Diffusivity measurements of methane and hydrogen in wet compacted clay

An experimental determination of the diffusivities of methane and hydrogen through a barrier of compacted clay at a temperature of 50 deg C has been made. The methance molecule is somewhat larger than oxygen, while hydrogen is smaller. Methane and hydrogen were used instead of oxygen in the experiments to circumvent the experimental difficulties in measuring oxygen. The measured diffusivity of methane in compacted clay was 3.9.10-11 m2/s and the diffusivity of hydrogen in compacted clay 1.8.10-11 m2/s. The clay was compacted to a density of 2.1 g/cm3 on an air dry basis