I fitted breakthrough curves of a gas mixture of 78% H2, 20% CO2 and 2% CH4 on the LDF model for an activated carbon adsorption bed. As usual, CH4 MTC (overall mass transfer coefficient) is much (ten times) greater than that of CO2. How can I justify these values?
Carbon in CH4 is partially negative while in CO2 is partially positive, and because activated carbon has potentially hybridized electron deficient orbitals, they interact with C of the CH4 stronger.
Dear Dr. Aiman Eid Al-Rawajfeh
Thank you for your answer.
This explanation raises other questions: if AC interactions are stronger with CH4, why AC adsorbs more CO2 than CH4 in an equal partial pressure?
and why the CO2 enthalpy of adsorption is greater than that of CH4?
Can you send the whole image of the results you have. The thermodynamics results should be explained afetr looking at all values, enthalpy, entropy and Gibbs free energy
Dear javad,
Actually, overall mass transfer consist of 3 terms and different parameters such as pore size and molecular diffusion and etc affected on mtc
Dear Aiman,
Attached is a file containing equilibrium isotherms and break-through curves along with heat of adsorptions and resistance values (film resistance, macro pore resistance and micro pore resistance from LDF model).
Dear Hossein,
You are absolutely right. These coefficients were estimated and you can find them in attachment. As you will see, pore size effect (macro pore resistance) and molecular diffusion effect (macro pore and film resistance) are insignificant compared to micro pore resistance. The main question is why CO2 resistance is much greater than that of CH4?
nachdem es eine Vielzahl von Versuchen gibt es die Möglichkeit Parameterstudien durch Einbeziehung der wichtigsten Größen deren technologiische Bedeutung zu analysieren.Das ist harte Grundlagenforschung.
I have a related question, forgive the intrusion, but it appears there may be someone here who knows the answer to a question I posted elsewhere.
https://www.researchgate.net/post/If_I_placed_granular_activated_charcoal_GAC_in_a_container_and_purged_it_with_CO2_gas_would_the_CO2_displace_oxygen_that_was_adsorbed_on_the_GAC
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