Introduction to Aspen Plus

Introduction to Aspen Plus Speaker: Bor-Yih Yu(余柏毅) Date: 2013/09/02 [email protected] PSE Laboratory Department of Chemical Engineering Nation Taiwan University (綜合 room 402) Edited by: 程建凱/吳義章/余柏毅

Introduction to Aspen Plus Part 1: Introduction

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What is Aspen Plus • Aspen Plus is a market-leading process modeling tool for conceptual design, optimization, and performance monitoring for the chemical, polymer, specialty chemical, metals and minerals, and coal power industries.

Ref: http://www.aspentech.com/products/aspen-plus.cfm

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What Aspen Plus provides • Physical Property Models – World’s largest database of pure component and phase equilibrium data for conventional chemicals, electrolytes, solids, and polymers – Regularly updated with data from U. S. National Institute of Standards and Technology (NIST)

• Comprehensive Library of Unit Operation Models – Addresses a wide range of solid, liquid, and gas processing equipment – Extends steady-state simulation to dynamic simulation for safety and controllability studies, sizing relief valves, and optimizing transition, startup, and shutdown policies – Enables you build your own libraries using Aspen Custom Modeler or programming languages (User-defined models)

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Ref: Aspen Plus® Product Brochure

More Detailed • Properties analysis – Properties of pure component and mixtures (Enthalpy, density, viscosity, heat capacity,…etc) – Phase equilibrium (VLE, VLLE, azeotrope calculation…etc) – Parameters estimation for properties models (UNIFAC method for binary parameters, Joback method for boiling points…etc) – Data regression from experimental deta

• Process simulation – pump, compressor, valve, tank, heat exchanger, CSTR, PFR, distillation column, extraction column, absorber, filter, crystallizer…etc 5

What course Aspen Plus can be employed for • • • • • • •

MASS AND ENERGY BALANCES PHYSICAL CHEMISTRY CHEMICAL ENGINEERING THERMODYNAMICS CHEMICAL REACTION ENGINEERING UNIT OPERATIONS PROCESS DESIGN PROCESS CONTROL

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Lesson Objectives • Familiar with the interface of Aspen Plus • Learn how to use properties analysis • Learn how to setup a basic process simulation

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Outline • • • • • • •

Part 1 : Introduction Part 2 : Startup Part 3 : Properties analysis Part 4 : Running Simulation in Aspen Plus (simple units) Part 5 : Running Simulation in Aspen Plus (Reactors) Part 6 : Running Simulation in Aspen Plus (Distillation) Part 7 (additional): Running Simulation in Aspen Plus (Design, spec and vary)

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Introduction to Aspen Plus Part 2: Startup

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Start with Aspen Plus

Aspen Plus User Interface

Aspen Plus Startup

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Interface of Aspen Plus

Help Setup Components Properties Streams Blocks Data Browser Next

Check Result Stop Reinitialize Step Start Control Panel ProcessFlowsheet Flowsheet Windows Process Windows

ModelLibrary Library (View| Model (View| Model ModelLibrary Library) )

Stream

Status message

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More Information

Help for Commands for Controlling Simulations

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Data Browser • The Data Browser is a sheet and form viewer with a hierarchical tree view of the available simulation input, results, and objects that have been defined

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Setup – Specification Run Type

Input mode

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Input components

Remark: If available, are

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Properties Process type(narrow the number of methods available)

Base method: IDEAL, NRTL, UNIQAC, UNIFAC…

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Property Method Selection—General Rule Example 1: water - benzene

Example 2: benzene - toluene

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Typical Activity Coefficient Models Non-Randon-Two Liquid Model (NRTL)

Uniquac Model

Unifac Model

Typical Equation of States Peng-Robinson (PR) EOS

Redlich-Kwong (RK) EOS

Haydon O’Conell (HOC) EOS

Thermodynamic Model – NRTL

NRTL

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NRTL – Binary Parameters

Click “NRTL” and then built-in binary parameters appear automatically if available.

