Using experimental data, I am currently trying to verify the thermodynamic model I chose for my CO2 capture flowsheet. I am currently trying to compare how the model fits the data of Jou et al ( see attached files ) to confirm that the model I chose is correct for my simulation.
I have set up the MEA 30%wt (aq), stream, and the CO2 stream and I mix those two and then feed it to a flash. Then I insert the pressure from the experimental data and the CO2 loading value to the streams and flash conditions, run the sim, and go to the distillate and find the CO2 partial pressure by dividing the moles of CO2 in the dist with total moles and multiplying by the total pressure value. This seemed to be going smoothly until I reached the data point with a 210kPa pressure, 36,1 Pco2, and a 0.609 CO2 loading value.
(the data set I am working on is in Table 2, for a 40C temperature). When I inserted the pressure values and the feed flow of CO2 to achieve the given loading value ( more on that later ) and ran the simulation, there was no flow in the distillate stream. I suspect because the gas phase is too little because of the low loading value and completely dissolved in the liquid. (?) But this doesn't seem right since Aspen Plus has a template (also attached) that uses the same thermodynamic model (almost) as I do but has managed to provide a really good correlation between the model and the experimental data through the whole range of CO2 loading values (0-1,2).
So, if anyone has made such graphs using Aspen, please let me know how you did it and if you have found a more efficient way of doing so, maybe using a regression tool or something because as you might have understood, the process stated above is pretty time-consuming.
Aspen Version is V12.
I also attached the Excel and Aspen files.
I did not l;ook on your files, but as a general procedure you need to use the data regression option in Aspen Plus. Just you have to fit the interaction parameters of your thermodynamic model to the experimental data, and then use into your distillation column or what ever is your absorption unit.
Petar Petrov thanks for yor time.
I am having trouble with the input I have to insert in Aspen data and regression. i used the userx data type to input the fractions of MEA, H2O and CO2 (might not be 100% correct since I want to evaluate the partial pressure) and the partial pressure of CO2 from the experimental data.
But while trying to use the resgression tool there is not a parameter that can calculate the partial pressure. I tried inserting one in the property sets with the PPMX property but in didn't seem to make any difference. In both resgression and evaluation mode it's the same.
Is it not possible to reformulate your experimental data to a form what is convinient to Aspen?
I am not sure if this is possible since no property in the regression parameters menu can describe the partial pressure of CO2 or any pressure in general (as far as I am concerned). This is the parameter that needs to be calculated/regressed by the model and compared to the experimental data. The experimental data includes the Pco2 and CO2 loading values (mol CO2/mol MEA in a 30%wt MEA-H2O solution at 40 degrees C ).
You can create a CO2 partial pressure to CO2 loading of a diagram using Aspen plus software first you have to improving and putting some important predictions on a rate-based accuracy model based on carbon-capture process by maximizing he frame work of commercial development.
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