Reforming Of Gasoline Research Articles

Automation of the Formation of a Mathematical Formulation of Kinetics for Multistage Chemical Reactions and Numerical Solution to a Direct Problem

Introduction. The basis for research, analysis and mathematical optimization of any chemical process is an adequate mathematical model that takes into account the kinetics of the object. Kinetic analysis is a challenge in chemical technology, since it allows for optimizing synthesis processes and predicting their efficiency. Numerous chemical processes involve several stage reactions. For successful design and optimization, a mathematical model that describes each stage is needed. Creating such a model manually can be time-consuming and costly, since it requires processing a large amount of information. The modern level of automation makes it possible to accelerate the obtaining of a mathematical formulation of the kinetics of multistage reactions. In this case, working with data is greatly simplified, and the probability of making mistakes is reduced. The resulting mathematical model can be applied for further analysis and optimization of the process. The paper considers the industrial reaction of catalytic reforming of gasoline, which occupies an important place in the modern scheme of oil refining, since it is a source of high-octane components of commercial gasolines and individual aromatic hydrocarbons. This process is characterized by the participation of a large number (up to 300) of various hydrocarbons, a change in the number of moles, and non-isothermality in it. Mathematical modeling of such processes involves detailing the stages to the required level. The detailing of up to 173 stages is considered. In this setting, automation of the formation of a mathematical formulation of kinetics for catalytic reforming of gasoline has not been carried out before. Therefore, the presented work aimed at implementing effective numerical methods and algorithms for automating the building of a mathematical model taking into account kinetics, thermodynamics, and changes in the number of moles.Materials and Methods. The mathematical formulation of the kinetics of multistage reactions was developed on the basis of the mass action law. The kinetic parameters values were taken from literary sources. The direct kinetics problem was solved using algorithms: the Gear method, the Runge-Kutta method of the 4th order, and the scipy.odeint() method of the Python language. The automation concept was implemented using the IDEF0 methodology. The software was written in the Python programming language.Results. A new software was created to automate the process of forming a mathematical model, taking into account the kinetics, thermodynamics, and the volume of the reaction mixture. The program results were presented by the example of catalytic reforming of gasoline. The model implemented the possibility of taking into account the intermediate heating of the mixture in the reactor cascade. Numerical values of temperature changes corresponding to industrial data were obtained.Discussion and Conclusion. The results obtained through modeling chemical transformations in the cascade of gasoline catalytic reforming reactors confirmed the exothermic nature of the reaction. The developed software product provides displaying changes in the concentrations of reactants, as well as temperature variations in the reactor, and it can be used in scientific research organizations for the analysis of multistage catalytic processes. The results of the reaction kinetics modeling will be used in the subsequent optimization of the process conditions in production.

Reduced Carbon Intensity of Ethanol Blend Gasoline

<div>Tank-to-wheels (TTW) CO<sub>2</sub> reduction for ethanol blends is determined from either gasoline composition or vehicle exhaust measurements. Fuels are characterized using a carbon intensity (CI), which is the ratio of carbon (as CO<sub>2</sub> mass) in the fuel to the net heating value. Our objective is to assess changes in CI of market gasoline with varying ethanol content that can be used to appreciate change in vehicle tailpipe greenhouse gases (GHG) in response to policy controlling the ethanol level in market fuels. Ethanol has both a reduced carbon content and a reduced net (lower) heating value relative to petroleum species, with a CI slightly lower than that of typical petroleum gasoline. However, ethanol blending offers additional CI reduction because it enables a reduction of aromatics in the petroleum blendstock for oxygenate blending (BOB) while maintaining octane rating of the blend. Aromatics have a CI about 20% higher than paraffins. The primary refinery option for aromatic reduction is through lower severity or throughput for the gasoline reformer, which ultimately reduces CI in the BOB and the finished blend. Expected gasoline market blends were projected by developing a model that addressed US refining and blending in response to octane requirements. A TTW blending CI, or BCI, for ethanol is proposed to describe the total CI reduction in the finished blend enabled by the ethanol. The ethanol BCI was found to average at 59 gCO<sub>2</sub>/MJ for E10, E15, and E20 (10%, 15%, and 20% ethanol by volume) market fuels in this study. This is substantially below the ethanol chemical CI of 71.0 gCO<sub>2</sub>/MJ and petroleum CI of 73.5 g CO<sub>2</sub>/MJ due to the enabling of aromatic reduction. E10 in comparison to E0 (purely petroleum) is estimated to offer a national US tailpipe CO<sub>2</sub> reduction of 16.6 billion kg annually.</div>

