Catalytic Naphtha Research Articles

Optimization of Isomerization Activity and Aromatization Activity in Catalytic Naphtha Reforming over Tri-Metallic Modified Catalyst using Design of Experiment Based on Central Composite Design and Response Surface Methodology

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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.

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.

IMPROVEMENT OF HYDRODYNAMICS PERFORMANCE OF NAPHTHA CATALYTIC REFORMING REACTORS USING CFD

Due to high applicability of the fixed bed catalytic naphtha reforming reactors, hydrodynamic features of this kind of reactors with radial flow pattern are improved in this work by utilising computational fluid dynamics technique. Effects of catalytic bed porosity, inlet flow rate and flow regime through the bed on the flow distribution within the system are investigated. It is found that the first reactor among three fixed bed reactors in series is working inappropriately. It is due to the effects of recirculating flow on the hydrodynamics. In addition, flow distribution at the end of each bed is discovered to be non-uniform. By applying computational fluid dynamics technique to the system and manipulating effective parameters, not only vortices are removed at the end of each bed, but also flow distribution through the first reactor is considerably improved. A new internal modification for all reactors is proposed, which allows reactors to become overloaded with the catalyst. Subsequently, inlet flow rate can rise by 10-15 per cent over its current value.

English

English

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.

Inter-conversion of light olefins on ZSM-5 in catalytic naphtha cracking condition

The inter-conversion of light olefins over four types of HZSM-5 based catalysts under cracking conditions was investigated systematically and various methods including XRD, Ar adsorption–desorption, NH3-TPD, 27Al and 31P MAS–NMR were used to characterize the effects of P modification and steaming on ZSM-5. Regardless the types of catalyst, the same behaviors of light olefin inter-conversion were observed only depending on conversion of light olefins. Also, the conversion and selectivity were not influenced by the presence of hydrogen, suggesting that light paraffins were mainly produced from hydrogen transfer during cracking rather than hydrogenation of light olefins. It can be suggested that the inter-conversion of light olefins occurs through oligomerization of light olefins and then re-cracking of the oligomerized products. To guarantee high light olefin yield in catalytic naphtha cracking, it is strongly required to suppress oligomerization of light olefins during catalytic cracking.

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

Applying response surface methodology to assess the combined effect of process variables on the composition and octane number of reformat in the process of reducing aromatization activity in catalytic naphtha reforming

This study is aimed at investigating the interactive effect of reaction variables on the composition and octane number of reformat in catalytic naphtha reforming gasoline fuel. The relationship between aromatization activity and RON, with three reaction variables, namely temperature (480–510 °C), total pressure (10–30 bar) and space velocity LHSV (1.2–1.8 h−1) were presented as empirical mathematical models. Experiments were performed based on the central composite rotatable design and analyzed using response surface methodology (RSM) and canonical analysis. First, the equation models are used to predict RON and aromatization activity as responses. Second, the regression analysis of RON and aromatization activity equations is obtained from the output of these developed models. Finally, the RSM is used to optimize these regression empirical models. R2 = 88.5 % for RON and 80.5 for the aromatization activity showed that RSM models fitted well with the observed data and considered to be accurate and available for predicting responses. The temperature and total pressure are the most effective variables as a linear (X1, X2) terms and have a significant role in the responses. Numerical results also revealed that the maximum predicted RON of 105 was attained at optimum reaction temperature of 515 °C, operating pressure of 17 bar and LHSV of 2.0 h−1.

English

  In this research, a layered-recurrent artificial neural network (ANN) using back-propagation method was developed for simulation of a fixed-bed industrial catalytic-reforming unit, called Platformer. Ninety-seven data points were gathered from the industrial catalytic naphtha reforming plant during the complete life cycle of the catalyst (about 919 days). A total of 80% of data were selected as past horizontal data sets, and the others were selected as future horizontal ones. After training, testing and validating the model using past horizontal data, the developed network was applied to predict the volume flow rate and research octane number (RON) of the future horizontal data versus days on stream. Results show that the developed ANN was capable of predicting the volume flow rate and RON of the gasoline for the future horizontal data with the AAD% of 0.238 and 0.813%, respectively. Moreover, the AAD% of the predicted octane barrel against the actual values was 1.447%, confirming the excellent capability of the model to simulate the behavior of the under study catalytic reforming plant.   Key words: Modeling, simulation, artificial neural network, catalytic reforming, naphtha  cycle life.

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.

Predictive Modeling for an Industrial Naphtha Reforming Plant using Artificial Neural Network with Recurrent Layers

In this research, a layered-recurrent artificial neural network (ANN) using the back-propagation method was developed for simulation of a fixed-bed industrial catalytic reforming unit called Platformer. Ninety-seven data points were gathered from the industrial catalytic naphtha reforming plant during the complete life cycle of the catalytic bed (about 919 days). Ultimately, 80% of them were selected as past horizontal data sets, and the others were selected as future horizontal ones. After training, testing, and validating the model with past horizontal data, the developed network was applied to predict the volume flow rate and research octane number (RON) of the future horizontal data versus days on stream. Results show that the developed ANN was capable of predicting the volume flow rate and RON of the gasoline for the future horizontal data sets with AAD% (average absolute deviation) of 0.238% and 0.813%, respectively. Moreover, the AAD% of the predicted octane barrel levels against the actual values was 1.447%, which shows the excellent capability of the model to simulate the behavior of the target catalytic reforming plant.

