Dehydrogenation of isopropyl alcohol

Production of acetone by dehydrogenation of isopropyl alcohol began in the early 1920s and remained the dominant production method through the 1960s. In the mid-1960s virtually all United States acetone was produced from propylene. A process for direct oxidation of propylene to acetone was developed by Wacker Chemie (12), but is not beheved to have been used in the United States. However, by the mid-1970s 60% of United States acetone capacity was based on cumene hydroperoxide [80-15-9], which accounted for about 65% of the acetone produced. 

Dehydrogenation of isopropyl alcohol accounts for most of the acetone production not obtained from cumene. The vapor is passed over a brass, copper, or other catalyst at 400—500°C, and a yield of about 95% is achieved (1.09 unit weight of alcohol per unit of acetone) (13). 

Dehydrogenation of Isopropyl Alcohol. In the United States about 4% of the acetone is made by this process, and in Western Europe about 19% (22). Isopropyl alcohol is dehydrogenated in an endothermic reaction. 

Dehydrogenation. Before the large-scale availabiUty of acetone as a co-product of phenol (qv) in some processes, dehydrogenation of isopropyl alcohol to acetone (qv) was the most widely practiced production method. A wide variety of catalysts can be used in this endothermic (66.5 kj/mol (15.9 kcal/mol) at 327°C), vapor-phase process to achieve high (75—95 mol %) conversions. Operation at 300—500°C and moderate pressures (207 kPa (2.04 atm)) provides acetone in yields up to 90 mol %. The most useful catalysts contain Cu, Cr, Zn, and Ni, either alone, as oxides, or in combinations on inert supports (see Catalysts, supported) (13-16). 

A similar difference in the adsorption coefficients of the starting reactant of branched reactions was also found in the parallel dehydration and dehydrogenation of isopropyl alcohol on some oxide catalyst (123) here, of course, the chemical nature of both branches is clearly different. It is of interest, however, to note that for the series of catalysts with varying... 

Dehydrogenation of Isopropyl Alcohol to Acetone Nonporous Pd membranes Mikhalenko, Khrapova and Gryaznov (1986)... 

Mikhalenko, N. N., E. V. Khrapova and V. M. Gryaznov. 1986. Influence of hydrogen on the dehydrogenation of isopropyl alcohol in the presence of a palladium membrane catalyst. Kinet. and Catal. 27(1) 125-128. 

Ketones.have the characteristic -C- signature group imbedded in them. Acetone, CH3COCH3, comes from two different routes. It is a by-product in the cumene to phenol/acetone process. It is the on-purpose product of the catalytic dehydrogenation of isopropyl alcohol. Acetone is popular as a solvent and as a chemical intermediate for the manufacture of MIBK, methyl methacrylate, and Bisphenol A. 

Dehydrogenation and hydrogenation of cyclohexene Hydrogenation of butadiene Dehydrogenation of isopropyl alcohol... 

Coupling of dehydrogenation of isopropyl alcohol and hydrogenation of cyclopentadiene Hydrogenation of acetylene and ethylene... 

The activation/deactivation model presented in an earlier work has been applied to the study of the dehydrogenation of isopropyl alcohol on a Cu/ SiOa catalyst. The model explains the appearance of activity maxima, and yields the values of the relevant kinetic parameters such as the initial fraction of PAS (which was found to be approximately the same for catalysts with the same pretreatment), the initial reaction rate and the activation and deactivation functions. 

Acetone which was formerly made almost exclusively by the dry distillation of calcium acetate obtained in the destructive distillation of wood, is now made on a large scale by the dehydrogenation of isopropyl alcohol obtained largely from the hydration of propylene contained in refinery gases.84 The other remaining sources of acetone at present are the wood distillation industry, the fermentation process of butanol manufacture,... 

Fig. 10.5. Acetone manufacture by liquid phase dehydrogenation of isopropyl alcohol. IFP process. 

Fig. 7. Dehydrogenation of isopropyl alcohol. The activation energy as a function of the interatomic distance d of metals.

The most active Tc metal catalyst was obtained at the lowest temperature used for the reduction of TCO2 to Tc metal. Die apparent activation energy for the dehydrogenation process was 13.7 kcal/mole. At 220 C 30 % of isopropyl alcohol was converted to acetone. ITie activity of the technetium metal catalyst for the dehydrogenation of isopropyl alcohol is superior to that of manganese and close to that of metallic rhenium when, however, the content of rhenium in the catalyst was 30 wt% instead of around 0.2 wt% of technetium [11]. 

In addition, the dehydrogenation of isopropyl alcohol was studied using technetium metal supported on the oxides Y2O3, Pi 407, Nd203 or Yb203. Table 8.1.A. summarizes the results,... 

Tabic 8.1.A Catalysts and activity for dehydrogenation of isopropyl alcohol (12]. 

Large changes in electrical conductivity occur in chromia-alumina catalysts during catalytic reactions such as the conversion of heptane to toluene (199), the dehydration of cyclohexane (200), and the Hg-Dg exchange reaction 188). Bremer and Stach 201) found a linear relationship between the logarithm of the specific electrical conductivity and the activity for the dehydrogenation of isopropyl alcohol. 

A few measurements of catalytic activity have been made on the reduced copper-alumina system. Comparison of catalysts containing varying proportions of copper was made as usual by mechanically mixing all samples, except the lowest in copper, with 7-alumina so that all samples contained 3.2 per cent copper. The catalytic measurements were not extended below that concentration. The reaction chosen was the dehydrogenation of isopropyl alcohol. 

Strongly basic catalysts can be prepared by impregnating CsNaX and CsNaY with cesium acetate followed by thermal decomposition of the acetate into the oxide (60-62). The cataljrtic activity for the dehydrogenation of isopropyl alcohol to acetone increased an order of magnitude by loading Cs onto CsY. The isomerization of 1-butene proceeds over these catalysts at 273 K. Various evidences including (133) Cs nmr indicate that the active species is nanophase cesium oxide occluded in the supercage of the zeolites. 

B.8 Batch Production of L-Phenylalanine and L-Aspartic Acid. Unit 900 B.9 Acrylic Acid Production via the Catalytic Partial Oxidation of Propylene B.IO Production of Acetone via the Dehydrogenation of Isopropyl Alcohol B.ll Production of Heptenes from Propylene and Butenes... 

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