Dynamic optimization of adsorptive chillers: Compact layer vs. bed of loose grains

This paper addresses the dynamic study on methanol ad-/desorption in compact adsorbent layers, performed by a Volumetric Large Temperature Jump (V-LTJ) method, appropriate for dynamic examination of adsorptive chillers. The commercial active carbon ACM-35.4 was used as an adsorbent, and polyvinyl alcohol as a binder. The influence of the carbon grain size and the layer thickness on the V-LTJ dynamics was studied at a fixed binder content of 12 wt%. To single out the effect of consolidation, a detailed comparison was made with reference beds of the loose carbon grains, having the same configuration, however, containing no binder. The following findings are reported for the compact layers: (i) near-exponential shape of the dynamic curves of methanol adsorption; (ii) invariance of the dynamics with respect to the ratio (S/m) = <heat transfer surface>/<adsorbent mass> (iii) linear relationship between the maximal specific power and this ratio. For the compact layers, the process becomes faster by a factor of 1.5–3.5 as compared to the reference beds.