Isomerization supported aluminum chloride catalyst

October, 1941. The isomerization is carried out in the vapor phase over a bauxite-supported aluminum chloride catalyst. A simplified flow diagram showing the essential features of the process (3) is given in Figure 12. 

Butane vapor-phase isomerization a process for isomerizing n-butane to iso-butane using aluminum chloride catalyst on a granular alumina support and with hydrogen chloride as a promoter. 

Initially, aluminum chloride was the catalyst used to isomerize butane, pentane, and hexane. Siace then, supported metal catalysts have been developed for use ia high temperature processes that operate at 370—480°C and 2070—5170 kPa (300—750 psi), whereas aluminum chloride and hydrogen chloride are universally used for the low temperature processes. 

The activation and isomerization reactions were looked at in much detail by Okuhara [58] and Paleta et al. [59], Okuhara made some pertinent observations such as (a) the isomerization did not occur with partially deteriorated aluminum chloride, (b) the rate of isomerization is sensitive to stirring efficiency, and (c) the rate of isomerization is retarded by highly chlorinated organics, e.g. CCU- Paleta et al. reported that the behavior of the catalyst in both activations and isomerizations depends on the kind of commercial aluminum chloride used. This has recently been supported by claims that catalyst life and efficacy are related to the surface area of the AICI3 catalyst precursor, which varies from batch to batch of commercial material [60]. 

During World War II, the great demand for aircraft fuel necessitated the production of large quantities of isobutane, a basic raw material in the production of high octane aviation gasoline. (See chapter on Alkylation of Alkanes. ) Various processes have been developed for the isomerization of n-butane to isobutane all of them employed aluminum chloride-hydrogen chloride as catalyst. The difference between the various processes consisted either in the method of introduction of aluminum chloride to the reaction zone, the catalyst support, or the state of the catalyst. The following summary describes some of the main features of the various processes which were developed ... 

This work resulted, over the period 1948-1952, in eight publications dealing with the isomerization of paraffins and their hydrogen-exchange reactions in acidic systems. The interfaces involved were either solid, with catalysts based on aluminum chloride, or liquid, with concentrated sulfuric acid. The results provided strong support for the utility of the carbonium-ion model and new information about the properties of the postulated transient intermediates. 

The ionic liquid process has a number of significant advantages over the industrial Cosden process. This system uses a supported or liquid phase aluminum(lll) chloride catalyst. Using the ionic liquid process, the polymer forms a separate layer, which is substantially free of catalyst and ionic liquid solvent. This effect greatly enhances the degree of control available to reduce undesirable secondary reactions (i.e., isomerization) without requiring alkali quenching of the reaction. 

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