ExerciciosPROII

Getting Started Workbook i

Contents

Estimating Component Data . . . . . . . . . . . . . . . . . . . . . . . . 1

Chiller PlantPart 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Part 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Part 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Part 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Part 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25Part 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Gas Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

MEK/Toluene Preheat. . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Hydrocarbon-Water Phase Separation . . . . . . . . . . . . . . . 35

Naphtha Assay Part 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Part 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Part 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Phase Envelope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Compressor Curves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Debutanizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Rigorous Heat Exchanger . . . . . . . . . . . . . . . . . . . . . . . . . 55

Two Stage Compressor . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Propylene Chlorination Reactor . . . . . . . . . . . . . . . . . . . . 63

Appendix A - Keyword (.INP) Files - English UOM . . . . 69

Appendix B - Keyword (.INP) Files - Metric UOM. . . . . 81

Getting Started Workbook 1

Estimating Component Data

# TASK In this exercise, you will use PRO/II and DATAPREP to create a user-defined component and predict its properties. To demonstrate the accu-racy of the predictive methods, we will try to reproduce the properties of acetone:

Retrieve the physical properties of acetone from PRO/II. Compare them with those that result from estimating the component properties in the procedures outlined below.

Part A Define acetone as a user-defined library component with a different name. Given its molecular structure above, use the UNIFAC structure and the fill option to generate all the component properties of acetone. In the second run add NBP = 329.44 K and see how the component proper-ties change.

Part B Supply the Joback structure and use the modified Joback methods within DATAPREP to estimate all the component properties of acetone (under a different name) with and without the NBP data.

SOLUTION - Part A

Use the following steps to enter ACETONE2 as a user-defined compo-nent.

Step 1 Create a User-Defined Component

Click the Component Selection button to open the Component Selec-tion dialog box.

Click . Name your component ACETONE2 and click .

Figure 1 shows the dialog box once you have entered the data.

O

H3C CH

3C

User-defined...

Add ->

2 Estimating Component Data

Figure 1:Component Selection

User-Defined Dialog

Box

Return to the flowsheet by clicking .

Step 2 Define the Component Properties

Click the Component Properties button. Click , highlight ACETONE2 as the component

to be filled and click . Click . Click and add the appropriate data.

ACETONE2 is comprised of two parts:

a Ketone, Group 1300

a Paraffin, Group 0900

Figure 2 shows the completed Define UNIFAC Structure dialog box.

Figure 2:Define UNIFAC

Structure Dialog Box

OK

Fill from Structure...

Move -> OK

UNIFAC Structures...


Step 3 Build the Flowsheet

Place a VALVE on the flowsheet and add two streams, one feed stream and one product stream.

Step 4 Select a Thermodynamic Method

Click on the red-bordered Thermodynamic Data button on the tool-bar.

Select the Most Commonly Used Category, and then select Soave-Redlich-Kwong as the Primary Method.

Click to add your selection to the Defined Systems box.

Step 5 Enter Stream Data

Double-click on the feed stream. Enter the thermal condition. Enter a flowrate and the composition, which should be 100 mol %

ACETONE2.

Step 6 Run the Simulation and View the Results

Run the simulation by clicking the Run button on the toolbar. Each unit should turn green and then blue in sequence indicating that it has solved.

To view your results, click the Generate Report button.

Run the simulation again to see how adding in some known data affects the predicted properties. Rename the simulation so as not to overwrite the previous output file.

Step 7 Change the Normal Boiling Point

Click the Component Properties button. Click and enter 329.44 K as the NBP. Run the simulation as before. Table 1 compares some of the predicted properties.

Add ->

Fixed...

4 Estimating Component Data

SOLUTION - Part B

In this approach, you use DATAPREP to estimate the component prop-erties. With DATAPREP, you can choose either UNIFAC or Joback structures.

Launch DATAPREP. Press for Property Prediction and for Automatic Property

Generation. Type ACETONE3 and define it as a SCRATCH component so that

it resides in memory and is not added into a database. Select the type of structure: UNIFAC, Joback. Move the cursor up and down and enter the number of occurrences

of each function group next to the appropriate identification number. UNIFAC: one 900 group and one 1300 group Joback: two -CH3 groups and one >C=O (non-ring) group

When finished, return to the main menu and use the File Utilities and Process Simulation options to write the data to a PRO/II keyword input format.

Again, you can enter specific data, such as the NBP, to increase the accuracy of the prediction. Table 2 compares the properties predicted with DATAPREP against published data.

Table 1: Comparison of Properties Predicted with PRO/II and Published Data

Property UNIFAC UNIFAC with NBP Data

Published Data

Molecular Weight 58.080 58.080 58.081

Specific Gravity 0.7099 0.7001 0.79543

Normal Boiling Point (K) 321.91 329.44 329.44

Critical Temperature (K) 500.25 511.95 508.15

Critical Pressure (kPa) 4802.5 4802.5 4701.5

Acentric Factor 0.2825 0.28253 0.32869

Table 2: Comparison of Properties Predicted with DATAPREP and Published Data

Property UNIFAC UNIFAC with NBP Data

Published Data

Molecular Weight 58.080 58.080 58.081

Specific Gravity 0.75338 0.70175 0.79543

Normal Boiling Point (K) 321.910 329.44 329.44

Critical Temperature (K) 500.248 511.95 508.15

Critical Pressure (kPa) 4802.500 4802.5 4701.5

Acentric Factor 0.282526 0.28253 0.32869


Figure 3 shows the keyword input file lines generated by DATAPREP for the Joback prediction without NBP data.

Figure 3:Keyword File for the

Joback Prediction

$ PRO/II physical property insert for: $ Name: ACETONE3$ Formula: C3H6O$$COMPONENT DATA NONLIBRARY 2, ACETONE3$ $ Thermo methods available for use:$ Data are missing to determine phase$ PHASE NONE = 2$ STRUCTURE 2, MW 2, 0.5808004E+02 SPGR 2, 0.7533822E+00 VC(M3/KG,MOLE) 2, 0.2095000E+00 ZC 2, 0.2419194E+00 ACENTRIC 2, 0.2825258E+00 NBP(K) 2, 0.3219100E+03 TC(K) 2, 0.5002482E+03 PC(PA) 2, 0.4802500E+07 FORMATION(V,J/KG,MOLE) 2, -.2178300E+09, -.1545400E+09 NMP(K) 2, 0.1730000E+03 HFUS(J/KG,MOLE) 2, 0.5123140E+07 RACKETT 2, 0.2657684E+00 SOLP 2, 0.9211874E+01 MOLV(M3/KG,MOLE) 2, 0.7716949E-01 SVTB 2, 0.0000000E+00 SLTB 2, 0.0000000E+00 SLTM 2, 0.0000000E+00 HVTB 2, 0.0000000E+00 HLTB 2, 0.0000000E+00 HLTM 2, 0.0000000E+00

6 Chiller Plant - Part 1

Chiller Plant - Part 1

# TASK Through guided practice, you will build a simulation of the process shown below. This is part of a chiller plant typical in natural gas process-ing. In subsequent parts of this example, you will add other sections of the plant to this simulation. Use the Peng-Robinson thermodynamic method.

Figure 4:Schematic of Chiller

Plant - Part 1

The process and equipment data are given in Table 3 and 4.

CompressorC-1

HX-1Cooler

D-2KnockoutDrum

P-1Pump

D-1Scrubber

InletGas

2 4 5

6

7

3 17

Table 3: Feed Stream Data

Component Mole % Component Mole %

Nitrogen 1.0 i-Butane 1.25

Carbon dioxide 1.6 n-Butane 3.0

Methane 72.5 i-Pentane 0.55

Ethane 11.5 n-Pentane 1.10

Propane 6.75 C6PLUS (PETRO Component) 0.75

Total Flowrate 4 X 107 standard vap ft3/day 1.0X 106 normal vap m3/day

Temperature 120F 50C

Pressure 205 psig 1520 kPa

C6PLUS Properties NBP 210F 99C

API Gravity 73 Specific Gravity 0.6919


SOLUTIONStep 1 Create a New Simulation

Select New... from the File menu.Note that several buttons on the toolbar, including the Run button have red borders. When you have satisfied PRO/II's input requirements all red borders will disappear.

Step 2 Build the Process Flow Diagram

If the PFD palette is not already visible, click the PFD Palette button on the toolbar to bring it up. Click on the appropriate unit icons on the PFD palette to draw the PFD. To select and position a unit, just click on its icon.

A pointer with a box and flash drum attached appears. Move this to the main window and click again when the unit is in position.

In this manner, select and position the units as shown in the diagram using these PFD buttons:

Click on the red-bordered on the PFD palette. Note that the pointer now has an S attached to it. All available exit ports appear on each unit once you select . Required exit ports are red and optional exit ports are green.

Table 4: Equipment Data and Operating Conditions

Unit Description Data

D-1 Scrubber TemperaturePressure

85F203 psig

30C1500 kPa

C-1 Compressor Outlet PressureAdiabatic Efficiency

600 psig72%

4250 kPa72%

HX-1 Cooler Hotside: Process StreamOutlet Temperature Pressure Drop

Coldside: Utility AirInlet TemperatureOutlet Temperature

110F5 psi80F100F

45C35 kPa27C38C

D-2 Knockout drum Flash drum with no change of pressure and no duty

P-1 Pump Outlet Pressure Efficiency

550 psig65%

3900 kPa65%

Streams

Streams


Draw the streams on the flowsheet to connect the units. After your first click, only the available feed ports are shown in red or green.

