DWSIM/C2/Plug-Flow-Reactor/English-timed

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Time Narration
00:01 Welcome to this spoken tutorial on Simulating a Plug Flow Reactor(PFR) in DWSIM.
00:07 In this tutorial, we will learn to: Define a kinetic reaction
00:13 Simulate a Plug Flow Reactor (PFR)
00:16 Calculate Conversion and Residence time for a reaction in a PFR.
00:22 To record this tutorial, I am using DWSIM 4.3 and Windows 7
00:30 The process demonstrated in this tutorial is identical in other OS also, such as- Linux, Mac OS X or FOSSEE OS on ARM.
00:42 To practice this tutorial, you should know : how to add components to a flowsheet
00:49 How to select thermodynamic packages
00:53 How to add material and energy streams and specify their properties.
00:59 The prerequisite tutorials are mentioned on our website
01:04 You can access these tutorials and all the associated files from this site.
01:10 We will develop a flowsheet to determine the exit composition from an Isothermal PFR.
01:16 Here we give reaction, property package and inlet stream conditions.
01:22 Next, we give Reactor Parameters and reaction kinetics.
01:28 I have already opened DWSIM on my machine.
01:33 Go to File menu and select New Steady-state Simulation.
01:38 Simulation Configuration Wizard window appears.
01:42 At the bottom, click on Next.
01:45 First, we will add the compounds.
01:48 In the Compounds Search tab, type Nitrogen.
01:52 Select Nitrogen from ChemSep database.
01:56 Similarly, add Hydrogen from ChemSep database.
02:01 Next, add Ammonia from ChemSep database. Now, all the compounds are added.

Click on Next.

02:11 Now comes Property Packages.
02:14 From Available Property Packages, double-click on Peng-Robinson (PR).

Then click on Next.

02:21 We are moved to Flash Algorithm.
02:24 From Default Flash Algorithm select Nested Loops(VLE). Click on Next.
02:31 Next option is System of Units.
02:35 Under System of Units select C5.
02:39 It has the desired system of units according to our problem statement.
02:44 Then click on Finish.
02:47 Let us maximize the simulation window.
02:50 Now let’s insert a feed stream that enters the PFR.
02:55 On the right hand side of main simulation window, go to Object Palette.
03:00 From Streams section, drag and drop a Material Stream to the Flowsheet.
03:05 Click on Material StreamMSTR-000” to view its properties.
03:11 Let’s change the name of this stream to Feed.
03:15 Now we will specify the Feed stream properties.
03:18 Under Input Data, select Flash Spec as Temperature and Pressure (TP), if not already selected.
03:26 By default, Temperature and Pressure are already selected as Flash Spec.

So let’s not change it.

03:33 Change Temperature to 425 degC and press Enter to accept the new value.
03:41 Change Pressure to 200 bar and press Enter.
03:46 Change Mass Flow to 3600 kg/h and press Enter.
03:52 Now let us specify the feed stream compositions.
03:57 Under Composition, choose the Basis as Mole Fractions, if not already selected.
04:05 By default, Mole Fractions is already selected as Basis. So, let’s not change it.
04:11 Now for Nitrogen, enter the Amount as 0.5 and press Enter.
04:18 Similarly, for Hydrogen, enter it as 0.5 and press Enter.
04:25 For Ammonia, enter 0 and press Enter.
04:30 On the right, click on this green tick to Accept Changes.
04:34 Now we will define the Kinetic Reaction.
04:38 Under Tools, click on Reactions Manager.
04:42 Chemical Reactions Manager window opens.
04:46 Under Chemical Reactions tab, click on the green coloured Add Reaction button.
04:52 Then click on Kinetic.
04:55 Add New Kinetic Reactions window opens.
04:59 First part is Identification. Under Identification, enter the Name as Ammonia Synthesis.
05:08 Next, enter the Description.
05:11 Irreversible reaction for synthesis of Ammonia from Nitrogen and Hydrogen
05:17 Next part is a table of Components, Stoichiometry and Reaction Orders.
05:23 First column Name, shows the available components here.
05:28 Second column corresponds to its Molar Weight.
05:32 Next column is Include. It indicates the components which will take part in the reaction.
05:39 Under Include, check all the check boxes against all the components’ names.
05:44 Fourth column is BC. It indicates the base component of the reaction.
05:51 Under BC, check the Nitrogen check box as Nitrogen is the base component.
05:57 Next column is Stoich. Coeff. (stoichiometric coefficients)
06:01 Under Stoic Coeff column, enter:


-1 for Nitrogen,

-3 for Hydrogen,

and for Ammonia 2

Then press Enter.

