Aspen Plus for Process
Design and Simulation
Design and Simulation
Resource Persons
Prof Dr Shahid Naveed Prof. Dr. Shahid Naveed Dr. –Ing. Naveed Ramzan
Associate Professor
Mr. Farhan Ahmad Mr. Farhan Ahmad
Lecturer
Ms Sana Yousaf
Course Organizing Officer Ms. Sana Yusuf
Course Agenda
• Role of Simulation in Process Design• AspenTech Products and Aspen Plus Features • Aspen Plus graphical User Interface
• Aspen Plus Basics
• Physical Properties Model and Properties Estimation • HEATX and Heat Exchanger Modelling
• RADFRAC and Distillation Column Modelling • Unit Operation ModelsUnit Operation Models
• Sensitivity Analysis • Final Workshop
• Final Workshop
Course Agenda (Day – 1)
• Role of Simulation in Process Design• AspenTech Products and Aspen Plus Features • Aspen Plus graphical User Interface
• Aspen Plus Basics
• Physical Properties Model and Properties Estimation • HEATX and Heat Exchanger Modelling
• RADFRAC and Distillation Column Modelling • Unit Operation ModelsUnit Operation Models
• Sensitivity Analysis • Final Workshop
• Final Workshop
Course Agenda (Day – 2)
• Role of Simulation in Process Design• AspenTech Products and Aspen Plus Features • Aspen Plus graphical User Interface
• Aspen Plus Basics
• Physical Properties Model and Properties Estimation • HEATX and Heat Exchanger Modelling
• RADFRAC and Distillation Column Modelling • Unit Operation ModelsUnit Operation Models
• Sensitivity Analysis • Final Workshop
4
• Final Workshop
Course Agenda (Day – 3)
• Role of Simulation in Process Design• AspenTech Products and Aspen Plus Features • Aspen Plus graphical User Interface
• Aspen Plus Basics
• Physical Properties Model and Properties Estimation • HEATX and Heat Exchanger Modelling
• RADFRAC and Distillation Column Modelling • Unit Operation ModelsUnit Operation Models
• Sensitivity Analysis • Final Workshop
5
• Final Workshop
Role of Simulation in
Process Design
Process Design
Resource Persons
Prof. Dr. Shahid Naveed
6 Aspen Plus for Process Design and Simulation
Simulation
7 Aspen Plus for Process Design and Simulation
Modelling and Simulation
1: What is Modeling
Description
of
any
complete
system
in
mathematical terms is called a mathematical
model
model
2: What is Simulation
2: What is Simulation
Solving
the
modeling
equations
either
numerically or analytically
8 Aspen Plus for Process Design and Simulation
Simulation and Modelling Problem in
Process Engineering
Nano
Micro
Meso
Macro
Mega
Molecular Processes, Bubbles, Drops, Particles Reactors, Columns, Exchangers, Pumps Production Plants, Petrochemical Environment, Atmosphere Oceans
Active sites Particles, Eddies Pumps, Compressors, ... Petrochemical Complexes Oceans Soils
Lit.: Charpentier, J.-C.; Trambouze, P.: Process Engineering and problems encountered by chemical and related Industries in the near future Revolution or cointinuity?
9
by chemical and related Industries in the near future. Revolution or cointinuity? Chemical Enginering and Processing 37(1998) 559-565
Why Process Simulation
The development of new industrial processes requires the solution of several unknown or expensive problems resulting from the scaling up, such as the impurities behaviour in a continuous run, the optimum such as the impurities behaviour in a continuous run, the optimum equipment design, the better fluid distribution, the pressure losses in different equipments, the operators training, etc. These problems shall be resolved with the high reliability and less costs as possible before the industrial plant installation.
To solve these problems it is necessary to run the process either in pilot plants or to construct prototypes, but this way is too expensive and normally very slow. Computer simulation applications can be used as a complementary development tool that in many cases lead to accurate solutions in shorter time and with much less consumption of resources solutions in shorter time and with much less consumption of resources. These computational tools are not used aiming to substitute traditional ones, but have demonstrated that can be a helpful complement in technological development and design engineering
11
Process Simulation Tools
Simulations tools can help to resolve several of these
problems, with low cost, high reliability and normally in less
problems, with low cost, high reliability and normally in less
time. Otherwise these tools can help to the process engineer
to understand what happen, and what are the problematic
points in the whole process or in a particular equipment
points in the whole process, or in a particular equipment.