Studying the Efficiency of Parallelization in Optimal Control of Multistage Chemical Reactions

In this paper, we investigate the problem of optimal control of complex multistage chemical reactions, which is considered a nonlinear global constrained optimization problem. This class of problems is computationally expensive due to the inclusion of multiple parameters and requires parallel computing systems and algorithms to obtain a solution within a reasonable time. However, the efficiency of parallel algorithms can differ depending on the architecture of the computing system. One available approach to deal with this is the development of specialized optimization algorithms that consider not only problem-specific features but also peculiarities of a computing system in which the algorithms are launched. In this work, we developed a novel parallel population algorithm based on the mind evolutionary computation method. This algorithm is designed for desktop girds and works in synchronous and asynchronous modes. The algorithm and its software implementation were used to solve the problem of the catalytic reforming of gasoline and to study the parallelization efficiency. Results of the numerical experiments are presented in this paper.

A Developed Plasmatron Design to Enhance Production of Hydrogen in Synthesis Gas Produced by a Fuel Reformer System

Feeding IC engines with hydrogen-rich syngas as an admixture to hydrocarbon fuels can decrease pollutant emissions, particularly NOx. It offers a potential technique for low-environmental impact hydrocarbon fuel use in automotive applications. However, hydrogen-rich reformate gas (syngas) production via fuel reforming still needs more research and optimization. In this paper, we describe the effect of a plasma torch assembly design on syngas yield and composition during plasma-assisted reforming of gasoline. Additionally, erosion resistance of the cathode-emitting material under the conditions of gasoline reforming was studied, using hafnium metal and lanthanated tungsten alloy. The gasoline reforming was performed with a noncatalytic, nonthermal, low-current plasma system in the conditions of partial oxidation in an air and steam mixture. To find the most efficient plasma torch assembly configuration in terms of hydrogen production yield, four types of anode design were tested, i.e., two types of the swirl ring, and two cathode materials while varying the inlet air and fuel flow rates. The experimental results showed that hydrogen was the highest proportion of the produced syngas. The smooth funnel shape anode design in Ring 1 at air/fuel flow rates of 24/4, 27/4.5, and 30/5 g/min, respectively, was more effective than the edged funnel shape. Lanthanated tungsten alloy displayed higher erosion resistance than hafnium metal.

Modelling Industrial Catalytic Reforming of Lowoctane Gasoline

Naphtha reforming is one of the most important industrial processes in refineries. The products include aromatic hydrocarbons such as benzene, toluene, and xylenes, which are frillier used as high octane additives to gasoline. To increase the efficiency of the process, it is necessary to develop a new method of naphtha reforming. In this work, we have proposed a mathematical model of catalytic refining of low-octane gasoline fracdons into high-octane fractions. The model is based on kinetic equations, established for commercial gasoline reforming in the presence of the platinum-rhenium catalyst on a γ-Al2O3 carrier in the industrial-scale conditions. The equation: describe the dependence of the content of paraffinic, naphthenic, and aromatic hydrocarbon fractions on the process parameters, including volumetric rate and the reaction temperature. The mathematical model had been validated by comparing calculated results with the industrial data obtained from the commercial naphtha reforming production.

