I have measured the CO2 and N2 sorption isotherm at two diff temp.(273 and 298 K). I want to calculate the selective uptake of CO2 over N2 by IAST (ideal adsorbed solution theory) method at the above given temperature.Please suggest, How to calculate selectivity by above said method?
A simple algorithm to solve the equations in IAST model is given in "Adsorption Equilibria and Kinetics" by D D Do. If you have the isotherm data and it fits well to a isotherm model say Langmuir, you can use this algorithm to get the IAST selectivity.
User-friendly Python code for IAST, pyIAST here!
https://github.com/CorySimon/pyIAST
@Adeela, so for, didn't get positive results. I am still making efforts, if I would get the solution, would let you know.
best
raeesh
Just to add something, in this article the IAST method is very well explained:
DOI: 10.1002/ceat.201100274
Dear Raeesh
Selectivity is a key parameter for the screening of adsorbents for use in a PSA process. More is the selectivity or separation factor (as it is better known in process industries), more will be the purity of the product at the PSA outlet. It is defined as:
S1/2 = (X1/X2) / (Y1/Y2) 'or'
SCO2/N2 = (XCO2/XN2) / (YCO2/YN2)
where, X = molar fraction in the adsorbed phase
Y = molar fraction in the gas (feed gas) phase
You can fit various models (like SIPS, TOTH, binary (as in your case) IAET etc.) onto your experimental data and choose the most promising (best fit) model as the base for the estimation of selectivity.
Further, Selectivity will be a function of T, P, adsorbent type, input gas feed.
Suggested reading: Article Adsorption performance indicators for the CO2/CH4 separation...
Hope this helps!
Dear Raeesh Muhammad , and Adeela Rehman
in case this post is still of interest, please check my manuscript Article Computing the temperature dependence of adsorption selectivi...
where i show how to employ the PyIAST code of Cory Simon at a full range of mole fractions for the components and also with a simple loop to expand these calculations at temperatures other than the experiments.
I hope it helps.
@Raeesh Muhammad, Can you please let me know what steps you used to calculate the selectivity of CO2 over N2? I have CO2 adsorption data at three different temperatures 273K, 283k and 298K, while N2 at 273K I want to calculate the CO2 selectivity over N2 by IAST but don't know the exact method and its detail. I would be really thankfull if you can give me some suggestions.
Cory Simon Sir Thank you for the link , it would be so kind of you if you can help me with word file/video to start with your software.
How to just start with your model data and then my data.
directory/ location for installing your software as well
I also want to know & learn about python, I downloaded their given files but it didn't work
Yes I know, if you want to know IAST selectivity calculations, first you need to fit your isotherms accoding to different models and then using formula
(e.g for CO2/N2 selectivity)
S = qCO2/qN2 x pN2/pCO2
"q" values you need to calculate from the the equations of non linear fitting models
as I already did that for CO2/N2 selectivity using dual site langmuir fit. You need to select that model for which you can get R value around 0.999, it means select that model which best fits your isotherms
Shumaila Ashraf
Its very easy
Use Newton Raphson approach to solve the the spreading pressure
For that you need to develop one Matlab program
First let me know that which method you used for pure gas calculation.
I solved it with Langmuir data
I didn't use python, just through dual site langmuir freundlich model
- Badges
- Science topic
- Similar topics
- Biological Science
- Bioecology
- Systems Ecology
- Landscape Ecology
- Connectivity