Modelling and performance analysis for cumene production process in a four-layer packed bed reactor

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Vinila Mundakkal Lakshmanan ◽  
Aparna Kallingal ◽  
Sreepriya Sreekumar
Keyword(s):  
Mathematical Model ◽  
Production Process ◽  
Packed Bed ◽  
Operating Conditions ◽  
Packed Bed Reactor ◽  
Condensation Process ◽  
Orthogonal Collocation ◽  
Explicit Finite Difference ◽  
And Performance ◽  
Combined Feed

Abstract A mathematical model is developed and designed for the cumene reactor in cumene production process in Hindustan Organic Chemicals Limited (HOCL), Kochi with improved operating conditions. High purity cumene is produced by the alkylation of benzene with propylene in this catalytic condensation process where solid phosphoric acid (SPA) is used as the catalyst. The mathematical model has been derived from mass and energy balance equations considering the reactor as fixed packed bed reactor and two different numerical methods are presented here to solve the modelling equations. The explicit finite difference method (FDM) involves the approximation of derivatives into finite differences, and in the other one, orthogonal collocation (OC), Ordinary Diffeential Equations (ODEs) are formed at the collocation points and are solved using Runge–Kutta fourth order numerical scheme. Here the analysis shows that the predictions from the model are in good alignment with the plant data. The combined feed has the optimum value of 1:2:8 for propylene, propane and benzene and the profiles of temperature and concentration can be obtained along the reactor. The model has been implemented in COMSOL Multiphysics as a packed bed reactor using the same parameters collected from the plant of study. It has been found that the reaction occurs at a satisfactory level even with a low temperature than the reactor temperature at the plant by changing the catalytic particle size. The reaction performance is also analysed for the physical properties like porosity and catalyst size.

scholarly journals Technological, economic and environmental evaluation of rice husk gasification in a biorefinery context to produce indirect energy as jet fuel

2017 ◽  
Vol 8 (2) ◽  
pp. 61-70
Author(s):  
Juan Jacobo Jaramillo Obando ◽  
Angie Vanessa Arias Suns
Keyword(s):  
Production Process ◽  
Rice Husk ◽  
Packed Bed ◽  
Jet Fuel ◽  
Operating Conditions ◽  
Packed Bed Reactor ◽  
Added Value ◽  
Total Production ◽  
Higher Alcohol ◽  
Environmental Evaluation

Higher alcohol 1-octanol was evaluated as jet fuel potential. The synthesis of the 1-octanol was modeled and the technological, economic and environmental evaluation of the global production process of the rice husk gasification was performed. The best operating conditions to 1-octanol synthesis were obtained in packed bed reactor PBR using Matlab software. Mass and energy balances were calculated using Aspen Plus Software. Economic assessment was developed using Aspen Process Economic Analyzer Software. Environmental impact evaluation was carried out using the waste reduction algorithm WAR. Process yield was 0.83 kg of 1-Octanol by kg of rice husk. Total production cost obtained was USD 0.957 per kg of 1-octanol and the total PEI of product leave the system is 0.08142 PEI/kg with a PEI mitigated of 12.97 PEI/kg. Production process of high alcohols from rice husk shows a high potential technological, economical and environmental as a sustainable industry at take advantage of an agroindustrial residue and transformed in products with added value and energy. 1-octanol as jet fuel has a potential but need to be more studied for direct use in jet motors.

scholarly journals New Approaches in Modeling and Simulation of CO2 Absorption Reactor by Activated Potassium Carbonate Solution

Processes ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 78
Author(s):  
Maria Harja ◽  
Gabriela Ciobanu ◽  
Tatjána Juzsakova ◽  
Igor Cretescu
Keyword(s):  
Mathematical Model ◽  
Potassium Carbonate ◽  
Energy Savings ◽  
Co2 Concentration ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Co2 Absorption ◽  
Operational Parameter ◽  
Proposed Model ◽  
Strong Relation