Double-click on each stream and unit and change its name to that shown on the diagram above. Do not change any other data in the dialog box.

Click to exit the dialog box. Note that spaces are not allowed in unit or stream names.

The completed PFD should now look like Figure 5 below.

Figure 5:Chiller Plant PFD in

PRO/II

After you finish building the flowsheet, the labels of all the internal streams are black and the available ports of all the units are green. At this point, all the unit labels have red borders and the border of the feed stream label is also red because you must still add data. Note that the border of is black, indicating that you have entered all neces-sary data for this function. To exit the stream connection mode, right-click, or click on so that it turns gray, indicating that the mode is no longer active.

Before continuing, save the simulation as CHILL1.PRZ.

Step 3 Modify the Input Units of Measure

Click on the green-bordered Units of Measure (UOM) button on the toolbar to verify the units of measure used in this simulation.

, Note: Although not critical in this example, it is good practice to con-nect the FLASH DRUM hydrocarbon liquid product to the side port and to reserve the bottom port for a decanted water or sec-ond liquid product.

OK

Streams

Streams


For this example you will use either modified SI units or modified English units. Click and select ENGLISH-SET1 or SI-SET1 from the drop-down list.

Check each item that it matches the input data given in the tables above.

Make any necessary changes and click .Notice that the border of the UOM button is now blue indicating that you have modified the data.

Step 4 Define the Components

Click on the red-bordered Component Selection button on the tool-bar.

Click . Select the Hydrocarbon Lightends Component Family and select

components from the list displayed. Select a single component or a group of components (using the shift or control keys) and then click

to add them to the component list below. Add the components in the order presented in Table 3.

Figure 6:Component Selection

When finished click to return to the Component Selection dia-log box.

Click to enter data for the petroleum component C6PLUS.

Enter its name, NBP and gravity data, and click .Note that and List of Selected Components box now have blue borders.

Initialize from Library....

OK

Select from Lists...

Add Components

OK

Petroleum...

OK

Petroleum...


Click to exit the dialog box.

Step 5 Select the Thermodynamic Method

Click on the red-bordered Thermodynamic Data button on the tool-bar.

Select the Most Commonly Used Category, and then select Peng-Robinson as the Primary Method.

Double-click on Peng-Robinson, or click to add your method selection to the Defined Systems box.

To specify the transport property methods, click and then .

Check the Compute Transport Properties box and select Petroleum Correlations from the Transport System drop-down list, as shown in Figure 7.

Figure 7:

Transport Properties

Click in each of the three dialog boxes to save the entered data.

Step 6 Define the External Feed Stream

Double-click on the feed stream INLET_GAS. Make sure that the stream type is Composition Defined.

Enter the stream's thermal condition: Select Temperature as the first specification and enter value. Select Pressure as the second specification and enter value.

Click . Select Total Fluid Flowrate and enter value.You will need to locally override the flowrate dimensional units. To do so, with the cursor in the fluid flowrate field, click at the top of

OK

Add ->

Modify...

Transport Properties...

OK

Flowrate and Composition...

UOM


the dialog box and change the basis to vapor volume and the units to ft3or m3 and day. Click to return to the dialog box.

Enter the individual component mole percentages into the compo-nent grid. You can move down the list using the key. After entering the composition data, check that the total equals 100.

Click to exit each dialog box and return to the PFD.You do not need to enter data for any streams other than the INLET_GAS(the external feed stream to the process) because PRO/II calculates the others for you, based on your process conditions.

Step 7 Enter Operating Conditions for Each Unit Operation

Double-click on each unit in turn and enter the required data includ-ing the unit identifier.

Enter data for flash drum D-1. The First Specification is Pressureand the Second Specification is Temperature.

Enter data for flash drum D-2. The First Specification is PressureDrop and the Second Specification is Duty. The duty of an adiabatic flash is zero.

Enter data for heat exchanger HX-1.

Click to set the heat exchanger specification. Select Hot Product Temperature from the list and enter value.

Change Units

OK

, Note: As you return to the PFD after each unit operation, its unit identifier has changed from red (data missing) to black (data satisfied).

, Note: By default, the horizontal stream is the hot side and the vertical stream is the cold side. Here this means that the utility stream is the cold side. You could use this dialog box to change the stream allocations if the reverse were true.

Specification...


Figure 8:Heat Exchanger

Specifications

Return to the Heat Exchanger dialog box by clicking . Click the cold side and enter the appropriate data.

Figure 9:Cold Side Utility

Stream

Close the Heat Exchanger dialog boxes and return to the PFD. Enter pressure and efficiency data for Pump P-1 and Compressor C-

1.When you have entered all the data, there should not be any red on the flowsheet. All stream and unit labels should have black borders. If any of the unit or stream labels has a red border, click on it and check the data. Save the simulation before continuing.


Run the simulation by clicking the Run button on the toolbar. Each unit should turn green and then blue in sequence indicating that it has solved.

To view your results, highlight PUMP P-1 and click the View Results button.

OK

Utility Stream...


Step 9 Save and Close the Simulation

You will use this simulation as a basis for a later example.

Select Save on the File menu and save as CHILL1.PRZ. Select Close on the File menu.

Figure 10:

Pump P-1 Results English UOM

Pump 'P-1'

Feeds 3 Products 17

User Input Calculated ---------- ----------

Temperature, F 88.15 Pressure, PSIG 550.00 550.00 Pressure Rise, PSI 347.00

Work, HP 2.44 Head, FT 1293.94 Efficiency 65.00 65.00

Metric UOM

Pump 'P-1'

Feeds 3 Products 17


Temperature, C 31.75 Pressure, KPA 3900.00 3900.00 Pressure Rise, KPA 2400.00

Work, KW 1.62 Head, M 395.50 Efficiency 65.00 65.00



# TASK Continue to build the chiller plant. Since you already entered the units of measure, components, and feed stream data in Part 1 you won't need to add these data again. Figure 11 shows the process schematic for this part. The portion of the flowsheet that you entered in Part 1 is gray, and the new units and streams you will now add are black.

Figure 11:Schematic of


The new equipment data and operating conditions are provided below.

SOLUTION Use the previous example, CHILL1.PRZ as the basis for this example. Select File/Save As... from the menu bar and save the example as

CHILL2.PRZ.

Step 1 Add to the Process Flow Diagram

Using Figure 11 as a guide, add units HX-2, HX-3, D-3, and V-1 to the flowsheet.

Connect the vapor product stream from D-2 to HX-2.

CompressorC-1

HX-1Cooler

D-2Knockout

Drum

P-1Pump

D-1Scrubber

InletGas

HX-2Gas/GasExchanger

HX-3Propane

Chiller

D-3Cold

Separator

V-1Valve

2 4 5

6

7

4 17

12

8 9

10

11 13

Table 5: Equipment Data


HX-2 Gas to Gas Exchanger

Hotside 'P Coldside 'PiApproach Temp (Hot In - Cold Out)

5 psi5 psi10F

35 kPa35 kPa5C

HX-3 Chiller Hotside Outlet TempHotside 'PColdside refrigerant saturated liquid

propane at

-13F5 psi-22F

-25C35 kPa-30C

D-3 Cold Separator Adiabatic Separation

V-1 Valve Outlet Pressure 245 psig 1800 kPa


Add the remaining streams to the flowsheet. Enter the unit and stream names. The PFD now looks like Figure 12.

Figure 12:Chiller Plant in PRO/II

Step 2 Enter Operating Conditions for Each New Unit Operation

Enter data for the new units.In the Heat Exchanger dialog box for HEAT EXCHANGER HX-3 (Chiller), click and choose Refrigerant as the Utility Type.Select Propane from the Component list and enter the saturation temper-ature.

At this point there should not be any red borders on the flowsheet. All stream and unit labels should have black borders. If any of the unit or stream labels has a red border, double-click on it and check the data.


Run the simulation. Highlight the cold separator overhead stream 10, click the View

Results button and look at the thermal recycle rate. As you can see, the stream is all vapor.

Generate an output report by clicking the Generate Report button or by choosing Generate Report from the Output menu.

Look at the HEAT EXCHANGER summary for HX-3. Find the flowrate of the refrigerant. You will use this rate as an initial estimate in the Part 3 of this exercise.


Please save this simulation as CHILL2.PRZ and you will use this simula-tion in the Part 3 of this exercise.

Utility Stream...

, Note: PRO/II's refrigerant utility, used in unit HX-3, considers only latent heat effects, so the refrigerant inlet and outlet conditions are a saturated liquid and a saturated vapor, respectively.