Rh- and Rh–Ni–MgO-based structured catalysts for on-board syngas production via gasoline processing

Rh/Ce0.75Zr0.25O2-δ-ƞ-Al2O3/FeCrAl and Rh/Ni–MgO/Ce0.75Zr0.25O2-δ-ƞ-Al2O3/FeCrAl FeCrAlloy wire mesh supported catalysts were prepared via multistep procedure. They were characterized by XRD, SEM and TEM techniques. A comparative study of autothermal reforming (ATR) of isooctane and simulated gasoline (blends of isooctane, ortho-xylene and naphthalene) over Rh/Ce0.75Zr0.25O2-δ-ƞ-Al2O3/FeCrAl and Rh/Ni–MgO/Ce0.75Zr0.25O2-δ-ƞ-Al2O3/FeCrAl was performed. Both catalysts showed excellent performance in ATR of isooctane at molar ratios of O2:C = 0.51 and H2O:C = 2.59, T = 750°С and GHSV = 10000 h−1. In the ATR of isooctane – o-xylene blend in presence of Rh–Ni-containing catalyst carbon formation was observed. Rh-containing catalyst demonstrated rather good activity and stability even in the case of isooctane – o-xylene – naphthalene blend.

FORENSIC INVESTIGATION OF PETROLEUM COMPONENTS OF MIXED MOTOR GASOLINES

The main types of petroleum components that are used in the manufacture of mixed motor gasolines are considered. For the manufacture of mixed motor gasolines, a low-octane base is used, to which high-octane components are added. In many cases, reformate (catalytic reforming gasoline) and isopentane (isopentane fraction) are used as high-octane components of mixed motor gasolines. Straight-run gasoline and stable gasoline are often used as the low-octane gasoline base of blended automobile gasolines. Reformate is a liquid mixture of aromatic and saturated hydrocarbons used as a high-octane component of automobile (aviation) gasolines and raw materials in the production of aromatic hydrocarbons (arenas). The reformate is obtained by catalytic reforming of straight-run gasoline fractions. Isopentane (2-methylbutane (CH3)2CHCH2CH3) is a colorless, flammable liquid. The technical product is a mixture of isomeric pentanes and boils within 24 - 34°C. The isopentane fraction can be isolated from gas gasoline, from gasoline direct distillation of oil and gasoline catalytic cracking. Straight-run gasoline (nefras) is obtained from the processing of crude oil or gas condensate, oil shale or coal, natural gas or oil and gas. Straight run gasoline contains light gasoline fractions of direct distillation of oil with a boiling range of 35 - 180°C. Gas gasoline (gas stable gasoline) is obtained from natural and petroleum gases containing vapors of gasoline hydrocarbons. To separate them, the gases are compressed and cooled (compression method) or absorbed with oil or activated carbon. Gas gasoline is similar in chemical composition to straight-run gasoline, but contains lighter hydrocarbon fractions. The article discusses the results of a study of the listed petroleum components of mixed gasoline by gas-liquid chromatography. This method allows you to establish the qualitative and quantitative composition of mixed motor gasolines and their components. It is shown that from readily available petroleum components (isopentane fraction, aromatic hydrocarbons and gas stable gasoline) without the use of sophisticated technological equipment, a gasoline mixture with high detonation resistance, which is falsified automobile gasoline, can be obtained by mixing method. When mixed in certain proportions of reformate, isopentane fraction and gas stable gasoline, it is possible to obtain marketable gasoline that will meet the requirements of regulatory documents for gasoline. The considered technology allows, when mixing commodity gasolines A-92 (A-95) with reformate, isopentane fraction and gasoline gas stable in the calculated proportions, to improve the operational characteristics (detonation resistance) of the obtained gasoline mixture or to increase the volume of the obtained gasoline mixture without improving its performance.

Clustering problem in modeling the composition of a mixture of catalytic reforming of gasoline

Clustering problem in modeling the composition of a mixture of catalytic reforming of gasoline