The increase of CO2 concentration in the atmosphere is in strong relation with the human-induced warming up due to industrial processes, transportation, etc. In order to reduce the CO2 content, end of pipe post-combustion methods can be used in addition to other methods and techniques. The CO2 capture by absorption in potassium carbonate–bicarbonate activated solutions remains a viable method. In this study, a mathematical model for a packed bed reactor has been developed and tested. The mathematical model is tested for an industrial reactor based on CO2 absorption in Carsol solutions. The proposed model was validated by resolving for CO2 and water content, carbonate–bicarbonate, concentrations etc. For each operational parameter the error was calculated. The error for CO2 concentration is up to 4%. The height of the packed reactor is calculated as function of CO2 concentration in the final gas phase. The validated model can also be used for absorbing other CO2 streams taking into account the fact that its efficiency was proved in industrial scale. Future reactors used for CO2 absorption should consist of two parts in order to use partially regenerated solutions in the first part, with significant energy savings in the operational costs.

scholarly journals Modeling and Simulation of the Hydrogenation ofα-Methylstyrene on Catalytically Active Metal Foams as Tubular Reactor Packing

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Farzad Lali ◽  
Felix-Aron Pahner ◽  
Rüdiger Lange
Keyword(s):  
Bubbly Flow ◽  
Experimental Studies ◽  
Tubular Reactor ◽  
Packed Bed ◽  
Hydrogenation Reaction ◽  
Experimental Results ◽  
Packed Bed Reactor ◽  
Orthogonal Collocation ◽  
Reactor Model ◽  
Catalytically Active

This work presents a one-dimensional reactor model for a tubular reactor packed with a catalytically active foam packing with a pore density of 30 PPI in cocurrent upward flow in the example of hydrogenation reaction ofα-methylstyrene to cumene. This model includes material, enthalpy, and momentum balances as well as continuity equations. The model was solved within the parameter space applied for experimental studies under assumption of a bubbly flow. The method of orthogonal collocation on finite elements was applied. For isothermal and polytropic processes and steady state conditions, axial profiles for concentration, temperature, fluid velocities, pressure, and liquid holdup were computed and the conversions for various gas and liquid flow rates were validated with experimental results. The obtained results were also compared in terms of space time yield and catalytic activity with experimental results and stirred tank and also with random packed bed reactor. The comparison shows that the application of solid foams as reactor packing is advantageous compared to the monolithic honeycombs and random packed beds.

Decomposition of Carbon Tetrachloride by a Packed Bed Plasma Reactor

1997 ◽  
Vol 2 (2) ◽  
Author(s):  
G. Prieto ◽  
O. Prieto ◽  
C. R. Gay ◽  
K. Mizuno ◽  
I. Tamori ◽  
...  
Keyword(s):  
Carbon Tetrachloride ◽  
Plasma Reactor ◽  
Packed Bed ◽  
Operating Conditions ◽  
Empirical Modeling ◽  
Atmospheric Pollutants ◽  
Packed Bed Reactor ◽  
Volatile Organic ◽  
Reactor Operating ◽  
Decomposition Efficiency

AbstractIn search of a technology capable of controlling atmospheric pollutants, like volatile organic compounds (VOCs) in low concentrations, this paper is concerned with the empirical modeling of a ferroelectric plasma packed-bed reactor at ambient temperature and pressure. The empirical model gives information about the decomposition efficiency of the process as a function of the reactor operating variables. The volatile organic compound selected is Carbon Tetrachloride balanced with air in the concentration-range of 150 to 600 ppm and flow-range of 175 to 325 ml/min. Regarding the decomposition efficiency as the objective function, this modeling provides valuable information about the optimal operating conditions.

A New Reactor Concept for Efficient Solar-Thermochemical Fuel Production

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Ivan Ermanoski ◽  
Nathan P. Siegel ◽  
Ellen B. Stechel
Keyword(s):  
Solar Energy ◽  
High Efficiency ◽  
Packed Bed ◽  
Operating Conditions ◽  
Packed Bed Reactor ◽  
Reactive Material ◽  
Starting Point ◽  
Wide Range ◽  
Solar Thermochemical ◽  
The U.S