Figure 13:

Heat Exchanger HX-3 Results

English UOM

OPERATING CONDITIONS

DUTY, MM BTU/HR 6.534 LMTD, F 31.835 F FACTOR (FT) 1.000 MTD, F 31.835 U*A, BTU/HR-F 205245.904

HOT SIDE CONDITIONS INLET OUTLET ----------- -----------

FEED 8 MIXED PRODUCT 9 VAPOR, LB-MOL/HR 4102.011 3460.975 M LB/HR 88.249 66.131 CP, BTU/LB-F 0.580 0.631 LIQUID, LB-MOL/HR 250.147 891.183 M LB/HR 11.943 34.061 CP, BTU/LB-F 0.602 0.600 TOTAL, LB-MOL/HR 4352.158 4352.158 M LB/HR 100.192 100.192 CONDENSATION, LB-MOL/HR 641.035 TEMPERATURE, F 55.574 -13.000 PRESSURE, PSIG 590.000 585.000

COLD SIDE CONDITIONS INLET OUTLET ----------- -----------

REFRIGERANT, LB/HR 36843.185 36843.185 SATURATION PRESSURE, PSIG 9.620 SATURATION TEMPERATURE, F -22.000

Metric UOM

OPERATING CONDITIONS

DUTY, M*KJ/HR 6.546 LMTD, C 17.864 F FACTOR (FT) 1.000 MTD, C 17.864 U*A, KW/K 101.787

HOT SIDE CONDITIONS INLET OUTLET ----------- -----------

FEED 8 MIXED PRODUCT 9 VAPOR, KG-MOL/HR 1737.399 1462.350 K*KG/HR 37.413 27.927 CP, KJ/KG-C 2.428 2.646 LIQUID, KG-MOL/HR 107.456 382.506 K*KG/HR 5.166 14.652 CP, KJ/KG-C 2.515 2.510 TOTAL, KG-MOL/HR 1844.856 1844.856 K*KG/HR 42.579 42.579 CONDENSATION, KG-MOL/HR 275.049 TEMPERATURE, C 13.748 -25.000 PRESSURE, KPA 4180.000 4145.000

COLD SIDE CONDITIONS INLET OUTLET ----------- -----------

REFRIGERANT, KG/HR 15868.730 15868.730 SATURATION PRESSURE, KPA 167.655 SATURATION TEMPERATURE, C -30.000

, Note: The utility calculations for the heat exchanger are performed during output generation and cannot be viewed by clicking the View Results button.



# TASK Continue to build the chiller plant. Suppose that the refrigerant for the chiller HX-3 consists of a mixture rather than pure propane. You want to determine the flowrate of that mixture required to maintain a process stream (hotside) outlet temperature of -15F (-26C). Instead of using the HEAT EXCHANGER refrigerant utility in PRO/II, which is designed for use with single components, you now must introduce a refrigerant stream, with the correct composition, and use a CONTROLLER to determine the refrigerant flowrate.

The diagram shows part of the process schematic. The portion of the flowsheet that you entered previously is gray, and the new units and streams you will now add are black.

Figure 14:Schematic of Chiller

Plant - Part 3

The equipment and refrigerant stream data are shown in Table 6.

SOLUTION Use the previous example, CHILL2.PRZ, as the basis for this example and save the example as CHILL3.PRZ.

Step 1 Change the Flowsheet Configuration

Add a controller unit to the flowsheet.

CompressorC-1

HX-1Cooler

D-2Knockout

Drum

P-1Pump

D-1Scrubber

InletGas


HX-3Propane

Chiller

D-3Cold

Separator

V-1Valve

2 4 5

6

7

3 17

12

9

10

11 13

51

50

CN1

8

Table 6: Refrigerant Stream Data

Component Mole%

Ethane 2.5

Propane 97

i-Butane 0.5

Pressure 11.5 psig 180 kPa

Condition Bubble Point


Remove the utility stream on HEAT EXCHANGER HX-3 by double-clicking on the unit and deactivating the check box for the utility stream.

Add inlet and outlet streams to the cold side of HX-3. Name the inlet stream 50 and the outlet stream 51.

Figure 15:Chiller Plant PFD in

PRO/II

Step 2 Enter Stream Data

Enter the composition data and define the thermal conditions for stream 50.

Even though the flowrate of this stream is going to be calculated by the controller, you must enter a flowrate here. This not only satisfies the data requirements of the dialog box but also serves as an initial estimate.

Use the propane refrigerant rate from the previous example as the initial flowrate for this stream.

Step 3 Enter Unit Data

Change the specification for HEAT EXCHANGER HX-3 so that the new refrigerant stream exits at its dew point. Select the Cold Product Liquid Fraction specification and set the value to 0.00.

Double-click on the CONTROLLER. The Feedback Controller dialog box appears.

You want to vary stream 50 flowrate so that the temperature of stream 9 is -15F (-26C).

In the Specification group: Click on Parameter. Choose the hotside outlet stream for HEAT EXCHANGER HX-3

(stream 9) as the stream to specify. Click on Parameter in the Parameter dialog box. Select Temperature and return to the Feedback Controller dialog

box.


Enter -15F (-26C) as the value of the hotside outlet temperature.

In the Variable group box: Click on Parameter. Choose stream 50 as the stream to vary. Click on Parameter and

choose Flowrate as the variable. When complete, the Feedback Controller dialog box looks like Figure16.

Figure 16:

Completed Feedback Controller Dialog Box

Click to save the entries and return to the flowsheet. Save the simulation before continuing.


Run the simulation. Create a STREAM PROPERTY TABLE for stream 50 with the Stream

Summary list selected.A portion of this table is shown below. Compare the quantity of refriger-ant required to that obtained in the previous example. Why are the results different?



OK


Figure 17:Refrigerant Stream

Results

English UOM Metric UOM

For Evaluation Only.Copyright (c) by Foxit Software Company, 2004 - 2007Edited by Foxit PDF Editor



# TASK Continue to build the chiller plant. Add a COLUMN and a COMPRESSOR.Use MIXER units to combine the plant liquid streams into one product and the plant vapor streams into another product.

Figure 18:

Schematic of Chiller Plant - Part 4

SOLUTION Use the previous example, CHILL3.PRZ, as the basis for this example and save the example as CHILL4.PRZ.

Step 1 Add to the Process Flow Diagram

Place a COMPRESSOR, two MIXERs and a COLUMN on the PFD. Con-nect the streams as shown in Figure 18. Name the units and streams.

CompressorC-1

HX-1Cooler

D-2Knockout

Drum

D-1Scrubber

InletGas


HX-3Propane

Chiller

D-3ColdSeparator

V-1Valve

P-1Pump

PipelineGas

C-2Compressor

T-1Stabilizer

M-2Mixer

M-1Mixer

Natural GasLiquids (NGL)

1

2

3

4 5

6

7

8 9

10

11

12

13

14

15

16

17

18

19

Table 7: Equipment Data

Stabilizer Column T-1

Actual Number of Trays 22

Overall Tray Efficiency 55%

Feed Location Tray 1

Top Tray Pressure 200 psig 1480 kPa

Column 'P 2.5 psi 17 kPaBottom Product TVP 235 psig 1720 kPa

Compressor C-2

Outlet Pressure 600 psig 4240 kPa

Adiabatic Efficiency 73%


When you place the column, you will be asked to give the number of theoretical trays and to state whether the column has a condenser and a reboiler. Note that the Table 7 gives actual trays and tray efficiency. From this you must calculate the number of theoretical trays in the body of the column (22*55% = 12 stages). The kettle reboiler is simulated as a theoretical stage and thus is stage 13. This column has no condenser.

When complete, the PFD should look similar to Figure 19.

Figure 19:

Complete Chiller Plant in PRO/II

Step 2 Enter the Unit Data

The mixers require no data. Enter the COMPRESSOR data from the table.

Double-click on the COLUMN. Check that the Number of Trays is correct and that the default selections for Algorithm and CalculatedPhases are appropriate to your simulation.

Click and enter the Top Tray Pressure and the Pressure Drop for the entire Column.

Click to set the feed tray number. Check that the default entry for the Phase of each Product is correct.

Estimate the rate of the overhead product. You can make a good guess from the results of the previous run. You could also use the Define pro-cedure, assuming that the overhead stream consists of all the Nitrogen through Methane from the column feed (Figure 20).

Figure 20:Overhead Flowrate

Definition

Pressure Profile...

Feeds and Products...


Click to check that Kettle (Conventional) has been selected.

Click to select the Conventional initial estimate method.

Click to enter the true vapor pressure specification. Check the Add Specifications and Variables box. In the Specifications grid, click on Parameter, choose the bottoms stream, 15, and select Vapor Pressure and True from the lists. Return to the Specifications and Variables dialog box and enter a value of 235 psig (1720 kPa).

In the Variables grid, click on Parameter, choose Column and select Heat Duty of the Reboiler from the lists. The completed dialog box is shown in Figure 21.

Figure 21:

Bottoms True Vapor Pressure

Specification

Click to return to the PFD.


Run the simulation. Highlight the COLUMN and click the View Results button. Find the

reboiler duty required to meet the liquid product specification. Select Output/Generate Plot... from the menu bar to plot an over-

view of the temperature and flowrates, as shown in Figure 22 below.



Reboiler...

Initial Estimates...

Performance Specifications...

OK


Figure 22:Column

T-1 Profiles



# TASK Suppose that a nearby refinery has been shut down and some columns are available at bargain prices. Your company is exploring a joint ven-ture with the Royal Gas Company to build a fractionation plant as shown in Figure 23 to process the liquids from your chiller plant and their plant.

Figure 23:Light Ends

Fractionation Plant

You have been asked to provide a quick design for such a plant. To save time, you want to perform a shortcut analysis. SHORTCUT COLUMNs are unsupported in PROVISION. However, using keyword input files you can run the problem in either Run Batch or Run-Only mode. Use the keyword input file, CHILL5.INP, found in the TRAINING directory, to determine the number of theoretical trays, feed locations, and approxi-mate reflux ratios for the three distillation columns.

SOLUTIONStep 1 Import the Keyword Input File

Select Import... from the File menu. Import the keyword input file CHILL5.INP from the TRAINING directory.

