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Modeling and Simulation of Catalytic Reactors for Petroleum Refining: Ancheyta/Modeling Catalytic Reactors

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... Mathematical models are crucial and useful tools to develop proper design and scale-up of reactors for industrial application, as well as to predict their performance under different commercial conditions. Different reactor models have been developed to simulate the performance of hydrotreating process of petroleum fractions [3]. These models have different levels of sophistication and include various kinetic models for the diverse reactions that are taking place. ...
... Higher consumption of hydrogen is obtained (1640 scf/bbl) for HDT of vegetable oil as compared with HDT of petroleum gas oil (300e800 scf/bbl) [3]. This value is consistent with the range reported for palm oil hydrotreating (1100e1900 scf/bbl) due to the high hydrogen demand of cracking triglycerides molecules [18]. ...
Article
A dynamic trickle-bed reactor model was developed to predict the behavior of reactive species and products during the catalytic hydrotreating of vegetable oil. The prediction capability of the model was verified with experimental information obtained during the hydrotreating of a jatropha oil at temperature of 420 °C, hydrogen pressure of 80 bar, 1500 Nl/l of H2/oil ratio and WHSV of 1–12 h⁻¹ using a NiW/SiO2–Al2O3 catalyst. The proposed model allows to predict the partial pressure and concentration profiles along the catalytic bed as a function of the time-on-stream. The dynamic simulation results agree with experimental data reported at steady-state conditions. A comparison of experimental data and calculated results provides a correlation coefficient of 0.988.
... The high temperature catalytic reaction results in the breakdown of large hydrocarbon molecules to lighter fractions of gasoline and diesel, as well as gaseous fuel (LPG) and coke. [17,20,27] The catalyst spends a short time, usually few seconds in the riser reactor, and is separated from hydrocarbon by stripper in the cyclone. After stripping of residual hydrocarbons with steam, the catalyst is regenerated and the coke deposited on the catalyst is burned off with hot air. ...
... [5] In addition to hydrocarbons, crude oil fractions for FCC units contain non-negligible amounts of sulfur, nitrogen, carbon residue, and metals such as nickel, iron and vanadium. [19,27,57,58] The overall performance of the FCC process in the production of liquid fuels is strongly affected by the feedstock properties including the feedstock composition and contaminants. For example, the vacuum and atmospheric residue cuts consist of mainly resins and asphaltenes. ...
Article
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The fluid catalytic cracking (FCC) technology is one of the pillars of the modern petroleum industry which converts the crude oil fractions into many commodity fuels and platform chemicals, such as gasoline. Although the FCC field is quite mature, the research scope is still enormous due to changing FCC feedstock, gradual shifts in market demands and evolved unit operations. In this review, we have described the current status of FCC technology, such as variation in the present day feedstocks and catalysts, and particularly, great attention is paid to the effects of various contaminants of the FCC catalysts of which the latter part has not been sufficiently documented and analyzed in the literature yet. Deposition of various contaminants on cracking catalyst during FCC process, including metals, sulfur, nitrogen and coke originated from feedstocks or generated during FCC reaction constitutes a source of concern to the petroleum refiners from both economic and technological perspectives. It causes not only undesirable effects on the catalysts themselves, but also reduction in catalytic activity and changes in product distribution of the FCC reactions, translating into economic losses. The metal contaminants (vanadium (V), nickel (Ni), iron (Fe) and sodium (Na)) have the most adverse effects that can seriously influence the catalyst structure and performance. Although nitrogen and sulfur are considered less harmful compared to the metal contaminants, it is shown that pore blockage by the coking effect of sulfur and acid sites neutralization by nitrogen are serious problems too. Most recent studies on the deactivation of FCC catalysts at single particle level have provided an in-depth understanding of the deactivation mechanisms. This work will provide the readers with a comprehensive understanding of the current status, related problems and most recent progress made in the FCC technology, and also will deepen insights into the catalyst deactivation mechanisms caused by contaminants and the possible technical approaches to controlling catalyst deactivation problems.
