Naphtha Reforming Research Articles

Experience in Processing Alternative Crude Oils to Replace Design Oil in the Refinery

A comprehensive investigation of a highly complex petroleum refinery (Nelson complexity index of 10.7) during the processing of 11 crude oils and an imported atmospheric residue replacing the design Urals crude oil was performed. Various laboratory oil tests were carried out to characterize both crude oils, and their fractions. The results of oil laboratory assays along with intercriteria and regression analyses were employed to find quantitative relations between crude oil mixture quality and refining unit performance. It was found that the acidity of petroleum cannot be judged by its total acid number, and acid crudes with lower than 0.5 mg KOH/g and low sulphur content required repeated caustic treatment enhancement and provoked increased corrosion rate and sodium contamination of the hydrocracking catalyst. Increased fouling in the H-Oil hydrocracker was observed during the transfer of design Urals crude oil to other petroleum crudes. The vacuum residues with higher sulphur, lower nitrogen contents, and a lower colloidal instability index provide a higher conversion rate and lower fouling rate in the H-Oil unit. The regression equations developed in this work allow quantitative assessment of the performance of crucial refining units like the H-Oil, fluid catalytic cracker, naphtha reformer, and gas oil hydrotreatment based on laboratory oil test results.

Prediction and optimisation of gasoline quality in petroleum refining: The use of machine learning model as a surrogate in optimisation framework

AbstractHardware‐based sensing frameworks such as cooperative fuel research engines are conventionally used to monitor research octane number (RON) in the petroleum refining industry. Machine learning techniques are employed to predict the RON of integrated naphtha reforming and isomerisation processes. A dynamic Aspen HYSYS model was used to generate data by introducing artificial uncertainties in the range of ±5% in process conditions, such as temperature, flow rates, etc. The generated data was used to train support vector machines (SVM), Gaussian process regression (GPR), artificial neural networks (ANN), regression trees (RT), and ensemble trees (ET). Hyperparameter tuning was performed to enhance the prediction capabilities of GPR, ANN, SVM, ET and RT models. Performance analysis of the models indicates that GPR, ANN, and SVM with R2 values of 0.99, 0.978, and 0.979 and RMSE values of 0.108, 0.262, and 0.258, respectively performed better than the remaining models and had the prediction capability to capture the RON dependence on predictor variables. ET and RT had an R2 value of 0.94 and 0.89, respectively. The GPR model was used as a surrogate model for fitness function evaluations in two optimisation frameworks based on genetic algorithm and particle swarm method. Optimal parameter values found by the optimisation methodology increased the RON value by 3.52%. The proposed methodology of surrogate‐based optimisation will provide a platform for plant‐level implementation to realise the concept of industry 4.0 in the refinery.

Tuning the interfacial interactions between alumina support and pseudo single atom platinum-tin catalytic sites for heavy naphtha reforming

Heavy naphtha reforming, a crucial downstream process in oil refineries for improving the octane number of the gasoline feedstock, requires expensive Pt metal catalysts and it accounts for 60% of the catalyst cost. These conventional Pt nanoparticle sizes range between 1 – 2 nm and thus, only ≈ 80% of the Pt atoms of the particle are available for the catalytic reactions. In this work, we hypothesized that it might be possible to achieve 100% atom utilization if the Pt atoms are distributed as single or pseudo-single atom clusters, where all the atoms are exposed to the reactant molecules and by tuning their Interfacial Interactions. We aimed to significantly reduce the Pt contents by dispersing the active Pt sites as pseudo-single atoms on industrially relevant γ-Al2O3 support. Interfacial Interactions and stability of Pt sites were then tuned by using tin (Sn) as a promoter. These catalysts were then evaluated for heavy naphtha reforming in a fixed-bed reactor. The catalyst with Sn/Pt mole ratio of 1.68 showed excellent performance with aromatics of 83 wt% and research octane number (RON) of ≈ 103. These results indicated our catalyst preparation methodologies and interfacial interaction tuning successfully disperse Pt on the spherical alumina support leading to better atom economy. With 30–50% less Pt content when compared to the industrially used catalyst, made the heavy naphtha reforming process economical and sustainable.

