Post on 16-Apr-2017
INTRODUCTION TO CHEMICAL PROCESS SIMULATORS
A. Carrero, N. Quirante, J. Javaloyes
October 2016
DWSIM Chemical Process Simulator
A. Carrero , N. Quirante & J. Javaloyes
Introduction to Chemical Process Simulators
2
Contents
Monday, October 3rd 2016
Introduction to Sequential – Modular Steady State ProcessSimulators
Get used to working with DWSIM and COCO
Monday, October 10th 2016
Simulation of Chemical Reactors
Monday, October 17th 2016
Simulation of Distillation Columns
Monday, October 24th 2016
Case studies
A. Carrero , N. Quirante & J. Javaloyes
Introduction to Chemical Process Simulators
3
Simulation of Distillation Columns
Feed
Distillate
Bottoms
Condenser
Reboiler
Rectifying section
Stripping section
Equilibrium Stage
Conventional Distillation Column
Feed
Distillate
Bottoms
A. Carrero , N. Quirante & J. Javaloyes
Introduction to Chemical Process Simulators
4
Simulation of Distillation ColumnsjV
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FeedHeat Transfer
Liquid
Side Stream
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Side Stream
Stage j
A. Carrero , N. Quirante & J. Javaloyes
Introduction to Chemical Process Simulators
5
Simulation of Distillation ColumnsjV
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Material Balance
Vapor-Liquid Equilibrium Relation
Summation Equations
Energy BalanceMESH Equations
A. Carrero , N. Quirante & J. Javaloyes
Introduction to Chemical Process Simulators
6
Simulation of Distillation Columns
MESH Equations fully describe the behavior of a distillation column.
External to de column: these equations define the overall column totalmaterial balances, energy balances and product composition
Internal to de column: they describe equilibrium conditions, internalcomponent, total material and energy balances in each tray.
Bubble-point methods (BP)
Sum-rate methods (SR)
2N Newton methods
Nonlinear and Nonconvex algebraic system of equations
Simultaneous correction methods (SC)
Inside-out methods (IO)
Rigorous Computational Methods
A. Carrero , N. Quirante & J. Javaloyes
Introduction to Chemical Process Simulators
7
Main Steps for the Simulation of a Conventional Distillation Column
# 1. Component Selection
# 2. Fluid package Selection
# 3. Flash Algorithm Selection
# 4. Add Distillation Column Object
# 5. Set Column Properties Condenser & Reboiler Pressure Condenser type Condenser & Reboiler Specifications
# 6. Set Number of Stages
# 7. Set Column Pressure Profile
# 8. Edit Column Connections
# 9. Solving Method Selection
# 10. Run Model
Simulation of Distillation Columns
A. Carrero , N. Quirante & J. Javaloyes
Introduction to Chemical Process Simulators
8
Example
Molar Flow 200 kmol/hPressure 1.1 barVapor fraction 0
Molar CompositionxBz = 0.35xT = 0.29xM-xy = 0.12xO-xy = 0.12xP-xy = 0.12
99% recovery of Bz98% purity of Bz
Simulation of Distillation Columns
A. Carrero , N. Quirante & J. Javaloyes
Introduction to Chemical Process Simulators
9
Column Diameter Estimation
V LLV
L V
MLF
V M
0.22
2
exp 2.979 0.717ln 0.0865 ln20
0.997ln 0.07973ln ln
0.256 ln
T LV LV
T LV T
T
K F F
H F H
H
L VT F T
V
v f K
4 Vcolumn
A V S T
M VD
f f v
FLV Liquid-Vapor flow parameter
L, V Liquid/Vapor molar flowrate [kmol s-1]
ML,MV Liquid/Vapor molar mass [kg kmol-1]
L, V Liquid/Vapor density [kg m-3]
KT Parameter for terminal velocity [m s-1]
Surface tension [dyne cm-1]
HT Tray spacing [m] (0,25 – 0,6 m)
vT Vapor flooding velocity [m s-1]
fF Foaming factor
Low/ Moderate foaming ~ [0,9 - 0,85 ]
fA Net area factor (~0,9)
fS Flooding velocity safety factor (~0,8)
[R. Smith. Chemical Process Design and Integration][H. Kister. Distillation Design]