We describe and analyze the efficiency of a new solar-thermochemical reactor concept, which employs a moving packed bed of reactive particles produce of H2 or CO from solar energy and H2O or CO2. The packed bed reactor incorporates several features essential to achieving high efficiency: spatial separation of pressures, temperature, and reaction products in the reactor; solid–solid sensible heat recovery between reaction steps; continuous on-sun operation; and direct solar illumination of the working material. Our efficiency analysis includes material thermodynamics and a detailed accounting of energy losses, and demonstrates that vacuum pumping, made possible by the innovative pressure separation approach in our reactor, has a decisive efficiency advantage over inert gas sweeping. We show that in a fully developed system, using CeO2 as a reactive material, the conversion efficiency of solar energy into H2 and CO at the design point can exceed 30%. The reactor operational flexibility makes it suitable for a wide range of operating conditions, allowing for high efficiency on an annual average basis. The mixture of H2 and CO, known as synthesis gas, is not only usable as a fuel but is also a universal starting point for the production of synthetic fuels compatible with the existing energy infrastructure. This would make it possible to replace petroleum derivatives used in transportation in the U.S., by using less than 0.7% of the U.S. land area, a roughly two orders of magnitude improvement over mature biofuel approaches. In addition, the packed bed reactor design is flexible and can be adapted to new, better performing reactive materials.

scholarly journals Modeling and Design of a Multi-Tubular Packed-Bed Reactor for Methanol Steam Reforming over a Cu/ZnO/Al2O3 Catalyst

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 610 ◽  
Author(s):  
Jimin Zhu ◽  
Samuel Simon Araya ◽  
Xiaoti Cui ◽  
Simon Lennart Sahlin ◽  
Søren Knudsen Kær
Keyword(s):  
Steam Reforming ◽  
Packed Bed ◽  
Methanol Conversion ◽  
Operating Conditions ◽  
Packed Bed Reactor ◽  
Inlet Temperature ◽  
Methanol Steam Reforming ◽  
Shell Side ◽  
Co Concentration ◽  
The Impact

Methanol as a hydrogen carrier can be reformed with steam over Cu/ZnO/Al2O3 catalysts. In this paper a comprehensive pseudo-homogenous model of a multi-tubular packed-bed reformer has been developed to investigate the impact of operating conditions and geometric parameters on its performance. A kinetic Langmuir-Hinshelwood model of the methanol steam reforming process was proposed. In addition to the kinetic model, the pressure drop and the mass and heat transfer phenomena along the reactor were taken into account. This model was verified by a dynamic model in the platform of ASPEN. The diffusion effect inside catalyst particles was also estimated and accounted for by the effectiveness factor. The simulation results showed axial temperature profiles in both tube and shell side with different operating conditions. Moreover, the lower flow rate of liquid fuel and higher inlet temperature of thermal air led to a lower concentration of residual methanol, but also a higher concentration of generated CO from the reformer exit. The choices of operating conditions were limited to ensure a tolerable concentration of methanol and CO in H2-rich gas for feeding into a high temperature polymer electrolyte membrane fuel cell (HT-PEMFC) stack. With fixed catalyst load, the increase of tube number and decrease of tube diameter improved the methanol conversion, but also increased the CO concentration in reformed gas. In addition, increasing the number of baffle plates in the shell side increased the methanol conversion and the CO concentration.

Reaction-driven instabilities in down-flow packed beds

1995 ◽  
Vol 450 (1938) ◽  
pp. 1-21 ◽  
Keyword(s):  
Hot Spots ◽  
Three Dimensional ◽  
Packed Bed ◽  
Operating Conditions ◽  
Packed Bed Reactor ◽  
Three Dimensional Model ◽  
One Dimensional ◽  
Packed Bed Reactors ◽  
First Order ◽  
The One

Flow maldistributions and corresponding hot spots may cause adverse effects in the operation of down-flow packed-bed reactors. To avoid these phenomena it is necessary to know when and how they occur. In this work, a three-dimensional model that considers the effects of fluid flow, mass transfer by diffusion, heat transfer by conduction and reactant consumption by an exothermic irreversible first-order reaction is used to analyse an adiabatic packed-bed reactor with down-flow. It is shown that the one-dimensional uniform down-flow can become unstable to three-dimensional stationary and time-dependent perturbations, giving rise to non-uniform flow fields that lead to fixed as well as moving hot spots. The boundary of the region of the operating conditions at which these instabilities occur is determined as a function of the various physicochemical parameters that characterize the packed-bed reactor.

Sign in / Sign up

Export Citation Format

Share Document