These tools can be classified in three groups depending on
the problem that are going to be resolved:
Æ
Process Simulation tools.
Æ
A computational fluid dynamics (CFD) tools.
Æ
Other particular simulation software
12
Process Simulation Tools
Objectives of Process Simulation Tools:
Optimizing the design and performance of product assets
Opt
g t e des g a d pe o
a ce o p oduct assets
Increasing throughput and yield improving quality and
Increasing throughput and yield, improving quality, and
reducing energy costs
Responding more quickly to unexpected events or
changes in customer demand
g
Managing the profitability of operations in real time
13
Types of Process Simulation Tools
In process engineering two types of simulations tools are
used:
used:
Æ
Steady-State Simulators:
Or Static simulators.
Typically used in process design, they simulate the
yp
y
p
g ,
y
process at steady state conditions, usually at the design
operating conditions. In this kind of tools Time is not a
variable
variable.
Æ
Dynamic models
: consider time as a variable and
simulate the process over a period of time A dynamic
simulate the process over a period of time. A dynamic
simulation can be used to estimate or illustrate the
response, over time, to a change in the process.
Steady State Process Simulation Tools
The steady state simulation tool produce a
static simulation
,
which typically used in process design, to simulate the
yp
y
p
g ,
process at steady state conditions, usually
at the design
operating conditions
. This simulator don’t use Time as
variable
variable.
Th
i
l ti
t
l
ll
th
i
t
d
il
d
These simulation tools allow the engineer to do easily and
strictly
mass balance and energy balance
for a high variety of
chemical and petrochemical processes. Equipment and
p
p
q p
instrument design, plant design, capital costs, and technical
evaluations are all dependent on such calculations.
Steady State Process Simulation Tools
All of this tools contains:• A Physical and chemical properties Data Base for several elements and compounds and different methods to calculate the elements and compounds, and different methods to calculate the properties of mix.
• A Drawing tool, which can help to produce the Process Flow Di (PFD)
Diagrams (PFD).
• A Pre-modelled unit operation; like abortion columns, heaters, reactors, etc.
There are several different software for the steady state process simulation as:
- VMG Sim - Aspen plus
- Metsim - Chemcad
Others
16
Dynamic Process Simulation Tools
Dynamic simulation tools consider
time as a variable
and
simulate the process over a period of time. A dynamic
simulation can be used to estimate or illustrate the response,
over time, to a change in the process.
This technology is commonly used for
design and revamp
studies, operator training, testing of DCS configurations
and
the development of operating procedures
the development of operating procedures.
Several of the steady state software tools have an especial
module to produce the dynamic simulation of the process. For
example
Aspen Dynamics
Computational Fluid Dynamic (CFD) Tools
Computational Fluid Dynamic (CFD) simulation software has
been used for more than twenty years in the aerospace and
automobile industries but it is recently being applied to new
automobile industries, but it is recently being applied to new
industry fields where
heat transfer and fluids distribution
problems are present.
CFD is based on finite elements calculations. The simulation
software divides the 3D surface in discrete cells creating a
mesh. The software creates and calculates the
Navier–
Stokes equations
for every cell within the mesh starting from
defined
boundary
conditions
It
is
possible
to
define
defined
boundary
conditions.
It
is
possible
to
define
calculation objectives, for instance pressure, temperature,
and flow velocity, at selected sites of the simulated volume.
Computational Fluid Dynamic (CFD) Tools
The following analyses can be performed:
•2D and 3D analysis of Newtonian fluids
•2D and 3D analysis of Newtonian fluids
•External and internal flows
•Steady-state and transient-state flows
C
ibl
d
ibl fl
•Compressible and non-compressible flows
•Laminar, turbulent and transitional flow regimes
•Flows with vortex
There are several different CFD
software as:
- Fluent
•Multicomponent flows
•Heat transference effects
•Gravitational effects
- Fluent
- Floworks
- Flow Science
•Gravitational effects.