... The atmospheric column includes pump-around and side-strippers, together with other stages, to accomplish accurate divisions of crude oil into desired cuts, while the pre-flash column draws free water, light gas, and light naphtha [10]. There are three cuts (kerosene, light gas oil, heavy gas oil) and two pump rounds in this study. ...
Article
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Crude oil distillation (CDU) is a crucial unit in refinery plants for producing various crude oil cuts, such as naphtha, kerosene, light gas oil, heavy gas oil, and Atm residue. This study used ASPEN HYSYS V11 software to examine the parameters that affect CDU efficiency in South Refinery Company /Iraq-Mishriff crude oil, like temperature, pressure, and flow rate. Optimization of these variables was applied to identify suitable values for separation products. The study reveals that the increased mass flow rate of crude oil to CDU increases the flow rates of naphtha, kerosene, and HGO. The study also examines the impact of the temperature of feed crude oil on CDU. Results show that the volume flow of products increases with increased temperature except the naphtha values decrease. The simulated liquid volume flow for the Naphtha value was 57.96 m 3 /h higher than the original data of 50.7 m 3 /h and the kerosene value was 49.24 m 3 /h lower than the plant value of 51.5 m 3 /h. The effect temperature was also studied, the volume of liquid flow is directly proportional to the increase in temperature of the crude oil, whether it was a TBP or ASTM blend. The refinery and simulated values were compared, and a satisfactory agreement between the simulated and real results was observed, with some clear differences in the LGO values. The cause of this difference may be the result of the changes during the laboratory tests, or Sampling strategies may affect the accuracy of ASTM D86 tests and laboratory results. Optimization is crucial for optimal operating conditions for efficient product production. Most plant data align with optimized conditions, except for some. For instance, the perfect temperature of crude oil in the distillation unit is 382 °C instead of 375 °C, and the better mass flow of LGO steam is 1431 kg/h rather than 1100 kg/h.
... The atmospheric column includes pump-around and side-strippers, together with other stages, to accomplish accurate divisions of crude oil into desired cuts, while the pre-flash column draws free water, light gas, and light naphtha [10]. There are three cuts (kerosene, light gas oil, heavy gas oil) and two pump rounds in this study. ...
Article
Full-text available
Crude oil distillation (CDU) is a crucial unit in refinery plants for producing various crude oil cuts, such as naphtha, kerosene, light gas oil, heavy gas oil, and Atm residue. This study used ASPEN HYSYS V11 software to examine the parameters that affect CDU efficiency in South Refinery Company /Iraq-Mishriff crude oil, like temperature, pressure, and flow rate. Optimization of these variables was applied to identify suitable values for separation products. The study reveals that the increased mass flow rate of crude oil to CDU increases the flow rates of naphtha, kerosene, and HGO. The study also examines the impact of the temperature of feed crude oil on CDU. Results show that the volume flow of products increases with increased temperature except the naphtha values decrease. The simulated liquid volume flow for the Naphtha value was 57.96 m 3 /h higher than the original data of 50.7 m 3 /h and the kerosene value was 49.24 m 3 /h lower than the plant value of 51.5 m 3 /h. The effect temperature was also studied, the volume of liquid flow is directly proportional to the increase in temperature of the crude oil, whether it was a TBP or ASTM blend. The refinery and simulated values were compared, and a satisfactory agreement between the simulated and real results was observed, with some clear differences in the LGO values. The cause of this difference may be the result of the changes during the laboratory tests, or Sampling strategies may affect the accuracy of ASTM D86 tests and laboratory results. Optimization is crucial for optimal operating conditions for efficient product production. Most plant data align with optimized conditions, except for some. For instance, the perfect temperature of crude oil in the distillation unit is 382 °C instead of 375 °C, and the better mass flow of LGO steam is 1431 kg/h rather than 1100 kg/h.
