Adsorption/Desorption of Tetrahydrothiophene from Natural Gas onto Granular and Fiber-Cloth Activated Carbon for Fuel Cell Applications

Natural gas with a high methane concentration is an important source of primary fuel for fuel cells, although it contains sulfur compounds, such as tetrahydrothiophene (THT), known as a poison for the fuel cell catalyst parts. Desulfurization of natural gas fuel in ambient conditions is thus essential before it enters the reforming process. Adsorptive removal of THT from natural gas was tested on three different activated carbon materials: two granular materials (GAC) and one fiber-cloth material (ACFC). The adsorption isotherms, fitted by nonlinear regression procedures, of the THT onto the materials showed the promising adsorptive capacity of the ACFC compared to the GAQ validated by adsorption kinetics in favor of ACFC. The continuous adsorption of THT from the natural gas pipe determined the adsorption capacity of the ACFC (100 mg g(-1)). Thermal regeneration investigations were carried out on the ACFC to confirm the adsorption/desorption capacity and process feasibility of the material. ne formation of thiophene and elemental sulfur was noted as catalytic products of the oxidative reaction of THT during the thermal desorption from the activated carbon material. The Joule-effect heating used as an electro-regeneration process for the ACFC offers a great choice in terms of the desorption operating procedure and highlights the potential of this material for the desulfurization of natural gas for fuel cell applications.