CHEMCAD Distillation

David WegleinSavannah Green

Heather CookMichael Wellen

Recently used files

Tabs to access other things

Data tree from simulation

Access VBA programming

Errors and warnings, run trace, and notes

Palette

Workspace

Checklist

What if…• You have a Japanese client working in Yen, who liked everything about the metric scale

except length measurements, thinks the Rankine scale is underrated, and likes his vapor density in lb/ft3

• No problem!

Checklist

Choosing a Thermodynamic Model

Recommendations

Gas Phase Only

Ideal Solution

Non-ideal Solution

Checking Equilibrium Data

CHEMCAD Distillation Columns

• 4 types of columns, differ in:– What algorithm they use– What information load they can handle– What parameters you can find from simulation

#1 – Shortcut Column• Uses Fenske-Underwood

method• One feed, bottoms and

distillate• Typically used as a way to

get rough estimates– Reboiler/condenser duties,

number of theoretical stages, optimum feed location, fractional recoveries.

• Industrial users will (should) not use this one

#2 - SCDS• Simultaneous Correction Distillation

System– Uses a “simultaneous correction”

algorithm• Can do reactive distillation, mass

transfer distillation (packing)• Stable with non-ideal

thermodynamics• Handles a large number of stages• Multiple feeds, side stream possible• In addition to what the SHOR

column can do, can also do mass transfer and tray efficiency

• Commonly used

#3 - Tower• “Inside-out algorithm”• Used for large number of

components, small number of stages

• Can do dynamic (non-steady-state) simulations

• No efficiencies, mass transfer, or reactive distillation

• Used more for hydrocarbons

#4 – Tower+

• Used for crude oil• Complex columns

Recommendations

Demo