(338n) Charge and Discharge Cycles in a Prototype Storage Vessel for Adsorbed Natural Gas

Natural Gas (NG) composition plays a major role on the deactivation of an adsorbent bed used several times in storage processes. The successive cycles of charge and discharge of the storage vessel let gradually accumulate the heavier components of the gas, which can hardly desorb. This study intends to carry out experimental charge and discharge cycles of NG in a prototype storage vessel filled with activated carbon to investigate the effects of the composition on the adsorption capacity decrease. The adsorption properties were evaluated by measuring isotherms of each component through gravimetry. The relative selectivity of the several constituents of natural gas in relation to methane was also evaluated and the effect of pressure on this selectivity was also observed. The results allowed us to observe a loss of adsorption capacity on the NG storage vessel and a preferential adsorption for the heavier components and CO2, causing partial deactivation of the adsorbent over several charge and discharge cycles.