06:15 Negative sign is to indicate the components as Reactants.
06:20 In the Stoichiometry field, we can see it is showing OK.
06:25 So the reaction is balanced after entering the stoichiometric coefficients.
06:31 Here the Equation field shows the reaction equation.
06:36 Next column is DO, which indicates direct/forward reaction order.
06:43 We are considering the reaction to be First order with respect to Nitrogen.
06:49 So we will enter 1 in the DO column against Nitrogen. And then press Enter.
06:57 Next column is RO which indicates reverse reaction order.
07:03 Since we are considering an irreversible reaction, we will not enter anything here.
07:09 Then comes Kinetic Reactions Parameters.
07:13 Our rate is in terms of molar concentration.
07:17 So, we will select Basis as Molar Concentrations.
07:21 Select Fase as Vapor.
07:25 Next is Tmin and Tmax.
07:29 It gives temperature range within which rate expression is assumed to be valid.
07:35 So, enter Tmin (K) as 500 and Tmax (K) as 2000.
07:41 Now go to Direct and Reverse Reactions Velocity Constant.
07:46 In Direct Reaction, enter A as 0.004
07:51 Click OK and close the Chemical Reactions Manager window.
07:57 Now let us insert a Plug-Flow Reactor (PFR) into the flowsheet.
08:02 Go to Object Palette.
08:04 Under Unit Operations, click on Plug-Flow Reactor (PFR). Click on it and drag it to the flowsheet.
08:11 Let us now arrange it as required.
08:14 We will insert one Output Stream. To do so, drag one Material Stream.
08:20 Let us once again arrange it. As this is an output stream, we will leave it unspecified.
08:27 We will change the name of this stream to Product.
08:31 Next, we will insert one Energy Stream. And name this stream as Energy.
08:38 We are now ready to specify the Plug-Flow Reactor. Click on it.
08:44 On the left, we can see a tab displaying properties related to the PFR.
08:50 This tab is called Property Editor Window.
08:54 Under Connections, click on the drop-down against Inlet Stream. and select Feed.
09:01 Next, click on the drop-down against Outlet Stream and select Product.
09:07 Then click on the drop-down against Energy Stream and select Energy.
09:13 Now go to the next section, Calculation Parameters.
09:18 Here, the first option is Reaction Set. By default, it is Default Set.
09:26 Since we have only one reaction, we leave it as it is.
09:31 Next, click on the drop-down against Calculation Mode. Select Isothermic.
09:38 Then click on the field against Reactor Volume and enter 1 meter cube

Then press Enter.

09:47 Click on the field against Reactor length and enter it as 1.5 m.

Then press Enter.

09:56 Now we will run the simulation.
09:59 So, from the toolbar click on Solve Flowsheet button.
10:04 When the calculations are completed, click on PFR in the Flowsheet.
10:09 From the Property Editor Window of PFR locate Results section.
10:15 Under General tab, check Residence time. It is 0.013 hour.
10:23 Under Conversions tab, check conversion for both the reacting compounds.
10:29 For Nitrogen, the conversion is 17.91% and for Hydrogen, it is 53.73%.
10:40 Now we will check the material balances.
10:44 Go to Insert menu and select Master Property Table.
10:49 Double click on the Master Property Table to edit it.
10:53 Configure Master Property Table window opens.
10:57 Enter Name as Results - Plug Flow Reactor
11:01 Enter Object Type as Material Stream.
11:05 By default, Material Stream is already selected. So we will not change it.
11:11 Under Properties to display, select Object as Feed and Product.
11:17 Under Property, scroll down to see all the parameters.
11:22 Now select the properties as:

Temperature

Pressure

Mass Flow

Molar Flow

11:32 Vapor Phase Volumetric Fraction
11:36 Molar Flow (Mixture) / Nitrogen
11:39 Mass Flow (Mixture) / Nitrogen
11:42 Molar Flow (Mixture) / Hydrogen
11:45 Mass Flow (Mixture) / Hydrogen
11:48 Molar Flow (Mixture) / Ammonia
11:51 Mass Flow (Mixture) / Ammonia
11:54 Close this window.
11:56 Move the Master Property Table for better visibility.
12:01 Here we can see the corresponding results for Product and Feed.
12:06 Let us summarize.
12:08 In this tutorial, we have learnt to Define a kinetic reaction
12:14 Simulate a Plug-Flow Reactor (PFR)
12:17 Calculate Conversion and Residence time for a reaction in a PFR
12:23 As an assignment, Repeat this simulation with different compounds and thermodynamics.
12:29 Different feed conditions
12:31 Different PFR dimensions and reaction kinetics
12:36 Watch the video available at following link.

http://spoken-tutorial.org/

12:38 It summarizes the Spoken Tutorial project.
12:42 The Spoken Tutorial Project Team, Conducts workshops Gives certificates
12:48 For more details, please write to contact@spoken-tutorial.org
12:51 Please post your times queries in this forum.
12:55 The FOSSEE team coordinates coding of solved examples of popular books.
13:00 We give honorarium and certificates for those who do this.
13:05 For more details, please visit this site.
13:09 The FOSSEE team helps migrate commercial simulator labs to DWSIM.
13:14 We give honorarium and certificates for those who do this.
13:19 For more details, please visit this site
13:23 The FOSSEE team coordinates conversion of existing flow sheets into DWSIM.
13:29 We give honorarium and certificates for those who do this. For more details, please visit this site.
13:37 Spoken Tutorial and FOSSEE projects are funded by NMEICT, MHRD, Government of India.
13:45 This tutorial is contributed by Kaushik Datta and Priyam Nayak.

Thanks for joining.

Contributors and Content Editors

PoojaMoolya, Sandhya.np14, Udayana