%0 Journal Article
%T Characterization of ZSM-5 modified with niobium pentoxide: the study of thiophene adsorption
%A Cavalcanti
%A Rodrigo M.
%A Barros
%A Ivoneide de C. L.
%A Dias
%A Jos¨¦ A.
%A Dias
%A S¨ªlvia C. L.
%J Journal of the Brazilian Chemical Society
%D 2013
%I Sociedade Brasileira de Qu¨ªmica, SBQ
%R 10.1590/S0103-50532013000100007
%X zsm-5 adsorbents impregnated with nb2o5 were applied in the sulfur removal in the form of thiophene, refractory substance of difficult removal of liquid fuels. for this purpose, a model fuel containing iso-octane contaminated with thiophene in concentrations of 877.5 to 1155 ppmw was prepared. the samples were characterized by x-ray diffractometry (xrd), fourier transform infrared (ftir) and fourier transform-raman (ft-raman) spectroscopies for confirmation of the adsorbents, being prioritized the adsorption study with that containing 5 wt.% of niobium pentoxide, because it showed a greater capacity for removal of thiophene. the best results of adsorption were achieved at 353 k, a longer time to reach equilibrium was observed. under these conditions, the best kinetic fitting was achieved using the equation of pseudo-second order, demonstrating the domain of the phenomenon of chemisorption. while under lower temperatures, the diffusion model presented a better approximation of the experimental results. also, the increasing of temperature did enhance spontaneous processes.
%K zsm-5 zeolite
%K niobium pentoxide
%K kinetics
%K adsorption
%K thiophene.
%U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S0103-50532013000100007&lng=en&nrm=iso&tlng=en