Naphtha Reforming Research Articles

Improving Plasma Regeneration Conditions of Pt–Sn/Al2O3 in Naphtha Catalytic Reforming Process Using Atmospheric DBD Plasma System

The catalytic naphtha reforming is one of the largest processes of petroleum industry that is used to rebuild the low-octane hydrocarbons in the naphtha to more valuable high-octane gasoline called reformate without changing the boiling point range. An atmospheric pressure pin to plate dielectric barrier discharge (DBD) plasma was used to remove carbonaceous contaminant from the coked Pt–Sn/Al2O3 catalysts during the naphtha reforming process. The effects of treatment time and flow ratios of O2/Ar and O2/He on the carbon content of the coked catalysts were investigated. The produced radicals and active species of the plasma process were identified by optical emission spectroscopy. To confirm removing the coke from the catalyst, thermal gravimetric/differential thermal analysis and temperature programmed oxidation analysis were done. Effects of treatment time and flow ratios of O2/Ar and O2/He on the carbon content of the coked catalysts were investigated by applying elemental analysis. The results of X-ray diffraction, X-ray fluorescence, Brunauer–Emmett–Teller, and CO adsorption showed that the structure and specifications of regenerated catalysts remained without significant changes during the plasma treating. The catalyst performance test revealed that DBD plasma regenerated catalysts increased the aromatic content of the feed as well as the fresh catalysts. The results showed that the plasma treatment method for regeneration of Pt–Sn/Al2O3 can be applied at lower temperature and pressure relative to the thermal regeneration method.

A Novel Chemical Looping Combustion (CLC)-Assisted Catalytic Naphtha Reforming Process for Simultaneous Carbon Dioxide Capture and Hydrogen Production Enhancement

The application of chemical looping combustion (CLC) in order to eliminate the commonly used furnace in catalytic naphtha reforming has been analyzed. A mathematical model has been proposed to evaluate the performance of naphtha reforming coupled with chemical looping combustion (NR-CLC). NiO18-α-Al2O3 particles have been used as oxygen carriers in NR-CLC. These particles have been shown to have very high reactivity with complete CH4 conversion, because of the Ni-based oxygen carriers. In the NR-CLC configuration, three reactors have been applied. In the first and second reactors, CLC is coupled with naphtha reaction. In this new configuration, the reforming tubes have been located vertically inside the air reactor, so the catalytic naphtha reforming occurs in these fixed-bed catalytic tubes. The results obtained from the model proposed for NR-CLC have been compared with the corresponding results reported in the literature for conventional naphtha reforming (CNR). The values of some important parameters (such as temperature, mole fraction, molecular weight, aromatic and hydrogen production rates) that resulted from these two configurations have been compared. The results revealed that, by employing NR-CLC, the hydrogen and aromatics flow rates increases significantly. A great amount of almost-pure carbon dioxide can be captured by water removal from the fuel reactor through condensation.

Coproduction of liquid transportation fuels and C6_C8 aromatics from biomass and natural gas

The coproduction of liquid transportation fuels and C6C8 aromatics from the thermochemical conversion of biomass and natural gas (BGTL+C6_C8) is investigated in this article. An optimization‐based process synthesis framework incorporating multiple synthesis gas conversion technologies, such as Fischer–Tropsch synthesis or methanol conversion, is described. Production of aromatics can proceed through several technologies, such as naphtha reforming and aromatization of hydrocarbons via a metal‐promoted H‐ZSM‐5 catalyst. This is the first article in the literature to incorporate an aromatics complex for the coproduction of liquid fuels and C6C8 petrochemicals within a rigorous process synthesis and deterministic global optimization framework. The optimal process topologies across several case studies are discussed and the results indicate that the coproduction of aromatics with liquid fuels can significantly increase the profitability of these refineries. © 2015 American Institute of Chemical Engineers AIChE J, 2015 2014 American Institute of Chemical Engineers AIChE J, 61: 831–856, 2015