RESEARCH OF COMPOSITION OF ANTIWEAR ADDITIVES FOR JET FUELS

In the framework of the state import substitution program for the development of a domestic antiwear additive for jet fuels the physicochemical characteristics of the approved foreign antiwear additives of DNK, HITEC 580 and Unicor J were analyzed at the first stage. The analysis revealed that using solvents during the production of HITEC 580 additives and Unicor J improve their consumer properties (low temperature characteristics). At the second stage of the study the composition of currently used additives HITEC 580 and Unicor J was studied by gas chromatography-mass spectrometry. It was shown, that the same active component is used in their composition - dimers of unsaturated fatty acids C18, namely a mixture of dimers of linolenic, linoleic and oleic acids, among which the dimer formed from linoleic and oleic acids prevails. An analysis of the solvents used in the additive composition showed that in the production of Unicor J additives they use an aromatic solvent containing 92% of monoaromatic compounds, mainly of the C10 series, which is probably the product of gasoline reforming, and HITEC 580 additives use an aliphatic solvent containing mainly n alkanes (41%). From the presented results of the study it follows that when developing a domestic antiwear additive formulation, it is necessary to choose compounds containing 1 or 2 carboxyl groups as the active component, and as the solvent either aromatic or aliphatic, depending on the cost and availability on the domestic market.

Исследование математической модели каталитического риформинга бензина методами анализа чувствительности

Для изучения одного из важнейших процессов нефтепереработки — каталитического риформинга, требуется детализированная кинетическая модель. При разработке кинетической модели возникает сложность в связи с большим количеством компонентов реакционной смеси и большим количеством стадий химических превращений. Альтернативой могут быть сокращенные механизмы реакций, которые применимы для решения задачи и обеспечивают реалистичное описание процесса. В данной работе для анализа кинетической модели и получения сокращенного механизма реакции используются методы анализа чувствительности математической модели. Применение указанной методики позволяет выявить стадии каталитического риформинга бензина, наименее влияющие на общую динамику изменения концентраций значимых веществ реакции. Исследовано влияние исключения данных стадий на кинетику процесса с химической точки зрения. Предложена редуцированная схема каталитического риформинга бензина с исключением данных стадий. Редуцированная схема обеспечивает вполне удовлетворительное согласие как по профилям температуры, так и по профилям концентраций значимых веществ реакции. A detailed kinetic model is required to study one of the most important oil refining processes known as catalytic reforming. The difficulty arises in connection with a large number of components of the reaction mixture and a large number of stages of chemical transformations in developing the kinetic model. An alternative may be reduced reaction mechanisms that are applicable to solve the problem and provide a realistic description of the process. In this paper, to analyze the kinetic model and to obtain an abbreviated reaction mechanism, the sensitivity analysis methods of the mathematical model are used. The least influential stages of catalytic reforming of gasoline, which do not affect the general dynamics of changes in the concentrations of significant reaction substances are identified using this technique. The effect of eliminating these stages on the kinetics of the process from the chemical point of view is analyzed. A reduced scheme for catalytic reforming of gasoline by excluding these stages is proposed. A reduced scheme provides a quite satisfactory agreement both in temperature profiles and in concentration profiles of significant substances.

Catalytic reforming and compounding processes as methods for increasing the octane number in gasoline, used on an industrial scale

The article discusses the urgent problem of industrial methods for increasing the octane number that improve the quality of gasoline produced. These methods include the processes of catalytic reforming and compounding of gasoline. Reforming from "to reform" (English) — to remodel, to improve. Reformate, depending on the production technology and composition of the raw material, may contain up to 70 % of the mass. aromatic hydrocarbons. Attention to this problem is due to the tightening of environmental requirements for the quality of motor fuel that must comply with modern standards. An effective solution to this problem is to model refining processes with programming. In this article, we apply methods of correlation and regression analysis. Using these methods, you can establish the relationship between two or more variables, thus finding the most effective solution to both technological and economic issues.

Kinetic Model of Catalytic Gasoline Reforming with Consideration for Changes in the Reaction Volume and Thermodynamic Parameters

For an industrially significant process of the catalytic reforming of gasoline, an increase in the octane number of gasoline and limitations on the concentrations of aromatic hydrocarbons and benzene are the most important problems. To solve these problems, an analysis of the reactor unit based on a detailed kinetic model of the process was proposed. In the grouped kinetic model of the catalytic reforming of gasoline, changes in the volume of the reaction mixture in the course of chemical transformations were taken into account. For the process of catalytic gasoline reforming, an algorithm was formulated and thermodynamic parameters were determined for grouped individual hydrocarbons. The inverse kinetic problem of restoring the kinetic parameters of stages was posed for the developed mathematical model. The residual functionals that take into account the experimental data on component concentrations and temperature changes during the entire process were determined. The concentrations of the group components in the catalytic reaction of gasoline reforming and the full temperature profile of the process were calculated. The results of solving the two-criterion optimization problem for a minimum concentration of aromatic hydrocarbons at a maximum octane number of the reformate based on the developed kinetic model are presented.

