Selectivity of molybdenum catalyst in hydrodenitrogenation, hydrodesulfurization and hydrodeoxygenation: Effects of sulfur and oxygen compounds on acridine hydrodenitrogenation

Reactivities, reaction networks, and kinetics in high-pressure catalytic hydroprocessing

“…In a more rigorous analysis of Bhinde's data, Lo (1981) estimated the inhibition parameter for quinoline to be 2 orders of magnitude greater than that for dibenzothiophene. Nagai et al (1986a) investigated the effect of several sulfur compounds (Table XXIX) on the HDN of acridine at HDN conversions less than 20% (assumed to be differential). The addition of the sulfur compounds inhibited acridine HDN, with the yield of dicyclohexylmethane decreasing with increasing concentration of the sulfur compound.…”

“…This inhibition of HDN by an oxygen compound does not agree with the results of Satterfield and co-workers mentioned above, possibly because the conversions were differential and any promotional effect of water was minimized. Nagai et al (1986a), in an investigation of various additives on acridine HDN (Table XXIX), also examined the effect of xanthene, which was found to inhibit the acridine reactions in the same manner as the organosulfur compounds, i.e., by retarding the hydrogenolysis of per- Table XXXII. Variation of Selected Peeudo-First-Order Rate Constants in L/(g of catalyst ••) for the Quinoline HDN Network for Various Feed Quinoline Concentrations" (Bhinde, 1979)_ quinoline feed concn, wt % reaction 0.2 0.5 2.0 quinoline + 2H2 -* 3.2 X 10"8 1.8 X 10"3 7.8 X 10"4 5,6,7,8-tetrahydroquinoline Hi decahydroquinoline -7.5 X 10"3 3.1 X 10~3 1.5 X 10™3 hydrocarbons + NH3 Hi quinolinehydro-6.7 X 10"4 2.8 X 10"4 9.7 X 10"6 carbons + NH3…”

A Review on the Reaction Mechanism of Hydrodesulfurization and Hydrodenitrogenation in Heavy Oil Upgrading

“…An earlier reaction network proposed by Zawadski et al 128 did not report any N-free hydrocarbon compound. However, Nagai et al 129 reported more comprehensive findings. They proposed a reaction network that proceeds first via hydrogenation to dihydroacridine and then saturation to octahydroacridine.…”

“…It is a bit tricky to ascertain the inhibiting effects of sulfur, since they can modify the catalyst surface to maintain its sulfide state and also increase the number of Bronsted acid sites for the HDN . Nagai et al studied the effects of sulfur compounds (DBT, BT, thiophene, dimethyl sulfide, and ethanethiol) on HDN of acridine over a sulfided and reduced Mo/Al 2 O 3 . They discovered that, at 360 °C, the N atom removal from perhydroacridine (one of acridine hydrogenation intermediates) was depressed.…”

Surface Properties and Active Sites of Nitrided Mo/Al2O3 Catalysts for the Hydrodenitrogenation of Carbazole

“…Nitrogen compounds are more harmful during deep HDS and more difficult to remove from gas oil compared to sulfur compounds. The HDN reaction on molybdenum sulfides has been extensively studied in terms of further development of NiMo and CoMo sulfides with additives containing phosphorus and fluorine, competitive reaction with HDS and the effect of the generated H 2 S, and the active surface sites [1][2][3][4][5][6][7][8][9][10]. In recent years, new types of catalyst, such as transition metal nitrides and oxynitrides [11][12][13][14] have been studied for hydrotreatment [15][16][17], HDS [18][19][20][21][22][23] and HDN [24][25][26][27][28][29][30][31][32][33][34].…”