The paper presents the development of a non-stationary mathematical model of alkylbenzene sulfona-tion in a falling-film reactor accounting for the formation of high-viscosity and chromophoric by-products to predict the duration of the inter-washing cycle

A numerical model for practical simulation of hydrotreatment of vacuum gas oil in a trickle-bed reactor is developed. The model is based on the mass balance of species; it incorporates a seven-lump chemical scheme that describes the reactions of hydrodesulphurisation and hydrodearomatisation, the accuracy of calculations using the model is no less than 93.7

The development of alternative liquid fuels based on renewable and secondary carbon-containing feedstocks is of strategic importance due to growing shortage of fossil resources and increasingly stringent environmental requirements. This review analyzes the current state of research in the field of alternative liquid fuels for engine and power systems. The most significant achievements and limitations that hinder the extensive practical use of biofuel compositions are outlined. The nomenclature of raw materials is defined. The requirements to the main properties of components of alternative liquid fuels are formulated. The most promising production processes are characterized. The possibility of integration of hybrid engineering solutions into existing plants is substantiated, considering multicriteria selection of components and catalysts, which opens up new prospects for the development and scaling of sustainable fuel systems. The techno-economic and environmental features of the thermal conversion of fuels in engine and power systems are identified. The bibliography includes 410 references.

Энергия шығындарының артуы мен экологиялық талаптардың күшеюі жағдайында мұнайды өңдеу процестерін оңтайландыру ерекше маңызға ие болып табылады. Энергияны ең көп қажет ететін процестердің бірі – вакуумдық газойльді алу және оны одан әрі қарай өңдеу, бұл шикізат каталитикалық крекинг үшін пайдаланылады. Мұнайды ұтымды өңдеу, экологиялық қасиеттері жақсартылған сапалы өнімдер алу мәселесі өте өзекті. Осыған байланысты мұнайды терең өңдеуге дайындау өте маңызды. Вакуумдық газойль – қайта өңдеудің маңызды шикізаты, оны алу және қайта өңдеу процестерінің энергия сыйымдылығы жоғары. Вакуумдық газойльді гидротазарту процесінің математикалық моделі қайта өңделетін шикізат пен алынған өнімнің энергетикалық сипаттамаларын жақсартудың және күкірт қосылыстарының қоршаған ортаға әсерін азайтудың, сондай-ақ крекинг катализаторының улануын азайтудың маңызды құралы болып табылады. Энергия тиімділігін арттыру арқылы энергия тұтынудың салыстырмалы түрде төмендеуімен өндіріс өсімінің энергия тұтынудың өсуімен ажырамас байланысы бар. Математикалық модель әдісін қолдану нәтижелері шикізат түріне байланысты қондырғының технологиялық режимін оңтайландыру, процестің жұмыс параметрлері, өңделетін шикізаттың құрамы өзгерген кезде қондырғының материалдық балансын болжау және вакуумдық газойльді гидротазарту процесінің энергетикалық тиімділігін арттыру сияқты бірнеше өндірістік мәселелерді шешуге мүмкіндік береді. Кілтті сөздер: вакуумдық газойль, гидротазарту, математикалық модель, фракциялық құрам, болжау, талдау.

The patterns of deactivation of liquid reaction media during the formation of highly viscous components, along with the mechanism and chemistry of hydrocarbon conversions in multicomponent feedstock, as well as the kinetic and hydrodynamic parameters of the process, were considered. A mathematical model was developed that takes all these factors into account. The reliability of the results obtained from numerical modeling of the alkylbenzene sulfonation reactor with SO3was confirmed by their strong agreement with industrial data collected from an operating alkylbenzene sulfonic acid production facility over an extended period. Using the developed mathematical model, an optimal set of design characteristics for the alkylbenzene sulfonation reactor was determined. Modifying the reactor design by increasing the diameter of the reaction tubes from 25 mm to 43 mm and reducing their number from 120 to 40 while maintaining a constant reaction volume led to a 45.5 % increase in the duration of the reactor's washing cycle.