Required Competency
Impact on Chemical Process Industry
Problem
definition
Problem definition
AspenTech Products & Aspen Plus
Graphical User Interface
Graphical User Interface
Lesson Objectives
Aspen Tech Company Information
Simulation Targets
Li t f A
T
h P d
t
List of AspenTech Products
AspenTech Company Information
•
Advanced System for Process Engineering
(ASPEN)
• Project conducted at the Massachusetts Institute of
Technology (MIT) in Cambridge Massachusetts
Technology (MIT) in Cambridge Massachusetts,
from 1976 to 1981
• Over 2000 Employees world wide
• HQ in Cambridge, MA (Boston)
• Offices in 35 Countries
• Public held since 1994, NASDAQ
•
www.aspentech.com
http://support aspentech com
Process Simulation Targets
Process Simulation Debottlenecking R i Optimization,design etc. H t i t ti t Steady State Simulation RevampingOperation
Heat integration etc.
Sensitivity, maintenance Steady State Simulation
Process Control Real time optimization
Operation Dynamic Simulation
Start up, Shut down, safety
Operator Training
Operational failures Safety examinations, design Disturbance Simulation
Products
• Process Engineering» Process simulation Chemicals (10 products : AspenPlus) » Process simulation Oil&Gas (8 products : AspenHYSYS)( p p ) » Process simulation Refining (11 products : Aspenadsim+)
» Process simulation Batch/Pharma (8 products :Aspenproperties) » Model Deployment (3 products : AspenModelrunner)
» Equipment modeling (8 products :AspenAcol+) » Basic Engineering (2 products :AspenKbase)
» Economic Evaluation (3 products : Aspn Icarus Project Manager) • Advance Process Control (14 products : Aspen Apollo, Aspen IQ) • Planning & Scheduling (10 products : Aspen Advisor Aspen MBO) • Planning & Scheduling (10 products : Aspen Advisor, Aspen MBO) • Supply & Distribution (3 products : Aspen Retail)
Products
• Aspen Plus
Aspen Plus is the most popular product (accounted 48%
of sales in 1995)
of sales in 1995)
a steady state modeling system built around the core
technology
• Properties PLUS
It is a database of chemicals properties underlying its
other products popular with customers ~ developed in
other products, popular with customers ~ developed
in-house modeling software
Oth
d l
• Other modules
» offers to the customers ~ license separately
» use with its other products to model subsystems used
i hi hl
i li
d h
i
l
i
li
i
Starting with Aspen Plus
Exercise-I
Basic Input to Run Aspen Plus
Simulation
Simulation
Exercise-II
Property Packages
&
&
Property Estimation
Resource Person
FARHAN AHMADContents
• Introduction
• Properties of Unit Operations • Property Packages » Ideal model » Equation-of-state model A i i d l » Activity model » Special models
• Selection of Property Package • Selection of Property Package
Types of properties
Th th t f ti
There are three types of properties:
» Thermodynamic properties » Transport properties
Why are physical properties important ?
• A key requirement of process design is the need to • A key requirement of process design is the need to accurately reproduce the various physical properties that describes chemical species.
• Accurate representation of physical properties is essential key to meaningful simulation result.
• Aspen Plus also allow you to predict properties of mixtures ranging from well defined light hydrocarbon systems to omple oil mi t es and highl non ideal (non ele t ol te) complex oil mixtures and highly non-ideal (non-electrolyte) chemical systems.
Can we believe simulation results?
Reasons: Reasons:
• Improperly selected thermodynamic models.
• Inadequate model parameters.
• Incorrect hypothetical components generation • Incorrect hypothetical components generation.
Property Package
• Property package is a collection of models that simulation tool (Aspen Plus) uses to compute thermodynamic tool (Aspen Plus) uses to compute thermodynamic, transport and other properties.
P t k d fi d b l l ti th ( t )
• Property packages are defined by calculation paths (routes) and physical property equations (models), which determine how properties are calculated.