Understanding the Promotional Effect of Silver in Naphtha Reforming over a Ga/ZSM-5 Catalyst to Enhance Liquid Yield

Understanding the Promotional Effect of Silver in Naphtha Reforming over a Ga/ZSM-5 Catalyst to Enhance Liquid Yield

Fluid dynamics and erosion analysis in industrial naphtha reforming: A CFD-DPM simulation approach

This paper explores using Computational Fluid Dynamics-Discrete Phase Model simulation in an industrial naphtha reforming unit. It analyzes the reformer process, including the reformer, hopper, and three elbow types. Objectives encompass catalyst residence time, fluid flow, and erosion due to the catalyst in these geometries. Simulation results unveil insights, showing varying erosion rates among the elbows. The 90-degree elbow has the highest erosion rate 4.42×10−8kgm2s, followed by the 60-degree elbow3.49×10−8kgm2s, and the 45-degree elbow with lower erosion rate 2.65×10−8kgm2s. Results align with literature, emphasizing flow dynamics' role in optimization and maintenance. The study validates simulation with only 1.58% deviation from plant data, highlighting model's precision. Catalyst residence time is 1.28 s. Erosion patterns in the hopper pinpoint high-density zones as erosion-prone areas, guiding preventive measures. This research enhances continuous catalytic reformer systems' efficiency and integrity, aiding decisions for design and maintenance, ultimately improving overall process efficiency and stability.

Synthesis and Determination of Active Acidic/Basic Sites on Zn Loaded Zeolite (ZSM-5) Catalyst & Its Role in Catalytic Reforming of Naphtha Using HPMR Reactor

Synthesis and Determination of Active Acidic/Basic Sites on Zn Loaded Zeolite (ZSM-5) Catalyst & Its Role in Catalytic Reforming of Naphtha Using HPMR Reactor

Catalyst regeneration techniques in naphtha reforming: Short review

Catalyst regeneration techniques in naphtha reforming: Short review

Conventional Synthesis of Zinc Loaded Extruded ZSM-5 Its Surface Analysis by TPD Technique and Application in Catalytic Reforming of Naphtha Using HPMR Reactor

Conventional Synthesis of Zinc Loaded Extruded ZSM-5 Its Surface Analysis by TPD Technique and Application in Catalytic Reforming of Naphtha Using HPMR Reactor

Modeling and Parameter Tuning for Continuous Catalytic Reforming of Naphtha in an Industrial Reactor System

A two-dimensional mathematical model was developed to simulate naphtha reforming in a series of three industrial continuous catalytic regeneration (CCR) reactors. Discretization of the resulting partial differential equations (PDEs) in the vertical direction and a coordinate transformation in the radial direction were performed to make the model solvable using Aspen Custom Modeler. A sensitivity-based parameter subset selection method was employed to identify the most influential parameters within the model. Tuning of 8 out of 180 parameters was used to ensure that model predictions match experimental data from one steady-state run. The updated parameter values improved the model fit to the data, reducing the weighted least-squares objective function for parameter estimation by 73%. The proposed model was used to predict reactor temperatures, catalyst coke weight fraction at the exit of the third reactor, and benzene flowrate from the outlet of the third reactor. The simulation results demonstrated a good agreement between the simulated values and the industrial measurements. Finally, the reactor model was utilized to explore the effects of changes in inlet temperatures and inlet level of catalyst deactivation, providing valuable insights for identifying desirable operational conditions that will improve the overall efficiency of the CCR process.

From Basic Research on Supported-Metal Catalysts to their Practical Applications for Reduction of Food Waste

Abstract Supported metal catalysts are one of the most important heterogeneous catalysts, and they are widely used in chemical processes such as naphtha reforming, purification of exhaust gas from automobiles and so on. However, rational design of supported metal catalysts is still a target in heterogeneous catalysis. The author had a hypothesis that metal nanoparticles in ordered pores of zeolite or mesoporous silica may exhibit novel catalytic properties. Based on this idea, we used micropores of zeolites to accommodate metal carbonyl clusters, and then mesoporous silica to prepare metal nanoparticles. First, we studied ship-in-bottle synthesis of Rh carbonyl clusters in zeolite and its reactivity. Rh6(CO)16 was synthesized in NaY zeolite accompanied with formation of a mononuclear Rh(CO)2, which acted as a carrier of 13CO in 12CO-13CO exchange reaction. Then we worked on synthesis of platinum nanoparticles in mesoporous silica, and found that high activity in preferential oxidation of CO in hydrogen and in low-temperature oxidation of ethylene. The high catalytic performance in ethylene oxidation has led to practical application of platinum/silica catalysts for preservation of fruits and vegetables, resulting in reduction of food waste. This article describes the development process of this research.