... Накопление загрязнителей на внешней поверхности гранул катализатора ограничивает доступ реагентов к активным центрам катализатора, что может привести к снижению активности гидрообессеривания и гидроазотирования [5,[15][16][17][18][19], а также к росту перепада давления. В промышленности основной вклад в увеличение перепада давления вносит эффект засорения мехпримесями пустот между частицами катализатора за счет глубокого фильтрования [20][21][22][23][24][25]. ...
... Накопление загрязнителей на внешней поверхности гранул катализатора ограничивает доступ реагентов к активным центрам катализатора, что может привести к снижению активности гидрообессеривания и гидроазотирования [5,[15][16][17][18][19], а также к росту перепада давления. В промышленности основной вклад в увеличение перепада давления вносит эффект засорения мехпримесями пустот между частицами катализатора за счет глубокого фильтрования [20][21][22][23][24][25]. ...
Article
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A study was made of the efficiency of trapping solid microparticulates contained in diesel fuel for catalyst loading – an analogue of an industrial package of guard beds of hydroprocesses. The package of catalysts consisted of catalyst granules ranked by shape and size: segmented rings, hollow cylinders of two standard sizes and trilobe shape. The experiments were carried out in the trickle flow regime with a constant ensemble of microparticulates – iron scale with a size of 5 to 150 μm at the inlet of the catalysts loading. It was found that the penetration coefficient of the catalysts loading of the guard beds did not change significantly (K ≈ 0.985) during the experiment. At the same time, a linear increase in the pressure drop on the catalysts loading of the guard beds with a height of 17 cm from 220 to 408 Pa was observed which occurred as a result of the trapping of solid microparticulates by the catalyst granules. The theoretical estimate of the initial pressure drop (228 Pa) coincides with the experimental data (220 Pa) with good accuracy.
... Οι πύργοι διύλισης βρίσκονται στον πυρήνα της διαδικασία διύλισης του αργού πετρελαίου για την παραγωγή των τελικών προϊόντων του, καθώς σε αυτούς εκτελούνται πολυάριθμες χημικές και φυσικές διεργασίες [5]. Από δομικής πλευράς, πρόκειται για λεπτότοιχα μεταλλικά κελύφη με στατικό σύστημα αυτό του κατακόρυφου προβόλου, λειτουργώντας υπό μεταβλητές συνθήκες θερμοκρασίας και εσωτερικές πίεσης. ...
Conference Paper
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Ensuring the structural and operational integrity of oil refineries in case of an earthquake event is of utmost importance for the society, the environment, and the economy. A potential failure in such critical facilities may trigger a number of undesirable situations, such as fire, injuries, environmental pollution, etc. Hence, improving safety plan and increasing seismic resilience is a necessity that requires the development of reliable models and seismic risk assessment tools. Towards this direction, this paper presents a seismic fragility study of two characteristic steel high-rise stacks encountered in oil refineries, namely a relatively low-rise chimney and a process tower. The developed of reduced-order numerical models, the selection of appropriate engineering demand parameters to capture the seismic response of the structures, the calculation of the fragility curves, and finally the evaluation of the overall seismic response are presented. The results could be exploited in the context of a seismic risk assessment study of an oil refinery, as an integrated system.
... Hydrogen consumption for the hydroprocessing of jatropha oil in this study is estimated at 353 Nm 3 /m 3 . This value is several times higher as compared to conventional petroleum gas oil hydrotreating (50e150 Nm 3 /m 3 ) [29], but within the typical range reported for renewable feedstock hydroprocessing (300e400 Nm 3 /m 3 ) [7,30,31]. Fig. 9 also shows that the formation of CO 2 and H 2 O increases continuously along the reactor due to decarboxylation and hydrodeoxygenation reactions. ...
