Selective water adsorption from aqueous ethanol containing vapours by phillipsite rich volcanic tuffs

The use of Neapolitan yellow tuff (NYT), a phillipsite/chabazite-containing volcaniclastic rock, rich in phillipsite, is proposed for an inexpensive dehydration process of ethanol vapours. NYT selective water adsorption kinetics was investigated both in a continuous microbalance apparatus and in laboratory-scale fixed-bed columns. The influence of operational parameters such as tuff grain dimensions, column temperature and pressure, volumetric flow-rate and partial pressure of adsorbates was studied. A preliminary study on the fluid dynamics of the column is also described. Finally, evidence is reported that a partial, but economical bed regeneration can be attained at the column working temperature by simply flushing the system with dry nitrogen.