Isobutane oxidative dehydrogenation

Kaddouri, A., Mazzocchia, C., and Tempesti, E. Propane and isobutane oxidative dehydrogenation with K, Ca and P-doped a- and 8-nickel molybdate catalysts. Appl. Catal. A Gen. 1998,169, L3. 

Catalytic testings have been performed using the same rig and a conventional fixed-bed placed in the inner volume of the tubular membrane. The catalyst for isobutane dehydrogenation [9] was a Pt-based solid and sweep gas was used as indicated in Fig. 2. For propane oxidative dehydrogenation a V-Mg-0 mixed oxide [10] was used and the membrane separates oxygen and propane (the hydrocarbon being introduced in the inner part of the reactor). 

Most of the results have been already partly presented in [9] (isobutane dehydrogenation) and [10] (propane oxidative dehydrogenation). Let us recall that the membrane presented in this paper has been associated with a fixed bed catalyst placed within the tube. 

Figure 14.3 Different strategies for integration of isobutane (oxi)dehydrogenation to isobutene and isobutene oxidation to methacrolein and to methacrylic acid.

Another well-studied catalyst system is Cr203 loaded onto various supports used in almost exclusively in the oxidative dehydrogenation of isobutane to isobutylene.361-364 In the case of Cr203 on La2(C03)3, the surface active center was found to be a chromate species bound to the surface La carbonate.361 With optimum loadings between 10-15% selectivities exceed 95% below 250°C. Correlations between... 

Liebmann LS, Schmidt LD (1999) Oxidative dehydrogenation of isobutane at short contact times. Appl Catal A Gen 179 93... 

We shall first show that it is still far fiom clear which are the families of catalysts to be used for the various reactions mainly oxidative dehydrogenation or oxidation to oxygen-containing molecules of ethane, propane or isobutane. Much research is still necessary for understanding the mechanisms leading to high selectivity. In this context, we shall suggest that many concepts inherited from the development in selective oxidation and ammoxidation of olefins are probably of little use. 

As the olefins and to a lesser extent the alkanes are basic one may expect the desorption to be favored by surface basic sites. In other words oxidative dehydrogenation of alkanes is expected to be easier on surface exhibiting basic properties. As a matter of fact the results given in table 5 from ref 41 show that Mg2V207 which is more basic as shown in table 4 is more selective for olefins in propane conversion and to a lesser extent for n-butane and isobutane oxidation reactions than the other two phases. Such a feature is even more pronounced for the samples with excess MgO at least for propane oxidation, samples which were also shown to present higher basicity (table 4). 

Catalytic data for oxidative dehydrogenation of propane (A) n-butane (B) and isobutane (C) at 540°C (from ref 41). 

Catalytic Oxidative Dehydrogenation of Isobutane in a Pd Membrane Reactor... 

Figure 1 Schematic of the oxidative dehydrogenation of isobutane reaction system.

The oxidative dehydrogenation of isobutane to isobutylene has been carried out with a salt of a Dawson acid, K7P2Wi7Mn06i, with 79% selectivity to isobutylene, 3%... 

The activation of higher alkanes is also being intensively investigated. An example is the oxidative dehydrogenation of ethane, propane, and isobutane to the corre-... 

B. Grzybowska, J. Sloczynski, R. Grabowski, K. Wcislo, A. Kozlowska, J. Stoch and J. Zielinski, Chromium oxide alumina catalysts in oxidative dehydrogenation of isobutane, J. Catal, 178(2), 687-700, 1998. 

J. Sloczynski, B. Grzybowska, R. Grabowski, A. Kozlowska and K. Wcislo, Oxygen adsorption and catalytic performance in oxidative dehydrogenation of isobutane on chromium oxide-based catalysts, Phys. Chem. Chem. Phys., 1(2), 333-339, 1999. A. Bielanski and J. Haber, Oxygen in catalysis, Dekker New York, 1991. 

A detailed kinetic study of oxidative dehydrogenation of propane, isobutane, n-butane (23 runs) and LPG (27 runs) was conducted over a wide range of partial pressures of pure and mixed hydrocarbons (0-0.3 atm), oxygen (0-0.2 atm) and steam (0.2-0.7) atm and temperature 600-670°C. Oxidation of Hj, CjHg, C H, CH and CO was also tested at 600-650°C. A set of reactions was selected based on the distribution of products ... 

Dfaz-Veldsquez, J., Carballo-Suarez, L. and Figueiredo, J. (2006). oxidative dehydrogenation of isobutane over activated carbon catalysts, A/ / /. Catal. A Gen., 311, pp. 51-57. 

Agafonov, Yu.A., Nekrasov, N.V., and Gaidai, N.A. Kinetic and mechanistic study of the oxidative dehydrogenation of isobutane over cobalt and nickel molybdates. Kinet. Catal. 2001, 42, 821. 

Comuzzi, C., Primavera, A., Trovarelli, A., Bini, G., and Cavani, F. Thermal stability and catalytic properties of the Wells-Dawson K P2Wi8062 IOH2O heteropoly compound in the oxidative dehydrogenation of isobutane to isobutene. Top. Catal 1999, 9, 251. 

Cavani, R, Comuzzi, C., Dolcetti, G., Etienne, E., Finke, R.G., SeUeri, G., Trifiro, F., and TrovareUi, A. Oxidative dehydrogenation of isobutane to isobutene Dawson-type heteropolyoxoanions as stable and selective heterogeneous catalysts./. Catal 1996,160, 317. 

Takita, Y, Sano, K., Muraya, T., Nishiguchi, H., Kawata, N., Ito, M., Akbay, T., and Ishihara, T. Oxidative dehydrogenation of isobutane to isobutene II. Rare earth phosphate catalysts. Appl. Catal A Gen. 1998,170, 23. 

Zhang, Y.J., Rodriguez-Ramos, L, and Guerrero-Ruiz, A. Oxidative dehydrogenation of isobutane over magnesium molybdate catalysts. Catal Today 2000, 61, 377. 

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