Hydroisomerization and hydrocracking of normal pentane over various mordenite catalysts

Gray, J. A.; Cobb, J. T.

doi:10.1016/0021-9517(75)90018-4

Cited by 20 publications

(5 citation statements)

References 15 publications

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“…Thus in terms of activity, the catalysts may be placed in the order Ni/900H > Ni/CaY > Ni/NaY > Ni/NaA. Gray and Cobb (1975) reported similar behaviour of nickel catalysts over various mordenite supports carrying different percent cations for n-pentane isomerization. Addition of nickel to Ca-M support showed higher activity compared to Na-M support.…”

Section: Effect Of Nickel Concentrationmentioning

confidence: 88%

Isomerization of n‐hexane over nickel‐loaded zeolite catalysts

Jothimurugesan

Bhatia

1984

Can J Chem Eng

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The isomerization of n‐hexane to branched‐chain isomers was studied over various zeolite supports containing nickel between 1 to 5 wt%. NaA, NaY, CaY and Zeolon 900H were loaded with nickel by an impregnation technique. It was observed that at a nickel content of about 2.5 wt%, all the catalysts showed maximum activity for isomerization. A catalyst containing 1 wt% Ni/CaY gave the maximum selectivity among all the catalysts studied. Increasing the nickel loading beyond 2.5 wt% Ni with CaY and Zeolon 900H led to more hydrocracking. No major change in the activity and selectivity of Ni/NaA catalysts was observed beyond 2.5 wt% Ni, whereas the activity of Ni/NaY catalysts remained almost constant over the range of nickel content studied. A catalyst containing 2.5 wt% Ni on Zeolon 900H gave the maximum yield of isomers at 643°K. The apparent activation energy of the reaction was found to be 48.6 kJ/mol for 1 wt% Ni on Zeolon 900H catalyst.

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Section: Effect Of Nickel Concentrationmentioning

confidence: 88%

Isomerization of n‐hexane over nickel‐loaded zeolite catalysts

Jothimurugesan

Bhatia

1984

Can J Chem Eng

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“…Their occupancy depends strongly upon the characteristic of the considered cation (size, polarizability) but also upon some structural properties of the host crystal lattice [46][47][48][49][50][51][52][53]. In the case of the sodium mordenite of Si/Al ratio equal to 5.5, the occupancy rates [9,[54][55][56][57] of sites I, II, III, IV, and VI are, respectively, 3.1, negligible, negligible, 2.6, and 1.5.…”

Section: Structural Illustration Of Thementioning

confidence: 99%

Behavioural Change according to the Si/Al Ratio of Successive Na-Mordenites Observed through Their Dielectric Relaxation during Water Vapour Adsorption Process

Diaby

2016

Journal of Materials

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The experimental study of water vapour adsorption phenomenon on a zeolite, by dielectric relaxation measurement, makes it possible to determine the variations in the exchangeable cation hopping activation energy, on the surface of the solid, in relation to the number of adsorbed molecules. The present work shows that it is possible to explain the change observed in the energy, by means of simple assumptions based, on the one hand, on the models used in order to simulate the adsorption process and, on the other hand, on the distribution of the molecules adsorbed near the exchangeable cations. Thus, the phenomenological interpretation suggested here, about the change in the exchangeable cation hopping energy, obtained by dielectric relaxation measurement, makes us with a mind to conceive a simple method for explaining the results leading to new information on the organization of the first adsorbed molecules on the surface of the studied zeolite. Then, it can be verified that these conclusions confirm the assumptions already developed for interpreting the inferences from previous experiments carried out by means of other techniques.

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“…Even though more stable than Pt/Al 2 O 3 and HPAs, SZ catalysts suffer by severe deactivation due to coke deposition [22] and H 2 S in situ generation [44,46] in the presence of H 2 O [46,47]. Zeolites are stable materials [38] but less selective [27,48], since they require higher reaction temperature [6,9,26,38,49] that shifts the equilibrium towards cracking vs. isomerization.…”

Section: Introductionmentioning

confidence: 97%

“…Strong acid catalysts [1] such as chlorinated Pt/Al 2 O 3 [2][3][4] and heteropoly acids (HPAs) [5][6][7][8][9][10] have the ability to isomerize light alkanes such as n-butane (nC 4 ) and n-pentane (nC 5 ) and heavier ones such as n-hexane (nC 6 ) and n-heptane (nC 7 ) via a monomolecular reaction pathway. Sulfated zirconia (SZ) [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25], tungstated zirconia (WZ) [11] and various zeolites [4,6,[26][27][28][29][30] have been extensively investigated [25,[31][32][33][34][35][36], and unlike Pt/Al 2 O 3 and HPAs, they appear to isomerize lighter alkanes primarily through a bimolecular mechanism.…”

Section: Introductionmentioning

confidence: 99%