00(Creating theInitial Model)

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Transcript 00(Creating theInitial Model)

Overview of Methanol Model
We will start with Start.hsc and
use it to do equipment design and
cost estimation
Start.hsc
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This is a simplified model to represent
the SynGas process
The units you see are not intended to
represent the actual pieces of
equipment in the plant
It’s purpose is to do the heat and mass
balances necessary to create a feed
stream for the methanol plant
Idea from Last Year
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Heat removal in methanol reactors was
a big problem
Both CO=>CO2 and methanol reactions
are exothermic
Reduce heat load in methanol section
by converting as much of the CO as
possible in the syngas section and then
cooling the stream
Feed and Syngas Reactor
Water Gas Shift Reactors
Structure of Methanol Process
Recycle
CO2*
Reaction
Section
Syngas
* 126.667 kmol/hr
Purge
Recycle
Section
Water
Separation
Section
Lights
MeOH
Heavies
Reaction Section
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Reactor: Like a S&T heat exchanger
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Multi tubed
Packed with catalyst
Cooled with water in shell
Uses HYSYS Plug Flow Reactor Unit
Feed and coolant temperature are
important
Defining Reactions
Check Rxn Phase & Rate Units
Kinetic Constants
Kinetic Constants
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Syngas, water gas, methanol values are
in Start.hsc
For the impurities use:
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Ethanol: 1E24, 2E5
Acetone: 1E28, 2E5
Fusel Oil: 1E25, 2E5
Plug Flow Reactor Design
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Read Process in Basic Data very
carefully before you strat work on the
reactor
It contains much vital information on
techniques and selection of parameters
HYSYS Plug Flow Reactor Unit
Develop Reactor Design
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Guess at T,P,Conc. of recycle stream
Optimize four parameters
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T of feed and coolant (max MeOH)
Flow of coolant (max MeOH)
Number of tubes (95% to equilibrium)
Compare actual recycle rate with
assumed value
If difference > 1%, start again
Close the Loop
Recycle Section
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Cool reactor product to condense
methanol and water
Collect liquid and send to Separation
Purge some vapour to prevent buildup
of light components
Compress the rest of the vapour and
send it back to the reactor
Questions to Think About
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At what temperature and pressure
should the flasher operate?
Why?
Distillation Train
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Purpose
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Purify product
Recover light gases and heavy impurities
for fuel
Recover water for reuse
See my feedback for the Initial Review
for suggestions on the designs
Step 1: Water Column
V
From Recycle
Section
Dry Organics to
Lights Column
L
Water for Reuse
Step 2: Lights Column
Residual Gases
and Acetone
Dry Organics
Alcohols
Step 3: Product Column
Methanol Product
Alcohols
Ethanol & Fusel Oil
Report for Modeling Assignment
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In your group folder set up folder
“Model”
Put in it by 2:15 Wed Oct 15:
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HYSYS model - .hsc file
Summary of our progress with the task
Anything else you want me to consider
Summary of Progress
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An engineer from our client is coming to
review our progress
Our supervisor has asked us to prepare
a summary of:
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What we have accomplished
What we learned in working out the design
Any issues of concern that have arisen
Summary continued
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Our visitor has 15 minutes to read and
digest the report before discussing it
with us
Both the analysis assignment (mass
balance and catalyst characterization)
and the building of the model should be
covered
This probably means 3 to 6 pages