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Beckmann rearrangement acid catalysis

Acid catalysis by titanium silicate molecular sieves another area characterized by recent major progress. Whereas only two categories of acid-catalyzed reactions (the Beckmann rearrangement and MTBE synthesis) were included in the review by Notari in 1996 (33), the list has grown significantly since then. In view of the presence of weak Lewis acid sites on the surfaces of these catalysts, they can be used for reactions that require such weak acidity. [Pg.127]

As the Beckmann rearrangement is believed to be a typical acid-catalysed reaction, many researchers have reported the relationship between the vapour phase reaction catalysis and the acidity of the catalysts tested on non-zeolitic catalysts - i2s- i3i. 318-334 and on zeolitic catalysts Another interesting point for the heterogeneous gas-phase Beckmann rearrangement is the location of the reaction on the catalyst and different studies have been published ° . The outer surface of the catalyst particle seems to be the most probable place for the Beckmann rearrangement supported by the traces of reagents, and notable amounts of by-products found only in the outer layers of the zeolite crystal. Development of new and more efficient catalysts have also been reported " . ... [Pg.472]

As already discussed in Chapter 1, the commercialization, by Sumitomo [GO-64], of a vapor phase Beckmann rearrangement of cyclohexanone oxime to caprolactam over a high-silica MFI (ZSM-5 type) zeolite (Fig. 2.21) is another benchmark in zeolite catalysis. The process, which currently operates on a 90000 tpa scale, replaces a conventional one employing stoichiometric quantities of sulfuric acid and producing ca. 2 kg of ammonium sulfate per kg of caprolactam. [Pg.67]

Although many solid-acid catalysts have been reported for the vapor-phase Beckmann rearrangement [2], their performance has been less than satisfactory from an industrial standpoint and the heterogeneously catalyzed Beckmann rearrangement has not yet been commercialized. In this chapter heterogeneous catalysis of the Beckmann rearrangement, its mechanism, and acid properties and reaction conditions suitable for the reaction will be reviewed. [Pg.185]

Envirocat EPIC General acid catalysis Beckmann rearrangements Acylations with carboxylic acids and alkylations with alkenes Strong, solid Bronsted acid Improved product quality Easier separation... [Pg.542]


See other pages where Beckmann rearrangement acid catalysis is mentioned: [Pg.132]    [Pg.388]    [Pg.206]    [Pg.210]    [Pg.24]    [Pg.1502]    [Pg.2806]    [Pg.119]    [Pg.469]    [Pg.2789]    [Pg.582]    [Pg.1501]    [Pg.314]    [Pg.378]    [Pg.717]    [Pg.717]    [Pg.67]   
See also in sourсe #XX -- [ Pg.124 ]

See also in sourсe #XX -- [ Pg.124 ]




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