The Dependency of Diffusion Coefficients and Geometric Factor on the Size of the Diffusing Molecule: Observations for Different Clay-Based Materials

Table 9

Predicting the gas effective diffusion coefficients of sample K4 after measuring the Ne and C₂H₆ (both in italic) effective diffusion coefficients. In a first phase, the prediction is based only on expression (14). Subsequently, this prediction is improved by multiplication with a “correction factor” (see Table 8), which takes into account the gas specific deviation between the experimental and the predicted value.

		He	Ne	H2	Ar	CH4	Xe	C2H6
Kinetic diameter	( m)	2.58	2.79	2.97	3.42	3.82	4.06	4.42
(experiment)	( m^2/s)	74.7	22.9	51.2	14.5	15.5	6.6	5.9
(prediction)	m^2/s)	27.2	22.9	19.7	13.6	9.7	8.0	5.9
Ratio (exp)/ (pred)	( )	2.7	1.0	2.6	1.1	1.6	0.8	1.0
Correction factor	( )	1.7	0.8	2.1	0.9	1.3	1.0	1.0
(pred) Corr factor	( m^2/s)	45.8		41.2	12.2	12.4	7.7
Ratio (exp)/( (pred) Corr factor)	( )	1.6		1.2	1.2	1.2	0.9