Aspen Tutorial
Terry A. Ring
ChEN 4253
Process Simulation Software
• Steady State Process
Simulation
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AspenPlus
ProMax
ChemCad
Hysis
HySim
ProSim
CADSim
OLI Process Simulator
KemSimp
Chemical Workbench Code
Ascend IV
• Dynamic Process
Simulation
– Aspen Dynamics
– CADSim
– Simulation Solutions, Inc.
Types of Simulators
• ProMax
• Equation Based
– Solves block by block
• Aspen
• Puts all equations into
one Matrix equation
– Solves all Mass and
Energy Balances at
once
Basic Elements of a Simulation Program
*
*
Thermodynamics
Numerical Methods
Thermodynamics
Other Subjects : Solid
Mechanics, Manufacturing
Science
Economics
* - Reaction Engineering, Mass Transfer, Heat Transfer, Fluid Mechanics
Towler and Sinnott , “Chemical Engineering Design : Principles , Practice, Economics of Plant and Process
Design” , Elsevier (2008)
Aspen
• Aspects of Aspen
– Next Button
– Many units that perform a given function
• Degrees of Freedom are chosen for you
– Setup for kinetic reactions are tricky
– Accounts for particle sizes
• Simple block models
– Automatic Plant Costing (Aspen Economics)
Steps to Run
• Aspen (Left Hand Bar)
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Wiring up Process
Title
Components
Thermopackage
Process Flow Sheet
• Feed Stream
• Unit Specifications
– Fixed degrees of
freedom
– Run
– Results
– Report
ThermoPackage Choice
• Questions for ThermoPackage Choice
• Are the components?
– Polar
– Non-Polar
• System Pressures?
– P< 10 atm - ideal gas
• Interaction Parameters Available?
Eric Carlson’s Recommendations
Non-electrolyte
Figure 1
See Figure 2
Polar
E?
Electrolyte NRTL
Or Pizer
Electrolyte
Real
All
Non-polar
Peng-Robinson,
Redlich-Kwong-Soave
Lee-Kesler-Plocker
R?
Polarity
R?
Real or
pseudocomponents
P?
Pressure
E?
Electrolytes
Pseudo & Real
P?
Vacuum
Chao-Seader,
Grayson-Streed or
Braun K-10
Braun K-10 or ideal
Yes
Figure 2
Yes
LL?
P < 10 bar
ij?
(See also
Figure 3)
P?
NRTL, UNIQUAC
and their variances
No
Yes
No
No
Yes
P > 10 bar
P?
Pressure
ij?
Interaction Parameters
Available
UNIFAC LLE
LL?
Polar
Non-electrolytes
LL? Liquid/Liquid
WILSON, NRTL,
UNIQUAC and
their variances
ij?
No
UNIFAC and its
extensions
Schwartentruber-Renon
PR or SRK with WS
PR or SRK with MHV2
PSRK
PR or SRK with MHV2
Hexamers
Figure 3
Yes
DP?
Dimers
Wilson
NRTL
UNIQUAC
UNIFAC
VAP?
DP?
Wilson, NRTL, UNIQUAC,
or UNIFAC with special EOS
for Hexamers
VAP?
No
Wilson, NRTL, UNIQUAC,
UNIFAC with Hayden O’Connell
or Northnagel EOS
Wilson, NRTL,
UNIQUAC, or UNIFAC*
with ideal Gas or RK EOS
Vapor Phase Association
Degrees of Polymerizatiom
UNIFAC* and its Extensions
Bob Seader’s Recommendations
Bob Seader’s Recommendations
Yes
Figure 4
Yes
Yes
Yes
No
HC?
No
Hydrocarbons
LG?
Light gases
See Figure 5
E?
Electrolyte
See Figure 6
PC?
Organic Polar
Compound
PC?
No
Yes
HC?
PC?
No
LG?
PSRK
See Figure 5
Modified NRTL
E?
No
Special: e.g., Sour Water (NH3, CO2, H2S, H2O)
Aqueous amine solution with CO2 and H2S
Figure 5
Critical
Cryogenic
Narrow or
wide
HC and/
or LG
P?
Non-Critical
T?
Non- Cryogenic
BP?
Very wide
PR
LKP
PR, BWRS
SRK, PR
T?
Boiling point range
of compound
Temperature region
P?
Pressure region
BP?
Figure 6
Yes
Available
PC with HC
NRTL, UNIQUAC
PPS?
BIP?
Not Available
No
Wilson
UNIFAC
BIP?
Binary Interaction
Parameters
PPS?
Possible Phase
Splitting
Hyprotech Recommendations
ProMax Guidance
(5 more pages like this)
Model
Pure
Binary
Mixture
VLE
VLLE
Notes
EOS (Equation of State)
SRK (Soave
Redlich
Kwong)
Gas Processing with No
Methanol, Refinery Distillation
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Peng-Robinson
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Gas Processing with No
Methanol
SRK Polar
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Gas Processing with Methanol or
NMP
Peng-Robinson
Polar
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Gas Processing with Methanol or
NMP
Lee-Kesler
Tillner-Roth
and Friend
NH3 + H2O
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Light Hydrocarbon Systems with
H2S and CO2, No 2nd Liquid
Phase
Ammonia Absorption
Refrigeration, Ammonia and/or
Water Only
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Problem-1
• Problem 5.12
• Alternatives in preparing a feed. A
process under design requires that 100
lbmol/hr of toluene at 70F and 20 psia be
brought to 450 F and 75 psia.
• Flow sheets using Peng-Robinson
– Boil-Superheat-Compress
– Pump to 75 psi-Boil-Superheat
– Which process uses the most energy?
Design Spec
– What Then How (WtH)
• What do I want to specify?
• What do I want to vary to control it?
Which System has the most
Energy?
• Moving from To, Po to Tf, Pf
– STATE PROPERTY
• Enthalpy change is the same if the end
points are the same.
• Why is Boil then Compress not
suggested? Heuristic 43
Problem -2
• Use Gibbs
CO  2 H 2  CH 3OH
Minimization reactor
in Aspen to determine CO  H 2  H 2O  C ( s)
the products of
reaction at 10 atm and
200 C.
• Feed equimolar in CO
and H2
Sensitivity Analysis
• Produces Table of Results using a Do
Loop to vary one (or more variables)
• What Then How
Problem 3
• Use Equilibrium Reactor to determine
reactor conversion for methanol reaction
at 10 atm and 200C
CO  2 H 2  CH 3OH
• Use sensitivity analysis to determine
reactor conversion at a suite of
temperatures
Problem -4
• Determine the
resulting
equilibrium at 10
atm and 200 C
using an
equilibrium reactor
in Aspen with both
of the reactions
listed.
CO  2 H 2  CH 3OH
CO  H 2  H 2O  C ( s)
Problem 5
– Vapor-Liquid Equilibrium
• 40mole% Ethanol – water
Problem 6
• Liquid-Liquid Equilibria
– Polar - polar
Problem 7
• Liquid-Liquid Equilibria
– Polar - non-polar
Problem 8
• Multiple component phase equilibria
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Methane – 0.1 mole fraction
Ethane – 0.2
Propane- 0.3
Butane- 0.3
Methyl ethyl keytone -0.1
– 10 atm, 10°C
– Use Ideal and Peng Robinson Thermo Pkg.
• Compare results
Example-9
• Distillation/Flash
• Methanol – Water
– 100 lbmole/hr
• Flash at 90C, 1 atm
• Distillation
– R=2
– BoilUp Ratio=3