Enhancement of the Texture & Morphology of Nano γ-Alumina as a Support for Naphtha Reforming Catalyst

The morphology of nano gamma alumina affects the molecule adsorption-desorption phenomena. In this case, manipulating the surface area, pore volume, and pore size by the technique of preparation to control the morphology and textural properties of gamma alumina. Washing of the synthesized boehmite gel with methanol has a significant effect. The co-precipitation method was used to prepare nano gamma alumina, which is involved by adding drop-by-drop ammonium hydroxide and aluminum nitrate nonahydrate solutions to a cetyltrimethylammonium bromide (CTAB) cationic surfactant solution at 30 C and adjust PH to 8. Nitrogen adsorption-desorption analysis (ASAP 2020), Atomic Force Microscope (AFM), and X-Ray Diffraction (XRD) were used to examine the obtained material. Surface area (362 m2/g), pore volume (0.51 cm3/g), pore size (5.2 nm), and narrow pore size distribution were obtained.

Design of New Composites Nano-Catalysts for Naphtha Reforming Process: Experiments and Process Modeling

The naphtha catalytic reforming process is evaluated by designing new composite nano-catalysts. Three catalysts were prepared for this process. The first catalyst was molybdenum carbide composite with platinum over HY zeolite (Mo2C.Pt/HY zeolite), the second catalyst was molybdenum carbide composite with platinum over modified zeolite by cerium nitrate (Mo2C.Pt/CeY zeolite), and the last catalyst was bimetallic titanium and platinum with a titanium content of 1% and platinum content of 0.11% over HY zeolite (Pt.Ti/HY zeolite). All catalysts were tested with several tests, mainly X-Ray Diffraction (XRD), BET surface area, and pore volume. All these substances were applied as catalysts for the reforming process of Iraqi heavy naphtha at the following operating conditions: reaction temperature (480, 500, and 520 ), reaction pressure (10, 12.5, and 15 bar), liquid hourly space velocity (LHSV) at 2 hr-1, and constant hydrogen to hydrocarbon ratio (H2/ HC) of 4. All the reforming reactions occurred in a packed bed pilot plant reactor to investigate its stability and activity during the reforming process. All the developed catalyst samples showed sensational stability even at operating under difficult circumstances. The best catalyst was Pt.Ti/HY zeolite based on the results obtained with respect to the octane number (86.2) at 520 and 15 bar. Also, a mathematical model to describe the reforming process with high accuracy was built and simulated using gPROMS software. The results were very satisfying since the most significant error with the wt% of reformate was 4.9% (the experimental aromatics content was 23.94 wt.%, while the predicted result was 21.67 wt.%), while Research Octane Number (RON) error was 4.7% (the experimental RON was 81, whereas the predicted value of RON was 85) among all the results meaning that the simulating was valid to describe the process.

Graphical Revamping of a Crude Distillation Unit under Two Variable Operational Scenarios – Naphtha Stabilizer and Reformer Operated

Graphical Revamping of a Crude Distillation Unit under Two Variable Operational Scenarios – Naphtha Stabilizer and Reformer Operated

Selective regulation of Pt clusters inside KY zeolite using atomic layer deposition for n-octane reforming

Engineering the chemical environment of active metal phase plays vital role for the alkane reforming, yet great challenges remain. Herein, ABC-type atomic layer deposition (ALD) with methanol as surface modifier was considered to regulate the distribution of metallic Pt on KY zeolite to obtain high-efficient catalysts for n-alkane reforming. The pre-adsorbed methanol occupied the reactive sites of Pt precursors on the external surface of KY zeolite, and thus trapped Pt clusters inside the zeolite cages. The obtained catalyst (Pt/KYC2) exhibited enhanced n-octane aromatization performances with aromatics selectivity up to 78.9% and the proportion of C8 aromatics among total aromatics reached up to 97%. Systematic characterizations revealed that the addition of potassium eliminated the acidity of Y zeolite and induced the formation of electron-rich Pt clusters inside cages, which inhibited the side reactions effectively. Meanwhile, density functional theory (DFT) calculations and temperature programmed desorption (TPD) demonstrated that the Pt clusters inside cages contributed to the initial dehydrogenation and the adsorption of intermediates (1-octene and 2-octene), promoting the dehydrocyclization process. These findings paved a way for engineering the location of Pt clusters, and provided prospective catalytic system to obtain C8 aromatics (ethylbenzene and o-xylene) from naphtha reforming.

