Quantification of the available acid sites in the hydrocracking of nitrogen-containing feedstocks over USY shaped NiMo-catalysts

Pedro S.F. Mendes (1, 2) , João Silva (1, 3) , M. Filipa Ribeiro (1) , Christophe Bouchy (2) , Antoine Daudin (2)

1 Instituto Superior Técnico, Universidade Técnica de Lisboa
2 IFPEN - IFP Energies nouvelles
3 ISEL - Instituto Superior de Engenharia de Lisboa

The inhibition of Brønsted acid sites by nitrogen-containing molecules was quantified under industrially relevant hydrocracking conditions. This was achieved by testing bifunctional catalysts based on HUSY zeolite in cyclohexane hydroconversion. For ammonia partial pressures within 0.2-2.8 kPa, the percentage of inhibited Brønsted sites was superior to 98% at 623 K. Significant reduction in the ammonia content caused rather moderate variations on the number of available sites. Conversely, a temperature raise from 600 to 640 K triplicated the vacant Brønsted sites due to the significant endothermicity of ammonia desorption. The inhibiting effect of ammonia can be therefore easily modulated by temperature.

Mots clés: hydrocracking; HUSY zeolite; catalyst deactivation; ammonia; operando Brønsted acidity; bifunctional catalyst

Domaines: Génie chimique

Pedro S.F. Mendes, João Silva, M. Filipa Ribeiro, Christophe Bouchy, Antoine Daudin. Quantification of the available acid sites in the hydrocracking of nitrogen-containing feedstocks over USY shaped NiMo-catalysts. Journal of Industrial and Engineering Chemistry, 2019, 71, pp.167-176. ⟨10.1016/j.jiec.2018.11.019⟩. ⟨hal-02409000⟩