Kinetic study of the selective catalytic hydrogenation of 1,3-butadiene in a mixture of n-butenes

ALVES, JAVIER A.; BRESSA, SERGIO P.; MARTÍNEZ, OSVALDO MIGUEL; BARRETO, GUILLERMO FERNANDO

JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY

KOREAN SOC INDUSTRIAL ENGINEERING CHEMISTRY

Lugar: Seoul; Año: 2012 vol. 18 p. 1353 - 1365

1226-086X

The selective hydrogenation in liquid phase of 1,3-butadiene in the presence of n-butenes, over a commercial Pd/Al2O3 catalyst of the egg-shell type was studied. Experiments were carried out in a batch reactor at 44 C. Initial concentration were in the range of 1% to 2% of 1,3-butadiene, up to 10% of 1-butene, trans 2-butene and cis 2-butene. Partial hydrogen pressures (pH2) were between 1 and 8 atm.The results demonstrate the presence of severe diffusional limitations inside the catalyst. Therefore, the conservation equations inside the catalyst pellet must be solved to estimate the intrinsic values of the kinetic parameters. Two kinetic models were proposed to fit the experimental data. Both models give an adequate representation of the experimental data, allowing a satisfactory estimation of kinetic parameters (confidence intervals between 3 and 20%). Statistical analysis of discrimination did not allow selecting any of the models as "the best alternative". Experiments performed with different commercial catalysts strength the significance of the kinetic characterization of the specific catalyst chosen. The set of kinetic expressions is expected to apply to most available catalysts in the market.