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8/10/2019 3 Hysys Training Distillation Tutorials 3 4 5
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Steady State Simulation Using Aspen Hysys
8/10/2019 3 Hysys Training Distillation Tutorials 3 4 5
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Designing Distillation System Using Hysys
Objective:
Become comfortable and familiar with various
distillation column models in Hysys and use of sizing
module
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Distillation Models
Four models are available which can be used to model
and design industrial fractionation system
Distillation Column
Model with Condenser and Reboiler in-built
Used for conventional solvent separation
Refluxed Absorber
Model with Condenser and no Reboiler
8/10/2019 3 Hysys Training Distillation Tutorials 3 4 5
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Distillation Model (Continue.)
Absorber
Model without Condenser and Reboiler
Used for absorber or stripper
Reboiled Absorber
Model with Reboiler and no Condenser
Used to model reboiled stripping or absorber
8/10/2019 3 Hysys Training Distillation Tutorials 3 4 5
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Tutorial 3 De-Methaniser
0.00270.0001C8
0.00470.0002C7
0.00370.0003C6
0.01020.0020N-C5
0.01470.0036i-C50.01970.0085N-C4
0.02040.0112i-C4
0.07500.0706C3
0.11760.1921C2
0.72270.7041C1
0.00290.0048CO2
0.00570.0025N2
Mole FractionMole fractionComponents
215 kmol/hr1620 kmol/hrFlowrate
2290 kPa2275 kPaPressure
-85 deg C-95 deg CTemperature
Feed 2Feed1Name
Build a flowsheet in Hysys to model De-Methaniser
8/10/2019 3 Hysys Training Distillation Tutorials 3 4 5
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Tutorial 3 De-Methaniser Study
Study Feed Streams 2 Feed Streams contain Methane and heavier vapours
Also contain traces of non condensables N2 and CO2
Feed conditions low temp and high pressure
Decide Thermodynamic System
Which are key components?
What are boiling points of methane and ethane
Configure streams in simulation and study their state (liq/vap)
Can methane be separated by flashing to lower pressure? To
study using a simple flash Need distillation column
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De-Methaniser To Decide Column inputs
To Decide Column Inputs
What type of column? Fractionator / Stripper / Rectifier?
No need of condenser why?
Number of theoratical stages based on difficulty of separation
Column top pressure and pressure drop per stage
Feed Locations
Feed-1 at top stage to provide reflux
Feed-2 at stage 4
Configure column specs -
Reboiler Duty
Distillate Rate
Provide Temperature Estimates
8/10/2019 3 Hysys Training Distillation Tutorials 3 4 5
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Tutorial 3 De-Methaniser Column flowsheet details
kmol/hr1338Distillate Rate
kPa2310Bottom Stage Pressure
kPa2275Top Stage Pressure
10Number of Stages
Main TS
kJ/hr2.1e+06Heat Flow
Ex Duty
4Feed 2
2Ex Duty
1Feed 1
Feed StageStream
Property : Peng Robonson
27 CBottom
-68 CTop
Temperature Estimates
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Tutorial 3 De-Methaniser Answer Fol lowings..
What is mole fraction of methane in overhead?
:______________
Add design specification to get 95 % (mole) ofmethane in overhead. You have to add Column
Component Fraction spec from Specs page and
deactivate distillate flowrate. What is mole fraction of methane in overhead?
:______________
What is flowrate of overhead product? :______________
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Tutorial 4 De-Ethaniser
Add pump to transfer bottom product of De-Methaniser to De-
Ethaniser column with following data
2790 kPaDC2 Feed Pressure
WorksheetP=100-HPEnergy
DC2 FeedOutlet
DC1 BtmInlet
Connections
EnterIn This cell
8/10/2019 3 Hysys Training Distillation Tutorials 3 4 5
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Tutorial 4 De-Ethaniser (Continue)
De-Ethaniser is modeled using Distillation column with
following details
DC2 Cond QCondenser Duty
DC2 BtmBottom Liquid Outlet
DC2 Reb QReboiler Duty
DC2 Feed / 6Feed stream/Stage
DC2 OvhdOverhead Vapour ProductDC2 DistOverhead Liquid Product
14No. of stages
DC2Name
Connections EnterIn This cell
8/10/2019 3 Hysys Training Distillation Tutorials 3 4 5
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Tutorial 4 De-Ethaniser (Continue)
2.5 (Molar)Reflux Ratio
0 kmol/hrDistillate Rate
320 kmol/hrOverhead Vapour Product
95 CReboiler
Specifications
2792 kPaReboiler
Temperature Estimates
-4 CCondenser
35 kPaCondenser Delta P
2725 kPaCondenser
Pressures
EnterIn This cell
Answer this
What is flowrate of C2 and C3 in DC2 Btm?
C2 _____________, C3_______________, Ratio C2/C3 ________________
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Tutorial 4 De-Ethaniser (Continue)
Add design specification to maintain ratio of C2/C3 to 0.01,
deactivating Ovhd Vap Rate. Select Column Component
Ratio as specification type with following information
PropaneDenominator
EthaneNumerator
0.01Spec Value
LiquidPhase
Mole FractionFlow Basis
ReboilerStage
C2/C3Name
EnterIn This Cell
What is the flowrate of DC2 Ovhd ? : _____________________
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Tutorial 5 Methanol Water Separation
Feed:63.2 wt% Water
36.8 wt% Methanol
Total flow = 120,000 lb/hr
Pressure 18 psia
Saturated liquid
Desired Purity of Products: 99.95 wt% methanol in the distillate
99.90 wt% water in the bottoms
8/10/2019 3 Hysys Training Distillation Tutorials 3 4 5
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Tutorial 5 Methanol Water Separator Study
Study Feed and Required Column Specs Decide Thermodynamic System
Any Azeotrope between Methanol Water?
What are boiling points of Methanol and Water?
What type of column? Fractionator / Stripper / Rectifier?
Number of theoratical stages based on difficulty of separation
Column top pressure and pressure drop per stage
Feed Location
Configure column specs -
Distillate Rate Reflux Ratio
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Tutorial 5 Methanol Water Separation
Part A:
Perform a rating calculation of a Methanol tower using thefollowing data:
Use the NRTL Property Method
Feed:63.2 wt% Water36.8 wt% MethanolTotal flow = 120,000 lb/hrPressure 18 psiaSaturated liquid
Column specification:38 trays (40 stages)Feed tray = 23 (stage 24)Total condenserTop stage pressure = 16.1 psiaPressure drop per stage = 0.1 psi
Distillate flowrate = 1245 lbmol/hrMolar reflux ratio = 1.3
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Part B:
Set up design specifications within the column so the following
two objectives are met:
99.95 wt% methanol in the distillate
99.90 wt% water in the bottoms
What are condenser and reboiler duty?
Condenser Duty :_________
Reboiler Duty :___________
What is reflux ratio ? :______________________
Tutorial 5 Methanol Water Separation (Continue)
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Part C:
Perform the same design calculation after specifying
a 60% Murphree efficiency for each tray. How do these efficiencies affect the condenser and
reboiler duties of the column?
Part D: Perform a tray sizing calculation for the entire column,
given that Bubble Cap trays are used.
What is column diameter required for this separation ? : _____________
Tutorial 5 Methanol Water Separation (Continue)