Investigating Three Different Models for Simulation of the Thermal Stage of an Industrial Split-Flow SRU Based on Equilibrium-Kinetic Approach with Heat Loss
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Mohammad Hossein Kardan
Abstract
Modified Claus process is the most important process that recovers elemental sulfur from H2S. The thermal stage of sulfur recovery unit (SRU), including the reaction furnace (RF) and waste heat boiler (WHB), plays a critically important role in sulfur recovery percentage of the unit. In this article, three methods including kinetic (PFR model), equilibrium and equilibrium-kinetic models have been investigated in order to predict the reaction furnace effluent conditions. The comparison of results with industrial data shows that kinetic model (for whole the thermal stage) is the most accurate model for simulation of the thermal stage of the industrial split-flow SRU. Mean absolute percentage error for the considered kinetic model is 4.59 %. For the first time, the consequences of considering heat loss from the reaction furnace on calculated molar flows are studied. The results show that considering heat loss only affects better prediction of some effluent molar flow rates such as CO and SO2, and its effect is not significant on the results. Eventually the effects of feed preheating on some important parameters like sulfur conversion efficiency, H2S to SO2 molar ratio and important effluent molar flows are investigated. The results indicate that feed preheating will reduce the sulfur conversion efficiency. It is also noticeable that by reducing the feed temperature to 490 K, H2S/SO2 molar ratio reaches to its optimum value of 2.
Nomenclature
| A | Frequency factor | |
| Cj | [mole m-3] | Concentration of component j |
| Cp | [J mol-1 K-1] | Specific heat capacity |
| D | [m] | Furnace Internal diameter |
| Ea | [J mole-1] | Activation energy |
| Fj | [mole s-1] | Molar flow rate of component j |
| Ft | [mole s-1] | Total molar flow rate |
| g | [m s-2] | Acceleration of gravity |
| Gt | [j] | Free Gibbs energy |
| h | [W m-2.K] | Heat transfer coefficient |
| [j mole-1] | Enthalpy of reaction i | |
| K | Reaction rate constant | |
| L | [m] | Characteristic length |
| Nu | Nusselt number | |
| P | [pa] | Pressure |
| Pr | Prandtl number | |
| qc | [W m-1] | Rate of convection heat transfer (per unit length) |
| qr | [W m-1] | Rate of radiation heat transfer (per unit length) |
| r | [mole m-3 s] | Rate of reaction |
| positive error factor | ||
| R | [j mole-1 K-1] | Universal gas constants |
| Re | Reynolds number | |
| T | [K] | Temperature |
| U | [W m-2.K] | Overall heat transfer coefficient |
| total number of atoms of element k in component i | ||
| Gas absorptivity | ||
| Gas emissivity | ||
| [kg m-1s-1] | Gas viscosity | |
| Stoichiometric coefficient of component i in reaction j | ||
| ρ | [kg m-3] | Gas density |
| [W m-2 K-4] | Stefan-Boltzman constant |
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- Investigating Three Different Models for Simulation of the Thermal Stage of an Industrial Split-Flow SRU Based on Equilibrium-Kinetic Approach with Heat Loss
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Articles in the same Issue
- Research Articles
- Effect of Pin-Fin Geometry on Microchannel Performance
- Study of Process Factor Effects and Interactions in Synthesis Gas Production via a Simulated Model for Glycerol Steam Reforming
- Robust Prediction of Filtrate Flux for Separation of Catalyst Particles from Wax Effluent of Fischer-Tropsch Bubble Column Reactor via Regularization Network
- Modelling and Simulation of Multiphase Flow Applicable to Processes in Oil and Gas Industry
- CH4 Direct Reduction of In-Flight Fe3O4 Concentrate Particles
- Determination of Optimum Concentration of Nanofluid for Process Intensification of Heat Transfer Using Corrugated Plate Type Heat Exchanger
- Investigating Three Different Models for Simulation of the Thermal Stage of an Industrial Split-Flow SRU Based on Equilibrium-Kinetic Approach with Heat Loss
- Analytical Design of Enhanced Fractional Filter PID Controller for Improved Disturbance Rejection of Second Order Plus Time Delay Processes