A message will appear indicating that unsupported features were found in your keyword file. You can examine a list of these features by click-ing .

Close the Flowsheet Status dialog box to continue.

T-2SDeethanizer

T-3SDepropanizer

T-4SDebutanizerV-2

60Royal

Liquids

19 20

22

23

21

24

25

26

V-3 V-4

C2

C327

28Gasoline

C4s

Yes



You will have been automatically placed into Run-Only mode. Run the simulation and create an output file.

Read the results from the output (Figure 24). For example, for the deeth-anizer column, the recommended number of theoretical trays is 24, which is twice the calculated Fenske minimum trays. For a 24 tray col-umn, the feed should be introduced at tray 13.

Figure 24:Shortcut Column

Summaries

UNIT 2, 'T-2S', 'DEETHANIZER'

SUMMARY OF UNDERWOOD CALCULATIONS

MINIMUM REFLUX RATIO 2.08175 FEED CONDITION Q 1.40594 FENSKE MINIMUM TRAYS 12.14568

THEORETICAL TRAYS 2.00 * M-MINIMUM

TOTAL FEED R/R-MIN M/M-MIN REFLUX DUTY, MM BTU/HR TRAYS TRAY RATIO CONDENSER REBOILER ----- ---- ------- ------- ------ ---------- ----------

18 9 1.975 1.500 4.111 -4.024E+00 1.022E+01 21 11 1.467 1.750 3.053 -2.989E+00 9.182E+00 24 13 1.284 2.000 2.673 -2.616E+00 8.810E+00 27 14 1.163 2.250 2.420 -2.369E+00 8.563E+00 30 16 1.077 2.500 2.243 -2.196E+00 8.389E+00

UNIT 4, 'T-3S', 'DEPROPANIZER'





17 8 1.950 1.500 4.487 -1.238E+01 1.084E+01 20 10 1.454 1.750 3.347 -9.810E+00 8.265E+00 23 11 1.277 2.000 2.939 -8.888E+00 7.343E+00 26 13 1.159 2.250 2.668 -8.277E+00 6.732E+00 29 14 1.075 2.500 2.475 -7.842E+00 6.297E+00

UNIT 6, 'T-4S', 'DEBUTANIZER'





19 10 2.185 1.500 2.688 -1.116E+01 9.679E+00 23 12 1.568 1.750 1.928 -8.861E+00 7.381E+00 26 14 1.344 2.000 1.653 -8.030E+00 6.550E+00 29 16 1.196 2.250 1.471 -7.479E+00 5.999E+00 32 17 1.094 2.500 1.346 -7.099E+00 5.618E+00



# TASK Use the shortcut results from Part 5 to set up a rigorous simulation of the light ends fractionation plant shown in Figure 25. Begin with the flow-sheet built in Part 4, or create a new flowsheet and provide the feed data given below. Size each column for valve trays through the Tray Hydrau-lics dialog box. Use the I/O distillation algorithm for the calculations and choose Conventional as the initial estimate method. Vary the column duties to meet the specifications given in Table 10.

Figure 25:Light Ends

Fractionation Plant

T-2SDeethanizer

T-3SDepropanizer

T-4SDebutanizerV-2

60Royal

Liquids

19 20

22

23

21

24

25

26

V-3 V-4

C2

C327

28Gasoline

C4s


Component Royal Gas Liquids Stream 60 (kg-mol/hr)

Royal Gas Liquids Stream 60 (lb-mol/hr)

Nitrogen 0.0454 0.1

Carbon dioxide 0.8165 1.8

Methane 1.8144 4.0

Ethane 56.699 125.0

Propane 99.7902 220.0

i-Butane 35.3802 78.0

n-Butane 68.0388 150.0

i-Pentane 4.5359 10.0

n-Pentane 21.7724 48.0

C6PLUS (petro. comp.)

NBP =

Density =

13.6078

98.9 C

0.6919 sp gravity

30.0

210 F

73 API

Temperature 37.8 C 100 F

Pressure 4238 KPa 550 psig


SOLUTION Use the previous example, CHILL4.PRZ, as the basis for this example and save the example as CHILL6.PRZ. Build the flowsheet continually and run the simulation.

Compare the duties and overhead product rates determined in this exer-cise with those from the shortcut calculation done in Part 5. The over-head rate estimates from the shortcut calculation were quite good, but the duty estimates were more approximate.

Table 9: Column Data

T-2 T-3 T-4

Condenser Data

Type Partial Subcooled Subcooled

Pressure (psig) 410 240 100

Temperature (F) --- 110 110

Pressure Data

Top Tray Pressure (psig) 415 245 105

Column 'P (psi) 5 5 5Estimates from Shortcut Results

Theoretical Stages 24 23 26

Feed Location 13 11 14

Reflux ratio 2.673 2.940 1.653

Overhead product rate (lb-mol/hr) 271.7 414.1 390.7

Table 10: Column Specifications

Deethanizer T-2:

C3 in overhead product 2 mol %

C2/C3 mole ratio in bottom product 0.025

Depropanizer T-3:

C4s in overhead product 2 mol %

C3 in bottom product 2 mol %

Debutanizer T-4:

IC5 in overhead product 0.25 vol %

NC4 in bottom product 1 vol %

Table 11: Valve Operating Conditions

Unit Outlet Pressure (psig)

Valve V-2 425

Valve V-3 260

Valve V-4 130


Plot the liquid and vapor fractions of ethane and propane in column T-2 on a single plot. For column T-3, plot the separation factor of the light and heavy components. For column T-4, plot the overview of the tem-perature and flowrates.

Figure 26:Mole Fractions of

Ethane and Propane

in Column T-2

Figure 27:Separation Factor in

Column T-3


Figure 28:Overall Temperature

and Flowrate Profiles

in Column T-4


Gas Cooling

# TASK Solve the flowsheet, shown in Figure 29, for all process conditions and flowrates. Solve it first with a recycle loop and then break the loop using a reference stream (Figure 30). Compare the calculation histories in both runs. Determine the number of iterations it takes to run with the recycle in place and how many it takes to run with the broken recycle.

Figure 29:Gas Cooling

Flowsheet with Recycle

Figure 30:Gas Cooling

Flowsheet with

Broken Recycle


Component Mole Percent

Carbon Dioxide 1.39

Methane 85.92

Ethane 7.73

Propane 2.45

i-Butane 0.36

n-Butane 0.56

i-Pentane 0.21

n-Pentane 0.26

n-Hexane 1.12

Pressure 3600 psia 24820 kPa


Flowrate 1000 lb-mol/hr 455 kg-mol/hr

32 Gas Cooling

SOLUTION The original flowsheet requires three iterations to converge and the bro-ken-recycle version converges without iterating. Figure 31 contains a portion of the output for the broken-recycle flowsheet.

Heat Exchangers: 'P for all streamsT2 - T8

E2 outlet temp

5 psi

15F

-20F

35 kPa

8C

-29C

Valves: 'P across V1'P across V2

1600 psi

900 psi

11030 kPa

6205 kPa

Flash Drum: Adiabatic

Reference Stream: Temperature

Pressure

-20F

1090 psi

-29C

7515 kPa

Figure 31:

Stream Molar Component Rates

English UOM

STREAM ID 5 5X 6 7 NAME PHASE MIXED MIXED VAPOR LIQUID

FLUID RATES, LB-MOL/HR 1 CO2 13.9000 13.9000 12.3398 1.5602 2 METHANE 859.2000 859.2000 812.3919 46.8081 3 ETHANE 77.3000 77.3000 63.1335 14.1665 4 PROPANE 24.5000 24.5000 15.8709 8.6291 5 IBUTANE 3.6000 3.6000 1.7665 1.8335 6 BUTANE 5.6000 5.6000 2.3734 3.2266 7 IPENTANE 2.1000 2.1000 0.5862 1.5138 8 PENTANE 2.6000 2.6000 0.6487 1.9513 9 HEXANE 11.2000 11.2000 1.3286 9.8714

TOTAL RATE, LB-MOL/HR 1000.0000 1000.0000 910.4396 89.5604

TEMPERATURE, F -20.0000 -20.0000 -20.0000 -20.0000 PRESSURE, PSIA 1090.0000 1090.0000 1090.0000 1090.0000 ENTHALPY, MM BTU/HR -0.0177 -0.0177 0.0913 -0.1090 MOLECULAR WEIGHT 19.6397 19.6397 18.2536 33.7306 MOLE FRAC VAPOR 0.9104 0.9104 1.0000 0.0000 MOLE FRAC LIQUID 0.0896 0.0896 0.0000 1.0000

Metric UOM

STREAM ID 5 5X 6 7 NAME PHASE MIXED MIXED VAPOR LIQUID

FLUID RATES, KG-MOL/HR 1 CO2 6.3245 6.3245 5.6107 0.7138 2 METHANE 390.9360 390.9360 369.5078 21.4282 3 ETHANE 35.1715 35.1715 28.6959 6.4756 4 PROPANE 11.1475 11.1475 7.2080 3.9395 5 IBUTANE 1.6380 1.6380 0.8018 0.8362 6 BUTANE 2.5480 2.5480 1.0770 1.4710 7 IPENTANE 0.9555 0.9555 0.2659 0.6896 8 PENTANE 1.1830 1.1830 0.2942 0.8888 9 HEXANE 5.0960 5.0960 0.6025 4.4935

TOTAL RATE, KG-MOL/HR 455.0000 455.0000 414.0639 40.9362

TEMPERATURE, C -29.0000 -29.0000 -29.0000 -29.0000 PRESSURE, KPA 515.0000 7515.0000 7515.0000 7515.0000 ENTHALPY, M*KCAL/HR -5.5392E-03 5.5392E-03 0.0222 -0.0278 MOLECULAR WEIGHT 19.6397 19.6397 18.2513 33.6831 MOLE FRAC VAPOR 0.9100 0.9100 1.0000 0.0000 MOLE FRAC LIQUID 0.0900 0.0900 0.0000 1.0000


MEK/Toluene Preheat

# TASK The process shown in Figure 32 preheats a stream that is fed to a distilla-tion column. The flash drum vaporizes 40 mole percent of the feed, and the heat exchanger further heats the flash drum liquid. Both the flash drum and heat exchanger have 1 psi (6.9 kPa) pressure drops. A total of 1.0 MM Btu/hr (1.05 MM kJ/hr) is available to the process.

