Kinetics of simultaneous hydrodesulfurization and hydrodenitrogenation reactions using CoMoP/Al2O3 and NiMoP/Al2O3

Hydrodesulfurization (HDS) is a key reaction to achieve diesel production at the specified low sulfur levels and is highly affected by a competing reaction involving nitrogen removal through hydrodenitro-genation (HDN). This work evaluated kinetic parameters of simultaneous reactions of HDS of dibenzoth-iophene (DBT) and HDN of quinoline (Q) using CoMoP/Al2O3 and NiMoP/Al2O3 catalysts under operational conditions that allow a wide range of reagent conversions. Estimated parameters were eval-uated using rigorous statistical analysis. Good fits for the evaluated experimental data were provided by both power-law and Langmuir-Hinshelwood models. Turnover frequency values highlight adsorption and competition effects between nitrogen-containing compounds and sulfur-containing compounds. NiMoP catalyst showed higher hydrogenating power than CoMoP, with larger absolute value of the esti-mated adsorption enthalpy (-120 kJ.mol-1 for NiMoP and-75 kJ.mol-1 for CoMoP), suggesting strong adsorption of nitrogen compounds. A catalyst with more hydrogenating power is also more capable of performing both HDN and HDS reactions simultaneously. (c) 2023 Elsevier Ltd. All rights reserved.

Automated summary

This work evaluated the kinetic parameters of the simultaneous reactions of HDS and HDN using CoMoP/Al2O3 and NiMoP/Al2O3 catalysts. Both power-law and Langmuir-Hinshelwood models provided good fits for the experimental data. The NiMoP catalyst showed higher hydrogenating power and stronger adsorption of nitrogen compounds compared to the CoMoP catalyst. Catalysts with higher hydrogenating power are more capable of performing both HDN and HDS reactions simultaneously.