Modification of Claus Sulfur Recovery Unit by Isothermal Reactors to Decrease Sulfur Contaminant Emission: Process Modeling and Optimization

2018 ◽  
Vol 14 (2) ◽  
Author(s):  
H. Ghahraloud ◽  
M. Farsi ◽  
M.R. Rahimpour
Keyword(s):  
Fixed Bed ◽  
Recovery Process ◽  
Coolant Temperature ◽  
Inlet Temperature ◽  
Sulfur Recovery ◽  
Catalytic Reactors ◽  
Steady State Condition ◽  
Conventional Process ◽  
Decision Variables ◽  
Simulation Results

Abstract Due to environmental limitations and issues, the main goal of this research is modification of conventional Claus sulfur recovery process to decreases sulfur contaminant emission. In this regard, two environmentally friendly alternatives are proposed based on the isothermal concept in reactors. Since Claus reaction is exothermic and reversible, the adiabatic fixed bed reactors in the catalytic section of Claus process are substituted by the isothermal reactors. The furnace and catalytic reactors are modeled based on the mass and energy conservation laws at steady state condition. To prove accuracy of the developed model, the simulation results of conventional process are compared with the available plant data. Then, the optimal condition of modified processes are calculated considering sulfur recovery as the objective function using the Genetic algorithm as a useful method in global optimization. The attainable decision variables are inlet temperature of furnace and reactors, coolant temperature, feed split fraction and air flow rate in the furnace. The simulation results show that H2S conversion in the proposed cases increases about 1.87 % and 1.78 % compared to the conventional process. Generally, the main advantages of proposed structures are higher sulfur recovery and lower sulfur contaminant emission such as COS and CS2 emission.

Three-phase modeling and optimization of benzene alkylation in commercial catalytic reactors

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Donya Danesh ◽  
Mohammad Farsi ◽  
Mohammad Reza Rahimpour
Keyword(s):  
Production Capacity ◽  
Solid Catalyst ◽  
Process Conditions ◽  
Catalytic Reactors ◽  
Benzene Alkylation ◽  
Conventional Condition ◽  
Liquid Phases ◽  
Decision Variables ◽  
Three Phase ◽  
Simulation Results

Abstract The main object of this research is heterogenous modeling of benzene alkylation in three phase reactors based on the mass and energy balance equations by coupling the kinetic and equilibrium models and optimization the process conditions to enhance production capacity. In the first step, the alkylation reactors are simulated considering a three-phase model including heat and mass transfer resistances in the solid catalyst, gas and liquid phases. To prove the accuracy of developed model and adopted assumptions, the simulation results are compared with the plant data. Based on the simulation results, the benzene conversion and ethylbenzene selectivity in the alkylation reactors are 15.03 and 94.60% at the conventional condition. In the second step, considering the temperature of inlet streams to the reactors as decision variables, an optimization problem is formulated to maximize the ethylbenzene production rate as the objective function. Based on the simulation results, applying optimal condition on the system improves the ethylbenzene production by 1.33% at the same ethylene conversion compared to the conventional condition.

Intensification of cooling in a batch reactor with an exothermic reaction by nonisothermal control in stable pseudostationary states

1984 ◽  
Vol 49 (11) ◽  
pp. 2566-2578 ◽  
Author(s):  
Josef Horák ◽  
Petr Beránek ◽  
Dagmar Maršálková
Keyword(s):  
Batch Reactor ◽  
Exothermic Reaction ◽  
Reaction Model ◽  
Order Reaction ◽  
Zero Order ◽  
Coolant Temperature ◽  
Inlet Temperature ◽  
Adaptive Parameter ◽  
Zero Order Reaction ◽  
Set Up

An algorithm is set up and tested for the temperature control of a batch reactor consisting in jump changes in the inlet temperature of entering coolant. This temperature is so chosen that its difference from the temperature of the reaction mixture is near the highest difference at which the stable pseudostationary state of the system still exists. For the prediction of the new coolant inlet temperature, a zero-order reaction model is used with an adaptive parameter estimated from the experimentally established value of the maximum of the reaction mixture overheating at the previous coolant temperature.

Construction of an Elementary Model for the Dynamic Analysis of a Pressurized Water Reactor

2013 ◽  
Vol 284-287 ◽  
pp. 652-656 ◽  
Author(s):  
Chiung Wen Tsai ◽  
Chun Kuan Shih ◽  
Jong Rong Wang
Keyword(s):  
Transfer Functions ◽  
Feedback Loops ◽  
Dynamic Responses ◽  
Coolant Temperature ◽  
Inlet Temperature ◽  
Pressurized Water Reactor ◽  
Elementary Model ◽  
Pressurized Water ◽  
Water Reactor ◽  
Neutron Kinetics

A lumped-parameter numerical model was constructed based on the conservation laws of mass and energy and the point neutron kinetics with 6 groups of delayed neutron to represent the dynamics of primary loop of a pressurized water reactor (PWR) core. On the viewpoint of control theory, the coupled phenomenon of neutron kinetics and thermohydraulics can be recognized as a dynamic system with feedback loops which is caused by the Doppler effect and the coolant temperature difference. Scilab was implemented to representing the equivalent transfer functions and associated feedback loops of a PWR core. The dynamic responses were performed by the perturbations of coolant inlet flow, coolant inlet temperature, and reactivity insertion.

Application of Honey-Bee Mating Optimization to Naphtha Reforming Reactor

2013 ◽  
Vol 11 (1) ◽  
pp. 293-308 ◽  
Author(s):  
Somayeh Karimi ◽  
Navid Mostoufi ◽  
Rahmat Sotudeh-Gharebagh
Keyword(s):  
Objective Function ◽  
Honey Bee ◽  
Process Model ◽  
Global Optimum ◽  
Inlet Temperature ◽  
Local Optimum ◽  
Naphtha Reforming ◽  
Decision Variables ◽  
Algorithm Comparison ◽  
Honey Bee Mating Optimization

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.

scholarly journals Suiting Dynamic Models of Fixed-Bed Catalytic Reactors for Computer-Based Applications

Engineering ◽  
2011 ◽  
Vol 03 (07) ◽  
pp. 778-785 ◽  
Author(s):  
Eduardo Coselli Vasco de Toledo ◽  
Edvaldo Rodrigo Morais ◽  
Delba Nisi Cosme Melo ◽  
Adriano Pinto Mariano ◽  
João F. C. A. Meyer ◽  
...  
Keyword(s):  
Dynamic Models ◽  
Fixed Bed ◽  
Catalytic Reactors ◽  
Computer Based

Fixed-bed gas-solid catalytic reactors

2016 ◽  
pp. 53-79
Author(s):  
João P. Lopes ◽  
Alírio E. Rodrigues
Keyword(s):  
Fixed Bed ◽  
Catalytic Reactors
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