title: Selective adsorption of thiophene and 1-benzothiophene on metal-ion-exchanged zeolites in organic medium.
abstract: Adsorption of the organic sulfur compounds thiophene (TP) and 1-benzothiophene (1-BTP) in an organic model solution of hydrodesulfurizated gasoline (heptane with 1 wt% toluene and 0.156 mM (5 ppmw as sulfur) TP or 1-BTP) was studied by a batch method at 80 degrees C using metal-ion-exchanged Y-zeolites. Although NaY-zeolite or its acid-treated material rarely adsorbed the organic sulfur compounds, NaY-zeolites exchanged with Ag+, Cu2+, and Ce3+ ions and NH(4)Y-zeolites exchanged with Ce3+ ions showed markedly high adsorptive capacities for TP and 1-BTP. The sulfur uptake increased in the order CuY-zeolite(Na)<AgY-zeolite(Na)<CeY-zeolite(Na) for both the organic sulfur compounds. The adsorption isotherms for TP and 1-BTP followed the Langmuir's relationship and the saturation capacities by CeY-zeolite(Na) were calculated as 0.022 and 0.033 mmol/g, respectively. The mole ratios of TP/Ce and 1-BTP/Ce were 0.031 and 0.047, respectively. CeY-zeolite(NH4) which was prepared from NH4Y-zeolite showed less uptake of TP and 1-BTP than CeY-zeolite(Na), probably due to its lower cerium content.
authors.affiliation: Research Institute for Environmental Management Technology, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi, Takamatsu, 761-0395, Japan.
authors.forename: Mei
authors.initials: M
authors.lastname: Xue
authors.forename: Ramesh
authors.initials: R
authors.lastname: Chitrakar
authors.forename: Kohji
authors.initials: K
authors.lastname: Sakane
authors.forename: Takahiro
authors.initials: T
authors.lastname: Hirotsu
authors.forename: Kenta
authors.initials: K
authors.lastname: Ooi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Yoshimura
authors.forename: Qi
authors.initials: Q
authors.lastname: Feng
authors.forename: Naoto
authors.initials: N
authors.lastname: Sumida