DWSIM/C2/Continuous-Stirred-Tank-Reactor/English

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Visual Cue Narration
Slide Number 1

Title Slide

Welcome to this tutorial on simulating a Continuous Stirred Tank Reactor (CSTR) in DWSIM.
Slide Number 2

Learning Objective

In this tutorial, we will learn to:
  • Simulate a Continuous Stirred Tank Reactor (CSTR)
  • Calculate Conversion and Residence Time for a reaction in a CSTR
Slide Number 3

System Requirements

To record this tutorial, I am using
  • DWSIM 4.3 and
  • Windows 7

The process demonstrated in this tutorial is identical in other OS also such as-

  • Linux,
  • Mac OS X or
  • FOSSEE OS on ARM.
Slide Number 4


Pre-requisites

To practice this tutorial, you should know how to-
  • add components to a flowsheet.
  • select thermodynamic packages.
  • add material and energy stream and specify their properties.
  • and add kinetic reaction in reaction manager.
Slide Number 5

Prerequisite Tutorials and Files

The pre-requisite tutorials are mentioned on our website, spoken-tutorial.org

You can access these tutorials and all the associated files from this site.

Slide Number 6


Reaction, Package and Inlet Condition


Reaction:


C2H5OH (l) + CH3COOH (l) ⇔ CH3COOC2H5 (l) + H2O (l)


Property Package: NRTL


Inlet Stream:


Mass Flow: 3600 kg/h

Mole Fraction(C2H5OH): 0.48

Mole Fraction(CH3COOH): 0.5

Mole Fraction(H2O): 0.02

Temperature: 70 degree C

Pressure: 1 bar

We will develop a flowsheet to determine the exit composition from an isothermal CSTR.


Here we give Reaction, Property Package and Inlet Stream Conditions.

Slide Number 6


Reactor Parameters and Reaction Kinetics


CSTR Dimensions:

Volume: 1 m3,


Reaction rate: rA = K0CACB, K0 = 0.005, n = 2

Next, we give CSTR dimensions and reaction kinetics.
File >> New Steady-state Simulation


Point to Simulation Configuration Wizard window


Click on Next.

I have already opened DWSIM on my machine.


Go to File menu and select New Steady-state Simulation.


Simulation Configuration Wizard window appears.


At the bottom, click on Next.

Type Ethanol in the Search tab


ChemSep database >> Ethanol

Now, in the Compounds Search tab, type Ethanol.


Select Ethanol from ChemSep database.

Type Acetic Acid in the Search tab Similarly, add Acetic Acid.
Type Water in the Search tab Next, add Water.
Type Ethyl Acetate in the Search tab Next, add Ethyl Acetate.
Click on Next. Click on Next.
Point to Property Packages Now comes Property Packages.
Property Packages >> Available Property Package


Double click on NRTL

From Available Property Packages, double-click on NRTL.
Click on Next. Then click on Next.
Point to Flash Algorithm We are moved to Flash Algorithm.
Default Flash Algorithm >> Nested Loops (VLE) From Default Flash Algorithm select Nested Loops(VLE)
Click Next Click on Next.
Point to System of Units The next option is System of Units.
System of Units >> C5 Under System of Units, we will select C5.
Click on Finish Then click on Finish.
Maximize the simulation window Let us now maximize the simulation window.
Now let’s insert a feed stream that enters the CSTR.
Go to Object Palette Go to Object Palette.
Go to Streams Section


Click and drag Material Stream to the flowsheet

From Streams section, drag and drop a Material Stream to the Flowsheet.
Type Feed Let’s change the name of this stream to Feed.
Now we will specify the Feed stream properties.
Input Data >> Flash Spec >> Temperature and Pressure (TP) Go to Input Data.


Select Flash Spec as Temperature and Pressure (TP), if not already selected.


By default, Temperature and Pressure are already selected as Flash Spec.

Input Data >> Temperature >> 70 C

Press Enter

Change Temperature to 70 degC and press Enter.
Input Data >> Pressure >> 1 bar

Press Enter

Change Pressure to 1 bar and press Enter.
Input Data >> Mass Flow >> 3600 kg/h

Press Enter

Change Mass Flow to 3600 kg/h and press Enter.
Now let us specify the feed stream compositions.
Composition>>Basis >> Mole Fractions Under Composition, choose the Basis as Mole Fractions, if not already selected.


By default, Mole Fractions is already selected as Basis.