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Access Properties Models and Parameters

Review Databank Data

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Review Databank Data Including: Ideal gas heat of formation at 298.15 K Ideal gas Gibbs free energy of formation at 298.15 K Heat of vaporization at TB Normal boiling point Standard liquid volume at 60°F

….

Description of each parameter 24

Pure Component Temperature-Dependent Properties

CPIGDP-1

ideal gas heat capacity

CPSDIP-1

Solid heat capacity

DNLDIP-1

Liquid density

DHVLDP-1

Heat of vaporization

PLXANT-1

Extended Antoine Equation

MULDIP

Liquid viscosity

KLDIP

Liquid thermal conductivity

SIGDIP

Liquid surface tension

UFGRP

UNIFAC functional group 25

Example: PLXANT-1 (Extended Antoine Equation) Corresponding Model Click “↖?” and then click where you don’t know

?

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Example: CPIGDP-1 (Ideal Gas Heat Capacity Equation) Corresponding Model

?

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Basic Input---Summary • The minimum required inputs to run a simulation are: – – – – –

Setup Components Properties Streams Blocks

Property Analysis

Process Simulation

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Introduction to Aspen Plus Part 3: Property analysis

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Overview of Property Analysis Use this form Pure Binary Residue Ternary Azeotrope

To generate Tables and plots of pure component properties as a function of temperature and pressure Txy, Pxy, or Gibbs energy of mixing curves for a binary system Residue curve maps Ternary maps showing phase envelope, tie lines, and azeotropes of ternary systems This feature locates all the azeotropes that exist among a specified set of components.

Ternary diagrams in Aspen Distillation Synthesis feature: Azeotropes, Ternary Maps Distillation boundary, Residue curves or distillation curves, Isovolatility curves, Tie lines, Vapor curve, Boiling point ***When you start properties analysis, you MUST specify components , thermodynamic model and its corresponding parameters. (Refer to Part 2) 30

Find Components

Component ID : just for distinguishing in Aspen. Type : Conventional, Solid….etc Component name : real component name Formula : real component formula

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Find Components

TIP 1: For common components, you can enter directly the common name or molecular equation of the components in “component ID”. (like water, CO2, CO, Chlorine…etc)

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Find Components

TIP 2: If you know the component name (like N-butanol, Ethanol….etc), you can enter it in “component name”.

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Find Components

TIP 3: You can also enter the formula of the component. (Be aware of the isomers)

You can also click “Find” to search for component of given CAS number, molecular weight without knowing its molecular formula, or if you don’t know the exactly component name 34

Select Thermodynamic Model

Select NRTL

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Check Binary Parameter Properties Parameters

NRTL-1

Click This, it will automatically change to red if binary parameter exists.

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Find Components

TIP 2: If you know the component name (like N-butanol, Ethanol….etc), you can enter it in “component name”.

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Find Components You can enter the way of searching…

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Properties Analysis – Pure Component

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Available Properties Property (thermodynamic)

Property (transport)

Availability Free energy Constant pressure Enthalpy heat capacity Heat capacity ratio Fugacity coefficient Constant volume heat Fugacity coefficient capacity pressure correction Free energy departure Vapor pressure Free energy departure Density pressure correction Enthalpy departure Entropy Enthalpy departure Volume pressure correction Enthalpy of Sonic velocity vaporization Entropy departure

Thermal conductivity Surface tension Viscosity

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Example1: CP (Heat Capacity)

1. Select property (CP) 4. Specify range of temperature 2. Select phase 5. Specify pressure Add “N-butyl-acetate”

3. Select component

6. Select property method

7. click Go to generate the results 41

Example1: Calculation Results of CP

Data results

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Properties Analysis – Binary Components

Binary Component Properties Analysis Use this Analysis type To generate Temperature-compositions diagram at Txy constant pressure Pressure-compositions diagram at Pxy constant temperature Gibbs energy of mixing diagram as a function of liquid compositions. The Aspen Physical Property System uses this Gibbs energy of mixing diagram to determine whether the binary system will form two liquid phases at a given temperature and pressure.

