EXAMINATIONS TO THE ADSORPTION OF HALOGEN ATED HYDROCARBONS .3. DETERMINATION OF THE ZERO ADSORPTION HEAT Q(0) ON ACTIVATED CARBON USING GAS-CHROMATOGRAPHY

Using the technique of gaschromatography the zero adsorption heats Q(0 ) were determined on activated carbon for 11 halogenated hydrocarbons (FCC's and perfluorinated n-paraffins) and the corresponding n-alkanes with the same number of C-atoms. The total substitution of H- by F-at oms in the n-paraffins results in an increase of the Q(0) values as we ll as a consecutive substitution of F- by Cl-atoms in CF4. Large diffe rences were found comparing the zero heats of adsorption of the adsorp tives investigated on activated carbon with Q(0) data measured on a DY zeolite. The carbon adsorbent exhibits zero adsorption heats which ar e up to 100% higher than those of the DY zeolite. Simple equations are presented for the dependence of the Q(0) values on physico chemical c onstants of the adsorptives.