Theoretical Study of the Adsorption and Separation of Gases

Theoretical Study of the Adsorption and Separation of Gases in Metal-Organic Frameworks Silvina M. Gatica, Department of Physics and Astronomy, Howard University. We performed grand-canonical Monte Carlo simulations to study the adsorption properties of mixtures containing CH4 and CO2 in MOFs. We use a simple model of the MOFs that permit us change the interaction parameters and size in the simulation. • •

The selectivity of CO2 is enhanced by compressing the unit cell of the MOF by only 10% or by inserting dipoles at the corners of the MOF. The adsorpion properties are sensitive to the detailed charge distribution of the MOF, only if it contains dipolar components. CH4 - CO2, 10% compressed MOF

1600

CH4,300K

1400

CH4,140K

3000

CO2, 140K

1200

CH4 - CO2, 20% expanded MOF

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CH4, 300K CH4, 140K CO2 140K

CO2, 300K

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CO2, 300K

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200 0 1.E-04

1.E-03

1.E-02

1.E-01

1.E+00

P(atm)

1.E+01

1.E+02

0 1.E-04

1.E-03

1.E-02

1.E-01

1.E+00

1.E+01

1.E+02

P(atm)

Compared adsorption of CO2 and CH4 in a compressed (left panel) and expanded MOF (right panel). Large gaps between the isotherms indicate high selectivity for CO2