Gas flow through highly porous graphite matrices

Highly porous graphite matrices with 20-200 kg m(-3) of bulk densities have been characterized using helium pycnometer, mercury porosimeter, and fluid flow methods, i.e. both gas permeation and diffusion measurements. The gas permeability is ranging from 10(-12) to 10(-15) m(2) and decreases as the bulk density of the graphite matrix increases. According to the Carman-Kozeny correlation, the evolution of the gas permeability with respect to the bulk density is very well correlate with, on the one hand, the increase of the tortuosity, and on the other hand, the decrease of the porosity as well as the pore diameter with the bulk density of the graphite matrix. (C) 2002 Elsevier Science Ltd. All rights reserved.