The Way of Increasing Resource Efficiency of Naphtha Reforming Under Conditions of Catalyst Acid and Metal Activity Balance by Mathematical Modeling Method

Industrial bifunctional reforming catalysts are promoted by chlorides for providing adequate acid activity in izomerization and dehydrocyclization reactions. Chlorine content on the reforming catalyst surface is not only the most important, but also one of the hard controllable process parameters. On the basis of numerical and experimental studies, the authors investigated the influence of chlorine-containing compounds on the activity and selectivity of platinum catalyst of reforming process with fixed granular bed. For the balance of acid and metallic active catalyst centers, optimal interval of chlorinated derivatives and water demand as crude naphtha is accumulated on catalyst is calculated. The influence of molecular ratio H2O:HCl, crude naphtha accumulation and process temperature on chlorides content on catalyst surface is studied. The developed method of supply chlorinated derivatives into the reactor section, provides the increase of the end product yield by 1-1.5%.

Optimization of Catalytic Naphtha Reforming Process Based on Modified Differential Evolution Algorithm

Catalytic naphtha reforming is one of the most important processes for high octane gasoline manufacture and aromatic hydrocarbons production. In this article, a modified differential evolution (DE) algorithm is proposed to optimize an actual continuous catalytic naphtha reforming (CCR) process. The optimization problem considers to minimize the energy consumption and maximize the aromatics yield. The CCR process model is established by adopting the 27-lumped kinetics reaction network, and all parameters are adjusted based on the actual process data. The DE algorithm is modified to maintain the diversity of the population. In this mechanism, individuals further from the best individual have larger possibilities to be selected in the mutation operator. The modified DE is evaluated by solving 6 benchmark functions, and the performance is compared with classic DEs. The results demonstrate that the modified DE has better global search ability and higher computation efficiency. Furthermore, the optimization results of catalytic naphtha reforming process indicate that the proposed algorithm has the ability of locating the optimal operating points, in which the aromatics yield is improved, while energy consumption is reduced. Meanwhile, the optimal operating points and results are discussed at the end of the article.

Heavy Naphtha Fractions 85-155 ̊C Recycling in the Catalytic Reforming Industrial Unit

Catalytic naphtha reforming is a vital process for refineries due to the production of high-octane components, which is intensely demanded in our modern life. In these paper, the mathematical modelling method application for catalytic reforming installation of Komsomolsk oil-refinery is proposed. The mathematical model-based system “Catalyst Control” was used for catalytic reforming installation monitoring. The quality of the product from the unit was studied, with hydrocracking gasoline used as the feedstock. The impact of the feedstock on the product output was analyzed. It is shown that the feedstock replacement of catalytic reforming unit L-35-11/450K has positive impact on high-octane product output and increases the resource efficiency of the process.

Kinetics of Thiophene Hydrodesulphurization: Pore Diffusional Effects

AbstractHydrodesulfurization (HDS) of straight‐run naphtha (SRN) reformer feed significantly improves reformer catalyst life, gasoline yield, and its stability. HDS of SRN helps in protecting the expensive platinum‐based reforming catalyst. HDS is usually catalyzed by sulphided Co–Mo/Al2O3 or sometimes Ni–Mo/Al2O3. The design of naphtha HDS units requires the development develop a kinetic model. It is well‐known that among the sulphur types present in naphtha, the most persistent sulphur compound is thiophene. Therefore, the design of naphtha HDS units is governed by thiophene HDS rates. It is essential to have experimental conditions free from intraparticle diffusional limitations in order to obtain intrinsic kinetics data. This Communication discusses the calculation procedures involved in ensuring experimental conditions free from pore diffusional resistances before conducting detailed kinetics studies. The pore diffusional resistance was quantified in terms of Thiele modulus (Φ).

