HDS Of DBT Research Articles

Hydrotreating properties of mixed Nb xMo 1− xS 2 alumina supported catalysts

Niobium-molybdenum disulfide solid solution (Nb x Mo 1− x S 2) has been prepared in a dispersed state on gamma alumina. The existence of this solid solution supported on alumina carrier has been proven with the help of EXAFS technique. The catalytic properties of these materials have been studied in hydrogenation and hydrodesulfurization reactions. Interestingly, as already observed for niobium sulfide, the activity of the Nb x Mo 1− x S 2 solid solution (HDS of DBT, P tot=33 bar) is not decreased in the presence of H 2S up to p(H 2S)=200 Torr, at least up to x=0.4.

Hydrogenating properties of unsupported transition metal sulphides

Group VI and Group VIII transition metal sulfides (TMS) have been widely used in hydrotreating catalysis. In addition to hydrogenation reactions, these processes involve removal of sulfur (hydrodesulfurization: HDS) and nitrogen (hydrodenitrogenation: HDN). Until now, HDN has not received as much attention as HDS, probably because sulfur compounds have historically been of prime importance. As petroleum feedstocks dwindle, the need for hydroprocessing oils containing larger amounts of heteromolecules will increase and industry will require more active materials. For this purpose, researchers may either improve the current catalysts of develop a new generation of catalysts based on transition metal sulfides presenting higher activities, stabilities, and selectivities toward desired compounds. The objective of the present work is to classify the hydrogenation performances of well-defined unsupported transition metal sulfides. These catalysts have been chosen since their characterization by physiochemical techniques, mainly X-ray diffraction (XRD), is easier than that for supported materials. Actually, it has been shown in several cases that the catalytic properties are closely related to the crystalline structure and the stoichiometry of the different phases which can be encountered for a given element. The catalyst were tested in the hydrogenation of biphenyl (HN of BP) as well as in the hydrodesulfurizationmore » of dibenzothiophene (HDS of DBT) in order to compare the present results to previous studies. To evaluate the hydrogenating function, the HN of BP has been chosen preferably to the consecutive HN of BP resulting from the HDS of DBT.« less