Selective toluene methylation to p-xylene: current status & future perspective

ABSTRACT Industrially, petroleum naphtha reforming and steam cracking are two major multistep and energy-intensive sources for p-xylene production. Additionally, p-xylene is also produced by selective toluene disproportionation, heavy (C9) aromatics trans-alkylation and isomerization of xylenes. Rapidly changing market dynamics from fuels to petrochemicals coupled with growing petrochemicals demand has led to the further exploration of economical and highly p-xylene selective processes by using surplus low-value aromatics. Methylation of toluene with methanol has been envisaged as one such potential opportunity to produce p-xylene. For the purpose, significant efforts have been made in the past forty years to develop suitable shape selective zeolite catalysts and technologies to make toluene methylation a highly p-xylene selective process. Current paper briefly highlights various advancements in the toluene methylation process development and aims to provide an extensive review of several works put up in the past to design suitable catalysts, catalyst’s limitations and developmental challenges for toluene methylation. Further, this paper provides an useful insight for two competing chemistries of toluene alkylation and side-by-side methanol reactions. Finally, motivated by competitive chemistry of methanol conversion reactions, existing catalytic limitations and novel synthesis opportunities in engineering shape selective zeolite catalysis, a way forward is proposed to arrive at a logical and futuristic catalyst design strategy for p-xylene production via toluene methylation. The proposed strategy is envisaged to offer low-to-moderate catalyst acidity, improved toluene methylation activity, high p-xylene selectivity and improved catalyst life which, otherwise, up till now have been the bottlenecks to develop distinctly economical toluene alkylation to p-xylene process.

Increasing the propylene production in the MTP process through thermal coupling with naphtha reforming process

• Thermal coupling of naphtha reforming and methanol to propylene (MTP) process. • Using the MTP process as a heat source instead of naphtha reforming furnaces. • Enhancement in propylene production in the MTP process. • Mathematical modeling of MTP process. This paper presents the thermal coupling of the naphtha reforming process with methanol to propylene (MTP) process. In this integrated configuration, the required heat of the endothermic naphtha reforming process is provided by MTP which is an exothermic process. Therefore, intermediate heaters of conventional naphtha reforming (CNR), which were used to adjust the feed temperature of the reactors, were eliminated. The temperature of the MTP reactor increases slightly by transferring its heat to the naphtha reforming reactor; hence, the produced heat in the MTP reactor is controlled to prevent hotspot formation on catalysts. Furthermore, the MTP process is cooled inherently without extra equipment. MTP and naphtha reforming processes were considered to occur in fixed-bed reactors with axial co-current feed streams. The MTP reactor feed streams are parallel while the naphtha reforming feed streams are in series. Results show that in the MTP process, produced propylene and consumed methyl ether in the three parallel reactors are 878 kmol/h and 0.034 kmol/h, respectively. Also, the molar flow rate of aromatics in naphtha reforming is 112 kmol/h. The propylene yield in thermally coupled reactors is 10% more than the conventional one.

Emergy evaluation of aromatics production from methanol and naphtha

Aromatics are traditionally produced by the catalytic reforming of naphtha. However, with the demand of aromatics increasing and the reserves of petroleum resources declining, measures should be made to reduce the dependence of aromatics production on petroleum resources. Methanol-to-aromatics is proved to be an effective way to replace traditional naphtha-to-aromatics path. In order to compare the economic and environmental performance of aromatics production from naphtha and methanol, this paper carries out an emergy evaluation for each system by sorting out the simulation and literature data. Based on the emergy data collected, the emergy indices of each system are calculated. The results show that the sustainabilities of methanol-to-aromatics systems are higher than that of the naphtha-to-aromatics system, indicating the advantages of aromatics production from methanol. Among the methanol-to-aromatics systems, the aromatics from biomass-methanol system has the highest sustainability, indicating that the biomass based methanol-to-aromatics system is worth promoting. The sustainability indexes of methanol-to-aromatics systems based on coal and coke oven gas are less than 1, which means unsustainable. Meanwhile, the sustainability of natural gas based system is slightly higher than 1. The economic and environmental benefits of these systems can be optimized by improving resource utilization and reducing investment costs. Furthermore, the combination of different raw materials for methanol production should be considered.