Computer Modelling System Application for Catalytic Reforming Unit Work Optimisation

Catalytic reforming of naphtha is one of the most important processes for high octane gasoline manufacture and aromatic hydrocarbons production. The application of computer modelling system “Catalyst's Control” for monitoring of catalytic reforming unit of Achinsk oil-refinery is stated. The mathematical model-based system takes into account the physical and chemical mechanisms of hydrocarbon mixture conversion reaction as well as the catalyst deactivation. The models created can be used for optimization and prediction of operating parameters (octane number, reactors outlet temperature and yield) of the reforming process. It is shown, that the work on the optimal activity allows increasing product output with a constant level of production costs, and get the information about Pt-Re catalyst work efficiency.

Modeling of naphtha reforming unit applying detailed description of kinetic in continuous catalytic regeneration process

Naphtha reforming is one of the most important processes in refineries in which high value-added reformate for gasoline pool and aromatics such as benzene, toluene, and xylene are produced. It is necessary to establish new naphtha reforming units and develop the traditional units to increase the efficiency of the processes. In this study, according to the recent progresses in the naphtha reforming technology, mathematical modeling of this process in continuous catalyst regeneration mode of operation is accomplished in two dimensions (radial and axial) by considering cross flow pattern. In addition, a new catalyst deactivation model has been proposed and a new reaction network model based on 32 pseudo-components with 84 reactions is investigated. Then, this model has been validated by comparing with industrial data, and its results have acceptable agreement.

Prediction and measurement of phase equilibria for the extraction of BTX from naphtha reformate using BMIMPF6 ionic liquid

New Liquid–Liquid Equilibrium (LLE) data for three ternary systems namely; hexane+benzene+BMIMPF6, heptane+toluene+BMIMPF6, octane+o-xylene+BMIMPF6, and a fourth system consisting of synthetic naphtha reformate which is composed of hexane/heptane/octane+benzene/toluene/o-xylene+BMIMPF6 were obtained. The LLE were determined at T=298.15K and atmospheric pressure. Effect of the number of substituted methyls attached to aromatic rings was evaluated in terms of selectivity and extractive capacity of the ionic liquid BMIMPF6. The results showed a decrease of the extracted amount of aromatics by the ionic liquid as the increase of the number attached methyl groups in the corresponding aromatic systems. Thus, the extraction capability of aromatics by BMIMPF6 was in the order of benzene>toluene>o-xylene, either present in individual ternary systems or as mixture in one pseudo ternary system. Five thermodynamics models were used to correlate satisfactorily the LLE data for the four studied ternary systems. These are T-K-Wilson, Dortmund UNIFAC, ASOG, NRTL, and UINQUAC. Different strategies and modifications are made to the group contribution models UNIFAC and ASOG. These modifications showed an improved prediction compared to their original expressions. However, among all models considered in this study, the UINQUAC model gave the best predictions.

Experimental and modeling study of a catalytic reforming unit

An experimental and modeling investigation of catalytic reforming of naphtha in a pilot-scale packed bed reactor is described in the present work. The effects of operating conditions on the reactor products were studied utilizing statistical method. A kinetic model including three pseudo species and eight light components was proposed and the coefficients of reaction rate equations were obtained. Good agreement was achieved between the proposed model results and the experimental measurements. Different regions of the reactor with different growth rate of pseudo species and light components were detected by analyzing concentration profiles along the reactor. It was concluded that the precision of the developed kinetic model make it suitable for implementing in a reactor model to predict the analysis of products of an industrial catalytic reforming unit. This is crucial for optimum operation of the industrial unit and its downstream processes, including steam reforming and hydrocracking units which uses light component streams of catalytic reforming process as feed stock or part of their inputs streams. Also, the achieved results about the effects of different operating conditions on the reactor productivity, may offer several clues for improvement of control philosophy, startup and shutdown procedure of this process.