Example: T-XY 1. Select analysis type (Txy)

2. Select two component

2. Select phase (VLE, VLLE)

5. Specify pressure

3. Select compositions basis

6. Select property method 4. Specify composition range

7. click Go to generate the results

Example: calculation result of T-XY

Data results

Example: Generate XY plot

Click “plot wizard” to generate XY plot

Example: Generate XY plot (cont’d)

Properties Analysis – Ternary (add one new components)

Properties Analysis – Ternary (Check NRTL binary parameter)

3 components -> 3 set of binary parameter (How about 4 components??)

Properties Analysis – Ternary

Ternary Map

1. Select three component 4. Select phase (VLE, LLE)

2. Specify number of tie line

5. Specify pressure


6. Specify temperature (if LLE is slected)

7. click Go to generate the results

Calculation Result of Ternary Map (LLE)

Data results

Property Analysis – Conceptual Design (Optional) Use this form

To generate

Binary

Tables and plots of pure component properties as a function of temperature and pressure Txy, Pxy, or Gibbs energy of mixing curves for a binary system

Residue

Residue curve maps

Pure

Ternary Azeotrope

Ternary maps showing phase envelope, tie lines, and azeotropes of ternary systems This feature locates all the azeotropes that exist among a specified set of components.

Ternary diagrams in Aspen Distillation Synthesis feature: Azeotropes, Ternary Maps Distillation boundary, Residue curves or distillation curves, Isovolatility curves, Tie lines, Vapor curve, Boiling point

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Conceptual Design

Azeotrope Analysis

Azeotrope Analysis 1. Select components (at least two)

2. Specify pressure

3. Select property method 6. click Report to generate the results 4. Select phase (VLE, LLE)

5. Select report Unit

Error Message

Close analysis input dialog box (pure or binary analysis)

Azeotrope Analysis Report

Ternary Maps

Ternary Maps 3. Select property method 1. Select three components

4. Select phase (VLE, LLE)

2. Specify pressure

5. Select report Unit

6. Click Ternary Plot to generate the results

6. Specify temperature of LLE (If liquid-liquid envelope is selected)

Ternary Maps Change pressure or temperature

Ternary Plot Toolbar: Add Tie line, Curve, Marker…

Introduction to Aspen Plus Part 4: Running simulation

Simple Units (Mixer, Pump, valve, flash, heat exchanger) 63

Example 1: Calculate the mixing properties of two stream 1 2

4

3 Mixer

Mole Flow kmol/hr WATER BUOH BUAC Total Flow kmol/hr Temperature C Pressure bar Enthalpy kcal/mol Entropy cal/mol-K Density kmol/cum

Pump 1

2

3

4

10 0 0 10 50 1 ? ? ?

0 9 6 15 80 1 ? ? ?

? ? ? ? ? 1 ? ? ?

? ? ? ? ? 10 ? ? ?

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Setup – Specification

Select Flowsheet

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Reveal Model Library

View|| Model Library or press F10

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Adding a Mixer

Click “one of icons” and then click again on the flowsheet window Remark: The shape of the icons are meaningless

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Adding Material Streams

Click “Materials” and then click again on the flowsheet window

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Adding Material Streams (cont’d)

When clicking the mouse on the flowsheet window, arrows (blue and red) appear.

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Adding Material Streams (cont’d) When moving the mouse on the arrows, some description appears.

Red arrow(Left) Feed (Required; one ore more if mixing material streams)

Red arrow(Right): Blue arrow: Water Product (Required; if decant for Free water mixing material streams) of dirty water.

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Adding Material Streams (cont’d)

After selecting “Material Streams”, click and pull a stream line. Repeat it three times to generate three stream lines.