Article
The complexity of designing and optimizing vegetable oil hydrotreating reactors lies in describing multiple phenomena, including heat and mass transfer, hydrogen consumption, pressure drop, and a complicated network of highly exothermic reactions. This study intends to analyze the behavior of a vegetable oil hydroprocessing unit in a commercial environment via modeling and simulation techniques. In order to describe the three-phase (gas-liquid-solid) system in a detailed manner, a commercial-scale reactor model having multiple catalyst beds and inter-bed quench gas injections was constructed accounting for the heat and mass transfer between phases, the dynamic response of the system, the variation in gas phase velocity, and intraparticle effects. Based on dynamic reactor simulations, quench gas injection strategies were proposed to control the reactor temperature profile and yield of the desired products. Simulation results showed that the selection of a feed inlet temperature plays a major role in reactor overheating and quench injections must start as soon as the reactant stream reaches the inter-bed quench zone to stabilize reactor temperature more rapidly during start-up. In addition, the lengths of the catalyst beds need to be adjusted such that the heat released by chemical reactions is properly distributed along the reactor. The results overall provide useful information for the design and optimization of commercial-scale catalyst bed configurations for hydrotreating renewable feedstock. In particular, it is highlighted that by means of an appropriate gas quenching configuration, reactor temperature can be adequately controlled allowing higher yields of green diesel.
Article
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In this work two samples of solid particulates obtained from the intergranular space of the guard beds catalyst of industrial gas oil hydrotreating reactors were investigated. The hydrotreating reactors were operated on feedstock of different composition. One of the samples of solid particulates was obtained during hydrotreating of feedstock containing a large amount of sodium and calcium. The compositions of the samples of solid particulates were determined. Quantitative elemental and structural analyses were carried out. As a result, the formed solid particulates contained a large amount of sodium chloride, sulfate and calcium sulfide. The qualitative calculations show that the pressure drop in the guard bed of five-segment rings with a diameter of 16.0 mm, due to the deposition of solid particulates in the intergranular space, increases by 108% more than the pressure drop during hydrotreating of feedstock not containing calcium and sodium compounds (under the same operating modes of the hydrotreating reactors and operating time). The obtained results on the effect of the feedstock composition on the pressure drop buildup can be used in optimizing the loading of reactors and in other oil refining processes.
Article
A virtual mid-size oil refinery, located in a high-seismicity region of Greece, is offered as a testbed for developing and testing system-level assessment methods due to direct impact from seismic shaking and without considering geohazards, such as liquefaction and surface faulting. Its characterization is offered in a dedicated repository (https://doi.org/10.5281/zenodo.11419659) and it comprises (a) a comprehensive probabilistic treatment of seismic hazard tied to an open-source seismological model; (b) a hazard-consistent set of ground motion records; (c) a full geolocated exposure model with all pertinent critical assets, namely tanks, pressure vessels, process towers, chimneys, equipment-supporting buildings, and a flare; (d) the corresponding record-wise asset demands and summarized fragilities derived via nonlinear dynamic analyses on reduced-order numerical models. Background information is provided on all refinery assets to delineate their role in the refining process. Furthermore, an explicit homogenization of the damage states is proposed, translating them from the asset level to the refinery system level considering the importance of each asset on the overall operational and structural integrity of the refinery. The results can form the basis of any follow-up study that seeks to characterize the effects of cascading failures (fires, explosions), mitigation measures, seismic sequences, and operational constraints on the functionality, risk, and resilience of refining facilities.
