Kinetics of Isothermal Ethanol Adsorption onto a Carbon Molecular Sieve under Conventional and Microwave Heating

The isothermal kinetics of ethanol adsorption from aqueous solution onto a zeolite type carbon molecular sieve (CMS‐3A) under conventional heating (CH) and microwave heating (MWH) was investigated. The adsorption kinetics is described by the model of a phase‐boundary controlled reaction for both heating modes. The activation energy (E_a) for the adsorption process under MWH is lower than under CH while the preexponential factor (lnA) is higher. Ethanol adsorption is a kinetically complex process whose complexity changes with the mode of heating. The established decrease in E_a and increase in lnA under MWH compared to CH is explained with the increase in the ground vibrational level of the – OH twisting vibrations in the ethanol molecule and with the decrease in its anharmonicity factor which is caused by the selective resonant transfer of energy from CMS‐3A to the OH oscillators.