Каталитический риформинг бензиновой фракции смеси нефтей Южного региона Республики Казахстан

В статье рассматриваются результаты исследования процесса каталитического риформинга прямогонного бензина, полученного из смеси нефти месторождений, расположенных в Южном регионе Казахстана. Изучен индивидуальный и групповой углеводородный состав исходного гидроочищенного бензина и риформата с целью установления степени превращения углеводородов на разных этапах каталитического риформинга. В результате исследования процесса каталитического риформинга прямогонного бензиновой фракции (85–180°С) установлен химизм и механизм реакций, которые основываются на следующих реакциях: дегидроциклизация парафиновых углеводородов, дегидрирование и дегидроизомеризация нафтеновых, изомеризация нафтеновых и парафиновых углеводородов. Сравнение физико-химических свойств и группового углеводородного состава гидрогенизата и продуктов риформинга показывает, что сумма н-парафиновых и нафтеновых углеводородов после каталитического риформинга уменьшается в 3–4 раза по сравнению с исходным бензином, а концентрация ароматических углеводородов значительно возрастает за счет реакции дегидрирования цикланов и дегидроциклизации нормальных парафинов.

Improving the thermal efficiency of a T-GDI engine using hydrogen from combined steam and partial oxidation exhaust gas reforming of gasoline under low-load stoichiometric conditions

Hydrogen (H2) addition is known to have features of increasing the laminar burning velocity (Di Sarli and Di Benedetto, 2007), the resistance of the flame to strain-induced extinction (Di Sarli and Di Benedetto, 2012, 2013), and also enlarging the operating window of stable combustion (Di Sarli, 2014). We experimentally investigated how to improve the thermal efficiency of a turbo gasoline direct injection (T-GDI) engine using H2 from combined steam and partial oxidation exhaust gas gasoline reforming under low-load stoichiometric conditions. During real driving, 4 and 6 bar brake mean effective pressure (BMEP) at 2,000 rpm are frequently used. Our experimental results show that reformed H2 improves the brake thermal efficiency (BTE) of T-GDI engines operating at 4 and 6 bar BMEP. Furthermore, the combustion speed (increasing heat release rate) and stability (reducing cyclic variation) were enhanced by reformed H2, making more heavy exhaust gas recirculation (EGR) operation. Combining steam and partial oxidation exhaust gas gasoline reforming with extra air injection to a reformer had a large effect on the fuel conversion efficiency of the reformer as the engine load decreased. Therefore, the BTE of the T-GDI engine with combined steam and partial oxidation reforming achieved further improvement over steam reforming only at 4 bar BMEP. Nitrogen oxide (NOX) emissions increased with reformed H2. However, on the basis of the improved combustion stability achieved using reformed H2, NOX emissions could be reduced further by using a higher EGR rate while enhancing the BTE.

Multiobjective optimization of a temperature mode in a reactor unit of gasoline catalytic reforming based on a kinetic model

Based on the previously developed kinetic model of gasoline catalytic reforming, the temperature regimes of gasoline catalytic reforming are optimized. Several target optimization functions are considered — yield of the main product required octane number with a restriction to benzene content (high-octane component, <2% by volume), etc. The proposed two-objective optimization problem for catalytic reforming of gasoline was solved with the Non-dominated Sorting Genetic Algorithm II (NSGA-II) in Matlab software environment The optimal inlet temperatures of the reaction mixture are determined for each reactor.