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Introducción: La alquilación en refinerías es crucial para la producción de gasolina de alto octanaje con bajas emisiones, cumpliendo con requerimientos ambientales y exigencias de la industria automotriz actual. Este estudio provee datos obtenidos mediante análisis con química computacional de los compuestos químicos del flujo de entrada al proceso de alquilación en refinería, con lo cual se prevé mejorar significativamente la calidad del combustible y la eficiencia del proceso. Objetivo: El objetivo de este estudio es analizar los valores de lipófilia de los compuestos químicos del flujo de entrada al proceso de alquilación en refinería, los cuales son identificados a través de una exhaustiva búsqueda bibliográfica y analizados mediante química computacional utilizando los métodos iLOGP, XLOGP3, MLOGP, WLOGP y SILICOS-IT. Se busca entender cómo la lipófilia de estos compuestos influye en su comportamiento durante este proceso de refinado de crudo, con el fin de mejorar la eficiencia y selectividad de dicho proceso. Metodología: En este estudio se realizan observación, medición, experimentación e interpretación sistemática y rigurosa de los resultados. Mediante análisis y búsqueda bibliográfica, se determinan los compuestos presentes en el flujo de entrada al proceso de alquilación en refinería. Estos compuestos son procesados mediante química computacional para obtener los valores de lipófilia de cada molécula. Posteriormente, se procede al análisis meticuloso de dichos valores y su influencia en las variables relevantes del proceso de refinado. Resultados: El Consensus Log Po/w combina métodos computacionales para estimar el Log Po/w de cada molécula, mejorando la precisión de las predicciones. Este estudio se centra en analizar la lipófilia de compuestos en el flujo de entrada para la alquilación en refinería. El propileno presenta el menor valor, mientras que el n-pentano tiene el mayor. La lipófilia garantiza la solubilidad y eficiencia del proceso. Conclusiones: Las características lipofílicas en compuestos del flujo de entrada a la alquilación son cruciales en el refinado de crudo. La comprensión y predicción de la lipofilia pueden lograrse con métodos computacionales como iLOGP, XLOGP3, WLOGP, MLOGP y SILICOS-IT. Los valores consensus de lipofilia oscilan entre 1.35 y 2.45, afectando la solubilidad en fases orgánicas y la interacción con catalizadores, lo que influye en la eficiencia y rendimiento de la alquilación en refinería.
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Spreading time, the time that an impacting droplet attains the maximum wetting area on a solid surface, plays a critical role in many engineering applications particularly where heat transfer or chemical reactions are involved. Although the impact dynamics of a droplet significantly differ across the different spreading regimes depending on various collision parameters, it still remains unclear how the spreading time changes for each spreading regime. In the present study, the spreading time during droplet impact on a large spherical target is systematically studied at the three different spreading regimes for a wide range of impact parameters (Weber number, equilibrium contact angle, and Ohnesorge number). The changes of spreading time depending on the impact parameters and underlying physical mechanisms are analyzed in detail at the level of three different spreading regimes. Our results show that the spreading time, proper time scales, dominant impact parameters and associated physical behaviors all significantly and non-linearly change across the three spreading regimes. An improved prediction model for the spreading time is also proposed for each regime, which is now based on only the controllable variables and has an explicit form. Finally, a data-driven prediction model is proposed to represent the complicated and non-linear nature of the spreading time broadly across the three spreading regimes. Graphic Abstract
Chapter
Description This one-of-a-kind, comprehensive handbook provides the latest industry and research advances in petroleum refining, natural gas processing, and refinery management. Over 40 scientists, experts and professionals from both academia and industry have contributed to the 33 chapters in this handbook. Unique features include:
Article
In this paper, a decentralized Proportional-Integral-Derivative control with an inverted decoupling structure is designed and implemented in an industrial diesel hydrotreating unit. The hydrotreating unit consists of two reactors with two catalytic beds each. The temperature control of each catalytic bed is disturbed by fluctuations in the preceding catalytic beds temperature, in addition to other inherent process disturbances. Neglecting this interaction in the controller design degrades the desired performance. Inverted decoupler implementation details in the digital control system are presented. Moreover, actual results on comparing the performance of temperature control loops with and without decoupler are discussed.
