Ethane catalytic dehydrogenation

Oxidative Dehydrogenation of Ethane. The dehydrogenation of alkanes also occurs, but in a catalytic manner, over molybdenum supported on silica (22,23). In addition to the stoichiometric reactions, the role of the 0 ion in this catalytic reaction is further suggested by the observation that N2O is an effective oxidant at temperatures as low as 280°C, but no reaction is observed at these temperatures with O2 as the oxidant (22). It should be noted that at moderate temperatues N2O gives rise to 0 , whereas O2 yields O2 over Mo/Si02. Under steady-state conditions the rates of formation of C2Hi were in the ratio of 7 1 at 375°C and 3.7 1 at 450°C when N2O and O2 were used as the oxidants, respectively (23). ... 

As chemical companies rely more heavily on ethane and propane feeds to their olefins plants to generate their ethylene and propylene supplies, the coproduction of butadiene in olefins plants has not kept up with demand. Industry has resorted to building plants that make on-purpose or swing supply butadiene. The processes involve catalytically dehydrogenating (removing hydrogen from) butane or butylene. 

Another route to ethylbenzene is available for those remote places where olefin plants or refinery crackers are not nearby but a supply of ethane is— catalytic dehydrogenation of ethane to ethylene followed by its reaction with benzene to produce EB. The first of two steps in Figure 8-4 use a gallium zinc zeolyte catalyst that promotes ethane dehydrogenation to ethylerie at 86% selectivity and up to 50% conversion per pass. 

Natural gas liquids represent a significant source of feedstocks for the production of important chemical building blocks that form the basis for many commercial and industrial products. Ethylene (qv) is produced by steam-cracking the ethane and propane fractions obtained from natural gas, and the butane fraction can be catalytically dehydrogenated to yield 1,3-butadiene, a compound used in the preparation of many polymers (see Butadiene). The -butane fraction can also be used as a feedstock in the manufacture of MTBE. 

Ethane is dehydrogenated to ethylene and acetylene in the following pair of catalytic reactions C2H6 - C2H4 + H2 [A B + D]... 

Although production of ethylene via catalytic dehydrogenation over Pt catalysts is very selective (about 95%), extension of this dehydrogenation technology to ethane has not taken place because of the need for even more severe operating conditions higher... 

Catalytic Dehydrogenation of Ethane in Hydrogen Membrane Reactor... 

Early contributions [5, 6] claimed substantial influence of a membrane reactor on the kinetics of catalytic dehydrogenation of ethane as increases between 6 and 8 times above the thermodynamically allowed ethane conversion were reported for the membrane assisted runs. It was observed, however, that a long contact time was necessary to get these results. 

We have made significant advances in hydrogen separating ceramic membrane (H-membrane) technology [10]. The purpose of this work is to demonstrate its application to catalytic dehydrogenation of ethane and assess the feasibility of enhancement of olefin production in a membrane reactor. 

Commercialization of catalytic dehydrogenation of ethane in a membrane reactor could possibly occur either by developing a catalyst that makes the rate determining step sensitive to the partial pressure of hydrogen or developing an ethylene permselective membrane. 

Coupling Membranes and Reaction A catalytic membrane reactor combining catalysis and separation in one reactor is an excellent example of such a hybrid reactor (Figure 4.10.73), although this system is not yet used commercially. The potential of this concept has been demonstrated by the example of the catalytic dehydrogenation of ethane, which was investigated on the bench scale (Champagnie, Tsotsis, and Minet, 1990 Moulijn, Makkee, and Van Diepen, 2004) ... 

Ethylene is obtained mainly by the steam-cracking process (Section 6.6) and by catalytic dehydrogenation of ethane (Section 5.3.1). Chemical transformations of ethylene to industrial relevant chemicals (Figure 5.3.4) can be classified in three main categories ... 

With respect to the catalytic reactions, there are well-established industrial reactions (as occurs in the case of n-butane to maleic anhydride), reactions in the preindustrial stage (such as the transformation of propane to acrylonitrile), very promising reactions (such as ethane oxidative dehydrogenation to ethylene), and potential reactions whose economical viability will depend on the prices of crude and natural gas in the future (such as propane selective oxidation to acrylic acid or methane transformation). 

Centi, G. (1993). Vanadyl Pyrophosphate A Critical Overview, Catal. Today, 16, pp. 5-26. Lopez Nieto, J., Botella Asuncion, P., Vazquez Navarro, M., et al. (2003). Worldwide Patent 2003064035 Al, Method for the Oxidative Dehydrogenation of Ethane (CSIC-UPV). Heracleous, E. and Lemonidou, A. (2006). Ni-Nb-O Mixed Oxides as Flighly Active and Selective Catalysts for Ethene Production via Ethane Oxidative Dehydrogenation. Part I Characterization and Catalytic Performance, J. Catal., 237, pp. 162-174. 

Katerina, N., Roman, B., and Blanka, W. On the effect of cobalt loading on catalytic activity of Co-BEA zeolites in ethane oxidative dehydrogenation and anunoxidation. Scientific papers of the University of Pardubice. Series A. Faculty of Chemical Technology 9, 111-128(2003). 

More than 90% of today s petrochemicals are produced from refineiy products. Most are based on the use of C2-C4 olefins and aromatics finm hydrocarbon steam cracking units, which are even more closely linked to refineries. In North America, the feedstock for steam cracker units have generally been ethane, propane, or LPG. As a result, most of the propylene and aromatics have been provided by FCC units and catalytic reformers. In maity other parts of the world where naphtha feed has been more readily available, suppUes of propylene and aromatics have been produced directly by steam cracking. When necessary, the catalytic dehydrogenation of paraffins or dealkylation of toluene can balance the supply of olefins or benzene. In Table 7.2 some of the catalytic processes that convert olefins and benzene from a steam cracker into basic petrochemicals for the modem chemical industry are shown. 

The catalytic properties are presented in Fig, 5 and Table 2. Dependences of activity on pH sluny for propane oxidation (curee 2), propane ammoxidation (curve 3) and ethane oxidative dehydrogenation (curve 1) as well as content of Ml phase (curve 4) have... 

Ethylene is a sole product of selective conversion in ethane oxidative dehydrogenation. The studied catalytic system is most selective in this reaction. 

Although ethylene is produced by various methods as follows, only a few are commercially proven thermal cracking of hydrocarbons, catalytic pyrolysis, membrane dehydrogenation of ethane, oxydehydrogenation of ethane, oxidative coupling of methane, methanol to ethylene, dehydration of ethanol, ethylene from coal, disproportionation of propylene, and ethylene as a by-product. 

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