Hydrodesulfurization thiophene

Figure 7.16. Dependence of the rate of thiophene hydrodesulfurization on the partial pressures of the reactants thiophene and hydrogen and of the product hydrogen sulfide,...

Figure 7.18. Dependence of the rate of thiophene hydrodesulfurization on the partial pressures of thiophene at different temperatures, along with fits according to the Langmuir-Hinshelwood model, Eq. (32). [Fron A. Borgna and J.W. Niemantsverdriet, to be published (2003).]...

Figure 5. The conversion and selectivity (0 -butane, A 1-butene, A wa/iv-2-butene, m-2-butene) of thiophene hydrodesulfurization (a,b) Co-380 and (c,d) 5wt% Co/Si02.

In a study of the deactivation by coking of an atmospheric residue HDM catalyst, we have been able to obtain coked catalysts almost free from metal deposits in batch reactor and coked catalysts containing small amounts of metal sulfide deposits in continuous flow reactor using a Safaniya atmospheric residue under similar experimental conditions (30). We report in this paper a study of the deactivating effects of the deposits using toluene hydrogenation, cyclohexane isomerization and thiophene hydrodesulfurization reactions. 

Toluene hydrogenation (HYD), cyclohexane isomerization (ISOM) and thiophene hydrodesulfurization (HDS) tests have been performed in a high pressure fixed bed continuous flow "Catalest" unit. 

The toluene hydrogenation test was followed by a thiophene hydrodesulfurization test performed at 6 MPa, 220°C, LHSV = 2 h H2/HC = 300N1/1, The liquid feed was composed of dimethyl-disulfide (lwt %), thiophene (2 wt %) and n-heptane (97 wt %),... 

Some samples of the TS and P series have been chosen for tests using model compounds in order to evaluate the deactivation. Conversions obtained for toluene hydrogenation at 3509C, cyclohexane isomerization at 380 and 400°C and thiophene hydrodesulfurization at 220°C are reported in Table 1. 

This conclusion has been reached from toluene hydrogenation and thiophene hydrodesulfurization tests of used catalysts containing 4 to 15 wt % C and either less than 200 ppm V or up to 1.3 wt % V which have been obtained by hydrotreating a Safanyia atmospheric residue in batch and continuous flow reactors respectively ... 

Zonnevylle, M. C., R. Hoffmann, and S. Harris (1988). Thiophene hydrodesulfurization on M0S2 theoretical aspects. Surface Sci. 199, 320-60. 

M. Arai, Y. Wada, and Y. Nishiyama, Thiophene hydrodesulfurization by catalytic palladium membrane systems, Sekiyu Cakkaishi 36 44 (1993). 

The texture and morphology of the synthesized objects were studied by the set of the instrumental methods XRD, FT-IR, SEM, TEM, BET, N2 adsorption-desorption. Model reaction of thiophene hydrodesulfurization (HDS) was used to investigate the chemical mobility of Ni-containing particles obtained by different ways. 

Cr- FILM from the different cationic forms of this clay [4], These materials exhibited dehydration and dehydrogenation activity in the decomposition of 2-propanol and ethanol. Cr-PILM catalysts activated by HjS/Hj mixture displayed also an interestingly high activity for thiophene hydrodesulfurization (HDS). Now, the Cr-PILM s have been prepared form different clays with the objective to obtain new porous materials with potential catalytic applicability. Their physicochemical properties and the catalytic behaviour for thiophene HDS have been investigated. 

Scheme 1. The possible mechanism of thiophene hydrodesulfurization over R/HZSM-5 catalyst.

In order to assess the viability of quantitative XPS as a tool in the physical characterization of coke deposits, we have studied a number of spent catalysts which contained considerable amounts of coke. The spent heavy-oll -processing catalysts were obtained from vacuum gas oil hydroconver ion experiments. The activity of fresh and spent catalysts was evaluated from thiophene hydrodesulfurization tests. 

It is interesting to note that Reddy and Manohar could show that M0S2 did also spread on the surface of AI2O3 supports. The resulting material developed a thiophene hydrodesulfurization activity which was identical to that measured on a conventionally impregnated and sulfided catalyst. 

LaVopa, V. Satterfield, C.N. Poisoning of thiophene hydrodesulfurization by nitrogen compounds. J. Catal. 1998, 110, 375-387. 

The thiophene hydrodesulfurization and cyclohexene hydrogenation activity of the catalysts were measured in a high pressure reactor. The experimental conditions for the activity tests were a feedstock of thiophene (15000 ppm), cyclohexane (90%) and cyclohexene (10%), flow rate 0.353 ml/min, total pressure = 26 Kg/cm and LHSV=52 l/h. Additional experiences with toluene (90%) and cyclohexene (10%) were also carried out. The operative conditions for the hydrotreating test were selected according to the recent experience about the C0M06 [3]. The products were analysed by gas chromatography by means of a Varian Start 3400 gas chromatograph, with FID detector. 

The thiophene hydrodesulfurization and cyclohexene hydrogenation activity of the catalysts have been measured in a high pressure reactor, the operative conditions having been selected according to the recent experience about the CoMoe and NiMoe based systems because of the common structural and physical-chemical properties [3, 4]. Table 3 shows chemical data and conversion obtained for selected catalysts based on RhMoe. In addition, the data for CoMoe Anderson, CoMo commercial and Rh commercial 7-AI2O3 supported catalysts are included for comparative purposes. 

The catalytic activities for the functionalities viz. HDS and HYD were evaluated at 400 C on catalysts sulfided at 400 C using CS2/H2 mixture. The catalytic activity for thiophene hydrodesulfurization and cyclohexene hydrogenation are presented in Fig. 4. as a function of... 

Catalytic functionalities of sepiolite supported Mo-sulfided catalysts were evaluated using thiophene hydrodesulfurization and cyclohexene hydrogenation reactions at 400 C. The presulfidation was carried out at 400°C for 2 hrs with mixture of CS2 and Hz- In both the cases first order rate constants are evaluated. The results of such experiments as a function of Mo-loading is given in table 2 and the activity of HDS and HYD reaction as a function of Mo-loading is shown in figure 5. 

Sulfided Mo-Y and Ni-Mo-Y catalysts were tested in thiophene hydrodesulfurization and hydrogenation of pentene-1 and cyclopentene. Catalysts were prepared by thermal decomposition of supported Mo(CO)g encaged in Y and stabilized Y zeolites. Cracking ability in both reactions is related to the surface acidity of catalysts but is not parallel to their HDS activity. H S generates protonic acidity over NaY and KY zeolites. Synergetic effect between Ni and Mo sulfided species in HDS reaction was observed. The presence of extra-lattice aluminum in stabilized forms of Y-zeolites favours selectivity towards formation of isopentane and cyclopentane during hydrogenation. 

Song, S. K. Wang, Y. Ihm, S. K. Effect of lanthanum addition on the thiophene hydrodesulfurization activity over Al-MCM-41 supported molybdenum catalysts. 

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