Adsorption isotherms and kinetics of HFC-404A onto bituminous based granular activated carbon for storage and cooling applications

• Experimental adsorption isotherms of GAC/HFC-404A have been investigated.
• D–A and Tóth models have been fitted with the experimental adsorption isotherms.
• Isosteric heat of adsorption has been presented.
• Adsorption kinetics have been investigated experimentally and theoretically.

Adsorption characteristics of granular activated carbon/HFC-404A has been investigated in terms of adsorption isotherms and kinetics. AquaSorb 2000 which is bituminous based carbon has been used as an adsorbent. Experimentally and theoretical investigations have been conducted within temperature range of 25–75 °C. Experimental results have been fitted with Dubinin–Astakhov (D–A) and Tóth equations for the isotherms and linear driving force and Fickian diffusion models for the kinetics. It has been reported that maximum adsorption capacity is about 0.52 kg/kg. Activation energy and the pre-exponential coefficient were estimated to be 10488.49 J/mol and 1.11 respectively. Isosteric heat of adsorption as a function of relative adsorption capacity with non-ideal consideration has been also estimated using Clausius–Clapeyron equation and is found to vary from 145 to 330 kJ/kg. Pressure–temperature–concentration diagram of the adsorption pair has been also presented.