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Reconnecting Material Streams (Feed Stream) Right Click on the stream and select Reconnect Destination

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Reconnecting Material Streams (Product Stream)

Right Click on the stream and select Reconnect Source

B1

1

3

2

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Specifying Feed Condition

Right Click on the stream and select Input

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Specifying Feed Condition (cont’d) 1

2

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Specifying Input of Mixer

Right Click on the block and select Input

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Specifying Input of Mixer (cont’d)

Specify Pressure and valid phase

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Run Simulation Click ► to run the simulation

Run

Start or continue calculations

Step

Step through the flowsheet one block at a time

Stop

Pause simulation calculations

Reinitialize

Purge simulation results

Check “simulation status” “Required Input Complete” means the input is ready to run simualtion 78

Status of Simulation Results Message Results available

Results with warnings

Means The run has completed normally, and results are present. Results for the run are present. Warning messages were generated during the calculations. View the Control Panel or History for messages.

Results with errors

Results for the run are present. Error messages were generated during the calculations. View the Control Panel or History for messages.

Input Changed

Results for the run are present, but you have changed the input since the results were generated. The results may be inconsistent with the current input. 79

Stream Results

Right Click on the block and select Stream Results

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Pull down the list and select “Full” to show more properties results.

Enthalpy and Entropy

Substream: MIXED Mole Flow kmol/hr WATER BUOH BUAC Total Flow kmol/hr Total Flow kg/hr Total Flow cum/hr Temperature C Pressure bar Vapor Frac Liquid Frac Solid Frac Enthalpy kcal/mol Enthalpy kcal/kg Enthalpy Gcal/hr Entropy cal/mol-K Entropy cal/gm-K Density kmol/cum Density kg/cum Average MW Liq Vol 60F cum/hr

1

2

3

10 0 0 10 180.1528 0.18582 50 2 0 1 0 -67.81 -3764.03 -0.6781 -37.5007 -2.0816 53.81564 969.5038 18.01528 0.1805

0 9 6 15 1364.066 1.74021 80 1 0 1 0 -94.3726 -1037.77 -1.41559 -134.947 -1.48395 8.619647 783.851 90.93771 1.617386

10 9 6 25 1544.218 1.870509 70.08758 1 0 1 0 -83.7476 -1355.82 -2.09369 -95.6176 -1.54799 13.36534 825.5604 61.76874 1.797886 81

Change Units of Calculation Results

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Setup – Defining Your Own Units Set

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Setup – Report Options

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Stream Results with Format of Mole Fraction

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Add Pump Block

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Add A Material Stream

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Connect Streams

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Pump – Specification 1. Select “Pump” or “turbine”

2. Specify pump outlet specificatio (pressure, power)

3. Efficiencies (Default: 1)

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Run Simulation Click ► to generate the results

Check “simulation status” “Required Input Complete” 90

Block Results (Pump)

Right Click on the block and select Results

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Streams Results

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Calculation Results (Mass and Energy Balances) 1 2

4

3 Mixer

Pump 1

2

3

Mole Flow kmol/hr WATER 10 0 10 BUOH 0 9 9 BUAC 0 6 6 Total Flow kmol/hr 10 15 25 Temperature C 50 80 70.09 Pressure bar 1 1 1 Enthalpy kcal/mol -67.81 -94.37 -83.75 Entropy cal/mol-K -37.50 -134.95 -95.62 Density kmol/cum 969.50 783.85 825.56

4 10 9 6 25 71.20 10 -83.69 -95.46 824.29

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Exercise 1 2 3

4 Mixer

Mole Flow kmol/hr Water Ethanol Methanol Total Flow kmol/hr Temperature C Pressure bar Enthalpy kcal/mol Entropy cal/mol-K Density kmol/cum

6

5 Pump

1

2

3

4

5

6

10 0 0 10 50 1 ? ? ?

0 5 0 15 70 1 ? ? ?

