Issue with mass balance and stream characterisation with Create new solid compound
Simulate chemical processes using advanced thermodynamic models
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I am simulating a bioethanol plant from eucalyptus as raw material.
I used the tool to create a new solid compound in DWSIM and export it as a JSON file.
I have three solid compounds with decimals or float numbers in their chemical formula.
When opening the JSON file as a text file, the chemical formula did not appear, so I edited it manually.
When setting up the simulation configuration, I called the JSON files to select them as compounds.
I started creating materials streams within the DWSIM simulation environment, and odds things happened.
I attached the simulation file.
1) The feed stream called "Eucalipto" has solids and liquids, the mass flows of the overall mixture are Ok, but the liquid phase does not match the mix.
2) The mass balance when using a conversion reactor is not working.
I also attached a JSON file of one of the solids, and a screenshot when putting the chemical formula.
Please give guidance on what might be wrong.
Also, when using the newest version of DWSIM, the computing time is very low and even does to compute.
I tried the old version 8.3.4 the computing time is faster.
Hi Daniela,
For the solid components you must check them in the Forced Solids tab on the property package settings. Also, it makes no sense to use NRTL on your simulation because you don't have the required interaction parameters, it is better to use Raoult's Law.
Not sure what changed from 8.3.4 to 8.3.5 that could slow down the calculations. Do you have the solution inspector enabled?
Regards
Daniel
Hi Daniel,
Many thanks for the reply!
The solids components were defined as Force Solids.
We are following another path that is working. I will post again here if we have more doubts.
Best, Daniela.
Dear Daniel,
My thesis student is trying to simulate in DWSIM a bioethanol plant from eucalyptus.
She is having issues with the convergence.
Let me explain the steps, she followed:
1) Creation of new components (organics):succinic acid, gluconic acid, cellobiose, diammonium phosphate, soluble lignin.
2) Creation of rapid solids: cellulose, xylan, lignin, cellulase, ash (calcium oxide), zymo (bacteria)
3) Import as JSON files the new componentes created
4) Select fluid packages: NRTL and Raoult. The created solids were forced as solids in the fluid packages settings.
5) Start simulation:
Her doubts are:
Is there a step I'm not doing or another way to set up the simulation so my streams converge better?
Is it possible that the data entered in the creation of the compounds is not enough, since there are problems with the phase equilibrium? (although I used the recommendations you made in the linkedin post and the software tools) link: https://www.linkedin.com/feed/update/urn:li:activity:7047203373594349568/
I also attached the simulation file for you to take a look.
Many thanks in advance, Daniela.
Hi Daniela,
This seems to be a difficult case for DWSIM as it involves a lot of solids. Please analyze the attached flowsheet and see if it is correct. As you pointed out, there are some mass balance errors but they seem to be specific to the default flash algorithm.
Regards
Daniel
Hi Daniel,
Sorry for my late response.
My student use your simulation as base to continue the whole process.
She finally achieved to simualte the entire process, except the distillation as DWSIM started to crushed.
So she created another simulation file.
All the best, Daniela.
Is there any way to save the simulation file as a json file?