Find the liquid fraction and temperature of the PROD stream and the two duties.

Table 13 shows the feed composition and condition. Use the NRTL ther-modynamic system, but replace its default vapor enthalpy and vapor density methods with SRKM.

Figure 32:Preheat Process

FDFeed

Prod

Vapor

HX

Table 13: Feed Stream

Component Mole %

Toluene 80

Methyl-Ethyl Ketone (MEK) 19

Water 1

Flowrate 100 lb-mol/hr 45 kg-mol/hr



Hint: Use one stream Specification and one Define.

34 MEK/Toluene Preheat

SOLUTION To vaporize 40% of the flash drum feed, use the following stream speci-fication:

The duty available to the heat exchanger is 1 MM Btu/hr (1.05 MM kJ/hr) minus however much duty the flash drum requires to vaporize 40% of its feed. Since the flash duty is unknown before the run, you cannot assign a value to the heat exchanger's duty. Instead, you should have PRO/II calculate the FLASH duty, and use the define feature to pass the calculated flash duty to the heat exchanger. The Define statement for the HEAT EXCHANGER will has the form:

Table 14 summarizes the results.

Table 14: Results of MEK/Toluene Preheat

English Units Metric Units

Flash Duty 0.7353 MM Btu/hr 0.7680 M kJ/hr

Heat Exchanger Duty 0.2650 MM Btu/hr 0.2970 M kJ/hr

PROD Temperature 233.96F 112.35C

PROD Liquid Fraction 0.6844 0.6619


Hydrocarbon-Water Phase Separation

# TASK This exercise illustrates the differences between a rigorous VLLE flash and a VLE flash with the water decant option. Simulate a three phase separator as an isothermal flash at 300F and 300 psia for the crude stream given in the tables below. Use VLLE SRK Kabadi-Danner (SRKKD) thermodynamics and VLE SRK thermodynamics with the water decant option, along with the three different water solubility corre-lations. Print the K-values for one of the VLE flash units and for the VLLE flash.

This exercise allows you to answer the following questions:

Is the assumption of a pure water phase valid for this simulation?

How do the results vary with respect to the water solubility correla-tions?


Pure Components Rate (lb moles/hr)

PetroleumComponents

Rate(lb moles/hr)

Water 3000 Cut 11 165

Carbon Dioxide 35 Cut 12 303

Nitrogen 30 Cut 13 560

Methane 890 Cut 14 930

Ethane 300 Cut 15 300

Propane 520

i-Butane 105

n-Butane 283

i-Pentane 100

n-Pentane 133

Temperature 150F

Pressure 1000 psia

Table 16: Petroleum Fraction Properties

Fraction Molecular Wt. API Gravity NBP(F)

Cut 11 91 64 180

Cut 12 100 61 210

Cut 13 120 55 280

Cut 14 150 48 370

Cut 15 200 40 495

36 Hydrocarbon-Water Phase Separation

SOLUTION Defining four thermodynamic sets allows PRO/II to flash the feed iso-thermally four times within one simulation run.

Figure 33 shows the Flash Drum Summary, which only reports the water decant flashes. There are three FLASH DRUMs, one for each of the solubil-ity correlations: SIMSCI, KEROSENE, and EOS. PRO/II reports the total liquid mole fraction and breaks down the liquid phases into the liquid hydrocarbon phase and the free water phase. Note that PRO/II provides this type of report only when you invoke the water decant option for a hydrocarbon-water system. You can observe that the three solubility methods produce very similar results for this problem.

The K-value printout for the first FLASH unit (DCNT-SIMSCI) follows the standard Flash Drum Summary. This report gives the vapor and liquid mole fractions and the K-value for each component, providing you with information about the relative volatilities of the components of the prod-ucts. If you choose to lump the vapor and liquid phases into one product, you can obtain the relative compositions of the different phases in the product.

Figure 33:

Flash Drum Summary with K-Value Report

FLASH ID DCNT-SIMSCI DECANT-KERO DECANT-EOS

NAME

FEEDS CRUDE CRUDE_R2 CRUDE_R1

PRODUCTS VAPOR 1V 2V 3V LIQUID 1L 2L 3L WATER 1W 2W 3W

TEMPERATURE, F 300.000 300.000 300.000 PRESSURE, PSIA 300.000 300.000 300.000 PRESSURE DROP, PSI 700.000 700.000 700.000 MOLE FRAC VAPOR 0.33552 0.33467 0.34579 MOLE FRAC TOTAL LIQUID 0.66448 0.66533 0.65421 MOLE FRAC H/C LIQUID 0.35887 0.36147 0.35919 MOLE FRAC FREE WATER 0.30561 0.30386 0.29502 DUTY, MM BTU/HR 59.02614 58.96749 60.00998 FLASH TYPE ISOTHERMAL ISOTHERMAL ISOTHERMAL

VAPOR-LIQUID COMPOSITIONS AND K-VALUES FOR UNIT 1, 'DCNT-SIMSCI'

COMPONENT VAPOR LIQUID K-VALUE ------------------- ---------- ---------- ----------

1 WATER 0.22197 0.03308 6.7112E+00 2 CO2 0.01219 0.00135 9.0594E+00 3 N2 0.01127 3.8836E-04 2.9011E+01 4 C1 0.32055 0.02432 1.3183E+01 5 C2 0.09736 0.01819 5.3508E+00 6 C3 0.14613 0.05268 2.7737E+00 7 IC4 0.02518 0.01468 1.7148E+00 8 NC4 0.06314 0.04399 1.4352E+00 9 IC5 0.01754 0.02001 8.7627E-01 10 NC5 0.02171 0.02812 7.7196E-01 11 CUT11 0.01434 0.04666 3.0732E-01 12 CUT12 0.02020 0.09143 2.2090E-01 13 CUT13 0.01813 0.18693 9.6967E-02 14 CUT14 0.00981 0.32940 2.9796E-02 15 CUT15 4.8360E-04 0.10877 4.4463E-03


Figure 34 shows the three-phase Flash Drum Summary from the output report. Note that this summary only reports the rigorous VLLE FLASHunits. If you invoke the VLLE option for a FLASH, but only one liquid phase exists, then PRO/II provides the results in the standard FlashDrum Summary. The results for the rigorous three-phase FLASH are very similar to those in Figure 33. The vapor and liquid mole fractions for each component in the three product phases are at the end of the standard three-phase Flash Drum Summary. PRO/II uses these results to calculate the two sets of K-values. You can obtain a set of LLE K-values by divid-ing the second set of VLE K-values by the first.

Figure 34:

Three-Phase Flash Drum Summary with

K-Value Report

FLASH ID RIG-SRKKD NAME

FEEDS CRUDE_R3

PRODUCTS VAPOR 4V LIQUID 1 4L LIQUID 2 4W

TEMPERATURE, F 300.000 PRESSURE, PSIA 300.000 PRESSURE DROP, PSI 700.000 MOLE FRAC VAPOR 0.34778 MOLE FRAC TOTAL LIQUID 0.65222 MOLE FRAC LIQUID 1 0.36325 MOLE FRAC LIQUID 2 0.28897 DUTY, MM BTU/HR 61.47417 FLASH TYPE ISOTHERMAL

VAPOR-LIQUID COMPOSITIONS AND K-VALUES FOR UNIT 4, 'RIG-SRKKD'

---------- COMPOSITIONS ---------- COMPONENT VAPOR LIQUID 1 LIQUID 2 ------------------- ---------- ---------- ----------

1 WATER 0.23782 0.05616 0.99963 2 CO2 0.01174 0.00131 5.3824E-05 3 N2 0.01087 3.8351E-04 3.2828E-06 4 C1 0.30942 0.02371 1.8329E-04 5 C2 0.09437 0.01751 3.9243E-05 6 C3 0.14269 0.05037 5.0834E-05 7 IC4 0.02481 0.01401 3.3863E-06 8 NC4 0.06243 0.04199 1.8011E-05 9 IC5 0.01757 0.01914 2.1698E-06

10 NC5 0.02183 0.02693 3.2412E-06 11 CUT11 0.01477 0.04520 5.6747E-06 12 CUT12 0.02102 0.08885 5.4152E-06 13 CUT13 0.01933 0.18291 1.4512E-06 14 CUT14 0.01079 0.32417 9.1229E-08 15 CUT15 5.5476E-04 0.10737 5.4406E-11

------ K-VALUES ------ COMPONENT VAP/LIQ 1 VAP/LIQ 2 ------------------- ---------- ----------

1 WATER 4.2353E+00 2.3793E-01 2 CO2 8.9758E+00 2.1803E+02 3 N2 2.8327E+01 3.3092E+03 4 C1 1.3048E+01 1.6877E+03 5 C2 5.3874E+00 2.4042E+03 6 C3 2.8323E+00 2.8063E+03 7 IC4 1.7703E+00 7.3241E+03 8 NC4 1.4865E+00 3.4657E+03 9 IC5 9.1766E-01 8.0958E+03 10 NC5 8.1044E-01 6.7340E+03 11 CUT11 3.2684E-01 2.6030E+03 12 CUT12 2.3656E-01 3.8813E+03 13 CUT13 1.0566E-01 1.3317E+04 14 CUT14 3.3278E-02 1.1825E+05 15 CUT15 5.1668E-03 1.0197E+07

38 Hydrocarbon-Water Phase Separation

Table 17 compares the different product flowrates for each of the four flash types. Note that PRO/II breaks down the two liquid phases into hydrocarbon and water content. For this example the second liquid (water) phase contains only 0.04 mol % (0.9/2211.7) of hydrocarbon. All three solubility correlations give similar results for the total flowrate of each product. The rigorous three-phase FLASH with SRKKD thermo-dynamics results in significantly more water in the hydrocarbon phase and thus less water in the water-dominated phase, than any of the three VLE FLASH units with water decant.

