ADSORPTION RATE COEFFICIENTS FOR GASES AND VAPORS ON ACTIVATED CARBONS

In order to estimate carbon bed breakthrough time (service life) for a given gas or vapor which is removed from flowing air by physical adsorption, both the adsorption capacity and adsorption rate need to be known. These parameters are available for only a small number of compounds at limited sets of conditions. For 27 hydrocarbons and fluorocarbons, 165 breakthrough curves were measured and analyzed to obtain adsorption rate coefficients. Reciprocals of rate coefficients at 1 and 10% of challenge breakthrough were linear functions of reciprocals of molar polarizations. Another database of breakthrough curves for 121 compounds determined at the Lawrence Livermore National Laboratory in the 1970s was also analyzed. Effects of linear flow velocity on adsorption rate coefficients were determined. Combining these two databases of 679 breakthrough curves for 147 compounds gave correlations of reciprocal adsorption rate coefficients as functions of molar polarization, linear airflow velocity, and breakthrough fraction. Only data for dry conditions and 2-cm deep beds have been considered so far.