Ethanol: 0.48 Now for Ethanol, enter the Amount as 0.48 and press Enter.
Acetic Acid: 0.5 For Acetic Acid, enter 0.5 and press Enter.
Water: 0.02 Similarly, for Water, enter 0.02 and press Enter.
Ethyl Acetate: 0 For Ethyl Acetate, enter 0 and press Enter.
Click Accept Changes On the right, click on this green tick to Accept Changes
Next, we will define the Kinetic Reaction.
Tools >> Reaction Manager


Point to Chemical Reactions Manager

Under Tools, click on Reactions Manager.


Chemical Reactions Manager window opens.

Chemical Reactions >> Add Reaction Under Chemical Reactions tab, click on the green coloured Add Reaction button.
Click on Kinetic Then click on Kinetic.
Point to Add New Kinetic Reaction Add New Kinetic Reaction window opens.
Identification >> Name >> Ethyl Acetate Under Identification, enter the Name as Ethyl Acetate.
Description >> Irreversible reaction for synthesis of Ethyl Acetate from Ethanol and Acetic Acid Now enter the Description.


“Irreversible reaction for synthesis of Ethyl Acetate from Ethanol and Acetic Acid.”

Point to Components, Stoichiometry and Reaction Orders Next part is a table of Components, Stoichiometry and Reaction Orders.
Point to Name field First column Name shows the available compounds here.
Point to Molar Weight Second column corresponds to its Molar Weight
Point to Include Next column is Include.


Under Include, check all the check boxes.

Point to BC


Check Ethanol check box

The fourth column is BC.


Under BC, check the Ethanol check box as Ethanol is the base component.

Point to Stoich. Coeff Next column is Stoich. Coeff. (stoichiometric coefficients)
Stoich. Coeff >> Ethanol: -1, Acetic Acid: -1, Water: 1, Ethyl Acetate: 1 Under Stoic Coeff column, enter:


-1 for Ethanol

-1 for Acetic Acid

1 for Water.

and 1 for Ethyl Acetate


Then press Enter.

Point to Stoichiometry field In the Stoichiometry field, we can see it is showing OK.
Point to Equation field Here the Equation field shows the reaction equation.
Point to DO Next column is DO.
DO >> Ethanol: 1

Acetic Acid : 1

We are considering the reaction to be elementary.


So under DO column, enter:

1 for Ethanol

1 for Acetic Acid.


And then press Enter.

Point to RO Next column is RO.


Since we are considering an irreversible reaction, we will not enter anything here.

Point to Kinetic Reactions Parameters Then comes Kinetic Reactions Parameters.
Basis >> Molar Concentrations Our rate is in terms of molar concentration.


So we will select Basis as Molar Concentrations.

Fase >> Liquid Select Fase as Liquid, if not already selected.
Tmin (K) >> 300


Tmax (K) >> 2000

Enter Tmin(K) as 300, Tmax(K) as 2000.
Point to Direct and Reverse Reactions Velocity Constant


Direct Reaction: A >> 0.005

Now go to Direct and Reverse Reactions Velocity Constant.


In Direct Reaction, enter A as 0.005.

Click on OK


Close Chemical Reactions Manager window.

Click on OK and close Chemical Reactions Manager window.
Now let us insert a Continuous Stirred Tank Reactor to the flowsheet.
Go to Object Palette>>Unit Operations


Click and drag Continuous Stirred Tank Reactor to the flowsheet

Go to Object Palette.


Under Unit Operations, Click on the Continuous Stirred Tank Reactor.


Drag and drop it to the flowsheet.

Let us now arrange it as required.
And then let us insert one Output Stream.
Click and drag Material Stream to the flowsheet To do that let us drag one Material Stream.
Let us once again arrange it.
Leave that stream as unspecified.
Type Product We will change the name of this stream to Product.
Click and drag Energy Stream to the flowsheet Next, we will insert one Energy Stream.
Type Energy. And name this stream as Energy.
Click Continuous Stirred Tank Reactor We are now ready to specify the Continuous Stirred Tank Reactor.


Let’s click on it.

On the left, we can see a tab displaying properties related to the CSTR.
Go to Connections


Click on drop down arrow against Inlet Stream


Select Feed.

Under Connections, click on the drop-down against Inlet Stream.


And select Feed.

Click on drop down arrow against Outlet Stream 1


Select Product.

Next, click on the drop-down against Outlet Stream 1 and select Product.
Click on the drop down against Energy Stream


Select Energy.

Then click on the drop-down against Energy Stream and select Energy.
Hover mouse at Calculation Parameters Now go to the next section, Calculation Parameters.
Reaction Set >> Default Set Here, the first option is Reaction Set.