Актуальность исследования заключается в необходимости повышения эффективности производства алкилбензосульфокислот как полуфабрикатов синтетических моющих средств с хорошими моющими характеристиками и высокой биологической разлагаемостью, потребление которых растет на мировом рынке со среднегодовым темпом 3,3 %. Применение современных методов мониторинга и контроля параметров реакции в режиме реального времени позволит оптимизировать технологический процесс и обеспечить стабильность качества алкилбензосульфокислот, обуславливая оптимальную активность реакционной среды. Цель: совершенствование жидкофазных процессов получения алкилбензосульфокислот в промышленных реакторах в условиях дезактивации реакционных сред с использованием нестационарных математических моделей. Объект: установка синтеза алкилбензосульфокислот. Методы: метод математического моделирования многокомпонентных нестационарных химико-технологических процессов нефтепереработки и нефтехимии, квантово-химические методы расчета термодинамических функций, численные методы решения систем нелинейных дифференциальных уравнений. Результаты. Были разработаны математические модели реакторов реакционных процессов алкилирования бензола олефинами и сульфирования алкилбензолов, которые позволяют рассчитывать активность HF-катализатора алкилирования в зависимости от количества кислото-растворимых масел в реакторе и динамику изменения активности реакционной среды процесса сульфирования в зависимости от концентрации высоковязких тетрелинов и сульфонов. Предложенa методика расчета текущей и оптимальной активности HF-катализатора на стадии алкилирования, которая позволяет точно оценить влияние концентрации кислото-растворимых масел на активность катализатора и оптимизировать технологический режим для поддержания его активности на оптимальном уровне. Получены результаты оптимизационного расчета соотношения SO3/алкилбензолы в процессе сульфирования алкилбензолов с различным содержанием легких ароматических соединений с боковым радикалом С1­–С4 в сырье.

Relevance. Expansion of catalytic cracking feedstock resources both due to the need to intensify the process to increase the yield of target products (high-octane gasoline, light olefins) and to deepen oil refining through the utilization of low-margin streams at refineries. Along with this, there is an urgent need to develop domestic mathematical tools for optimizing the catalytic cracking, predicting the process performance when the modes and feedstock qualities changes, as well as planning of production. This requires in-depth analysis and detailed study of the composition of oil fractions involved in processing and thermodynamics and kinetics of a heterogeneous process. The development and application of a mathematical model of the catalytic cracking, taking into account the composition and properties of the components involved in processing, makes it possible to quantitatively assess the yield and quality of target and by-products depending on the composition, physicochemical properties of the mixed feedstock, and the parameters of the technological regime, with an assessment of the possibility of their processing at an existing industrial facility. Aim. Experimental study of the composition and properties of mixed feedstock of catalytic cracking based on vacuum gas oil containing 5 to 20 wt % of extract of selective cleaning of oils, distillate, residual slack wax, and deasphalted oil, and prediction of the catalytic cracking indicators during their co-processing using a mathematical model. Methods. Liquid chromatography method to study the composition of feedstock materials of the catalytic cracking in combination with a number of standard methods for determining physico-chemical properties. Results. Using a set of experimental studies, the authors have established the patterns of changes in the composition and physico-chemical properties of the components and mixed feedstock of catalytic cracking containing 5–20 wt % of distillate and residual slack wax, deasphalted oil, and extract. The results obtained were used in development of a mathematical model of the heterogeneous catalytic cracking of feedstock, which takes into account the composition of oil fractions involved in processing and the patterns of catalyst deactivation by coke. Using a mathematical model, the authors established the patterns of changes in the composition and yield of process products when 5–20 wt % were involved in processing distillate slack wax and extracts of selective cleaning of oils mixed with vacuum distillate. Practical recommendations were developed on the possibility of expanding the hydrocarbon feedstock of the catalytic cracking, taking into account the fuel or petrochemical regime.

