Some aspects of the vapor phase Beckmann rearrangement for the production of ε-caprolactam over high silica MFI zeolites

Ichihashi, Hiroshi; Kitamura, Masaya

doi:10.1016/s0920-5861(01)00514-4

Cited by 111 publications

(66 citation statements)

References 12 publications

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“…Figure 5 shows the results of these experiments. 3 The selectivity and the conversion were not enough in the range of the atomic ratios below 100. However, when the ratio became larger, the selectivity and conversion increased, achieving high selectivity and high conversion in atomic ratios larger than 1000.…”

Section: Features Of the Catalyst For The Vapor-phasementioning

confidence: 99%

“…Figure 6 shows the results for some MFI zeolites. 3 These TPD spectra were obtained after ammonia adsorption at 100 C followed by evacuation at the same temperature. The zeolites with silicon to aluminum atomic ratios of 15 and 150 showed a clear desorption band corresponding to the desorption of ammonia from acidic sites.…”

Section: Features Of the Catalyst For The Vapor-phasementioning

confidence: 99%

“…Figure 7 shows the relationship between the weight ratio of methanol to cyclohexanone oxime and the activity results. 3 Without methanol in the reaction system, the selectivity was only about 80%. However, when the added amount of methanol was one or two times that of cyclohexanone oxime, the selectivity increased to around 95%.…”

Section: Features Of the Catalyst For The Vapor-phasementioning

confidence: 99%

“…3 A high silica MFI zeolite was treated with methanol vapor at 350 C, then the IR spectra was measured after evacuation. The zeolite that was not treated with methanol showed a sharp IR absorption at 3740 cm À1 , which was assigned to terminal silanols.…”

Section: Features Of the Catalyst For The Vapor-phasementioning

confidence: 99%

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Development and Industrialization of the Vapor-Phase Beckmann Rearrangement Process

Izumi¹,

Ichihashi²,

Shimazu³

et al. 2007

Bulletin of the Chemical Society of Japan

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The development of a new catalyst effective for the vapor-phase Beckmann rearrangement of cyclohexanone oxime has made it possible to establish a commercial process for the production of "-caprolactam without producing any ammonium sulfate. Through fundamental studies of the catalyst, it was discovered that an MFI-type zeolite composed exclusively of silica had a high selectivity and activity for the vapor-phase Beckmann rearrangement. Based on acidity measurements and on the reactivity of oximes with different sizes as well as the calculation results of the deprotonation energies of some silanols, we have suggested that the active sites are nest silanols located close to their mouth of the micro pores. By addition of methanol into the reaction system, the selectivity for "-caprolactam was markedly improved to the levels required for industrialization. A fluidized bed reactor was used for the reaction system in order to maintain a continuous production. By combining the ammoximation process for production of cyclohexanone oxime using the TS-1 catalyst and the vapor-phase Beckmann rearrangement, a commercial plant has been operating on a 60000 tons per year scale since April 2003, without any troubles.

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Section: Features Of the Catalyst For The Vapor-phasementioning

confidence: 99%

Section: Features Of the Catalyst For The Vapor-phasementioning

confidence: 99%

Section: Features Of the Catalyst For The Vapor-phasementioning

confidence: 99%

Section: Features Of the Catalyst For The Vapor-phasementioning

confidence: 99%

See 2 more Smart Citations

Development and Industrialization of the Vapor-Phase Beckmann Rearrangement Process

Izumi¹,

Ichihashi²,

Shimazu³

et al. 2007

Bulletin of the Chemical Society of Japan

Self Cite

View full text Add to dashboard Cite

show abstract

“…Furthermore, the theoretical approach to the reaction mechanism reveals that hydrogen bonding of the Si _ OH group of the nest silanols to cyclohexanone oxime (CHO) is the initial step of the rearrangement 17) . High silica MFI zeolite without acidity may be the most suitable catalyst for the vapor phase Beckmann rearrangement 18) . Sumitomo Chemical Co., Ltd. in Japan constructed the fi rst plant using the vapor phase Beckmann rearrangement in 2002.…”

Section: Introductionmentioning

confidence: 99%

Effect of Micropore Size on Catalyst Deactivation in Vapor Phase Beckmann Rearrangement over Zeolites

Takahashi

Nakanishi²,

Kai³

2006

J. Jpn. Petrol. Inst.

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The vapor phase Beckmann rearrangement of cyclohexanone oxime (CHO) was carried out over TS-1 with an MFI pore structure and SSZ-31 and SSZ-24 with pore sizes larger than that of MFI to elucidate the effect of the pore size on catalyst deactivation. The deactivation constant over SSZ-24 was the highest among the zeolites used in the study. Furthermore, when the ratio between the molecular size of ε-caprolactam (CL) and the pore size of zeolite was unity, the deactivation constant was maximum over the zeolites at similar acidity. These results indicate that since CL produced on the active sites cannot diffuse from the micropores, the CL reacts to form coke or its precursor over a long residence time. The pore size of the zeolite is the main controlling factor of catalyst deactivation during the Beckmann rearrangement.

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Rearrangements of Hydroxylamines, Oximes and Hydroxamic Acids

Pereira

Santos²

2010

Patai's Chemistry of Functional Groups

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Introduction The [3,3]‐Sigmatropic Rearrangements The [2,3]‐Sigmatropic Rearrangements The Dyotropic Rearrangements The B amberger Rearrangements The B eckmann Rearrangements The N eber Rearrangements The L ossen Rearrangement Other Rearrangements

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Some aspects of the vapor phase Beckmann rearrangement for the production of ε-caprolactam over high silica MFI zeolites

Cited by 111 publications

References 12 publications

Development and Industrialization of the Vapor-Phase Beckmann Rearrangement Process

Development and Industrialization of the Vapor-Phase Beckmann Rearrangement Process

Effect of Micropore Size on Catalyst Deactivation in Vapor Phase Beckmann Rearrangement over Zeolites

Rearrangements of Hydroxylamines, Oximes and Hydroxamic Acids

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