Plasma reforming of n-pentane as a simulated gasoline to hydrogen and cleaner carbon-based fuels

Nonthermal plasma is a promising technology for the on-board reforming of gasoline or diesel fuels into cleaner fuels. However, the formation of deep cracking products, such as carbon particulates, discourages the development of an environmentally friendly process. The authors report the reformation of n-pentane (C5H12) using methane (CH4) or carbon dioxide (CO2) in a temperature-controlled dielectric barrier discharge reactor to produce the H2 and carbon-based clean products. A mechanistic study suggests that electron-induced chemistry dominates C5H12 and the added gas conversion, whereas the thermochemistry controls the product distribution. On this basis, the product distribution is varied by the enriched CH3 and H, or the enriched O by adding CH4 or CO2. When increasing CH4 percentage from 0 to 75%, the production of short-chain alkanes (C1–C4 alkanes) and H2 were increased by around 29% and 45%, respectively. The increase in CO2 (0–75%) percentage resulted in the increased production of oxygenated fuels (0–9%). Our results emphasize the advantages of using low-temperature plasma for the co-production of H2 and clean carbon-based fuels (chemical intermediates), which may offer a new concept for the design of a practical on-board plasma reformer.

Benzene Reduction in Reformate Gasoline by Competitive Hydrogenation: Effect of the Preparation Method

AbstractThe hydrogenation of benzene in reformate gasoline was carried out over nickel supported on silica prepared by precipitation‐gel, co‐precipitation, deposition‐precipitation and sol‐gel techniques. The evaluation was investigated in a continuous fixed bed reactor fed by a stream of reformate gasoline at 398–473 K under atmospheric pressure. X‐ray diffraction, Field emission scanning electron microscopy, X‐ray fluorescence, energy dispersive X‐ray spectrometry‐map, H2 chemisorption and N2 adsorption/desorption techniques have been used to characterize the influence of preparation methods. In the present work, the influences of H2/benzene molar ratios and space velocities on catalytic activity were studied by calculating conversion, specific rate during the benzene hydrogenation. The results show that the surface area of supports is not effective on metal dispersion, and it depends upon the preparation method, the content of metal loading, and interaction between metal and supports. Benzene conversion with catalyst prepared by sol‐gel and deposition‐precipitation method was 4–6 times more than that of toluene. The best performance of benzene hydrogenation was achieved with catalyst prepared by deposition‐precipitation method at 448 K. Among the preparation method, deposition‐precipitation was the best method for preparation of nickel catalyst due to the high and homogeneous dispersion of nickel particles.

Mathematical modeling of multicomponent catalytic processes of petroleum refining and petrochemistry

Abstract This review summarizes Russian developments on the most important industrial processes of hydrocarbon feedstock refining according to the data of the last 15–20 years on the kinetics of deactivation of heterogeneous and liquid-phase catalysts under non-stationary conditions. The methodological aspects of the creation and application of kinetic models for the deactivation of heterogeneous and liquid-phase catalysts under non-stationary conditions are considered. It is shown that high efficiency of catalytic technologies is ensured by regulation of hydrodynamic and thermal conditions of industrial processes of gasoline reforming, alkane dehydrogenation, alkylation of benzene with higher alkenes and catalytic dewaxing using kinetic models, which take into account catalyst deactivation.

Pd and Pt supported on mesoporous silica, silica–alumina and alumina as catalysts for benzene elimination in reformate gasoline

Mesoporous silica FDU12 and mesoporous silica–alumina (MSA) were successfully synthesized and used as supports. The corresponding Pd and Pt catalysts were investigated to reduce the benzene in reformate gasoline at 423–473 K. The catalysts were characterized by XRD, XRF, EDS-map, H2-adsorption, NH3-adsorption, Py-IR and N2 adsorption/desorption techniques. The influences of temperature on catalytic activity were studied by calculating the conversion and specific rate. All prepared catalysts showed high activity at low temperature. To evaluate the performance of catalysts, different H2/benzene molar ratios were used. The highest conversion of benzene is achieved at the low temperatures. The results demonstrated that the Pd/FDU12 catalyst has the best catalytic performance with suitable Lewis acid site properties. The MSA support demonstrated high activity in toluene conversion due to pore size and Bronsted and Lewis acid site amounts. Benzene molecules find a greater chance of hydrogenation at a high resident time in low H2/benzene molar ratio.

Sensitivity analysis of the mathematical model of catalytic reforming of gasoline

Sensitivity analysis of the mathematical model of catalytic reforming of gasoline