Purification of hydrogen from hydrocarbons by adsorption for vehicles application

Adsorption of toluene and methylcyclohexane on various adsorbents was investigated to develop a process for the purification of hydrogen from H2/hydrocarbons mixtures. The development of vehicles using hydrogen in a fuel cell requires the storage of this gas on board for instance as an hydrogenated aromatic hydrocarbon (toluene), hydrogen being recovered by catalytic dehydrogenation. This technique however implies a perfect separation of hydrogen and toluene. An experimental study leads to the choice of a suitable adsorbent: Porapak®-Q, which gives together a good adsorption capacity (up to 0.078 kgTol kgPQ−1) and good regeneration properties (93% desorption in a given time). A representative model, including the Drachsel model of the adsorption isotherm and the thermal effects, is developed and emphasizes the lack of kinetic limitation.