Butane cracking catalyzed by the zeolite H-ZSM-5

Bizreh, Y. Walid

doi:10.1016/0021-9517(84)90071-x

Cited by 41 publications

(26 citation statements)

References 5 publications

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“…Again, the product distribution observed for this reaction by NMR is in agreement with that expected for isobutane cracking on acidic zeolites at T 623 K. [28] At T ! 773 K, the initial cleavage occurs most readily at the CÀC bond.…”

Section: Abstract In Russiansupporting

confidence: 73%

“…[30] Thus, at the moderate temperatures used in this study, the rate of primary activation of isobutane by C À H cleavage essentially exceeds that of C À C bond cleavage. [28] In order to check these results that were obtained by in situ NMR spectroscopy, we used GC analysis to investigate the product distribution after conversion of isobutane on the zeolite in the presence of CO and H 2 O in a static glass reactor. When about 1 mmol of isobutane was heated at 423 K in the presence of CO and water on H-ZSM-5 (3.6 g, i.e.…”

Section: Abstract In Russianmentioning

confidence: 99%

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Formation of Carboxylic Acids from Small Alkanes in Zeolite H-ZSM-5

et al. 2000

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The activation of propane and isobutane in acidic zeolite H-ZSM-5 in the presence of both CO and H2O has been studied by in situ solid-state NMR and GC analysis. Evidence was provided for the conversion of propane to isobutyric acid at 373-473 K by cleavage of the C-C bond; methane and ethane are also produced. Isobutane is transformed into pivalic acid with simultaneous production of hydrogen. The low conversion (1-2%) at this temperature was rationalized by the existence of a small number of sites that are capable of generating carbenium ions which are trapped by CO at this temperature. A formate species was observed when CO and H2O were present on H-ZSM-5. This species disappeared in the presence of the alkane. At 573 K, the generation of large amounts of CO2 indicates a much higher conversion of the alkanes into carboxylic acids which, however, decompose under the reaction conditions.

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Section: Abstract In Russiansupporting

confidence: 73%

Section: Abstract In Russianmentioning

confidence: 99%

Formation of Carboxylic Acids from Small Alkanes in Zeolite H-ZSM-5

et al. 2000

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“…Brenner and Emmett (7) postulated acidic dehydrogenation sites and excluded an earlier opinion about metal impurities to cause dehydrogenation. McVicker (8) suggested that strong electron deficient sites are present that effect a radical decomposition of the substrate, a view accepted by Bizreh and Gates (11). Marczewski (12), and Beyer (15) held Lewis acid sites responsible.…”

Section: Introductionmentioning

confidence: 96%

“…We discussed the principal scheme of protolytic dehydrogenation recently (1,2,5), using the conversion of n-butane as an example. However, the mechanism(s) of alkane dehydrogenation and the nature of the catalytically active sites are still controversial (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15). Brenner and Emmett (7) postulated acidic dehydrogenation sites and excluded an earlier opinion about metal impurities to cause dehydrogenation.…”

Section: Introductionmentioning

confidence: 99%

Dehydrogenation of Light Alkanes over Zeolites

Narbeshuber

Brait

Seshan

et al. 1997

Journal of Catalysis

114

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The conversion of light paraffins to olefins and the secondary reactions of the unsaturated compounds were investigated on H-ZSM5 and H-Y zeolites between 733 and 823 K. Steady stateand transient response-isotope tracing studies revealed that two mechanisms of dehydrogenation are operative. The main pathway is represented by monomolecular, protolytic dehydrogenation. This reaction contributes most to steady state olefin production. Additionally, at the initial stages of the reaction, extra framework aluminum moieties are speculated to participate in high dehydrogenation activity. This pathway is blocked at later stages of the reaction by product (hydrogen) inhibition. The intrinsic rates of protolytic dehydrogenation and olefin desorption range in the same order of magnitude. At high protolytic dehydrogenation rates, olefin desorption represents the rate determining step. Depending on the process conditions, olefins undergo secondary cracking, oligomerization, or isomerization. The latter proceeds via intramolecular rearrangement, possibly via a cyclopropylcarbenium ion at high temperatures and low conversions. At reaction conditions where bimolecular cracking prevails, isomerization is concluded to occur via secondary cracking of di-or oligomers.

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“…The experimental data used in this study along with details of the experiment were reported in an article [13] where n-butane catalytic cracking was performed over HZSM-5 catalyst having a Si/Al atomic ratio of 70, where most of the particles had sizes in the range 0.2-0.5 microns. The ZSM-5 catalyst is originally in the ammonium form; the converted catalyst H-ZSM-5 has little tendency to form coke and the results were obtained at low butane conversions.…”

Section: Methodsmentioning

confidence: 99%

Kinetic modeling based on complex reaction theory for n-butane catalytic cracking over HZSM-5

Barghi

Karimzadeh

2015

Reac Kinet Mech Cat

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The purpose of this study was to develop a kinetic model for normal butane catalytic cracking over H-ZSM-5. Experimental data were obtained from a previous study where catalytic cracking was carried out in a laboratory scale reactor at atmospheric pressure in the temperature range of 342-498°C. In this paper, a mathematical procedure is proposed for deriving reaction routes, overall reactions and the basic reaction routes based on the methodology of complex reactions theory, in order to describe the catalytic cracking kinetics of normal butane. A computer program developed in FORTRAN programming could execute the model automatically and MATLAB programming software to optimize the kinetic constants in order to obtain the product yields. The combined mechanism of normal butane catalytic cracking included complex reactions method and lumped model has been illustrated as a typical catalytic heterogeneous reaction. The kinetic parameters obtained from model are described by the Arrhenius equation. The model calculations were in appropriate accordance with the experimental data.

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Butane cracking catalyzed by the zeolite H-ZSM-5

Cited by 41 publications

References 5 publications

Formation of Carboxylic Acids from Small Alkanes in Zeolite H-ZSM-5

Formation of Carboxylic Acids from Small Alkanes in Zeolite H-ZSM-5

Dehydrogenation of Light Alkanes over Zeolites

Kinetic modeling based on complex reaction theory for n-butane catalytic cracking over HZSM-5

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