Effect of Nitrogen Compounds on Hydrodesulfurization on Petroleum Fractions

Kirsch, Frauke; Shalit, H.; Heinemann, H.

doi:10.1021/ie50599a035

Cited by 18 publications

(6 citation statements)

References 3 publications

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“…This agreement does not prove the concept, but it does provide a consistent interpretation that is also in agreement with other published results for sulfided cobalt-molybdena. For example, the accentuated electrophilic or acid nature of sulfided cobaltmolybdena and its retarded "contact" action have been described in earlier publications (6,7). In the present study, the acid nature was not demonstrated, but the experimental observations are in accord with the concept of accentuated electrophilic action and impaired "contact" action for a sulfided catalyst.…”

Section: Discussion Of Resultssupporting

confidence: 84%

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Selective Hydrogenation of Butadiene. Catalyst Poisoning and Stabilization

Kirsch¹,

Shull²

1963

I&EC Product Research and Development

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Section: Discussion Of Resultssupporting

confidence: 84%

“…Copper chromite did not produce equilibrium amounts of 1or 2-butene, but the ratio of 1 -butene-2-butene was about 7 to 93, which is identical with the equilibrium ratio at 200°F.…”

Section: Discussion Of Resultsmentioning

confidence: 51%

Selective Hydrogenation of Butadiene. Catalyst Poisoning and Stabilization

Kirsch¹,

Shull²

1963

I&EC Product Research and Development

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“…% nitrogen in feedstock) sulfur removal was 94%. Kirsch et al (1959) experimented with a synthetic gasoline (0.4 wt. % sulfur) blended from heptane, heptene, and thiophene.…”

Section: Hydrodesulfurization (Hds)mentioning

confidence: 99%

Interactions between catalytic hydrodesulfurization of thiophene and hydrodenitrogenation of pyridine

1975

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Pyridine hydrodenitrogenation (HDN) is more difficult than thiophene hydrodesulfurization (HDS), and there is a thermodynamic limitation on the first step of the HDN reaction mechanism which occurs, for example, at 5 to 11 bars, at temperatures above about 350°C. Pyridine inhibits the HDS reaction as previously reported, but sulfur compounds have a dual effect on HDN. At low temperatures, thiophene inhibits the reaction by competing with pyridine for hydrogenation sites on the catalyst. This retards the hydrogenation of pyridine to piperidine, reducing the overall reaction rate. At high temperatures the dominant effect is interaction of hydrogen sulfide, an HDS reaction product, with the catalyst to improve its hydrogenolysis (hydrocracking) activity. This increases the rate of piperidine hydrogenolysis, which is rate determining at the latter conditions, and enhances the overall rate of HDN. CHARLES N. SATT'ERFIELD SCOPEThe hydroprocessing of fuels containing relatively large amounts of organonitmgen compounds will become increasingly important in the future in the upgrading of synthetic fuels from oil shale and coal or processing of lower grades of crude petroleum. Organosulfur compounds are present, and the inhibiting effeet of organonitrogen compounds on catalytic hydrodesulfurization is established. However, very little has been published on the effect of organosulfur compounds on hydrodenitrogenation. These two groups of effects were explored by using as model compounds thiophene and PFidine which represent some of the less reactive organosulfur and organonitrogen compounds, respectively.Studies were made with a flow microreactor at temperatures of 200" to 500°C, 4.4 and 11.2 bars pressure, on commercial catalysts consisting of CoMo/Al,03, NiMo/ A1203, NiW/AI2O3 and NiW/SiO2-AlzO3. CONCUSIONS A N D SIGNIFICANCEPyridine, a basic nitrogen compound, severely inhibits the hydrodesulfurization of thiophene on sulfided cobaltmolybdate type of catalysts, in agreement with previous studies. The pattern of this inhibition suggests there are two types of HDS sites involved. The first are postulated to be very active for HDS but very sensitive to nitrogen bases. Sufficient quantities of these bases will completely block these sites and render them inactive for HDS. The second type of sites are much less active for HDS, but they are also less susceptible to pyridine poisoning. These latter sites are responsible for HDS activity after the first type of sites have been blocked.The hydrodenitrogenation of pyridine is more difficult than thioohene HDS, and there appears to be a thermodynamic limitation to the first step in the reaction mechanism. Sulfur compounds have a twofold effect on HDN. At low temperatures they are postulated to compete with pyridine for hydrogenation sites on the catalyst, thereby inhibiting the rate of the hydrogenation step in the pyridine decomposition mechanism. At high temperatures the HDS reaction product hydrogen sulfide interacts with the catalyst to improve the hydrogenolysis activity. Thi...

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“…However, as can be seen from Figure 6, addition of quinoline to raw anthracene oil changes the relative activities of these two catalysts. Kirsch et al (1959) found that there is a minimum concentration at which basic nitrogen has an immediate effect on selectivity towards hydrodesulfurization of petroleum fractions. Hence it seems probable that the nitrogen concentration in raw anthracene oil may be below the minimum concentration required to have an effect on selectivity.…”

Section: Resultsmentioning

confidence: 99%

“…Satterfield et al (1975) showed that increasing nitrogen concentration severely inhibits hydrodesulfurization of thiophene. The effect of nitrogen compounds on hydrodesulfurization of petroleum fractions has been studied by several researchers (Ahuja et al, 1970;Doleman, 1963;Kiovsky and Berg, 1964;Kirsch et al, 1959). However, very little information is available on the effect of nitrogen concentration on hydrodesulfurization of coal-derived liquids.…”

Section: Introductionmentioning

confidence: 99%

Effect of Nitrogen Concentration on Hydrodesulfurization of a Coal-Derived Liquid

Sivasubramanian¹,

Crynes²

1980

Ind. Eng. Chem. Prod. Res. Dev.

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Raw anthracene oil, a coal-derived liquid, has been doctored with quinoline. Both the undoctored and doctored feedstocks were hydrotreated over the same set of catalysts in a trickle bed reactor to study the effect of increasing nitrogen concentration on hydrodesulfurization of coal-derived liquids. Increasing nitrogen concentration has a detrimental effect on sulfur removal. The results confirm the existence of two different hydrodesulfurization sites as postulated by others. The percent sulfur removal varies linearly with percent nitrogen removal. Of the three catalysts tested, increasing nitrogen concentrations more severely affected the sulfur removal ability of that catalyst with the lowest denitrogenation activity.

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Effect of Nitrogen Compounds on Hydrodesulfurization on Petroleum Fractions

Cited by 18 publications

References 3 publications

Selective Hydrogenation of Butadiene. Catalyst Poisoning and Stabilization

Selective Hydrogenation of Butadiene. Catalyst Poisoning and Stabilization

Interactions between catalytic hydrodesulfurization of thiophene and hydrodenitrogenation of pyridine

Effect of Nitrogen Concentration on Hydrodesulfurization of a Coal-Derived Liquid

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