Relevance. The lack of a reliable mathematical model suitable for predicting the yield and quality of products in catalytic cracking units, with an assessment of the environmental indicators of fuel fractions when changing the hydrocarbon composition and distribution of sulfur compounds in the process feedstock, as well as the possibility of involving highly sulfur-containing oil streams in processing on existing catalytic cracking units. Aim. To develop and apply a mathematical model of the catalytic cracking to predict the content of sulfur compounds and total sulfur in the products during the processing of hydrotreated and non-hydrotreated petroleum feedstocks. Methods. A complex of experimental methods, including liquid and gas chromatography to determine the composition of the feedstock and the distribution of sulfur compounds in the feedstock and catalytic cracking products, methods of quantum chemical modeling of reactions involving sulfur compounds, as well as numerical methods for processing and solving systems of differential equations. Quantum chemical modeling methods were used to study the thermodynamic parameters of catalytic cracking reactions involving sulfur-containing compounds. Results. The authors have developed and implemented in software a mathematical model of catalytic cracking involving hydrocarbons C1–C40+ and sulfur compounds (thiophenes C0–C4, alkylbenzothiophenes C0–C6, C0–C3 dibenzothiophenes, and C4–dibenzothiophene-benzonaphthothiophenes). The model aims to predict the yield and composition of process products, as well as the environmental indicators of motor fuels. Thermodynamic and kinetic parameters of catalytic cracking reactions were determined using quantum chemical modeling methods and solving the inverse kinetic problem.

Linear alkylbenzene sulfonic acid (ABSA) is used to produce industrial and domestic synthetic detergents and is obtained via a multistage technology. Unsteady-state mathematical model considering mass transfer was developed for linear alkylbenzenes (LAB) sulfonation technological stage. With use of the developed model we studied how the modes in the film sulfonation reactor influence the product quality and yield. The varied parameters were SO3 concentration in the air flow, process temperature and SO3/LAB molar ratio. It was found that the air flow rate of 10,000 m3/h, temperature 30 °C, pressure 170 kPa are the optimal process conditions. Under these conditions, the degree of the feedstock conversion is close to 1, and the share of the target product is about 98.4 wt.%.

Ссылка для цитирования: Инженерные модели процессов нефтепереработки: повышение эффективности многостадийного производства бензинов / Е.И. Ивашкина, А.Г. Кокшаров, А.Г. Иванчина, В.А. Чузлов, Г.Ю. Назарова, Е.С. Чернякова, И.М. Долганов // Известия Томского политехнического университета. Инжиниринг георесурсов. – 2023. – Т. 334. – № 4. – С.195-208. Актуальность работы обусловлена необходимостью импортозамещения программного обеспечения в области проектирования, моделирования и оптимизации процессов подготовки и переработки нефти и газа. Практически все используемые на предприятиях нефтегазового сектора пакеты моделирующих систем представляют собой разработки США, Канады, Великобритании и других стран. В сложившихся условиях санкционных рисков по использованию импортного программного обеспечения для моделирования технологических процессов крайне актуальной задачей является разработка и быстрая адаптация инженерных математических моделей всех базовых процессов нефтепереработки, которые в дальнейшем станут основой российских импортозамещающих программных продуктов. В Национальном исследовательском Томском политехническом университете более 30 лет проводятся исследования процессов получения моторных топлив, на основании которых разработаны надежные математические модели таких технологий, как каталитический риформинг бензинов, изомеризация пентан-гексановой фракции углеводородов, каталитический крекинг вакуумного дистиллята и смесевого нефтяного сырья, гидропереработки нефтяных фракций, компаундирование высокооктановых бензинов и других. Отличительной особенностью разработанных математических моделей является то, что они, с одной стороны, построены на основе фактических промышленных данных по эксплуатации установок на различных НПЗ, а с другой, учитывают основные фундаментальные физико-химические закономерности механизмов реакций, дезактивации катализаторов, макрокинетические факторы процессов производства моторных топлив. Решение многокритериальной задачи оптимизации технологии приготовления моторных топлив (бензинов и дизельных топлив) возможно с применением метода математического моделирования на физико-химической основе, т. е. с учетом термодинамики и кинетики превращений углеводородов на поверхности катализатора, а также нестационарности протекания процессов ввиду закоксовывания, старения и отравления вредными примесями катализатора, изменения химического состава перерабатываемого сырья. Цель: разработка технических решений, направленных на повышение эффективности многостадийного производства бензинов с использованием инженерных моделей процессов нефтепереработки. Методы исследования базируются на использовании математического моделирования многокомпонентных процессов переработки углеводородного сырья. В качестве исходных данных использованы результаты хроматографического определения группового и индивидуального состава различных нефтяных фракций. Результаты. Выполнены оценка и прогнозирование влияние компонентного состава перерабатываемого сырья каталитического риформинга на качественные и количественные характеристики компонентов товарного бензина. Применение модели каталитического крекинга показало, что выход целевых продуктов процесса и активности катализатора выше на 4,9 и 6,7 % масс. при переработке сырья с более низким содержанием ароматических углеводородов и смол (29,9 и 1,6 % масс.), что связано со снижением содержания кокса на катализаторе на 0,15 % масс. Определен максимальный выход бензина для двух типов сырья (55,4 и 56,5 % масс.), который достигается при 536,0 и 534,0 °С, что объясняется их углеводородным составом. Выполнены прогнозные расчеты с оценкой влияния состава потока бензиновой фракции каталитического крекинга на рецептуру и товарные качества получаемого товарного бензина при использовании более легкого сырья на установке крекинга. Показана возможность увеличения доли потока бензиновой фракции каталитического крекинга в рецептуру приготовления товарного бензина. Себестоимость производства моторного топлива в этом случае снижается на величину от 0,1 до 1,0 %.

