(460f) Selective Adsorption From Liquid Fuels by Silver Loaded Adsorbents

The fuel cell systems such as PEMFC require “zero-sulfur” fuels with ultra-low sulfur contents. Deep desulfurization is applied in order to get ultra low sulfur level. Adsorption desulfurization (ADS) is one of the simplest technologies to remove the sulfur aromatics from the transportation liquid fuels under ambient temperature and pressure. Silver has shown the highest sulfur capacity and regenerability in adsorptive sulfur removal among those transition metals used for ADS. And the sulfur capacity and adsorption rate can be affected by the surface area and pore volume of the adsorbents according to our research. Activated carbon (AC) with high surface area and large pore volume has been demonstrated high sulfur adsorption rate and high sulfur capacity according to many literatures. In this work, high surface area activated carbon was applied as the support in order to get high silver dispersion which was measured by O2 chemisorption. The surface characteristics of this new silver loaded activated carbon were investigated by X-ray Diffraction (XRD), SEM and X-ray Photoelectron Spectroscopy (XPS). The performance of the high surface area activated carbon and silver loaded adsorbents were analyzed by using model fuels with different Ag loading weight. Then the performance of this activated carbon supported silver adsorbent was compared with Ag/TiO2. By analyzing those samples, the activated carbon can provide significant high surface area support which can increase the dispersion of silver on the support. And the oxygen functional groups on the AC surface play an important role in ADS. However, the aromatic hydrocarbons will inhibit the desulfurization effect of AC by the electron interaction. The Ag loaded activated carbon adsorbents were designed to enhance sulfur adsorption and selectivity in terms of acid-base interaction. Also not so much research has been carried out on regeneration of activated carbon and this silver adsorbent. Thus, the thermal regeneration of this adsorbent under a relative low temperature needs further investigated.