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It is proposed to take into account the influence of uncontrolled disturbances on the regulation of pressure in the stabilization column of a catalytic reforming unit by changing the coefficients of the denominator polynomial of the transfer function of the automatic pressure control system based on robust stability methods. To describe the problem in a general form, a general view of the polynomial of the denominator of the transfer function of the automatic pressure control system in the stabilization column of the catalytic reformer is obtained. The purpose of the study is to determine the maximum range of change in the coefficients of the polynomial of the denominator of the transfer function of an automatic pressure control system in the stabilization column of a catalytic reformer, at which robust stability is maintained. Methods - methods of robust stability, automatic control theory. A family of polynomials of the denominator of the transfer function of the automatic pressure control system in the stabilization column of a catalytic reformer with squared uncertainty parameters is considered.The problem of determining the area of robust stability of a family of polynomials is reduced to determining the areas of stability of four edge polynomials and the intersection of all areas to determine the area of robust stability of the family. In general, the problem of determining the robust stability of each edge polynomial is described. To determine the area of robust stability of the family of polynomials of the denominator of the transfer function of the automatic pressure control system in the stabilization column of the catalytic reformer, three polynomials, including the nominal one, are specified. Based on the general description of the problem, the radius of stability of each edge polynomial is determined using a graphical criterion and the construction of a Tsypkin-Polyak hodograph. Results - based on the intersection of the stability regions of four rib polynomials, the robust stability region of the family of polynomials of the denominator of the transfer function of the automatic pressure control system in the stabilization column of the catalytic reformer with a stability radius of 1.5 was determined. Conclusion - this result can be used in the development of an automatic pressure control system in the stabilization column of the catalytic reformer and the choice of regulator settings.
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The seismic fragility is assessed for typical high-rise stacks encountered in oil refineries, namely process towers, chimneys, and flares. Models of varying complexity were developed for the structures of interest, attempting to balance computational complexity and accuracy regarding the structural dynamic and strength properties. The models were utilized along with a set of hazard-consistent ground motions for evaluating the seismic demands through incremental dynamic analysis. Demand/capacity-related uncertainties were explicitly accounted for in the proposed framework. Damage states were defined for each of the examined structure considering characteristic serviceability and ultimate limit states. Τhe proposed resource-efficient roadmap for the analytical seismic fragility assessment of typical high-rise stacks, as well as the findings of the presented research work are available to be exploited in seismic risk assessment studies of oil refineries.
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Conference Paper
In this research, modernistic optimization techniques, like Genetic Algorithm (GA), Particle Swarm Optimization (PSO) and Artificial neural network (ANN) were employed for estimate the best reactions kinetic parameters founded on minimizing the mean absolute errors (MAE) between the real and predicted data for catalytic reforming unit situated in AL-Daura refinery-Baghdad/Iraq. In this unit, sweet heavy naphtha feedstock is achieved in four fixed bed semi regenerative reactors utilizing commercial platinum on alumina (Pt/Al2O3) as a catalyst. Each reactor temperature differed from (450-500) °C, and the pressure was (25-34) bar. The proposed kinetic model has 87 reactions and 33 reacting components and all reactions are pseudo-first order. The model explains the distribution of composition, temperature and pressure over the four reactors. The simulation and optimization results showed that, GA is faster than PSO in getting the global optimum values, while the ANN does not produce acceptable accuracy due to the huge number of input/output variables and high nonlinearity of the reforming process. GA has strong capacity of global searching and could achieve good global searching ability compared with the other optimization methods. Using GA, the model was fine tuned against the refinery data and the final results such as outlet reformate compositions, temperature, pressure and RON have shown well agreement with actual values.
Chapter
Oil, either conventional or unconventional, will continue to be the main source of future nonrenewable energy. The high energy demand worldwide is causing a decline in the conventional crude oil reserves, and thus, new alternative and cost-effective technologies for upgrading and recovery of conventional and unconventional oils are needed to sustain industrial activities. Unfortunately, the presence of high asphaltene content in heavy and extra-heavy crude oils can cause many issues such as high viscosity and low specific gravity that hinder processing, production, and transportation. This chapter presents the use of nanoparticle technology as an emerging potential alternative for enhancing heavy oil upgrading and recovery. Because of their unique properties, nanoparticles have considerable potential applications as adsorbents and catalysts in the heavy oil industry, for both surface and subsurface applications. In subsurface applications, the use of nanoparticles may enhance the upgrading and recovery of heavy oil by significantly increasing its H/C atomic ratio and reducing both viscosity and coke formation. Nanoparticles are also employed as adsorbent/catalysts for separating asphaltenes followed by their catalytic decomposition.
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Article
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Article
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