Abstract We develop a numerical model for practical simulation of hydrotreatment of vacuum gas oil in a trickle-bed reactor. The model is based on the mass balance of species; it incorporates a seven-lump chemical scheme that describes the reactions of hydrodesulphurisation and hydrodearomatisation. The novelty of the model is splitting of sulphur-containing compounds into different lumps by their reactive abilities. The splitting is supported by the chromatographic analysis of hydrocarbon mixtures that are sampled from the inlet and outlet ends of an industrial hydrotreatment unit. The analysis reveals different susceptibilities of sulphides, benzothiophene, and dibenzothiophenes to hydrotreatment. The new model is applied for simulation of the hydrotreatment at a refinery, adjusting kinetic parameters, and demonstrating that the model provides an adequate (and, at the same time, simple) description of the process, giving guidance for optimisation that is needed after each variation of the feedstock.

Link for citation: Nazarova G.Y., Ivashkina E.N., Maltsev V.V. Calculation of thermodynamic and kinetic parameters of catalytic cracking reactions on Lewis and Brønsted acid sites. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 7, рр. 214-225. In Rus. The relevance of the research is caused by the emerging necessity of developing a mathematical model to optimize the heterogeneous process of catalytic cracking. This tools should take into account both the chemical transformations of a wide range of hydrocarbon groups (different feedstock types), as well as the stages of adsorption, reactants diffusion, conversion of hydrocarbons on the catalyst surface, acid characteristics and pore size of the catalysts. The study of the hydrocarbon conversion patterns on Lewis or Brønsted acid sites using quantum-chemical modeling methods allow us to quantify the thermodynamic parameters of reactants adsorption, the kinetic parameters of carbocations formation and cracking on acid sites. These results are necessary to develop a mathematical model based on the of heterogeneous catalytic reaction mechanism. The aim of this work is to identify the level of quantum chemical theory and to determine the thermodynamic and kinetic parameters of reactants adsorption, carbenium ions formationand hydrocarbons cracking on Lewis and Brønsted acid sites. Methods: quantum-chemical modeling methods to optimize the molecular geometry of reactants and products of catalytic cracking reactions, calculate vibrational frequencies, thermodynamic parameters of adsorption and catalytic cracking of hydrocarbons and heteroatomic compounds with the participation of Bronsted and Lewis acid sites. Results. The chosen level of quantum-chemical theory allowed obtaining the results that are consistent with the laws of the process and the experimental reactivity of hydrocarbons in cracking reactions on acid catalysts. The thermodynamic parameters of the adsorption of C6–C16 hydrocarbons and thiophenes on Lewis and Brønsted acid sites were identified. We found that during the cracking of n-hexane on the Lewis acid site, the reaction is limited by the carbenium ion formation stage.The activation energy of this stage was 281,3 kJ/mol whereas the value for the cracking stage was 277,2 kJ/mol. Further study shows that the activation energy of carbenium ion formation from izohexane and C8–C10 alkanes with normal structure on the Lewis acid site was 257,6 and 279,2…277,9 kJ/mol. The most energetically favorable is the formation of carbocation from hexene at Brønsted acid sites (76,59 kJ/mol). The results of the work will be used to create a mathematical model of a heterogeneous process based on the Langmuir–Hinshelwood equations.