Graph-theoretic Analysis of Complex Energy Integrated Networks

Complex process networks featuring multiple energy integration agents (process-to-process heat exchangers) offer significant cost benefits while adding additional operational constraints. These networks show potential for multi-time scale dynamics owing to the presence of energy flows spanning multiple orders of magnitude. In previous work, we have developed a graph-theoretic framework to systematically uncover this time scale multiplicity. In this paper, we present an application of this framework to a reactor-heat exchanger system used for naphtha reforming. This system involves energy flows spanning three orders of magnitude and the underlying energy balance variables evolve over two time scales. The framework allows for the derivation of control-relevant models in each time scale and classifies the control objectives leading to a hierarchical control strategy. We demonstrate that the analysis uses minimum process information, is efficient, and scalable to large networks.

MODELING AND APPLICATION OF RESPONSE SURFACE METHODOLOGY IN OPTIMIZATION OF A COMMERCIAL CONTINUOUS CATALYTIC REFORMING PROCESS

A kinetic model based on five groups of 26 lumped pseudo-components, including C6 to C9 carbon atoms in categories of paraffins, isoparaffins, cyclohexanes, cyclopenthanes, and aromatics was developed for modeling and optimization of a commercial continuous catalytic naphtha reformer in Bandar Abbas Refinery. The reaction network consisted dehydrogenation, hydrogenation, ring expansion, paraffin and isoparaffin cracking, naphthene cracking, paraffin isomerization, and hydrodealkylation of aromatics as well as coke formation. The product compositions, temperature profile, pressure drop, and coking profiles were determined in the four radial-flow moving bed reactors. The kinetic parameters were derived from the literature and used without tuning the parameters in the CCR model. The outlet temperature, reformate yield, and research octane number (RON) were compared and validated with the outlet results of the commercial CCR. Optimization of operational conditions was carried out using the CCR model and response surface methodology (RSM) based on the statistical analysis. The influence of inlet feed temperature, bed pressure, inlet hydrogen to feed ratio, and the number of adiabatic beds was analyzed simultaneously on the yield and research octane number of the reformate product, and the optimal results were calculated and discussed to approach to the highest RON and reformate yield.

Correlation Study of Safety, Health and Environmental Properties at Inherent Level: Benzene Synthesis Routes

Selection of chemical process route at early stage is one of the major tasks during the RD do the SHE properties correlate with each other at inherent level. In this paper, a study is conducted to determine the correlation between inherent SHE properties by applying six SHE assessment methods to three routes for benzene production - toluene hydrodealkylation (TDA), pyrolysis gasoline hydrogenation (pygas) and catalytic naphtha reforming. Overall, the study reveals a low correlation between safety, health and environmental criteria with an average R 2 value of 0.15. This poor correlation is contributed by fugitive emission aspect, which is included in health assessment and also due to the different assessment characteristics of SHE methods such as catastrophic vs. normal operating and chronic vs. acute scenarios. Besides, it is believed that the selection of the case study, in which all the three routes have only single sub-process, has contributed to this poor correlation.

Simulation, Sensitivity Analysis and Optimization of a Commercial Continuous Catalytic Naphtha Reformer

Simulation, Sensitivity Analysis and Optimization of a Commercial Continuous Catalytic Naphtha Reformer

Unsteady-state kinetic simulation of naphtha reforming and coke combustion processes in the fixed and moving catalyst beds

The work is dedicated to the construction of kinetics models for the naphtha reforming process and the adjacent process of catalyst regeneration by coke combustion. The proposed kinetic model for the reforming process is based on the use of common rate equations for the groups of similar reactions with account of difference in reaction rates for individual homologs within these groups by simple correlations with thermodynamic properties (first of all – with the values of Gibbs free energy) of individual reactions and by other simplification methods. Such approach gives the way to construct the kinetics models optimal from the point of view of compromise between accuracy and simplicity. The proposed naphtha reforming model is characterized with the high level of kinetic scheme detailization (62 individual and group reactants and 146 individual reactions), at the same it is rather simple and provides the accurate description of the experimental data using only 22 kinetic parameters. This model is thermodynamically consistent and provides accurate description of experimental data in a wide range of process parameters. Account of catalyst deactivation by coke deposition in the model gives the way to simulate transient reforming process performance both in fixed and moving catalyst beds. Kinetics of coke combustion for catalysts with moderate coke content (up to 3% mass) may described by simple kinetic equation with apparent reaction rate orders closed to unit for relative coke content and to 1/2 for oxygen. Demonstration simulations of naphtha reforming and coke combustion processes are presented.

