Author Topic: Enthalpy of adsorption for binary mixture  (Read 1426 times)


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Enthalpy of adsorption for binary mixture
« on: January 26, 2022, 01:56:40 PM »
Hello RASPA community,

I wonder if enthalpy of adsorption of individual components in a binary mixture can be reliably computed using the fluctuation formula?

I am simulating a system for competitive adsorption of CH4 and N2 in NaY zeolites using the GCMC technique. Although RASPA can calculate "total enthalpy of adsorption" correctly, it returns "-nan" values for enthalpy of adsorption of each component in the mixture (i.e. CH4 and N2).

I wonder if anyone has a clue why this is the case? Is this a RASPA problem or the fluctuation formula cannot be used for this purpose?

Many thanks in advance.

David Dubbeldam

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Re: Enthalpy of adsorption for binary mixture
« Reply #1 on: March 14, 2022, 07:13:39 PM »
The fluctuation formula has to be used in the grand-conical ensemble, i.e. the molecules must fluctuate.
Numerical problems might also occur at high loadings where the lack of accepted insertions/deletions can become a problem.