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

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

Simulation, Sensitivity Analysis and Optimization of an Industrial Continuous Catalytic Naphtha Reforming process

Continuous catalytic regeneration (CCR) is a key process in petroleum refineries to produce high octane gasoline. In this article, a commercial scale CCR plant with the nominal capacity of 22000 bbl/day was simulated using Ref-sim module and Petro-sim simulator. The validity of this plant wide simulator was evaluated by actual test runs obtained during 6 months of operation. Simulation results showed that the AAD% of momentous output variables i.e. outlet temperature of reactors, product volume yield, product RON, H 2 purity of recycle gas and coke deposition on the catalyst against actual data were 0.5%, 0.94%, 1.098%, 0.57% and 0.347%, respectively. Then, the optimal values for reactor temperatures, feed flow rate and recycle flow rate were determined using sensitivity analysis approach. After setting these decision variables on the proposed optimal values, the actual RON and volume yield of the CCR plant enhanced from 99.55 and 82.04% to 99.67 and 82.4%, respectively.

Optimal design of a radial-flow membrane reactor as a novel configuration for continuous catalytic regenerative naphtha reforming process considering a detailed kinetic model

The significance of the catalytic naphtha reforming process in the petroleum refining and petrochemical industry generates continuous evolution of the technology. These improvements would be observed in presenting more efficient reactor setups in order to improve production yield and operating conditions, as well as elucidating better kinetic and deactivation models with higher predicting ability. Both of these items have been considered in this work. An optimized radial-flow moving bed membrane reactor has been proposed as a novel configuration for naphtha reforming process. Optimization has been carried out by differential evolution (DE) method considering 40 decision variables. A detailed kinetic model has also been presented. The proposed kinetic model consists of 32 lumped pseudo-components and 84 reactions. Deactivation rate of catalyst has also been taken into account by considering coke deposition on both acidic and metallic sites. Plant data have been used to validate the modeling results. In order to assess the performance of the proposed configuration, the obtained modeling results have been compared with those of conventional configuration, which shows the superiority of the presented one.

Utilizing DE optimization approach to boost hydrogen and octane number, through a combination of radial-flow spherical and tubular membrane reactors in catalytic naphtha reformers

In this study, optimal design parameters and operating conditions of a combination of tubular membrane and radial-flow spherical reactors are determined to propose an alternative configuration for conventional naphtha reforming process (CTR). Operating conditions of such a combination are optimized by Differential Evolution (DE) method to maximize main products yield. In this regard, thirteen and eleven decision variables such as length per diameter (LOD) of the tubular membrane reactor, hydraulic diameter, membrane thickness, catalyst mass distribution, etc. are optimized for a combination of one or two tubular membrane reactors with two or one spherical reactor. Eight possible combinations are optimized. The optimization results show that the configuration of spherical–tubular membrane-spherical reactor (SMS) performs well among all the other ones. A considerable increase in aromatic (8.01%) and hydrogen (9.81%) production rates in addition to desirable pressure and temperature profiles are achieved in optimized SMS configuration. Experiments and cost evaluation of SMS should be supplemented to such a theoretical investigation as a future work to have an entire foresight for future plant designs.

Toward enhanced hydrogen production in a catalytic naphtha reforming process

Environmental regulations imposed on transport fuels, especially specifications on sulfur and nitrogen content, generally boost hydrogen requirements in refining industries. The catalytic naphtha reformer (CNR) process is one of the major sources of hydrogen in naphtha refinery, thus improving its hydrogen production would be of great importance for refining industries. Close examination of the reaction kinetics of CNR processes has identified temperature, hydrogen concentration and catalyst activity as key variables affecting the process's performance. In this paper, a new reactor concept is developed that better exploits these process variables. The proposed membrane moving-bed reactor promises to significantly outperform the conventional continuous catalyst regenerative (CCR) design. A case study identifies improvements of 23.6 mol% in hydrogen production, 18.8 mol% in aromatics production. Moreover, the reformate yield was found to increase by 10.6 wt%, while the production of light gases decreases to a value of 18.6 wt%.

Boosting the gasoline octane number in thermally coupled naphtha reforming heat exchanger reactor using de optimization technique

Since the refineries are benefitted mostly from the catalytic naphtha reforming units, these units are of highly interest. This importance would generate continuous evolution of the technology in both the processing and equipment pieces of the technology. One of the promising developments in the naphtha reformers would be thermal coupling of the reactors in a heat exchanger configuration. In this study, the DE optimization technique has been used as a powerful tool to find the best operating parameters in the naphtha coupled reactors. Twenty-six decision variables have been considered in this optimization problem. The endothermic dehydrogenation of the catalytic naphtha reforming is coupled with an exothermic hydrogenation reaction (hydrogenation of nitrobenzene to aniline) through a shell and tube heat exchanger reactor. Catalyst mass distribution, exothermic inlet temperature, operating pressures, number of tubes in the exothermic side and the total molar flow rates are the most important optimized parameters. Maximizing the aromatics (octane number) in reformate is the best possible objective function in this research. The results show a significant increase in hydrogen and aromatics production rate of the optimized reactor compared with the non-optimized one. Hydrogen and aromatics have increased 72 and 41kmol/h, respectively. Besides, the exothermic tubes are considered for the third reactor in this work to maximize the aromatic and hydrogen production rates. These results are valuable for the procedure of designing a reactor in which both reactions are integrated.