Tungsten and Rhenium as Hydrogenation Agents in the Hydrodenitrogenation of Pyridine Using Stacked Bed Catalyst Systems

Abstract

This study analyses the hydrodenitrogenation (HDN) of pyridine using a stacked bed catalyst system, composed of a first hydrogenating bed of Re/γ-Al 2 O 3 or W/γ-Al 2 O 3 , over a second bed of Ni-Re/γ-Al 2 O 3 (HDN bed). Using potentiometric methods, it can be seen that the Re/γ-Al 2 O 3 shows higher acidic strength than the W/γ-Al 2 O 3 . The results show that higher activity levels are obtained working with stacked bed systems compared to the separate catalysts. These results suggest that the incorporation of the catalyst Re/γ-Al 2 O 3 or W/γ-Al 2 O 3 beds would favour the formation of hydrogenated intermediary products, facilitating the removal of N-containing molecules via HDN on the Ni-Re/γ-Al 2 O 3 catalyst.

Comparison of performance of Ni–Mo/γ-alumina catalyst in HDS and HDN reactions of main distillate fractions

“…There are serious regulations, especially in Europe and USA, which limit the impurities in the main petroleum fractions. These fractions contain various sulfur and nitrogen compounds that should be removed to help reaching a clean environment (Bassi et al 2015;González-Cortés et al 2006;Ling et al 2009;Rong et al 2014). Hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) have been widely used for removing sulfur and nitrogen compounds from liquid phases (Faro and dos Santos 2006;Furimsky and Massoth 2005;Gao et al 2011;Gutiérrez et al 2014;Huirache-Acuña et al 2012; Ledoux and Djellouli 1990;Mendoza-Nieto et al 2015;Prins 2001;Qian et al 2013;Soghrati et al 2012;Sundaramurthy et al 2006;Zepeda et al 2016;Zhao et al 2004).…”