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CFD simulation of multicomponent mixture within a packed Deethanizer column

  • Hajer TroudiEmail author
  • Moncef Ghiss
  • Mohamed Ellejmi
  • Zoubeir Tourki
Original
  • 31 Downloads

Abstract

The aim of this study is to develop a model of a Deethanizer Column (DC). A fuel mixture of Methane CH4, Ethane C2H6, Propane C3H8, N-butane n-C4H10 and some hydrocarbons is used to get an insight on the DC operation. A multicomponent gas-liquid flow in DC is investigated using the Computational Fluid Dynamics (CFD) method. The droplet size change, the droplet surface temperature and the pressure drop are investigated with a Eulerian-Lagrangian model using ANSYS-Fluent R15. The computation results are compared with the experimental data of a binary and multicomponent mixture in a stationary droplet. A good agreement between them is established. Additionally, the predicted pressure drop obtained at varied porosity is compared with the data got from the Ergun formulation. The results show that the presence of CH4 and C2H6 has a big impact on the droplet surface temperature. This temperature initially reaches the lower value because of the fastest evaporation of light components (CH4 and C2H6) rather than the heavy ones (C5+). The current work provides a better understanding of the behavior of light components in DC.

Keywords

Deethanizer column CFD Droplet Multicomponent Porosity 

Nomenclature

Abbreviations

AEI

Alpha Engineering International

CFD

Computational Fluid Dynamic

DDPM

Dense Discrete Phase Modelling

SIMPLEC

Semi-Implicit Method for Pressure Linked Equations Consistent

VOF

Volume Of Fluid

VLE

Vapor-Liquid Equilibrium

UDF

User Defined Fuctions

Greek letters

ρ

Mass density, (kg/m3)

μ

Dynamic viscosity, (kg/m.s)

ε

Porosity, (m3/m3)

τ

Stress strain tensor

ϑ

Volume, (m3)

List of symbols

C

Carbon

cp

Liquid specific heat, J/kg.°C

CD

Drag coefficient

D

Diameter of column, (m)

dd

Droplet diameter, (m)

E

Total energy

F

Interphase body forces between phases, (N)

g

Gravity, 9.81 (N/kg)

H

Column height, m

h

Interphase enthalpy, convective heat transfer coefficient, W/m2. °C

k

Thermal conductivity, (W/m.°C)

L

Packed bed length, (m)

N

Number of species in two-phases

Nu

Nusselt number, (−)

p

Pressure, (Pa)

Pr

Prandlt number, (−)

q

Heat flux, (W/m2)

R

Radius of packed bed, (m)

Re

Reynolds number, (−)

ro

Radius of nozzles, (m).

S

Generalized source terms

Sc

Schmidt number, (−)

t

Time, (s)

T

Temperature, (°C)

\( \overrightarrow{V} \)

Vector Velocity, (m/s)

X

Mass fraction in liquid phase (Droplet)

x

Mole fraction in liquid phase (Droplet)

Y

Mass fraction in gas phase

y

Mole fraction in gas phase

Subscripts

d

Droplets

eff

Effective

q

Continuous phase

i

(Species)

k

Phase indicator (k = q if gas phase is present; k = d if droplets are present)

m

Mixture

p

Particles

s

Droplet surface

T

Total volume of packed bed

Operators

Gradient operator

∇.

Divergence operator

2

Laplace operator

d/dt

Time derivative, (s−1)

Notes

Acknowledgements

The research reported in this paper is supported by Alpha Engineering International (AEI) and the Mechanical Laboratory of Sousse (Tunisia).

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Hajer Troudi
    • 1
    Email author
  • Moncef Ghiss
    • 1
  • Mohamed Ellejmi
    • 2
  • Zoubeir Tourki
    • 1
  1. 1.Mechanical Laboratory of Sousse, National Engineering School of SousseUniversity of SousseSousseTunisia
  2. 2.Alpha Engineering InternationalAEI. Sahloul III 4054SousseTunisia

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