INFLUENCE OF HYDROCARBON COMPOSITION OF NAPHTHA FEED ON THE YIELD AND OCTANE NUMBER OF REFORMATE

The rapidly increasing demand for high octane num- ber gasoline and aromatic hydrocarbon as a petrochemical feedstock has promoted refiners to seek methods of improving yields of these valuable products. The purpose of catalytic reforming is to convert a low-octane distillate fraction boiling within the gasoline range into high-octane blending stock and low aromatic hydrocarbons. The increase in the octane number of low-octane naphtha reformer feed can therefore be regardel as the transformation of naphthenes and paraffins into aromatics; resulting in the highest octane improvement. Paraffin and C,ring naphthene aromatization are guided by the metal and acid sites of bifunctional reforming catalyst. In order to obtain more information about the influence of hydrocarbon composition of naphtha reformer feed on the yield and research octane number of reformate, an experiment has been carried out to study the conversion of pure hydrocarbon (ie cyclohexane, methylcyclopentane and n.hexane); and naphthenes, and peraffins of three types of naphtha feeds with various hydrocarbon compositions using bifunctional reforming catalyst. The operating conditions: temperatures: 400 to 500 C, pressure: 10 to 30 bars and H/HC ratio = 8 mole/mole. A Catatest Unit operated in a continuous system was used in this experiment. Gas and liquid product samplers taken from gas and liquid samplers, respectively, were analyzed for their hydrocarbon using a Gas Liquid Chromatography.

Molecular Kinetic Modeling of Catalytic Naphtha Reforming: A Review of Complexities and Solutions

ABSTRACT Kinetic modeling is receiving more attention in recent years due to the availability of advanced computational tools and enhancement in the accuracy of analytical techniques. These advances facilitate investigation of the chemical transformations on a molecular level rather than on the bulk properties, such as density, distillation cuts, or octane number. Molecular kinetic modeling of catalytic naphtha reforming is of particular interest as it processes light petroleum fraction that enable full molecular-level analysis. Moreover, the process is an important source of valuable chemicals, hydrogen, and high-octane transportation fuel. Over the years, the goal of the kinetic modeling has evolved from predicting the octane number or other properties of reformate to tracking a particular molecule, such as benzene. Several kinetic models are published in the last decade – each of them strived to adopt somewhat different approach either in the complexity of proposed reaction network or in the methodology of estimating the kinetic parameters. The approaches that have been considered in formulating the rate expressions include: (i) classical power-law model; (ii) models based on Langmuir-Hinshelwood–Hougen–Watson kinetics; (iii) structure-oriented kinetics approach; and (iv) single-event fundamental model. The review presents a systematic comparison of these kinetic models in depth as well as their limitations. An appraisal of the mathematical methods for estimation of kinetic parameters and the computational tools employed for determination of the numerical values of these parameters is made. Finally, the current trends and outlook of this field is presented.

Model-Based Quality, Exergy, and Economic Analysis of Fluidized Bed Membrane Reactors.

In petroleum refineries, naphtha reforming units produce reformate streams and as a by-product, hydrogen (H2). Naphtha reforming units traditionally deployed are designed as packed bed reactors (PBR). However, they are restrained by a high-pressure drop, diffusion limitations in the catalyst, and radial and axial gradients of temperature and concentration. A new design using the fluidized bed reactor (FBR) surpasses the issues of the PBR, whereby the incorporation of the membrane can improve the yield of products by selectively removing hydrogen from the reaction side. In this work, a sequential modular simulation (SMS) approach is adopted to simulate the hydrodynamics of a fluidized bed membrane reactor (FBMR) for catalytic reforming of naphtha in Aspen Plus. The reformer reactor is divided into five sections of plug flow reactors and a continuous stirrer tank reactor with the membrane module to simulate the overall FBMR. Similarly, a fluidized bed reactor (FBR), without membrane permeation phenomenon, is also modelled in the Aspen Plus environment for a comparative study with FBMR. In FBMR, the continuous elimination of permeated hydrogen enhanced the production of aromatics compound in the reformate stream. Moreover, the exergy and economic analyses were carried out for both FBR and FBMR.