An Experimental Investigation of the Refrigerant Adsorption Performance of Carbon Nanotube-Activated Carbon Mixtures

The research reported here presents the results of an experimental investigation of the adsorption performance of different combinations of activated carbon and multi-walled carbon nanotubes mixtures (7.5–25%), as an adsorbent material for refrigerant R-134a, with the application potential in vapor adsorption refrigeration systems. The specific adsorbance was found to increase with the addition of carbon nanotubes to activated carbon. The experimental data were used to calculate the isosteric heat of adsorption using the Clausius–Clapeyron equation, and study its variation with the specific adsorbance for the mixture with the highest percentage of carbon nanotubes, and compare the results with that for activated carbon. The increase in the specific adsorption capacity upon addition of carbon nanotubes was interpreted as due to an increase in the pore volume, which in turn increases the specific surface area of the adsorbent material.