The best method for selecting a VLLE or a VLE thermodynamic system with a water solubility correlation is to compare the simulation results of each system with actual process data. Since this is not always possible, the PRO/II Keyword Manual and the PRO/II Reference Manual provide guidelines for the selection of an appropriate thermodynamic system and water solubility correlation.

Table 17: Comparison of VLE and VLLE Flash Results

Flowrate (lb-mol/hr)

Water Solubility Method

SIMSCI KEROSENE EOS RIGOROUS

Vapor 2568.1 2561.6 2646.7 2661.9

Liquid 1

Hydrocarbon

Water

2746.8

2655.9

90.9

2766.7

2661.1

105.6

2749.2

2626.0

123.2

2780.5

2624.4

156.1

Liquid 2

Water

Hydrocarbon

2339.1

2339.1

0.0

2325.8

2325.8

0.0

2258.1

2258.1

0.0

2211.6

2210.8

0.8


Naphtha Assay - Part 1

# TASK Enter the assay data for the naphtha feed described below and generate a set of petroleum components. Also create a plot of the calculated TBP curve and component cuts. The light ends make up 5% of the total liquid volume. Use SRK thermodynamics with API liquid density to model the system.

To represent the boiling curve more closely, increase the number of pseudocomponents by using twenty-one 18F (10C) cuts from 80F to 460F (30C to 240C). The process data is given in Table 18.

SOLUTION Build the flowsheet and enter the UOM, components, and thermody-namic data, as usual.

Step 1 Modify the Assay Characterization Data

To represent the boiling curve more closely, you must increase the num-ber of pseudocomponents by using twenty-one 18F (10C) cuts from 80F to 460F (30C to 240C).

Click the Assay Characterization button on the toolbar. Click .

Table 18: Naphtha Feed Data

ASTM D86 Data Light Ends

LV% T(F) T(C) Component Mole %

3 90 32 isobutane 0.70

5 125 52 butane 2.15

10 195 90 isopentane 0.86

30 250 121 pentane 3.58

50 280 138

70 310 154 Total 5% liq. volume

90 390 199

95 418 214

98 430 221

Flowrate 1000 lb/hr 450 kg/hr


Pressure 1 atm

Average API gravity 54.2 Average Specific Gravity 0.762

Modify Primary Set...

40 Naphtha Assay - Part 1

In the Primary TBP Cutpoints Definition dialog box, change the Minimum Temperature for First Interval to 80F (30C).

In first row, enter 460F (240C) as the Maximum Temperature for the Interval and 21 as the Number of Pseudocomponents in Interval.Leave the default data for the second and third intervals as they are.

Click to return to the Assay Cutpoints and Characterization Options dialog box.

Click and change the Initial Point from its default to 3%, and Distillation Curve Interconversion to API 1994.

Close the windows by Clicking .

Step 2 Define the Assay Stream

Add a stream into the flowsheet and double-click on the stream and select Petroleum Assay as the Stream Type.

Click and enter the rate.

To define a new assay: In the Stream Data - Flowrate and Assay dialog box, click

.

Choose ASTM D86 and enter the distillation data in the grid. You can use the key to move from cell to cell in the grid.

Select API Gravity and enter the average value.Figure 35 shows these entries.

Figure 35:Assay Definition

OK

Characterization Options...

OK

Flowrate and Assay...

Define/Edit Assay...


To enter the lightends composition: In the Assay Definition dialog box, click . Choose Percent of Assay and enter 5 as the LV percent figure. Check the box next to Assay lightends information for stream

NAPHTHA_FEED and enter the molar composition of each compo-nent in the grid.

Because the lightends compositions do not add up to 1 or 100, you must check the Normalize box.

Figure 36 shows these entries.

Figure 36:Assay Lightends Data

Back in the Stream Data dialog box, enter Temperature and Pres-sure values. Click to return to the flowsheet.

You will be asked whether you want to generate the pseudocomponents now or at a later time. Answer No.

Step 3 Generate the Pseudocomponents

If you have not already generated the pseudocomponents, you can do so at any time by selecting Input/Generate Assay Components from the menu bar. Then:

To view the list of pseudocomponents, open the Component Selec-tion dialog box.

To look at the petroleum property data generated for the pseudocom-ponents, generate an output report and view it.

Lightends...

OK


Figure 37:Component Summary

To view assay processing curve, click in the AssayDefinition dialog box.

Figure 38:Assay Processing

Plot


Please save this simulation as NAPHTH1.PRZ and you will use this simu-lation in the next exercise.

View Curve...



# TASK In this exercise you will use the assay stream you created in NAPHTH1and manipulate it using two flash drums. The first flash drum predicts the temperature at which 80% of the feed is recovered in the vapor. The second flash drum predicts the quantity of liquid that drops out when a temperature drop is imposed on that vapor.

SOLUTION Open the simulation named NAPHTH1.PRZ and save it under a new name, NAPHTH2.PRZ.

Step 1 Build the Process Flow Diagram

Add two flash drums to the flowsheet and connect, as shown below. Connect the stream NAPHTHA_FEED to the first flash drum.

Figure 39:PRO/II Flowsheet

Step 2 Enter Unit Operating Conditions

Enter unit data from Table 19 into both flash drums.

Express the recovery specification in Flash F1 as the ratio of one stream's flowrate to that of another. You can define a recovery on the basis of one component or a range of components or, as here, on the total stream. Set the specification so that it matches the figure shown below.



D-1 Flash drum Pressure = 0.8 atm80 / 20 vapor/liquid split

D-2 Flash drum Temperature Drop = 18F (10C)Pressure Drop = 0.1 atm


Because the feed temperature of flash F2 is unknown until the first flash has executed, you cannot enter an absolute value at this time. You can, however, enter a relative value, as shown below.


Add a STREAM PROPERTY TABLE to display a Short Property List for all the streams in the flowsheet.

Run the simulation and observe the temperatures, pressures and flowrates on the STREAM PROPERTY TABLE. Verify that they accu-rately reflect the specifications you entered.

Figure 40:Short Property Table


Please save this simulation as NAPHTH2.PRZ and you will use this simu-lation in the next exercise.



# TASK Using the assay stream and flashes from NAPHTH2, you will now exam-ine the effects of varying the vapor/liquid split in the first flash drum on the duty of the second flash drum. Run cases at vapor fractions from 80% (the base case) to 40% in 10% increments.

SOLUTION Open the simulation named NAPHTH2.PRZ and save it under a new name, NAPHTH3.PRZ.

Step 1 Enter Case Study Data

Click the Case Study button on the toolbar to open the Case Study Parameters and Results dialog box.

Check the Define Case Study box. In the first row of the Parameter field, click Parameter. Select Flash from the Unit/Stream list, F1 from the Unit Name list. Click Parameter and select Product Specification. Specify 5 cycles and a step size of -0.1. In the first row of the Result field, click Parameter and select Flash

F2 Duty.Figure 41 shows the completed dialog box.

Figure 41:Completed Case

Study Parameters Dialog Box


Step 2 Run the Simulation

Click the Run button to run the simulation.

Step 3 View Output in a Tabular Format

Select Output/Case Study from the menu bar and then Tables from the submenu to open the Case Study Tables dialog box.

Enter a table name in the first row and click . Move the variables you want to appear in the table from the Avail-

able Variables list to the Selected Variables list. Click on Columns to change the default to Display cycles in Rows. Click to view the results.

Figure 42:

Case Study Results in a Tabular Format

Step 4 View Output in a Graphical Format

Define a plot that shows the change in F2 duty with the change in F1 split.

Select Output/Case Study from the menu bar and then Plots from the submenu to open the Case Study Plots dialog box.

Enter a plot name in the first row and click . Highlight F1SPLIT from the Available Variables list and X-Axis

from the other list. Enter a label in the Label/Legend field, if desired. Click , followed by . Highlight F2DUTY from the Available Variables list and Y-Axis#1

in the other list. Enter a label in the Label/Legend field, if desired. Click , followed by .

Data...

View Table...

Data...

Update Add ->

Update Add ->


Figure 43:Case Study - Plot

Definition Dialog Box

To view the plot, click .

