Catalytic oxidative coupling methane

The Problems. Challenges and Opportunities Ahead In summary, though the catalytic oxidative coupling methane to form ethylene/ethane has now been amply demonstrated 1n many research laboratories worldwide, the commercial feasibility of such a process depends critically on ... 

J.H. Lunsford., The Catalytic Oxidative Coupling of Methane, 34, Angew. Chem. Ed. Engl, 970, (1995). 

Several reaction mechanisms have been proposed for the catalytic oxidative coupling of methane. This summary will focus only on the most impcxtant mechanisms, since it is believed that they give a good approximation of gas-phase and surface processes taking place during catalytic activation of methane. 

THE PRODUCTION OF LIQUID FUELS VIA THE CATALYTIC OXIDATIVE COUPLING OF METHANE... 

The production of higher hydrocarbons directly from methane by catalytic oxidative coupling is a novel methane conversion process which warrants further study. When combined with an ethylene oligomerisation step it is a potential alternative to conventional processes, based on synthesis gas, for producing liquid fuels from methane. However, further research is necessary to provide the information required to assess the commercial prospects for this route. 

Experiment 3 was carried out to see whether application of these ideas would give a further improvement of the yield of hydrocarbons using an improved catalyst. The total concentration of products obtained is, to our knowledge, the highest reported until now for the catalytic oxidative coupling of methane. 

This article provides a comprehensive review of advanced processes for direct conversion of methane. These processes include (1) direct partial oxidation of methane to methanol, (2) catalytic oxidative coupling, and (3) oxyhydrochlorination. The primary goal of this review is to present an overview of the state of the art of these technologies and provide an initiative for advancing the... 

The feasibility of the concept of coupled endo- and exothermic reactions has been investigated in silico for steam reforming of methane (Zanfir and Gavriilidis, 2003), as the fast and highly endothermic reaction with the energy being provided by the catalytic oxidation of methane. The studies show that it should be possible to reduce the size of steam reformers by two orders of magnitude. 

Mleczko L, Rothaemel M, Andorf R, Baerns M. Fluidized bed reactor performance for the catalytic oxidative coupling of methane to C2+ hydrocarbons. In Potter OE, Nicklin DJ, eds. Fluidization VII, Brisbane, Australia, 1992, pp 487-494. 

Homogeneous, catalytic, oxidative coupling of methane to acetic acid in one step. Top. CataL, 32,169 174. 

Lunsford JH (1995) The catalytic oxidative coupling of methane. Angew Chem hit Ed 34 970-980... 

Bi, Y., Zhen, K., Jiang, Y., Teng, C, and Yang, X. (1988) Catalytic Oxidative Coupling of Methane over Alkali, Alkaline Earth and Rare Earth Metal Oxides , Appl. Catal. 39,185-90. 

Sofranko, J.A., Leonard, J.J., Jones, C.A., Gaffney, A.M., and Withers, H.P. (1988b) Catalytic Oxidative Coupling of Methane Over Sodium-Promoted Mn/SiOi and Mn/MgO , Catalysis Today 3,127-35. 

These findings have been well documented in various review articles (for references see [7]). Therefore, only selected results are cited in this contribution to leave space for introducing more recent results in the area of catalytic oxidative coupling of methane. 

Figure 27. Process scheme for catalytic oxidative coupling of methane to ethylene [57].

Mleczko, L., Rothaemel, M., Andorf, R. and Baerns, M., Fluidized-Bed-Reactor Performance for the Catalytic Oxidative Coupling of Methane to C2+ Hydrocarbons, submitted as contribution to "Fluidization Conference 1992". 

The direct methane conversion technology, which has received the most research attention, involves the oxidative coupling of methane to produce higher hydrocarbons (qv) such as ethylene (qv). These olefinic products may be upgraded to Hquid fuels via catalytic oligomerization processes. 

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. 

Oxidative Coupling of Methane to Ethylene with 85% Yield in a Gas Recycle Electrocatalytic or Catalytic Reactor-Separator... 

Methane can be oxidatively coupled to ethylene with very high yield using the novel gas recycle electrocatalytic or catalytic reactor separator. The ethylene yield is up to 85% for batch operation and up to 50% for continuous flow operation. These promising results, which stem from the novel reactor design and from the adsorptive properties of the molecular sieve material, can be rationalized in terms of a simple macroscopic kinetic model. Such simplified models may be useful for scale up purposes. For practical applications it would be desirable to reduce the recycle ratio p to lower values (e.g. 5-8). This requires a single-pass C2 yield of the order of 15-20%. The Sr-doped La203... 

Cerium oxides are outstanding oxide materials for catalytic purposes, and they are used in many catalytic applications, for example, for the oxidation of CO, the removal of SOx from fluid catalytic cracking flue gases, the water gas shift reaction, or in the oxidative coupling reaction of methane [155, 156]. Ceria is also widely used as an active component in the three-way catalyst for automotive exhaust pollution control,... 

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