• Aspen Plus includes a large number of built-in property packages that are sufficient for most applications.
» Modification of existing package » Develop a new package
Available Property Packages
• Property methods ca be categorized into 4 groups: • Property methods ca be categorized into 4 groups:
» Ideal
» Equation-of-state
» Activity coefficient » Special
Ideal Property Method
Ideal Property method uses the following calculation methods and models:
• Most basic property methods and models:
• Most basic property methods based on ideal behavior of system.
• Mixture properties are based on mole fraction averages of pure components properties pure components properties.
Equation-of-state Property Packages
EOS property method uses the following calculation methods and models:
• It accounts the Departure from ideality.
• In EOS property methods, vapor and liquid properties are all calculated by the same
d l model.
• Extrapolates reasonably well with temperature and pressure.
• Inability to accurately predictab ty to accu ate y p ed ct highly non-ideal liquid mixtures.
Activity coefficient Property Methods
Activity coefficient property methods use the following calculation methods and models for pure component
• Vapor and liquid properties l l d b diff
properties:
are calculated by different models.
• Ability to represent highly non-ideal liquid mixtures.
• Inconsistent in the critical region.
Special Property packages
• Additional property packages use special correlations and are available for special applications:
Selection
of
Property Packages
p
y
g
How to choose the best property prediction method for simulation ?
Importance of Selecting the Appropriate
property package
p p
y p
g
• Correct predictions of the physical properties of the mixtureCorrect predictions of the physical properties of the mixture
as a function of temperature and pressure.
• Each method is suitable only for particular types of • Each method is suitable only for particular types of
components and limited to certain operating conditions.
Choosing the wrong method may lead to incorrect
• Choosing the wrong method may lead to incorrect
simulation results.
l l f l bl d
• Particularly important for reliable computations associated
Principle Steps in Selecting the Appropriate
Property Package
p
y
g
1. Choosing the most suitable model.g
2. Comparing the obtained predictions with data from the literature.
3. Adding estimates for components that not available in the chosen package.
4. Generation of lab data if necessary to check the property model.
Criteria of choosing suitable property package
• The choice of which the property package to use should be based on
based on
» Composition
» Temperature and pressure » Temperature and pressure » Availability of parameters
Issues in Selection of the Appropriate
property Package
p p
y
g
• Nature of mixture
(e.g., hydrocarbon, polar, electrolyte, etc.)
• Pressure and temperature range
Sources of Information
• Publications and professional literature that deal with the process in question or with the components in the process.
• Simulator reference manual (HELP).
• Databanks
Recommendations for the Selection of the
Appropriate Property Package
• Eric Carlson, “Don’t gamble with physical properties for simulations,” Chem. Eng. Prog. October 1996, 35-46
• Prof J.D. (Bob) Seader, University of Utah
• Hyprotech Recommendations • Hyprotech Recommendations
Example
• Find the best thermodynamic package for 1-Propanol • Find the best thermodynamic package for 1-Propanol ,
1-Propanol ,H2O mixture Non-electrolyte See Figure 2 Figure 1
E?
Polar Polarity R? Real or pseudocomponents P? Pressure E? ElectrolytesLL?
Yesij?
LL?
P < 10 bar No WILSON, NRTL, UNIQUAC and their variances Figure 2P?
j
No their variancesP?
UNIFAC and its Polar Non-electrolytes
LL?
No No extensions LL? Liquid/Liquid P? Pressure ij?ij? Interaction Parameters Available
HC? Hydrocarbons LG? Light gases Figure 3
LG?
Yes PC? Organic Polar Compound Yes See Figure 4HC?
No
PC?
Figure 4 Yes NRTL, UNIQUAC
PPS?
AvailableBIP?
