TY - JOUR
T1 - Relating gas dispersion in porous media to medium tortuosity and anisotropy ratio
AU - Pugliese, Lorenzo
AU - Poulsen, Tjalfe G.
AU - Andreasen, Rune R.
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012/9
Y1 - 2012/9
N2 - Gas dispersion in a set of three different porous materials with similar particle size, as a function of material tortuosity and anisotropy ratio, was investigated. The materials were packed with different spatial orientations of the individual particles so as to create media with different tortuosity and anisotropy ratios. Three different media (slate chips, wood chips, and pebbles) and four particle orientations have been used to generate a total of nine different porous media mimicking single porosity, dual porosity isotropic, anisotropic, aggregated, or granular materials. Resulting values of tortuosity and anisotropy ratio for each medium were determined via measurements of gas permeability and molecular gas diffusion coefficient. These values were then compared to measured values of gas dispersivity for each medium. The results showed that dispersivity is inversely proportional to tortuosity but directly proportional to anisotropy ratio and that the relations were approximately linear within the range of tortuosities and anisotropy ratios investigated. Wood chips (dual porosity material) yielded higher values of gas dispersivity compared to slate chips (single porosity material). A likely reason is in part the difference in pore structure between the materials and in part a difference in particle surface roughness (which was highest for wood chips) both of which affects dispersion.
AB - Gas dispersion in a set of three different porous materials with similar particle size, as a function of material tortuosity and anisotropy ratio, was investigated. The materials were packed with different spatial orientations of the individual particles so as to create media with different tortuosity and anisotropy ratios. Three different media (slate chips, wood chips, and pebbles) and four particle orientations have been used to generate a total of nine different porous media mimicking single porosity, dual porosity isotropic, anisotropic, aggregated, or granular materials. Resulting values of tortuosity and anisotropy ratio for each medium were determined via measurements of gas permeability and molecular gas diffusion coefficient. These values were then compared to measured values of gas dispersivity for each medium. The results showed that dispersivity is inversely proportional to tortuosity but directly proportional to anisotropy ratio and that the relations were approximately linear within the range of tortuosities and anisotropy ratios investigated. Wood chips (dual porosity material) yielded higher values of gas dispersivity compared to slate chips (single porosity material). A likely reason is in part the difference in pore structure between the materials and in part a difference in particle surface roughness (which was highest for wood chips) both of which affects dispersion.
KW - Anisotropy ratio
KW - Gas permeability
KW - Mechanical dispersion
KW - Particle orientation
KW - Particle shape
KW - Porous medium tortuosity
UR - http://www.scopus.com/inward/record.url?scp=84865447016&partnerID=8YFLogxK
U2 - 10.1007/s11270-012-1176-7
DO - 10.1007/s11270-012-1176-7
M3 - Journal article
AN - SCOPUS:84865447016
SN - 0049-6979
VL - 223
SP - 4101
EP - 4118
JO - Water, Air, and Soil Pollution
JF - Water, Air, and Soil Pollution
IS - 7
ER -