Sulphur/halogen promoted oxidative dehydrogenation of hydrocarbons

Abstract

Iodine is known to be an efficient promoter for the oxidative dehydrogenation of a wide variety of hydrocarbons. However, because of its high cost attempts have been made to reduce or eliminate it from the reaction system while still achieving high product yields. Theoretical considerations (thermodynamic and mechanistic) will be presented to show that it should be possible to use sulphur alone or together with chlorine and/or bromine in place of iodine or iodine/halogen mixtures in the oxidative dehydrogenation of different hydrocarbons. These considerations indicate that high product yields should also be possible with the new system if suitable catalysts are used.

Oxidative Dehydrogenation of Propane to Propylene with Soft Oxidants via Heterogeneous Catalysis

“…To obtain reactive, diradical species S 2 , high temperatures (i.e., 648−800 °C) are required. 43,44 However, thermal cracking of C 3 H 8 may occur at such high temperatures, making this reaction more challenging.…”

Propane chlorination over ruthenium oxychloride catalysts

“…There have been attempts to carry out propane dehydrogenation using organochlorine compounds [10,11], sulfur containing compounds [12][13][14], nitrous oxide [15,16], CO 2 [17], and halogens [18] as gentle oxidizers. Note that employing halogens in this process was suggested more than 50 years ago.…”

“…Note that employing halogens in this process was suggested more than 50 years ago. There have been thermodynamic calculations on the oxidative dehydrogenation of hydrocarbons with different halo gens [18]. According to these calculations, the thermo dynamically most favorable oxidizer is molecular chlo rine.…”

Oxidative dehydrogenation of propane by molecular chlorine

“…It is noteworthy that the application of halogens for the dehydrogenation was proposed more than 40 years ago, based on thermodynamic calculations [18]. Pasternak and Vadekar calculated the thermodynamics of the oxidative dehydrogenation of hydrocarbons in the presence of different halogens.…”

“…There are attempts to use various organochlorine compounds [11,12], sulfur-containing compounds [13,14], nitrous oxide [15,16], CO 2 [17], and halogens [18] as mild oxidants for the dehydrogenation of propane. It is noteworthy that the application of halogens for the dehydrogenation was proposed more than 40 years ago, based on thermodynamic calculations [18].…”