By default, it is Default Set.

Click drop down against Calculation Mode


Select Isothermic

Next, click on the drop-down against Calculation Mode and select Isothermic.
Specify Reactor Volume >> 0.14 m3


Press Enter

Then click on the field against Reactor Volume and enter 0.14 m3


Then press Enter.

Now we will run the simulation.
Click Solve Flowsheet So, from the toolbar, click on Solve Flowsheet button.
Click Continuous Stirred Tank Reactor When the calculations are completed, click on the Continuous Stirred Tank Reactor in the flowsheet.
Hover mouse at Results From the Property Editor Window of CSTR, locate Results section.
Results >> General Under the General tab, click Residence time.


It is 0.033 h.

Results >> Conversions Now go to Conversions tab.


Here for Ethanol, the conversion is 99.5% and for Acetic Acid, it is 95.5%.

Insert >> Master Property Table Now, go to Insert menu and select Master Property Table.
Double click on Master Property Table Double-click on the Master Property Table.
Point to Configure Master Property Table Configure Master Property Table window opens.
Type Results - Continuous Stirred Tank Reactor Enter Name as Results – Continuous Stirred Tank Reactor.
Type Material Stream Enter Object Type as Material Stream.


By default, Material Stream is already selected.


So we will not change it.

Object >> Feed and Product Under Properties to display, select Object as Product and Feed.
Configure Master Property Table>> Property Under Property, scroll down to see all the parameters.


Now select the properties as

Temperature

Pressure

Mass Flow

Molar Flow

Liquid Phase (Mixture) Volumetric Fraction

Molar Flow (Mixture) / Ethanol

Mass Flow (Mixture) / Ethanol

Molar Flow (Mixture) / Acetic Acid

Mass Flow (Mixture) / Acetic Acid

Molar Flow (Mixture) / Water

Mass Flow (Mixture) / Water

Molar Flow (Mixture) / Ethyl Acetate

Mass Flow (Mixture) / Ethyl Acetate

Close this window. Close this window.
Move the Master Property Table for better visibility.


Here we can see the corresponding results for Product and Feed.

Let's summarize.
Slide Number 7


Summary

In this tutorial, we have learnt to


Simulate a Continuous Stirred Tank Reactor Calculate Conversion and Residence time for a reaction in a CSTR

Slide Number 8


Assignment


Compounds:

Methyl Acetate, 1-Butanol, Methanol, N-Butyl Acetate


Property Package: Raoult's Law


Inlet stream:


Mass Flow: 3600kg/h

Mole Fraction(CH3OH): 0.1

Mole Fraction(C4H9OH): 0.45

Mole Fraction(CH3COOCH3): 0.45

Temperature: 75 degree C

Pressure: 5 bar


CSTR Dimensions:

Volume: 4 m3


Reaction rate:rA = KCACB = 0.01 1/s, n = 2

As an assignment,


Repeat the simulation with different compounds and thermodynamics.


Different feed conditions


Different CSTR dimensions and reaction kinetics

Slide Number 9

About the Spoken Tutorial Project

Watch the video available at the following link.

http://spoken-tutorial.org/

It summarizes the Spoken Tutorial project.

Slide Number 10

Spoken Tutorial Workshops

The Spoken Tutorial Project Team

Conducts workshops and

Gives certificates.

For more details, please write to us.

Slide Number 11


Forum Slide


Do you have questions in this Spoken Tutorial?

Please visit this site

Choose the minute and second where you have the question.

Explain your question briefly.

Someone from the FOSSEE team will answer them.

Please post your times queries in this forum.


Slide Number 12

DWSIM Flowsheeting Project

The FOSSEE team coordinates conversion of existing flow sheets into DWSIM

We give honorarium and certificates for those who do this.

For more details, please visit this site.

Slide Number 13

TextBook Companion Project

The FOSSEE team coordinates coding of solved examples of popular books.


We give honorarium and certificates for those who do this.


For more details, please visit this site.

Slide Number 14

Lab Migration Project

The FOSSEE team helps migrate commercial simulator labs to DWSIM.


We give honorarium and certificates for those who do this.


For more details, please visit this site


Slide Number 15

Acknowledgements

Spoken Tutorial and FOSSEE projects are funded by NMEICT, MHRD, Government of India.
Slide Number 16

Thanks

This tutorial is contributed by Kaushik Datta and Priyam Nayak.


Thanks for joining

Contributors and Content Editors

Kaushik Datta, Nancyvarkey