Results from calculating the thermochemical properties of molecules and the thermodynamic characteristics of vacuum distillate hydrotreatment reactions by quantum-chemical methods are presented. A mathematical hydrotreatment model is developed on the basis of a formalized scheme of reactions for hydrocarbons. The developed kinetic model is used in numerical studies to estimate the effect of the feedstock composition on the residual content of heteroatomic compounds in the vacuum gasoil hydrotreatment product, the effect of the temperature on the content of aromatic hydrocarbons, nitrogen, and sulfur in the hydrotreatment product, and flow rate of the hydrogen-containing gas on the content of sulfur and hydrogen sulfide in hydrotreated vacuum gasoil.

The relevance of this study is caused by the need for import substitution of software in the field of design, modeling and optimization of the gas and oil processing. Almost all software for modeling used at oil and gas entities are the developments of the USA, Canada, Great Bri-tain and other countries. In the current conditions of sanctions risks on using imported software for modeling technological processes, the development and rapid adaptation of engineering mathematical models of all basic oil refining processes are an extremely urgent task. These models will further become the basis of Russian import-substituting software products. Over the course of 30 years, the National Research Tomsk Polytechnic University has been researching the processes of the motor fuels production. On the basis of these studies the reliable mathematical models have been developed for technologies such as catalytic reforming of gasoline, isomerization of the hy-drocarbons pentane-hexane fraction, catalytic cracking of vacuum distillate and mixed petroleum feedstock, hydroprocessing of petroleum fractions, compounding of high-octane gasolines, and others. Distinctive features of the developed mathematical models are related to fol-lowing: firstly, they are built on the basis of real industrial data on the operation units at various refineries and, secondly, they take into ac-count the main fundamental physical and chemical laws of reaction mechanisms, the catalyst deactivation as well as the macrokinetic fac-tors of motor fuel production processes. The solution of multicriteria problem of optimizing the technology of preparation of motor fuels (gasoline and diesel fuels) is possible using the method of mathematical modeling on a physical and chemical basis. This approach takes into account the thermodynamics and kinetics of hydrocarbon conversions on the catalyst surface, as well as the non-stationarity of the processes due to coking, aging and poisoning by harmful impurities of the catalyst, changes in the chemical composition of the feedstock. The aim of this study is to develop the technical solutions aimed at improving the efficiency of multi-stage gasoline production using the engineering models of oil refining processes. The method of the research is based on using the mathematical modeling method for multi-stage processes of petroleum feedstock refining. The group and individual composition of various petroleum fractions determined by chromatographic methods, were used as an initial data. Results. The effect of the component composition of the processed feedstock of catalytic reforming on the qualitative and quantitative properties of the components of commercial gasoline was estimated and predicted. The use of the catalytic cracking model showed that when processing the feedstock with a lower content of aromatic hydrocarbons and resins the coke content on the catalyst is lower by 0,15 % wt. This leads to increasing the catalyst activity and the desired product yields by 6,7 % and 4,9 wt. % in comparison with the feedstock with higher content of resins and aromatics.The maximum gasoline yield for two types of the feedstocks (55,4 and 56,5 % wt.) which is achieved at 536,0 and 534,0 degrees C was determined according to their hydrocarbon compositions. The predictive calculations with an assess-ment of how the composition of the catalytic cracking gasoline influences the formulation and commercial quality of the commercial gaso-line using the lighter catalytic cracking feedstock, were performed. The possibility of increasing the amount of the catalytic cracking gaso-line into the commercial gasoline formula is shown. The cost of motor fuel production in this case is reduced from 0,1 to 1,0 %.

