Hydrodenitrogenation of quinoline over carbon-supported transition metal sulfides

Abstract

Transition metal sulfide (TMS) catalysts were prepared by impregnation of an activated carbon support with aqueous solutions of first-, second-, and third-row (group V-VIII) transition metal salts, drying and in situ sulfidation. The catalysts were tested in the hydrodenitrogenation of quinoline (653 K, 5.5 MPa) in microautoclaves and microflow reactors. The first-row transition metal sulfides had low quinoline conversions to hydrocarbons, and their periodic trend formed a U-shaped curve with a minimum at Mn/C and Fe/C and maxima at V/C and Ni/C. The quinoline conversions to hydrocarbons of the second-and third-row TMS formed volcano curves with maxima at Rh/C and Ir/C and with Mo/C and W/C having the lowest conversions. The transition metal sulfide catalysts with a low quinoline hydrogenation (first-row transition metal sulfides, Mo/C and W/C) also had a low quinoline conversion to hydrocarbons. The transition metal sulfides with the highest quinoline conversions to hydrocarbons (Rh/C, Pd/C, Os/C, Ir/C and Pt/C) had a very high quinoline hydrogenation and a high selectivity for propylcyclohexane. Ru/C and especially Re/C had a good quinoline conversion to hydrocarbons, but also an exceptionally high selectivity for propylbenzene.

Hydrocracking of N-Decane over Zeolite-Supported Metal Sulfide Catalysts. 1. CaY-Supported Transition Metal Sulfides

“…There are large differences in hydrocracking properties between the various metal sulfide catalysts, which correlate roughly with the activity trends observed for other sulfide catalyzed reactions like thiophene HDS (Vissers et al, 1984;Ledoux et al, 1986), HDS of dibenzothiophene at low (Lacroix et al, 1989) or high (Pecoraro and Chianelli, 1981) pressure, HDN of quinoline (Eijsbouts et al, 1988(Eijsbouts et al, , 1991a, and the hydrogenation (HYD) of biphenyl (Lacroix et al, 1989).…”

“…The differences in catalytic activity measured for the various metal sulfides are compared with the trends in activity observed for the above-mentioned test reactions (Pecoraro and Chianelli, 1981;Vissers et al, 1984;Ledoux et al, 1986;Eijsbouts et al, 1988Eijsbouts et al, , 1991aLacroix et al, 1989). In order to allow a meaningful comparison of the catalytic properties between the different metal sulfides, the composition of the metal sulfide phase present on the catalysts is examined by overall sulfur analysis, while samples are taken at the reactor exit and analyzed with an on-line gas chromatograph (GC) equipped with a UCON LB 550 X capillary column.…”

“…Besides Co, Ni, Mo, and W there are however many other transition metal sulfides which are comparably or even more active for a range of catalytic reactions, such as thiophene or dibenzothiophene hydrodesulfurization (HDS) (Pecoraro and Chianelli, 1981;Vissers et al, 1984;Ledoux et al, 1986;Lacroix et al, 19891, hydrodenitrogenation (HDN) (Eijsbouts et al, 1988(Eijsbouts et al, , 1991a, or hydrogenation of biphenyl (Lacroix et al, 1989). Combination of an acidic zeolite with these metal sulfides may result in highly active hydrocracking catalysts.…”

Remarkable improvement in adsorptive denitrogenation of model fossil fuels with CuCl/activated carbon, prepared under ambient condition

“…For example, this process requires large amounts of expensive hydrogen and is carried out at high temperature and pressure and, therefore, is not cost effective. In addition, compared to HDS, HDN is a kinetically slow multistep process because hydrogenation of heterocyclic rings (containing nitrogen) is required [7][8][9]. At this point in time, development of an economically feasible and selective NCC removal method is crucially needed, and adsorptive denitrogenation (ADN) may be one of the options to serve this purpose.…”

“…So far, several materials have been studied on a laboratory basis for applications in the ADN process. These include activated carbon (AC) [7][8][9][10], Cu(I)-Y zeolites [6,11], ion exchange resins [12], meso-silicas [13,14], Ti-HMSs [15], microporous carbons [16], activated aluminas [17], Ni-based adsorbents [17], Si-Zr cogel [18] and metal-organic frameworks (MOFs) [19][20][21][22][23].…”