PC with HC Binary Interaction UNIFAC Not Available PPS? Possible Phase SplittingBIP? Binary Interaction Parameters
1-Propanol, H
2O
98
100 TXY diagram for 1-Propanol, H2O Perry NRTL 94 96 98 NRTL PRSV UNIQUAC Van-Laar (Built-in Van-Laar(Perry) 90 92 94 T [ o C] 86 88 90 T 0 0 1 0 2 0 3 0 4 0 0 6 0 0 8 0 9 1 82 84 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
RADFRAC & Distillation Column
Modeling
Modeling
Resource Person
Dr. –Ing. Naveed Ramzan
Associate Professor
Mathematical Model Behind RADFRAC
Qc
V
2 Stage f-1D
Q
L
2 Stage2 vik V H Stage k-1 lik-1 L h vif VfHf lif-1 Lif-1hf- 1 Vif+Vif ViFD
L
1 StagefF
S
Stagep vik+1 Vk=1HK+ VkHK lik Lk hK Stage k L1k-1 h K-vif+1 lif lif-1+liF liF Stage fB
StageNS
StagepOverall Column Model
1
Simple Stage Model
Vf+1Hf+1 Ljhf
Feed Stage Model
+l l 0 l L F l 0
Overall Column Model
Fi+Si-Di-Bi=0 F+S-D-B=0 vik+1+lik-1-vik-lik=0 Vk+1+Lk-1-Vk-Lk=0 vif+1+lif-1+LiF-vif-lif=0 Vf+1+Lf-1+Ff –Vf – Lf =0
Mathematical Model Behind RADFRAC
The Equilibrium Equation The Summation Equation
yik = Kik xik OR vik/ Vk = Kik lik/ Lk Kik =Kik( Tk,Pk, xik yik )
For Liquid Phase ∑c
i xik –1 = 0
or ∑c l / L 1 = 0
For Vapor Phase ∑c i yik –1 = 0 or ∑c v / V 1 = 0 ik = ik( k, k, ik , yik ) or ∑c i lik/ Lk –1 = 0 or ∑c i yik/ Kik –1 = 0 or ∑c i vik/ Vk –1 = 0 or ∑c i Xik Kik –1 = 0
Mathematical Model Behind RADFRAC
Overall Energy Balance for Column
FHF-DHD-BhB +SHS-QC=0
For Condenser
V2H2+L1h1-DH1-Qc = 0
For Simple Stage
Vk+1Hk+1+Lk-1hk-1-Lkhk-VkHk=0
2 2 1 1 1 Qc
Hk = Hk( Tk,Pk , yik )
For Feed Stage
FH +V H +L h -L h -V H =0
hk = hk( Tk,Pk , xik )
Exercise
Exercise
Aspen Plus for Process
Design and Simulation
Design and Simulation
Course Agenda
• Role of Simulation in Process Design• Aspen Tech Products and Aspen Plus BasicsAspen Tech Products and Aspen Plus Basics
• Physical Properties Model and Properties Estimation • HEATX and Heat Exchanger Modelling
• HEATX and Heat Exchanger Modelling
• RADFRAC and Distillation Column Modelling
Unit Operation Models
• Unit Operation Models • Sensitivity Analysis
i l k h
• Final Workshop
Course Agenda (Day –3)
• Role of Simulation in Process Design
• Aspen Tech Products and Aspen Plus BasicsAspen Tech Products and Aspen Plus Basics
• Physical Properties Model and Properties Estimation
• HEATX and Heat Exchanger Modelling • HEATX and Heat Exchanger Modelling
• RADFRAC and Distillation Column Modelling
Unit Operation Models
• Unit Operation Models • Sensitivity Analysis
i l k h
• Final Workshop
Sensitivity Analysis using
Aspen Plus
Aspen Plus
Resource Person
Dr. Naveed Ramzan
Steps for Sensitivity Analysis
P it Purity (mole fraction) of cumene in Product Stream StreamSteps for Sensitivity Analysis
P it Purity (mole fraction) of cumene in Product Stream StreamSteps for Sensitivity Analysis
COOL COOL
Steps for Sensitivity Analysis
COOL COOL
Exercise
Exercise
Thermodynamic Model
What would be the effect of flow rate of phenol on
What would be the effect of flow rate of phenol on
MCH distillate purity, Condenser duty, reboiler duty
Aspen Plus for Process Design and
Simulation
Final Workshop
Resource Persons
Prof. Dr. Shahid Naveed Dr. –Ing. Naveed Ramzan Mr. Farhan Ahmad