INVESTIGADORES
SEDRAN Ulises Anselmo
congresos y reuniones científicas
Título:
ASSESSMENT OF HYDROCARBON ADSORPTION CONSTANTS UNDER REACTION CONDITIONS
Autor/es:
ADOLFO ÁVILA; CLAUDIA M. BIDABEHERE; ULISES SEDRAN
Lugar:
Río de Janeiro, Brasil
Reunión:
Congreso; EMPROMER, 4th Mercosur Congress on Process Systems Engineering, 2nd Mercosur Congress on Chemical Engineering; 2005
Institución organizadora:
Universidad Federal de Río de Janeiro
Resumen:
The assessment of adsorption parameters in heterogeneous catalytic systems under realistic conditions
is subjected to serious limitations due to the simultaneous existence of diffusion and reaction. The knowledge of
these parameters is particularly important for design and simulation purposes in some processes like, for
example, the stripping step in the catalytic cracking of hydrocarbons. The fluidized bed, stirred batch laboratory
reactor called Riser Simulator is an useful tool for experiments where injections of pure compounds or mixtures
are contacted with the catalyst for a short time, pressure evolutions are recorded, and system compositions are
determined by GC analysis. Experiments were performed with pure hexane, decane and toluene, using different
reactant concentrations on an equilibrium commercial catalytic cracking catalyst at temperatures between 250
and 350 ºC. The constants were assessed by calculating the masses of hydrocarbons that are adsorbed on the
catalyst and that are present in the gas phase at equilibrium with the catalyst. Results showed that the order of
adsorption was decane > toluene > hexane. At the highest temperature (350 ºC), some conversion was observed
in the case of decane. Results were consistent, and they were explained based on a heterogeneous model that
shows that apparent adsorption constants depend not only on well known parameters such as temperature, but
also on the ratio between solid and gas volumes and the contact time. Also a link was established with a previous
model of diffusive transport in zeolite solids.