Adsorptive desulfurization of petroleum fractions in ZSM-35 modified with molybdenum.
desulfurization, adsorption, ZSM-35, molybdenum.
The search for cleaner technologies for the removal of sulfur compounds in fuels is a
constant since that the commercial process of desulphurization currently used is
characterized by the high consumption of hydrogen and severe operating conditions
of temperature and pressure. In this work the use of zeolite ZSM-35 modified with
molybdenum in different concentrations (2.5% to 10%) applied in an adsorptive
desulphurization process at low temperatures and pressure was evaluated.
The materials were prepared by wet impregnation and characterized by X-ray diffraction,
scanning electron microscopy, thermal analysis and nitrogen adsorption.
The adsorptive desulphurization was conducted in a batch system at temperatures
ranging from 303 K to 323 K under agitation speed of 140 rpm using a synthetic
gasoline containing heptane and thiophene. The sulfur contained in the samples
was quantified according to ASTM D5443. The kinetics of adsorption was evaluated
by the kinetic models of pseudo-first order, pseudo-second order, intraparticle diffusion
and Elovich. The results showed that the adsorption capacity of the materials and
the desulphurization yield were influenced by the temperature and the molybdenum
concentration in the zeolitic structure, and the best process efficiency was obtained
at a temperature of 313 K using ZSM-35 with 5% molybdenum.