Diffusion of gases in porous solids: simulation and measurements. Eighth quarterly report, April 16, 1984-July 15, 1984

Technical Report · Sun Jan 01 04:00:00 EST 1984

OSTI ID:6765790

Evans, J W

This quarter experiments have been started to measure the viscosity and diffusivity of methane following a suggestion made by a review committee member at the PETC program review held in Washington in February. Viscosity data are presented. The data are seen to agree well with the predictions of the Chapman-Enskog theory. The experimental argon-nitrogen difusivity measurements carrid out over the past year have deviated somewhat from values predicted by the Chapman-Enskog theory. In an attempt to discover whether this represents an imperfection of the theory or the experiments, an error analysis has been carried out. The large possible errors were found to exist in the experimental data. The major source of error is the sensitivity of the diffusion bridge apparatus to pressure differential across the bridge. That pressure differential must be maintained at the lowest possible value during diffusion experiments in order that transport of gases through the porous plug be by diffusion (rather than viscous flow). Experiments are conducted at the limit of sensitivity of the differential pressure gauge (7.5x10/sup -5/ psi), and there is therefore little hope for improvement in this direction. The alternative is to use a porous plug with a smaller pore size. In the Monte-Carlo simulation of gas diffusion which makes up the theoretical phase of this investigation, the new algorithm described in previous quarterly reports is now being used to compute diffusivities for low porosity solids. 2 figures.

• Research Organization: California Univ., Berkeley (USA). Dept. of Materials Science and Mineral Engineering
• DOE Contract Number: FG22-82PC50796
• OSTI ID: 6765790
• Report Number(s): DOE/PC/50796-T6; ON: DE84016292
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
42 ENGINEERING
420400 -- Engineering-- Heat Transfer & Fluid Flow
ALKANES
ARGON
DATA
DIFFUSION
ELEMENTS
ERRORS
EXPERIMENTAL DATA
FLUIDS
GASES
HIGH TEMPERATURE
HYDROCARBONS
INFORMATION
LOW TEMPERATURE
MATERIALS
MEDIUM TEMPERATURE
METHANE
NITROGEN
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
PERMEABILITY
POROUS MATERIALS
RARE GASES
TEMPERATURE DEPENDENCE
VISCOSITY