Combining continuous catalytic regenerative naphtha reformer with thermally coupled concept for improving the process yield

Advancements in the catalytic naphtha reforming process, as one of the main processes in petrochemical industry, contributed to development of continuous catalytic regenerative naphtha reformer units. Increasing the yield of aromatic and hydrogen as well as saving the energy in this process through the application of thermal coupling technique is a potentially interesting idea. This novel idea has been assessed in this paper. In the proposed configuration, continuous catalyst regeneration naphtha reforming process is coupled with hydrogenation of nitrobenzene in a two co-axial reactor separated by a solid wall, where the generated heat in nitrobenzene hydrogenation reaction transfers to naphtha reforming reaction medium through the surface of the tube. A steady-state, homogeneous, two-dimensional model is used to describe the performance of this configuration and a kinetic model including 32 pseudo-components with 84 reactions is considered for naphtha reforming reaction. After validating the model with the commercial data of a domestic plant, the obtained results of coupled reactor are compared by the conventional one. The obtained results show the superiority of CCR coupled reactor against the conventional one.

Application of Honey-Bee Mating Optimization to Naphtha Reforming Reactor

Abstract Modeling and optimization of the process of continuous catalytic reforming (CCR) of naphtha was investigated. The process model is based on a network of four main reactions which was proved to be quite effective in terms of industrial application. Temperatures of the inlet of four reactors were selected as the decision variables. The honey-bee mating optimization (HBMO) and the genetic algorithm (GA) were applied to solve the optimization problem and the results of these two methods were compared. The profit was considered as the objective function which was subject to maximization. Optimization of the CCR moving bed reactors to reach maximum profit was carried out by the HBMO algorithm and the inlet temperature reactors were considered as decision variables. The optimization results showed that an increase of 3.01% in the profit can be reached based on the results of the HBMO algorithm. Comparison of the performance of optimization by the HBMO and the GA for the naphtha reforming model showed that the HBMO is an effective and rapid converging technique which can reach a better optimum results than the GA. The results showed that the HBMO has a better performance than the GA in finding the global optimum with fewer number of objective function evaluations. Also, it was shown that the HBMO is less likely to get stuck in a local optimum.

Modeling and Simulation of a Novel Membrane Reactor in a Continuous Catalytic Regenerative Naphtha Reformer Accompanied with a Detailed Description of Kinetics

Today, improving the performance of reformers by increasing the octane number of products has received more attention in refineries. In this regard, researchers have been looking for ways of increasing the content of high-octane number products such as aromatics. The present research proposes an alternative configuration for a conventional moving bed naphtha reactor. In this new configuration, the membrane concept is applied in the moving bed reactors to increase the aromatics and hydrogen yields. Most studies on the simulation of continuous catalytic regenerative (CCR) naphtha reactors focused on a one-dimensional mathematical model, while in this work, a two-dimensional mathematical model (in the radial and axial directions) is considered. In the process model, a new reaction network based on 32 pseudocomponents and 84 reactions, as well as a new deactivation model including the most effective parameters, is considered. To verify the efficiency of the conventional configuration model, its results are co...

Optimization of Al-Doura Catalytic Naphtha Reforming Process Using Genetic Algorithm

Optimization of Al-Doura Catalytic Naphtha Reforming Process Using Genetic Algorithm