Abstract
In this paper, the adsorption rate of ethanol on activated carbon fiber (ACF) of type (A-20) has been measured using a thenno-gravimetric analyzer (TGA) unit over a wide range of adsorption temperatures, typically from 27 to 60 degrees C, which is useful for adsorption chillers design. The mass uptake is measured accurately with a time interval of 0.5 second from which the diffusion time constant and consequently, the overall mass transfer coefficient could be evaluated. A novel concentration profile, w(rt)=a(0)+a(1)r(2+k), with an exponent parameter k, has been proposed in the theoretical model which accounts for the effect of meso- and micro-pore structures within the ACE The proposed concentration profile removes the restrictions between the overall mass transfer coefficient and the diffusion time constant. Using the measured kinetics, the numerical value of k is evaluated, leading to a new form of linear driving force (LDF) model for cylindrical adsorbent that could capture the higher ethanol uptake in ACF and this LDF model has been validated experimentally.