Hydrocarbons vapor-phase oxidation

Propanol has been manufactured by hydroformylation of ethylene (qv) (see Oxo process) followed by hydrogenation of propionaldehyde or propanal and as a by-product of vapor-phase oxidation of propane (see Hydrocarbon oxidation). Celanese operated the only commercial vapor-phase oxidation faciUty at Bishop, Texas. Since this faciUty was shut down ia 1973 (5,6), hydroformylation or 0x0 technology has been the principal process for commercial manufacture of 1-propanol ia the United States and Europe. Sasol ia South Africa makes 1-propanol by Fischer-Tropsch chemistry (7). Some attempts have been made to hydrate propylene ia an anti-Markovnikoff fashion to produce 1-propanol (8—10). However, these attempts have not been commercially successful. 

For the manufacturing of sulfosuccinic acid esters, which belong to a special class of surfactants, maleic acid anhydride is needed. Maleic acid anhydride is an important intermediate chemical of the chemical industry. Its worldwide output amounts to about 800,000 tons (1990) [64]. Maleic acid is produced by catalytic vapor phase oxidation process of benzene or n-C4 hydrocarbons in fixed bed or fluidized bed reactors according the following reaction equations. The heat of reaction of the exothermic oxidation processes is very high. 

Vapor-phase oxidation of toluene to benzaldehyde is a classical subject in the field of partial oxidation. Indeed, it has already been studied with various V- and Mo-based oxide catalysts [1-18]. However, the one-pass yield of benzaldehyde was still lower than that of other oxygenated compounds obtained in oxidation of olefins and aromatic hydrocarbons. For example, the maximum yield of benzaldehyde obtained with Bi-Mo oxides was around 10 mol% [7,11,12],... 

Essentially all maleic anhydride is manufactured by the catalytic vapor-phase oxidation of hydrocarbons. Prior to 1975, benzene was the feedstock of choice. By the early 1980s, however, many producers had... 

The predominant commercial synthesis of MA is by vapor-phase oxidation of hydrocarbons, e.g. benzene, n-butane, or a C-4 hydrocarbon mixture, over a solid catalyst [67]. The oxidation of benzene over a supported vanadium oxide catalyst is the preferred procedure. In a typical process, the reactor gas containing low concentrations of MA is passed through a heat exchanger and... 

Catalytic Vapor-Phase Oxidation of Some Four-Carbon Hydrocarbons. 

The majority of the work on the vapor phase oxidation mechanism of the hydrocarbons higher than butane has been for the purpose of studying the operation of gasoline internal combustion engines. As these studies have been largely devoted to anti-knock action a discussion may well be reserved for that section. However, some of the work is relevant. 

Novel Catalysts. - One other promising option exists that might, in the long run, lead to a viable alternative to the above process concepts. Recent advances in biomimetic catalysis have resulted in the development of molecular catalysts that are selective in liquid-phase oxidation of C,-Cj aliphatic hydrocarbons under mild conditions. The catalysts have now been placed on suitable support materials for vapor-phase oxidation of methane to methanol. Significant laboratory research is still required on the properties and synthesis of these special molecular catalysts before process conditions, products, and yields can be defined, even on a laboratory scale. 

Although the selectivity of isopropyl alcohol to acetone via vapor-phase dehydrogenation is high, there are a number of by-products that must be removed from the acetone. The hot reactor effluent contains acetone, unconverted isopropyl alcohol, and hydrogen, and may also contain propylene, polypropylene, mesityl oxide, diisopropyl ether, acetaldehyde, propionaldehyde, and many other hydrocarbons and carbon oxides (25,28). 

CoF is used for the replacement of hydrogen with fluorine in halocarbons (5) for fluorination of xylylalkanes, used in vapor-phase soldering fluxes (6) formation of dibutyl decalins (7) fluorination of alkynes (8) synthesis of unsaturated or partially fluorinated compounds (9—11) and conversion of aromatic compounds to perfluorocycHc compounds (see Fluorine compounds, organic). CoF rarely causes polymerization of hydrocarbons. CoF is also used for the conversion of metal oxides to higher valency metal fluorides, eg, in the assay of uranium ore (12). It is also used in the manufacture of nitrogen fluoride, NF, from ammonia (13). 

In addition to production of simple monofunctional products in hydrocarbon oxidation there are many complex, multifimctional products that are produced by less weU-understood mechanisms. There are also important influences of reactor and reaction types (plug-flow or batch, back-mixed, vapor-phase, Hquid-phase, catalysts, etc). 

Carbide. Zirconium carbide [12020-14-3] nominally ZrC, is a dark gray brittle soHd. It is made typically by a carbothermic reduction of zirconium oxide in a induction-heated vacuum furnace. Alternative production methods, especially for deposition on a substrate, consist of vapor-phase reaction of a volatile zirconium haHde, usually ZrCl, with a hydrocarbon in a hydrogen atmosphere at 900—1400°C. 

In the petroleum (qv) industry hydrogen bromide can serve as an alkylation catalyst. It is claimed as a catalyst in the controlled oxidation of aHphatic and ahcycHc hydrocarbons to ketones, acids, and peroxides (7,8). AppHcations of HBr with NH Br (9) or with H2S and HCl (10) as promoters for the dehydrogenation of butene to butadiene have been described, and either HBr or HCl can be used in the vapor-phase ortho methylation of phenol with methanol over alumina (11). Various patents dealing with catalytic activity of HCl also cover the use of HBr. An important reaction of HBr in organic syntheses is the replacement of aHphatic chlorine by bromine in the presence of an aluminum catalyst (12). Small quantities of hydrobromic acid are employed in analytical chemistry. 

Johnson, P.C., R.C. Lemon and J.M. Berty, Selective Non-Catalytic, Vapor-Phase Oxiation of Saturated Aliphatic Hydrocarbons to Olefin Oxides, 1964, US Patent 3,132,156. 

An explosion occurred in a vapor-phase hydrocarbon oxidation plant, injuring ten people and seriously damaging the plant, despite the fact that it was fitted with a protective system that measured the oxygen content and isolated the oxygen supply if the concentration approached the flammable limit. 

National Research Council. Committee on Medical and Biologic Effects of Environmental Pollutants. Vapor-Phase Organic Pollutants. Volatile Hydrocarbons and Oxidation Products. Washington, D.C. National Academy of Sciences, 1976. 411 pp. 

Vapor phase partial oxidation of hydrocarbons also yield H2O2. However, several by-products are generated, the separations of which make the process difficult and uneconomical. 

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