0 0 15 15 40 1 ? ? ?

? ? ? ? ? 1 ? ? ?

? ? ? ? ? 4 ? ? ?

? ? ? ? ? 2 ? ? ?

Please use Peng-Robinson EOS to solve this problem.

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Example 2: Flash Separation 120 T-x T-y

Saturated Feed P=1atm F=100 kmol/hr zwater=0.5 zHAc=0.5

o

T=105 C P=1atm

T ( C)

115 110 105 100 0.0

What are flowrates and compositions of the two outlets?

0.2

0.4

0.6

xWater and yWater

0.8

1.0

Input Components

Thermodynamic Model: NRTL-HOC

Check Binary Parameters

Association parameters of HOC

Binary Parameters of NRTL

Binary Analysis

T-xy plot 1. Select analysis type (Txy)

2. Select two component

3. Select compositions basis

2. Select phase (VLE, VLLE)

5. Specify pressure


4. Specify composition range 7. click Go to generate the results

Calculation Result of T-xy

Data results

Generate xy plot

Generate xy plot (cont’d)

Add Block: Flash2

Add Material Stream

Specify Feed Condition

Saturated Feed (Vapor fraction=0) P=1atm F=100 kmol/hr zwater=0.5 zHAc=0.5

Block Input: Flash2

Flash2: Specification

T=105 C P=1atm

Required Input Complete Click ► to run simulation

**Before running simulation, property analysis should be closed.

Stream Results

Stream Results (cont’d) 42.658 kmol/hr zwater=0.501 zHAc=0.409

Saturated Feed P=1atm F=100 kmol/hr zwater=0.5 zHAc=0.5

T=105 C P=1atm

57.342 kmol/hr zwater=0.432 zHAc=0.568

HEAT EXCHANGE 熱物流入口温度：200℃、入口壓力：0.4 MPa 流量：10000kg/hr 组成：苯 50%，苯乙烯 20%，水 10%

冷卻水入口温度：20℃、入口压力：1.0 MPa 流量：60000 kg/hr。

熱流出口氣相分率為 0 （飽和液相）

COMPONENTS – SPECIFICATION

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Thermodynamic Model – NRTL

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ADD BLOCK: HEATX

Feeds Conditions CLD-IN

HOT-IN

BLOCK INPUT

Check result

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Check result

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Reactor Systems (RGIBBS, RPLUG,RCSTR) 123

Equilibrium Reactor: RGIBBS

RGIBBS unit predicts the product by minimizing GIBBS energy in the system

It is very Useful When…: 1. Reaction Kinetics are unknown. 2. There are lots of products 124


Reactions: CO  3H 2  CH 4  H 2O CO2  4 H 2  CH 4  2 H 2O CO  H 2O  CO2  H 2

Fresh Feed Flow rate 1000 (kmol/h) CO 0.2368 H2 0.7172 H2O 0.0001 CH4 0.0098 CO2 0.0361

T=300 k

P=470 psia 125


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Equilibrium Reactor: RGIBBS Inside the Block:

Check result

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KINETICS REACTORS: RPLUG Reaction :Exothermic & reversible CO  H 2O  CO2  H 2

H  41.09( KJ / mol )

kmol Rate  k f YCOYH 2O  k rYCO2 YH 2 ( ) kgcat  s  47400 k f  51.545 exp( ) RT  85458 k r  3922.1exp( ) RT Rate [=] Kmol/Kgcat/s Activation Energy [=] KJ/Kmol

KINETICS REACTORS: RPLUG Reaction :Exothermic & reversible CO  H 2O  CO2  H 2 Fresh Feed Flow rate 200 (mol/h) CO 0.030 H2 0.430 H2O 0.392 CO2 0.148

H  41.09( KJ / mol )

Catalyst Loading = 0.1865 Kg Bed Voidage = 0.8928 Feed Temperature = 583K Feed Pressure = 1 bar Reactor Length = 10 m Reactor Diameter = 5m