Figure 44:F2 Duty as a Function

of F2 Liquid/Vapor

Ratio


Please save this simulation as NAPHTH3.PRZ.

Preview Plot...

48 Phase Envelope

Phase Envelope

# TASK A vapor stream normally condenses when you increase pressure and/or decrease temperature. Under certain conditions, however, it is possible for a vapor stream to undergo partial condensation as its pressure is reduced (at a fixed temperature) or as its temperature is increased (at a fixed pressure). This counter-intuitive phenomenon, called retrograde condensation, is particularly important in the production of petroleum from deep gas wells.

Typically, as a gas is brought to the surface its pressure decreases until it matches that of the receiving vessel, which is at ambient temperature. The pressure of the vessel is set to lie in the two-phase region at that temperature so that partial condensation of the gas occurs. The con-densed liquid, enriched in the more-valuable heavy components, is recovered. The remaining vapor is repressurized and injected back into the well.

Figure 45:Petroleum Recovery

from a Deep Gas Well

Gas

T = 150FP = 2500 psia


Component Mole %

C1 82

C2 7

C3 4

IC4 2

NC4 2

IC5 and heavier 3

Flowrate 100 lb-mole/hr 45 kg-mole/hr




You want to examine the characteristics of the gas in the receiving ves-sel so that you can make a decision about the pressure required to maxi-mize the amount of liquid condensed.

Generate a phase envelope plot for the feed stream. Also generate lines of constant liquid mole fraction at 5%, 10% and 15%.

At an ambient temperature of 50F (10C), what pressure will be needed to maximize the production of liquid?

SOLUTION After defining the components and thermodynamic method, add a stream to the flowsheet and enter stream data. Add a Phase Envelope to the flowsheet.

In the Phase Envelope dialog box, select the feed stream in the first row of the grid. In the second row, select the feed stream and enter a LiquidMole Fraction of 0.05. In the same way, enter the other liquid mole frac-tions in rows three and four. Click on , change Individualto Comparison for each curve, and enter 1 through 5 for Plot Symbols.

Plot five graphs: one for each of the plots and one showing all the plots together. Run the simulation. Select Output/Generate Plot... from the menu bar and plot the phase envelope.

The resulting phase envelope for this exercise is shown below.

Figure 46:

Phase Envelope, PH1

Plot Options

50 Compressor Curves

Compressor Curves

# TASK Set up a simulation of part of a refrigeration loop. The flowsheet, stream and process data are shown below.

Figure 47:Refrigeration Loop

Flowsheet

Compressor

Separator

8

1 32

Vaporizor

Valve Cooler

Surge

4

56

7


Component Mole%

Ethane 1.04

Propane 96.94

i-Butane 1.68

n-Butane 0.34

Total Flowrate 16500 lb-mol/hr 7485 kg-mol/hr

Temperature 15.5F -9.2C



Unit Data

Valve Outlet pressure 87 psia 600 kPa

Cooler Hotside: Process stream dutyPressure drop

2x106 BTU/hr4.4 psi

2.11x106 kJ/hr30 kPa

Separator Adiabatic flash, zero pressure drop

Vaporizer Coldside: Pressure drop

Process stream product at dew point8.8 psi 61 kPa

Surge Mixer. Outlet pressure 65 psia 450 kPa

Compressor Curves Flowrate(ft3/hr) (m3/hr)

Actual Head(ft) (m)

Adiabatic Efficiency

900000 25485 38000 11582 69

1000000 28317 37000 11278 71

1240000 35113 35300 10760 72

1360000 38511 33100 10089 73

1430000 40493 27250 8306 71


SOLUTION Place the minimum number of units on the PFD.

Name the units and streams so that the flowsheet looks like Figure 48.

Figure 48:Modified Flowsheet

In the Compressor dialog box, select Actual Head Curve and click . Enter the table of Volumetric Flowrate against Head

and click . Select Single Adiabatic Efficiency Curve from the Effi-ciency or Temperature Specification list and enter the efficiency data.

Hint: You can reduce the number of units by combining the cooler and separator. You cannot feed streams 4 and 6 directly into the compressor because the surge mixer has an outlet pressure specification.

V1H2

H3

M1

C1

1 2

4

56

7

8

Enter Curve...

OK

Figure 49:

Compressor C1 Results

English Units


Outlet Temperature, F 182.39 Outlet Pressure, PSIA 321.54 Pressure Increase, PSI 256.54

Actual Work, HP 13099.77 Head, FT 35525.17 Adiabatic Efficiency 71.89 Polytropic Efficiency 75.26

Metric Units


Outlet Temperature, C 83.55 Outlet Pressure, KPA 2216.81 Pressure Increase, KPA 1768.65

Actual Work, KW 9769.40 Head, M 10828.02 Adiabatic Efficiency 71.89 Polytropic Efficiency 75.26

52 Debutanizer

Debutanizer

# TASK A debutanizer removes C4 and lighter components from a mixed Naph-tha and LPG feed stream. The Naphtha feed has been changed and you must ensure that the column can still meet the process requirements such as product recoveries and column duties.

Figure 50:Debutanizer Process

All the data required for this simulation are summarized in the tables below.

OVHD

BTMS

Naphtha

LPG

338F15

32

1

270 psia

Table 23: LPG Feed Data

Component Mole %

H2 0.3

H2S 0.2

C1 0.7

C2 5.5

C3 28.5

IC4 11.7

NC4 49.0

IC5 4.1



Flowrate 400 ft3/hr 11.3 m3/hr


The VLE and enthalpies of natural gas systems are generally modeled well by equations of state such as Peng-Robinson or Soave-Redlich-Kwong. However, these methods are less good at predicting liquid den-sity so a different method, such as COSTALD or API, should be used.

Table 24: Naphtha Feed Data

ASTM D86 Data

Liquid Volume % Temperature (F) (C)

0 104 40

5 144 62

10 158 70

30 196 91

50 228 109

70 248 120

90 284 140

95 311 155

100 329 165

Average Specific Gravity = 0.75

Lightends Data

Component Liquid Volume %

C3 0.07

IC4 0.21

NC4 0.42

IC5 3.24

NC5 6.06

10% liquid volume of assay



Flowrate 3200 ft3/hr 90 m3/hr

Table 25: Column Operating Conditions

Feed Temperature 338F 170C

Condenser Type Bubble Point

Condenser Pressure 185 psia 1275 kPa

Top Tray Pressure 190 psia 1310 kPa

Column Pressure Drop 4.3 psi 30 kPa

Reboiler Type Kettle

Hint: Use the Define feature to set the overhead rate from the col-umn as all the C4 and lighter components in the column feed.

54 Debutanizer

Answer the following questions:1. Can the column still recover 99% of the C4 components overhead

with a loss of only 1% of the C5 components?2. What are the duties on the condenser and reboiler?3. What is the reflux ratio?

SOLUTION As the column has converged with the required recovery specifications, it can clearly cope with the new service.

Table 26: Results for Both English and Metric Input

English Metric

Duties (x 106)

Condenser -11.8808 Btu/hr -12.2126 kJ/hr

Reboiler 16.7205 Btu/hr 17.2770 kJ/hr

Reflux Ratio 4.4086 4.2643


Rigorous Heat Exchanger

# TASK An existing heat exchanger runs with a shellside outlet temperature of 161F. You want to increase the throughput of the exchanger and need to calculate the shellside outlet temperature under the new conditions. Set up the simulation of the exchanger. This exercise is in two parts:

Part A Determine the fouling of the heat exchanger under present operating conditions.

Part B Using the fouling results from Part A, rate the existing fouled exchanger for the increased throughput.

The flowsheet, stream and process data are provided below.

Figure 51:

Schematic of a Rigorous Heat

ExchangerBT1

FD1

FD2

BT2

EA1


Component FD1 Mole % BT1 Mole %

NC4 15 4

IC5 14 15

NC5 16 16

NC6 22 25

NC7 13 15

NC8 20 25

Temperature 70F 220F

Pressure 195 psia 135 psia

Current Flowrate 550000 lb/hr 500000 lb/hr

Increased Flowrate 606000 lb/hr 660000 lb/hr

56 Rigorous Heat Exchanger

Heat Exchanger Data


SOLUTIONPart A Determine the fouling of the heat exchanger under current operating

conditions. In this part of the exercise, you require a shellside outlet tem-perature of 161F.

Build the flowsheet and enter the UOM, components, and thermody-namic data, as usual. Enter stream data.

Step 1 Enter Unit Data

In this example, the shellside outlet temperature is given and we want to determine the fouling resistance. Select Shell Outlet Temperature from the list and enter the value in the Temperature field.

Click each button and enter the appropriate data. Fields outlined in green means that, if you do not enter a value, PRO/II calculates one.

In the Film Coefficients dialog box, set the tubing fouling resistance to 0.

You want PRO/II to calculate an overall fouling resistance to meet the specification. You could supply values for both the tubeside and a shell-side fouling resistances and have PRO/II adjust them to meet the perfor-mance specification. However, for simplicity, it is easier to set the tubeside fouling resistance to zero and allow PRO/II to report the calcu-lated overall resistance as the required shellside resistance.

Click to check the Extended box to request an addi-tional data sheet with information about stream properties, heat exchanger configuration and hydrodynamics.

Run the simulation and view the results. Make a note of the required shellside fouling resistance.

Print Options...

58 Rigorous Heat Exchanger

Part B Using the fouling results you have just calculated, rate the existing fouled exchanger for the increased throughput.

