Oxidative coupling of methane to ethane

IFP Oxypyrolysis Also called NGOP. A process for converting natural gas to gasoline, based on the oxidative coupling of methane to ethane in a fixed-bed reactor. Developed in 1991 by the Institut Frangais du Petrole. 

SELECTIVE OXIDATIVE COUPLING OF METHANE TO ETHANE AND ETHYLENE... 

The catalytic reactions of methane reforming to syngas, oxidative coupling of methane to ethane and ethylene, direct oxidation of methane to methanol and formaldehyde occur at relatively high temperatures, 400—1000 °C, i.e., can be qualified as high-temperature catalytic oxidation processes. Numerous studies of these reactions, different in many ways, showed, however, that they have a number of common features, the most important of which are ... 

Generally, the most developed processes involve oxidative coupling of methane to higher hydrocarbons. Oxidative coupling converts methane to ethane and ethylene by... 

In the 1980s, the oxidative coupling of methane to give ethylene and ethane was reported by Keller and Bhasin (8), whose discovery prompted numerous attempts to convert methane directly—and not only to ethylene and ethane (8), but also to methanol and formaldehyde (9) (Table I). Research on oxidative coupling of methane was motivated by results showing that the methane was... 

Considerably more progress has been made in the oxidative coupling of methane to form ethane and ethylene (C2 products). Since the early work of Keller and Bhasin [Ref. 3], the steady-state yields of C2 products have improved to a level of about 20%. Among the more effective catalysts are the Group IIA oxides which... 

The oxidative coupling of methane to give ethane and ethylene is an... 

Sometimes reaction rates can be enhanced by using multifunctional reactors, i.e., reactors in which more than one function (or operation) can be performed. Examples of reactors with such multifunctional capability, or combo reactors, are distillation column reactors in which one of the products of a reversible reaction is continuously removed by distillation thus driving the reaction forward extractive reaction biphasing membrane reactors in which separation is accomplished by using a reactor with membrane walls and simulated moving-bed (SMB) reactors in which reaction is combined with adsorption. Typical industrial applications of multifunctional reactors are esterification of acetic acid to methyl acetate in a distillation column reactor, synthesis of methyl-fer-butyl ether (MTBE) in a similar reactor, vitamin K synthesis in a membrane reactor, oxidative coupling of methane to produce ethane and ethylene in a similar reactor, and esterification of acetic acid to ethyl acetate in an SMB reactor. These specialized reactors are increasingly used in industry, mainly because of the obvious reduction in the number of equipment. These reactors are considered by Eair in Chapter 12. 

Oxidative coupling of methane to yield C2 and higher hydrocarbons The oxidative coupling of methane has been studied by several authors. The most elusive transformation has been the oxidative coupling of methane into C2 hydrocarbons (ethene, ethane), because the reaction is more endothermic than other transformations [2]. The application of rapid and efficient MW heating to endothermic reactions is particularly interesting. 

The conversion into methanol has, so far, shown very small yields (< 5%), whereas yields for oxidative coupling appear to approach a ceiling of 25% per pass, irrespective of catdysts and process conditions (McCarthy et al., 1990). Typical selectivities for oxidative coupling of methane to Cj-hydrocarbons are 80-85% (of which 40-50% as ethylene). The ethane product has a value comparable to that of the feed, but it can be converted into ethylene with an ultimate yield of 81% by pyrolysis (steam cracking) (Albright et al., 1983). 

Methane is the most abundant component of natural gas which is a raw material for ftiture liquid fuel and chemical production industries. Oxidative dehydrogenation and subsequent coupling of methane to ethane and ethylene is a simple, energy-efficient reaction scheme to use meAane as a precursor for ethylene. 

Oxidative coupling of methane to form ethane and ethylene proceeds with fairly good selectivity over basic solids such as Li-doped MgO and rare-earth oxides at very high temperatures. 

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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