Butadiene selective

J. P. Boitiaux, J. Cosyns, M. Derrien, and G. Leger, Proper design of butadiene selective hydrogenation process for maximum 1-butene yield by using comprehensive kinetic model, AIChE National Meeting (Houston, March 24, 1984). 

Reaction Orders and Butadiene Selectivities in Butene Oxidation over Ferrite Catalysts... 

Catalyst Temperature (°C) Feed (atm) Order Butene conversion (%) Butadiene selectivity (%) Reference... 

DegussaAG Butadiene-free C4 hydrocarbons C4 hydrocarbons with butadiene Selective hydrogenation of C4 streams without butene-1 isomerization 5 1992... 

In what concerns to products distribution, the effect of temperature is similar with both catalysts and corresponds to an increase in butane conversion the butenes selectivity decreases as the butadiene selectivity increases and the carbon oxides formation also increases, specially CO. These effects are more pronounced with the Cs doped sample. Butane partial pressure does not affect the products distribution with NiMo04 but increases the C4 s selectivity (specially butenes) decreasing mainly the CO2 formation with the 3% Cs doped catalyst. The effects of increasing P02 are the same for both catalysts. A decrease of C4 S selectivities and an increase of COx formation at low pressures is mainly observed. It is noteworthy that the main effects of Cs doping in the selectivities are increase in I-butene selectivity and decrease in CO formation. 

It takes place between 400 and 600 C, at 0.15.10 Pa absolnte, in the presence of catalysts based on bismuth molybdate and phosphate, doped with various transition metals. Operations are conducted with oxygen to butenes mole ratios of about 1 and steam to butenes ratios of 30 to 50. Once through conversion is np to 60 per cent and molar butadiene selectivity close to 95 per cent. 

Fresh n-butane feed is combined with recycle feed from a butadiene extraction unit. The total feed is then vaporized and raised to reaction temperature in a charge heater (1) and fed to the reactors (2). Reaction takes place at vacuum conditions to maximize n-butane conversion and butadiene selectivity. The reactor effluent gas is quenched with circulating oil, compressed (3) and sent to the recovery section (4), where inert gases, hydrogen and light hydrocarbons are separated from the compressed reactor effluent. Condensed liquid from the recovery section is sent to a depropanizer (5), where propane and lighter components are separated from the C s. The bottoms stream, containing butadiene, n-butenes and n-butane, is sent to an OSBL butadiene extraction unit, which recovers butadiene product and recycles n-butenes and n-butane back to the CATADIENE reactors. 

Figure 1 Butadiene selectivity for different particle sizes and temperatures from Voge and Morgan [135]). 

NIE Nie, H., Li, M., Bansil, R., Konak, C., HelmstedL M., and Lai, L, Structure and dynamics of a pentablock copolymer of polystyrene-polybutadiene in a butadiene-selective solvent, Polymer, 45, 8791, 2004. 

Furlong B, Hightower JW, Chan TY-L, Sarkany A, Guczi L. 1,3-Butadiene selective hydrogenation over Pd/alumina and CuPd/alumina catalysts. Appl Catal A Gen. 1994 117 41. 

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