ISSN 09655441, Petroleum Chemistry, 2013, Vol. 53, No. 4, pp. 233–244. © Pleiades Publishing, Ltd., 2013. Original Russian Text © V.A. Sal’nikov, P.A. Nikul’shin, A.A. Pimerzin, 2013, published in Neftekhimiya, 2013, Vol. 53, No. 4, pp. 267–279.
The Catalytic Properties of Transition Metal Sulfides Synthesized from AndersonType Heteropoly Compounds in Hydrogenation, Hydrodesulfurization, and Hydrodenitrogenation Reactions V. A. Sal’nikov, P. A. Nikul’shin, and A. A. Pimerzin Samara State Technical University, Samara, Russia email:
[email protected] Received October 17, 2012
Abstract—XMo6HPC/Al2O3 catalysts based on Andersontype heteropoly compounds (HPCs) with het eroatoms X = Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, and Al were synthesized. The catalytic properties of the pre pared samples were studied in naphthalene hydrogenation, dibenzothiophene hydrodesulfurization, and quinoline hydrodenitrogenation. The highest activity was exhibited by the catalysts with X = Co and Ni; the lowest, with X = Cu. It was found that dibenzothiophene hydrodesulfurization and naphthalene hydrogena tion occur on different active sites, whereas the sites of the hydrogenation of naphthalene and diben zothiophene have a similar nature. Quinoline (at a nitrogen content of 100 ppm) had a different effect on the catalytic properties: it inhibited the hydrogenation of dibenzothiophene and naphthalene, but promoted the desulfurization of dibenzothiophene. Keywords: hydrotreating, sulfide catalysts, heteropoly compounds, hydrodesulfurization, hydrogenation, hydrodenitrogenation, dibenzothiophene, naphthalene, quinoline DOI: 10.1134/S0965544113040129
It is well known that emissions of gases from the combustion of motor vehicle fuels (NOx and SOx) pol lute the atmosphere [1]. In order to address this prob lem, many countries have imposed restrictions on the total sulfur content in commercial petroleum prod ucts. The Russian State Standard GOST R 52368 2005 complies with European standard EN 590, according to which the sulfur content in diesel fuel shall not exceed the level of 50 and 10 ppm for Class 4 and 5, respectively [2]. Recently, the need for the pro duction of motor fuels with an ultralow sulfur content has increased [3–5]. In years to come, hydrotreating will remain the largestscale process of petroleum refining [6, 7], and its role will continue to grow in view of evertightening requirements on sulfur content standards in gasoline and diesel fuels and owing to increasing depth of petroleum refining and the involvement of unconventional hydrocarbon resources (oil shales, bituminous oils, plant raw mate rials, etc.) into the process. Hydrotreating catalysts are based on universal composite Co(Ni)Mo(W)S on a support, which has been prepared almost exclusively of γAl2O3 to the present day. This system exhibits significant flexibility and can change its activity and selectivity over a wide range upon a variation in the synthesis method, the introduction of various modifiers, a change in sulfid ing conditions, the use of different supports, etc; this
has made it possible to design hundreds of brands of commercial catalysts. According to van Looij et al. [8], in order to reduce the sulfur content in diesel fuels from 500 to 50 ppm, the activity of the used catalyst must be about 4 times higher, all other hydrotreating conditions being equal. To obtain diesel fuels with an ultralow sulfur content (
