Adsorption characteristics of the charcoal-nitrogen system at 79–320 K and pressures to 5 MPa Original Research Article

Adsorption isotherms are obtained for the charcoal-nitrogen system in the temperature range 79–320 K and pressures to 5 MPa for two samples of activated charcoal. Correlations relating temperature dependence of adsorption potential are obtained using four methods of extrapolating pseudo-saturation state beyond the critical point. The values obtained are compared with literature data. Using the experimental results and the BET theory surface area and micropore volume are calculated. It is brought out that samples of activated charcoal need to be characterized prior to their use in the design of low temperature adsorption based cryorefigeration systems.