Numerical Study of Coal Composition Effects on the Performance of Gasification Through Computational Fluid Dynamic
-
Imran Nazir Unar
,
Shaheen Aziz
Abstract
Pakistan is very rich in coal reserves specifically after exploration of Thar coal reserves. At the same time country is facing energy crises due to shortage or unavailability of sustainable fuel supply at a cheaper rate. One potential solution is coal gasification which gives clean synthetic gas usually called syngas for use as an alternative fuel source for electricity production at a cheaper rate as well as a source of recovering different chemicals used as basic raw materials in other industries. Numerical simulations have been performed in this work for the gasification process of indigenous coal on a 2D computational fluid dynamic (CFD) model of downdraft entrained-flow gasifier using commercial CFD software FLUENT®6.3.26. Navier-stokes equations along with transport equations for species have been solved using eddy-dissipation combustion model. The compositions of indigenous coals (Thar, Lakhra, and Sonda) were used in simulations as gasification feedstock. Rich oxidant conditions 95 % O2 and 5 % N2 were set for gasification. The gasification performance was studied by comparing efficiencies of gasification and quality of syngas produced for three types of coal feedings. The temperature and pressure profiles inside the gasifier were also studied. From simulation results, the great influence of coal composition was observed in the performance of gasification. Lakhra coal produced syngas with a maximum heating value of 20.55 MJ/kg whereas sonda coal produced syngas with a minimum heating value of 17.96 MJ/kg.
Nomenclature
Density
Velocity
Source Term
Source Term
- t
Time
- T
Temperature
Enthalpy
Thermal Conductivity
Source Term
Mole fraction of specie i
Source Term
Source Term
Diffusivity
Effective conductivity
Conductivity due to Turbulence
Stress Tensor
Force Vector
Species j diffusion
- E
Energy
Sensible Enthalpy
Specific Heat for specie j
- μ
Dynamic Viscosity
- k
Kinetic Energy for Turbulence
- ε
Dissipation Rate of Turbulence
- μt
Turbulence Viscosity
- Cμ
Constant
- Gk
Mean Velocity Gradients
- Dt
Diffusion Coefficient for Turbulence
- Prt
Prandtl number for Turbulence
- Sct
Schmidt number for Turbulence
- qr
Heat Flux for Radiation Heat
- σs
Coefficient for Scattering
- G
Incident Radiation
- C
Coefficient of Function for Linear-Anisotropic Phase
- σ
Stefan–Boltzmann Constant
- qr,w
Radiation Flux at Walls
- εw
Emissivity
Net Production Rate of Species i through Chemical Reaction
Species P Mass Fraction
Reactant R Mass Fraction
- A and B
An empirical constant
Stoichiometric Coefficient for Reactant i in Reaction r
Stoichiometric Coefficient for Product j in Reaction r
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Articles in the same Issue
- Articles
- Mars van Krevelen Mechanism for the Selective Partial Oxidation of Ethane
- Multi-Objective Optimization of an ABE Fermentation System for Butanol Production as Biofuel
- Synthesis of Ethyl Phenol over Modified HZSM-5 Catalyst in a Fixed Bed Reactor
- Signal Synthesis Model Reference Adaptive Controller with Genetic Algorithm for a Control of Chemical Tank Reactor
- Efficiency of Phosphotungstic Acid Modified Mn-Based Catalysts to Promote Activity and N2 Formation for Selective Catalytic Reduction of NO with Ammonia
- Mathematical Modelling and Simulation of a Trickle-Bed Reactor for Hydrotreating of Petroleum Feedstock
- Improving Wastewater Nitrogen Removal and Reducing Effluent NOx--N by an Oxygen-Limited Process Consisting of a Sequencing Batch Reactor and a Sequencing Batch Biofilm Reactor
- CFD Simulation of the Particle Dispersion Behavior and Mass Transfer–Reaction Kinetics in non-Newton Fluid with High Viscosity
- Comparison of Euler-Euler and Euler-Lagrange Approaches for Simulating Gas-Solid Flows in a Multiple-Spouted Bed
- Numerical Study of Coal Composition Effects on the Performance of Gasification Through Computational Fluid Dynamic
