Equilibrium constants for the conversion of aromatics to isoparaffins and cycloparaffins were calculated to determine reaction conditions for the production of high octane gasoline components without aromatics from hydrogenation/hydrocracking of 1-methylnaphthalene. These calculations, combined with screening studies of different catalysts, determined optimum hydrotreatment conditions.

Production of high octane gasoline components by hydroprocessing of coal-derived aromatic hydrocarbons

The catalytic conversion of coal liquids to desirable gasoline components was modeled by the hydroprocessing of 1-methylnaphthalene. The conversion aims at a maximum yield of non-aromatic high octane gasoline components, i.e. isoparaffins and substituted cyclohexanes and cyclopentanes. Experiments were performed in one or two stages using various catalysts. The highest single-stage conversion was achieved in 10 h with a sulfided NiW/SiO 2Al 2O 3 catalyst at 325°C and 6.7 MPa with a feed/catalyst ratio of 10:1. In the two-stage operation, 1-methylnaphthalene was first hydrogenated to methyldecalins at 325°C and 6.7 MPa with 100% conversion in 10 h using a sulfided NiMo/TiO 2Al 2O 3 catalyst. In the second stage, the methyldecalins underwent hydrocracking at 325°C and 4.7 MPa using a Pd/REX catalyst (where REX is a rare earth exchange X-type zeolite). The results showed promise for reducing the aromatic content in coal liquids to less than 2% while achieving a potential conversion to high octane gasoline components of 62.2 wt%.

98/00181 Production of high octane gasoline components by hydroprocessing of coal-derived aromatic hydrocarbons

98/00181 Production of high octane gasoline components by hydroprocessing of coal-derived aromatic hydrocarbons

Magnetic and Mössbauer study of metal-zeolite interaction in catalysts

Molecular sieve aluminosilicates, such as ZSM-5 and mordenite, when impregnated with highly dispersed Fe, yield catalysts for the selective conversion of coal-derived syngas (CO+H2) to liquid hydrocarbon fuels. Fe performs the primary Fischer-Tropsch (FT) syngas to yield light olefins which are converted by the acidic (H+) and shape-selective function of the zeolite to high octane gasoline components. The physical aspects of the Fe-mordenite interaction studied by magnetic measurements, Mössbauer, and IR spectroscopy are reported and correlations with the catalytic properties are drawn. Mordenite samples with [SiO2/Al2O3] ratio in the range 12 – 60 were impregnated with 15 wt. % Fe using Fe3(CO)12; decarbonylation yielded superparamagmetic dispersions of γ-Fe2O3, in the range 1.4–5.0 nm; the smallest particles were obtained for a ratio=17. Hydrogen chemisorption also revealed a similar trend in Fe dispersions. No samples, other than the one with a ratio=60 and containing the largest particles could be carbided under usual conditions. The acidity of the mordenite and the aromatics fraction in liquid hydrocarbons from syngas conversion also showed maxima at a ratio=17. The presence of a strong metal-support interaction between Fe and mordenite was thus influenced by the varying ratios in the mordenite in a manner that paralleled the acidity and catalytic activity.

Production and thermal hydrogenation of a high-sulfur feedstock

1. A two-stage scheme has been developed for the extractive separation of the kerosine-gas oil fraction of Arlansk petroleum to give 60% of a low-sulfur raffinate containing less than 0.2% sulfur and 39% of a concentrate of aromatic hydrocarbons and sulfur compounds. 2. It has been shown that by the thermal hydrogenation of the extract at 50 atm in the temperature range 625–700°C there can be obtained a concentrate (21.8% based on feedstock) of manocyclic aromatic C6–C10 hydrocarbons (a feedstock for the production of C6–C8 aromatic hydrocarbons, solvents, and high-octane gasoline components) together with 60% of a low-sulfur diesel fuel component, for a hydrogen consumption of 1.4%.