Electrothermal Desorption Using Joule Effect on an Activated Carbon Monolith

A new adsorbing material, an activated carbon monolith, was used for the adsorption of toluene vapors and their desorption by electrothermal heating using Joule effect. The monolith appears under shape of a parallelepiped of square section including four hundred parallel channels. Equilibrium isotherms for toluene on a piece of this material at various temperatures were measured by the gravimetric method. The adsorption breakthrough fronts measured on the monolith show that it is effective for cleaning the gas. Desorption was performed by heating of the monolith by means of a continuous electric current flowing transversely to the channels. The curves of desorption show that the toluene is desorbed with a high factor of concentration. Desorption rate can be controlled by regulating electrical current and purge gas flow rate. An equilibrium model shows that the tail of the desorption curve is mainly due to the curvature of the isotherm.