Change the flowrates of both feed streams. Click , and enter the new value for the shellside

fouling resistance calculated in Part A. In the Rigorous Heat Exchanger main dialog box, change the Calcu-

lation Type to Rating (Predictive). Run the simulation and view the results. Note the tubeside and shell-

side exit temperatures.

Figure 52:

Heat Exchanger Results - Part A

SHELL AND TUBE EXCHANGER DATA SHEET FOR EXCHANGER 'E1' I--------------------------------------------------------------------I I EXCHANGER NAME UNIT ID E1 I I SIZE 36 - 240 TYPE AES HORIZONTAL CONNECTED 1 PARALLEL 1 SERIES I I AREA/UNIT 2295. FT2 ( 1984.FT2 REQUIRED ) AREA/SHELL 2295. FT2 I I--------------------------------------------------------------------I I PERFORMANCE OF ONE UNIT SHELL-SIDE TUBE-SIDE I I--------------------------------------------------------------------I I FEED STREAM ID BT1 FD1 I I FEED STREAM NAME I I TOTAL FLUID LB/HR 500000. 550000. I I VAPOR (IN/OUT) LB/HR / / I I LIQUID LB/HR 500000./500000. 550000./550000. I I STEAM LB/HR / / I I WATER LB/HR / / I I NON CONDENSIBLE LB/HR I I TEMPERATURE (IN/OUT) DEG F 220.0 / 161.0 70.0 / 129.8 I I PRESSURE (IN/OUT) PSIA 135.00 / 133.26 195.00 / 189.64 I I--------------------------------------------------------------------I I SP. GR., LIQ (60F/60F H2O) 0.662 / 0.662 0.653 / 0.653 I I VAP (60F/60F AIR) / / I I DENSITY, LIQUID LB/FT3 35.822 / 38.094 40.509 / 38.539 I I VAPOR LB/FT3 / / I I VISCOSITY, LIQUID CP 0.147 / 0.210 0.289 / 0.220 I I VAPOR CP / / I I THRML COND,LIQ BTU/HR-FT-F 0.0587 / 0.0654 0.0754 / 0.0687 I I VAP BTU/HR-FT-F / / I I SPEC.HEAT,LIQUID BTU/LB-F 0.6317 / 0.5937 0.5328 / 0.5759 I I VAPOR BTU/LB-F / / I I LATENT HEAT BTU/LB I I VELOCITY FT/SEC 1.12 6.93 I I DP/SHELL PSI 1.74 5.36 I I FOULING RESIST HR-FT2-F/BTU 0.00200 ( 0.00343 REQD) 0.00000 I I--------------------------------------------------------------------I I TRANSFER RATE BTU/HR-FT2-F SERVICE 109.64 (94.78 REQD)CLEAN 140.43 I I HEAT EXCHANGED MM BTU/HR 18.207 MTD(CORRECTED) 83.7 FT 0.924 I I--------------------------------------------------------------------I I CONSTRUCTION OF ONE SHELL SHELL-SIDE TUBE-SIDE I I--------------------------------------------------------------------I I DESIGN PRESSURE PSIA 300. 300. I I NUMBER OF PASSES 1 2 I I MATERIAL CARB STL CARB STL I I INLET NOZZLE ID IN 8.0 8.0 I I OUTLET NOZZLE ID IN 8.0 8.0 I I--------------------------------------------------------------------I I TUBE: NUMBER 600 OD 0.750 IN BWG 14 LENGTH 20.0 FT I I TYPE BARE PITCH 1.3 IN PATTERN 60 DEGREES I I SHELL: ID 36.00 IN SEALING STRIPS 0 PAIRS I I BAFFLE: CUT 0.300 SPACING (IN/CENT/OUT): IN 24.0/24.0/24.0,SINGLE I I RHO-V2: INLET NOZZLE 4419.5 LB/FT-SEC2 I I TOTAL WEIGHT/SHELL,LB 10393.6 FULL OF WATER 30135.8 BUNDLE 11825.0 I I--------------------------------------------------------------------I

Film Coefficients...


Figure 53:

Heat Exchanger Results - Part B

SHELL AND TUBE EXCHANGER DATA SHEET FOR EXCHANGER 'E1' I--------------------------------------------------------------------I I EXCHANGER NAME UNIT ID E1 I I SIZE 36 - 240 TYPE AES HORIZONTAL CONNECTED 1 PARALLEL 1 SERIES I I AREA/UNIT 2295. FT2 AREA/SHELL 2295. FT2 I I--------------------------------------------------------------------I I PERFORMANCE OF ONE UNIT SHELL-SIDE TUBE-SIDE I I--------------------------------------------------------------------I I FEED STREAM ID BT1 FD1 I I FEED STREAM NAME I I TOTAL FLUID LB/HR 660000. 606000. I I VAPOR (IN/OUT) LB/HR / / I I LIQUID LB/HR 660000. / 660000. 606000. / 606000. I I STEAM LB/HR / / I I WATER LB/HR / / I I NON CONDENSIBLE LB/HR I I TEMPERATURE (IN/OUT) DEG F 220.0 / 170.1 70.0 / 130.9 I I PRESSURE (IN/OUT) PSIA 135.00 / 131.96 195.00 / 188.64 I I--------------------------------------------------------------------I I SP. GR., LIQ (60F/60F H2O) 0.662 / 0.662 0.653 / 0.653 I I VAP (60F/60F AIR) / / I I DENSITY, LIQUID LB/FT3 35.822 / 37.762 40.509 / 38.500 I I VAPOR LB/FT3 / / I I VISCOSITY, LIQUID CP 0.156 / 0.193 0.293 / 0.212 I I VAPOR CP / / I I THRML COND,LIQ BTU/HR-FT-F 0.0535 / 0.0578 0.0677 / 0.0609 I I VAP BTU/HR-FT-F / / I I SPEC.HEAT,LIQUID BTU/LB-F 0.6417 / 0.6008 0.5328 / 0.5767 I I VAPOR BTU/LB-F / / I I LATENT HEAT BTU/LB I I VELOCITY FT/SEC 1.48 7.64 I I DP/SHELL PSI 3.04 6.36 I I FOULING RESIST HR-FT2-F/BTU 0.00343 0.00000 I I--------------------------------------------------------------------I I TRANSFER RATE BTU/HR-FT2-F SERVICE 100.20 CLEAN 152.66 I I HEAT EXCHANGED MM BTU/HR 20.443 MTD(CORRECTED) 88.9 FT 0.940 I I--------------------------------------------------------------------I I CONSTRUCTION OF ONE SHELL SHELL-SIDE TUBE-SIDE I I--------------------------------------------------------------------I I DESIGN PRESSURE PSIA 300. 300. I I NUMBER OF PASSES 1 2 I I MATERIAL CARB STL CARB STL I I INLET NOZZLE ID IN 8.0 8.0 I I OUTLET NOZZLE ID IN 8.0 8.0 I I--------------------------------------------------------------------I I TUBE: NUMBER 600 OD 0.750 IN BWG 14 LENGTH 20.0 FT I I TYPE BARE PITCH 1.3 IN PATTERN 60 DEGREES I I SHELL: ID 36.00 IN SEALING STRIPS 0 PAIRS I I BAFFLE: CUT 0.300 SPACING (IN/CENT/OUT): IN 24.0/26.54/24.0,SINGLE I I RHO-V2: INLET NOZZLE 7700.6 LB/FT-SEC2 I I TOTAL WEIGHT/SHELL,LB 10393.6 FULL OF WATER 30135.8 BUNDLE 11825.0 I I--------------------------------------------------------------------I

60 Two Stage Compressor

Two Stage Compressor

# TASK A natural gas stream is compressed before entering a pipeline. The stream is first compressed to 12 bar and then to 26 bar. Liquid condenses in the compressor aftercoolers and is recycled back to the previous stage. The liquid product is removed from the feed flash.

Figure 54:Two Stage

Compressor

Flowsheet

Use the Peng-Robinson thermodynamic method with the COSTALD correlation for liquid density.

All the data required for this simulation are summarized in the tables below.

D-3

C-1

HX-1D-2D-1

Feed

C-2

HX-2

Vapor

Liquids

S2

S1

S3S7 S11

S4 S5 S6 S8 S9S10

100F70 psia


Component Flowrate

(lb-mol/hr) (kg-mol/hr)

Nitrogen 400 180

Carbon dioxide 4230 1920

Methane 32000 14520

Ethane 20000 9070

Propane 16000 7260

i-Butane 1700 770

n-Butane 6200 2810

i-Pentane 2100 950

n-Pentane 3600 1630

n-Hexane 3400 1540

C7 Plus (model as NC9) 7000 3180


Pressure 70 psia 5 bar


Part A Answer the following questions:1. What are the amounts of liquid and vapor leaving the process?2. What compressor work is required for each stage?3. What are the stream temperatures entering the aftercoolers?4. What are the aftercooler duties?

Part B If you have time, answer the following questions:1. Can the same information still be obtained with fewer units in the

flowsheet? If so, simulate it and check that the data are available and that the values are the same as in the original calculation.

2. Assuming that you only want to know the product streams from the process, simulate the process with the minimum number of units required.

SOLUTIONPart A The actual work is 43808 HP (32456 kW) for C-1 and 42804 HP (30893

kW) for C-2.

The temperatures entering

ExerciciosPROII

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Transcript of ExerciciosPROII