The relevance. Lack of experimental data that allow developing a scientifically based method for calculating and designing film-type reactors, which are also used to produce alkylbenzenesulfonic acids. These acids, in their turn, are currently the main components of synthetic detergents. The issue of increasing reactor equipment efficiency can be most effectively solved using mathematical models built on a physical and chemical basis. The aim. Development of a mathematical model of alkylbenzenes sulfonation, taking into account a substance mass transfer from a gas phase to a liquid phase. Software implementation of the developed model, as well as the use of the developed mathematical model for studying the influence of the process parameters on its efficiency. Object. Alkylbenzenes sulfonation with sulfuric anhydride in a multitube film reactor. Methods. Mathematical modeling is used to perform all computational operations, a modern high-level general-purpose programming language with automatic memory management is used. The quantum-chemical methods for determining thermodynamic parameters of chemical reactions were used. Results. The paper considers the principles of constructing a mathematical model of sulfonation. The authors have developed the calculation program in the Python programming language and assessed the accuracy of description of a real process and the influence of the system technological parameters on a product yield and quality, taking into account a substance interfacial transfer. The system of practical recommendations for improving the alkylbenzenes sulfonation resource efficiency was developed. The mathematical model adequately describes the process. The calculated data are compared with the real data from the operating unit for alkylbenzenes sulfonation with sulfuric anhydride.

The relevance. Lack of experimental data that allow developing a scientifically based method for calculating and designing film-type reactors, which are also used to produce alkylbenzenesulfonic acids. These acids, in their turn, are currently the main components of synthetic detergents. The issue of increasing reactor equipment efficiency can be most effectively solved using mathematical models built on a physical and chemical basis. The aim. Development of a mathematical model of alkylbenzenes sulfonation, taking into account a substance mass transfer from a gas phase to a liquid phase. Software implementation of the developed model, as well as the use of the developed mathematical model for studying the influence of the process parameters on its efficiency. Object. Alkylbenzenes sulfonation with sulfuric anhydride in a multitube film reactor. Methods. Mathematical modeling is used to perform all computational operations, a modern high-level general-purpose programming language with automatic memory management is used. The quantum-chemical methods for determining thermodynamic parameters of chemical reactions were used. Results. The paper considers the principles of constructing a mathematical model of sulfonation. The authors have developed the calculation program in the Python programming language and assessed the accuracy of description of a real process and the influence of the system technological parameters on a product yield and quality, taking into account a substance interfacial transfer. The system of practical recommendations for improving the alkylbenzenes sulfonation resource efficiency was developed. The mathematical model adequately describes the process. The calculated data are compared with the real data from the operating unit for alkylbenzenes sulfonation with sulfuric anhydride.

An ever-increasing complexity of the models of catalytic cracking (which is rarely justified by available monitoring data) makes "practical" modeling for industrial units challenging. In this work, we develop a simple numerical model for an industrial catalytic riser, the model with phenomenological parameters that are determined from available monitoring data. The model is based on a four-lump reaction scheme (with coke being one of the lumps), with the kinetic parameters determined for an industrial reactor with a zeolite-containing catalyst that is used for the production of wet gases. The expression for the reaction rate reflects that reactions in the gaseous phase occur in the presence of the solid (catalyst) phase. Hydrodynamics of nonisothermal reactive gas-solid mixtures is captured by a two-fluid model. The strong turbulence nature of the reactor flow makes it possible to disregard the kinetic theory-based values for viscous, diffusion, and thermal conductivity coefficients (additionally reducing the number of needed empirical coefficients). The resultant model is applied for an in-depth analysis of the flow fields in the reactor, demonstrating good agreement of the results with more sophisticated approaches. The model is also applied for the calculation of optimal intakes of water vapor and catalyst.

Changes in the quality of the feedstocks generated by involving various petroleum fractions in catalytic cracking significantly affect catalyst deactivation, which stems from coke formed on the catalyst surface. By conducting experimental studies on feedstocks and catalysts, as well as using industrial data, we studied how the content of saturates, aromatics and resins (SAR) in feedstock and the main process variables, including temperature, consumptions of the feedstock, catalyst and slops, influence the formation of catalytic coke. We also determined catalyst deactivation patterns using TG-DTA, N2 adsorption and TPD, which were further used as a basis for a kinetic model of catalytic cracking. This model helps predict the changes in reactions rates caused by coke formation and, also, evaluates quantitatively how group characteristics of the feedstock, the catalyst-to-oil ratio and slop flow influence the coke content on the catalyst and the degree of catalyst deactivation. We defined that a total loss of acidity changes from 8.6 to 30.4 wt% for spent catalysts, and this depends on SAR content in feedstock and process variables. The results show that despite enriching the feedstock by saturates, the highest coke yields (4.6–5.2 wt%) may be produced due to the high content of resins (2.1–3.5 wt%).