Propylene, MeOH, Water distillation
Propylene, MeOH, Water distillation
(OP)
Dear experts.
I'm studying chemical process design from biomass as a student.
I'm planning to design a distillation column that recycles propylene with 99.9% purity at a flow rate of 54,256 kg-mol/hr at the rectification section, where propylene+MeOH+Water enters as a feed.
We have to get propylene as a top product, MeOH and Water as a bottom product.
The reaction in the propylene reactor part before the distillation consists of the following steps 1 and 2.
* Reactions in Propylene Reactor:
1. 2MeOH -> Ethylene +2H2O(Conversion ratio of MeOH is 60%)
2. MeOH + Ethylene -> Propylene +H2O (Conversion ratio of Ethylene is 100%)
- operating condition : 450 degC , 2kg/cm2g
But I don't know how can I access for this distillation
Does anyone advice me how to solve the problem.
Thanks in advanced.
I'm studying chemical process design from biomass as a student.
I'm planning to design a distillation column that recycles propylene with 99.9% purity at a flow rate of 54,256 kg-mol/hr at the rectification section, where propylene+MeOH+Water enters as a feed.
We have to get propylene as a top product, MeOH and Water as a bottom product.
The reaction in the propylene reactor part before the distillation consists of the following steps 1 and 2.
* Reactions in Propylene Reactor:
1. 2MeOH -> Ethylene +2H2O(Conversion ratio of MeOH is 60%)
2. MeOH + Ethylene -> Propylene +H2O (Conversion ratio of Ethylene is 100%)
- operating condition : 450 degC , 2kg/cm2g
But I don't know how can I access for this distillation
Does anyone advice me how to solve the problem.
Thanks in advanced.





RE: Propylene, MeOH, Water distillation
Good luck,
Latexman
To a ChE, the glass is always full - 1/2 air and 1/2 water.
RE: Propylene, MeOH, Water distillation
I'm sorry I didn't know that policy.
I'm not really a college student. I am a new employee who is studying in the same way such as a student.
And I don't get your sentence. "the glass is always full - 1/2 air and 1/2 water."
Could you give me more advice, please?
RE: Propylene, MeOH, Water distillation
Is the glass half empty or half full?
Good luck,
Latexman
To a ChE, the glass is always full - 1/2 air and 1/2 water.
RE: Propylene, MeOH, Water distillation
RE: Propylene, MeOH, Water distillation
RE: Propylene, MeOH, Water distillation
Please I'm waiting for any advices
RE: Propylene, MeOH, Water distillation
Good luck,
Latexman
To a ChE, the glass is always full - 1/2 air and 1/2 water.
RE: Propylene, MeOH, Water distillation
RE: Propylene, MeOH, Water distillation
At first, I used a shortcut column for decision num tray of a distillation.
Component : propylene/ methanol/ water
Thermo : NRTL01
Feed : Total fluid flowrate : 220 kg-mol/hr
Composition Mole : propylene : 25 , methanol : 15, h2o : 60
Temperature : 311 K
Pressure : 1.5 kg/cm2
Shortcut: Condenser : subcooled, Fixed Temperature : 318 K
Spec : Propylene from top 99.9%
Water from bottom 99%
First, when I simulated this model , the result said " ** WARNING ** UNIT 1, 'SCD1' - MINIMUM REFLUX calculations FAILED to
converge. Incorrect specification of the KEY components MAY be
a possible cause."
Second, there are no values of 'total trays, feed tray, R/R-MIN' in the text result.
I can't solve this problems.
Thank you.
RE: Propylene, MeOH, Water distillation
as first step you should select the models, there are many sources of VLE data including propylene-methanol-water , you may also find many papers, see for example
http://www.hgxb.com.cn/EN/abstract/abstract8140.sh...
for similar mixtures and conditions I have used Peng-Robinson-NRTL with Huron Vidal or LCVM mixing rules, also CPA (or other models with association contribute) could be an option but slow,
for simulating the column I would manually vary the number of trays to find an optimal solution, I can do that automatically in Excel with Prode (a simple heuristic optimization),
I do not know if you have a similar option is PROII (some expert can add comments)