Overview of Methanol Model We will start with Start.hsc and use it to do equipment design and cost estimation
Dec 13, 2015
Overview of Methanol Model
We will start with Start.hsc and use it to do equipment design and cost estimation
Start.hsc 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 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
ReactionSection
SeparationSection
RecycleSectionCO2
*
Syngas
Recycle
Purge
MeOH
Water
Lights
Heavies
* 126.667 kmol/hr
Reaction Section Reactor: Like a S&T heat
exchanger 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 Syngas, water gas, methanol
values are in Start.hsc For the impurities use:
Ethanol: 1E24, 2E5 Acetone: 1E28, 2E5 Fusel Oil: 1E25, 2E5
Plug Flow Reactor Design 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 Guess at T,P,Conc. of recycle stream Optimize four parameters
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 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 At what temperature and pressure
should the flasher operate? Why?
Distillation Train Purpose
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
From RecycleSection
Water for Reuse
Dry Organics toLights Column
V
L
Step 2: Lights Column
Dry Organics
Alcohols
Residual Gases and Acetone
Step 3: Product Column
Alcohols
Methanol Product
Ethanol & Fusel Oil
Report for Modeling Assignment
In your group folder set up folder “Model”
Put in it by 2:15 Wed Oct 15: HYSYS model - .hsc file Summary of our progress with the
task Anything else you want me to
consider
Summary of Progress An engineer from our client is
coming to review our progress Our supervisor has asked us to
prepare a summary of: What we have accomplished What we learned in working out the
design Any issues of concern that have arisen
Summary continued 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