KINETICS REACTORS: RPLUG Feed Stream:

KINETICS REACTORS: RPLUG Reaction Setting:

KINETICS REACTORS: RPLUG Reaction Setting:

KINETICS REACTORS: RPLUG RPLUG Setting:



Check result

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Check result

138

Check result Select Reactor Length column Plot -> x-Axis variable

Select Temperature Column

Plot -> y-Axis variable

Display Plot

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TEMPERATURE K 585.0 587.5 590.0 592.5 595.0 597.5 600.0 602.5 605.0 607.5

Check result

0.0

Block B2 (RPlug) Profiles Process Stream

Temperature MIXED

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0 4.5 5.0 5.5 6.0 Reactor length MIXED meter

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

140

Check result

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Check result Select Reactor Length column Plot -> x-Axis variable

Select all other columns

Plot -> y-Axis variable

Display Plot

142

Check result

0.35

0.4

0.45

0.5

Block B2 (RPlug) Profiles Process Stream

fraction MIXED CO fraction MIXED H2O fraction MIXED CO2 fraction MIXED H2

0.05

0.1

0.15

0.2

0.25

0.3

Mole Mole Mole Mole

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0 4.5 5.0 5.5 6.0 Reactor length MIXED meter

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

KINETICS REACTORS: RCSTR Reaction :Exothermic & Irreversible Aniline + Hydrogen  Cyclohexylamine (CHA)

C6H7N + 3H2  C6H13N

Reactor Conditions Reactor : Reactor

Pressure

595 psi

Temperature

250 F

Volume

1200 ft3

condition

Reactor type Reactor liquid level

Vertical cylindrical vessel

80%

Reactor Conditions Input

Reaction Kinetics Reaction rate :

RCHA  kVRCACH

Where

ft 3

VR: reactor volume lbmole 3 ft CA: concentration of Aniline lbmole ft CH: concentration of Hydrogen • Reaction kinetics :

k  k0 exp( E

E  2000 Btu

k0  10

8

RT

lbmole

)

Where T : temperature (R) E : activity energy

3

Reaction Kinetics Input



Feeds Conditions Two fresh feed stream : Aniline feed

Hydrogen feed

mole rate

100 lbmolhr 1

400 lbmolhr 1

temperature

100 F

100 F

650 psia

650 psia

pressure

Feeds Conditions

Check result

Question:

(1) Compare the conversion between RSTOIC and RCSTR. (2) Compare the net duty inside the RSTOIC and RCSTR 153


Distillation Process (DSTWU, RADFRAC) 154

Distillation Separation 1 2

RR ?

xwater=0.99

20 Saturated Feed P=1.2atm F=100 kmol/hr zwater=0.5 zHAc=0.5

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QR ? 40 xHAc=0.99

• There are two degrees of freedom to manipulate distillate composition and bottoms composition to manipulate the distillate and bottoms compositions. • If the feed condition and the number of stages are given, how much of RR and QR are required to achieve the specification.

Distillation Separation Example : A mixture of benzene and toluene containing 40 mol% benzene is to be separated to dive a product containing 90 mol% benzene at the top, and no more than 10% benzene in bottom product. The feed enters the column as saturated liquid, and the vapor leaving the column which is condensed but not cooled, provide reflux and product. It is proposed to operate the unit with a reflux ratio of 3 kmol/kmol product. Please find: (1) The number of theoretical plates. (2) The position of the entry. (Problem is taken from Coulson & Richardson’s Chemical Engineering, vol 2, Ex 11.7, p.564)

1. By what you learned in Material balance and unit operation From Overall Material Balance: 100 = D+B

1

xben=0.9

37.5

Saturated Feed P=100 Kpa F=100 kmol/hr xben=0.4 xtol=0.6

From Benzene Balance: 100*0.4 = 0.9 * D+ 0.1* B Thus, D=37.5 and B=62.5.

n xben