Oxidation carbon monoxide, ethylene

A new route to ethylene glycol from ethylene oxide via the intermediate formation of ethylene carbonate has recently been developed by Texaco. Ethylene carbonate may be formed by the reaction of carbon monoxide, ethylene oxide, and oxygen. Alternatively, it could be obtained by the reaction of phosgene and methanol. 

Treatment of thietane with electron acceptors, such as tetracyanoquino-dimethane (TCNQ), tetracyanoethylene (TCNE), maleic anhydride, or tetra-nitromethane, induces polymerization, believed to occur through an intermediate charge-transfer complex. The reaction with tetranitromethane is unusual because nitric oxide, nitrogen dioxide, carbon monoxide, ethylene, ethane, and propane are... 

Table III. Carbon Monoxide, Ethylene, and Ethane Oxidation Activities of Unsupported Catalystsa...

These NDIR instruments are mainly used for gas samples although multiple reflection cells are available in a variety of materials that are applicable for the analysis of liquids. Filters are chosen according to the analyte to be determined and the other components of the matrix. Carbon dioxide, carbon monoxide, ethylene, nitrogen oxides and sulfur dioxide are typical analytes. 

Photolytic. Photolysis products include carbon monoxide, ethylene, free radicals and a polymer (Calvert and Pitts, 1966). Anticipated products from the reaction of acrylonitrile with ozone or hydroxyl radicals in the atmosphere are glyoxal, formaldehyde, formic acid and carbon dioxide (Cupitt, 1980). The major product reported from the photooxidation of acrolein with nitrogen oxides is formaldehyde with a trace of glyoxal (Altshuller, 1983). Osborne et al. (1962) reported that acrolein was stable at 30°C and UV light (2. = 313 nm) in the presence and absence of oxygen. 

Midi or H-Cube Maxi. This permits the use of another gas molecule in place of hydrogen - such as carbon monoxide, ethylene, nitric oxide, or oxygen - at up to 100 bar by adding an optional gas module, which ensures a variety of metal-catalyzed reactions under the flow conditions [60],... 

The changeover from ROO radicals to HOO radicals and the switch from organic peroxides to HOOH has been shown as temperature is increased in propane VPO (87,141). Tracer experiments have been used to explore product sequences in propane VPO (142—145). Propylene oxide comes exclusively from propylene. Ethylene, acetaldehyde, formaldehyde, methanol, carbon monoxide, and carbon dioxide come from both propane and propylene. Ethanol comes exclusively from propane. 

Other Methods. A variety of other methods have been studied, including phenol hydroxylation by N2O with HZSM-5 as catalyst (69), selective access to resorcinol from 5-methyloxohexanoate in the presence of Pd/C (70), cyclotrimerization of carbon monoxide and ethylene to form hydroquinone in the presence of rhodium catalysts (71), the electrochemical oxidation of benzene to hydroquinone and -benzoquinone (72), the air oxidation of phenol to catechol in the presence of a stoichiometric CuCl and Cu(0) catalyst (73), and the isomerization of dihydroxybenzenes on HZSM-5 catalysts (74). 

Lead sesquioxide is used as an oxidation catalyst for carbon monoxide ia exhaust gases (44,45) (see Exhaust control), as a catalyst for the preparation of lactams (46) (see Antibiotics, P-lactams), ia the manufacture of high purity diamonds (47) (see Carbon, diamond-natural), ia fireproofing compositions for poly(ethylene terephthalate) plastics (48), ia radiation detectors for x-rays and nuclear particles (49), and ia vulcanization accelerators for neoprene mbber (50). 

The reaction of methyl propionate and formaldehyde in the gas phase proceeds with reasonable selectivity to MMA and MAA (ca 90%), but with conversions of only 30%. A variety of catalysts such as V—Sb on siUca-alumina (109), P—Zr, Al, boron oxide (110), and supported Fe—P (111) have been used. Methjial (dimethoxymethane) or methanol itself may be used in place of formaldehyde and often result in improved yields. Methyl propionate may be prepared in excellent yield by the reaction of ethylene and carbon monoxide in methanol over a mthenium acetylacetonate catalyst or by utilizing a palladium—phosphine ligand catalyst (112,113). 

Chromium Oxide-Based Catalysts. Chromium oxide-based catalysts were originally developed by Phillips Petroleum Company for the manufacture of HDPE resins subsequendy, they have been modified for ethylene—a-olefin copolymerisation reactions (10). These catalysts use a mixed sihca—titania support containing from 2 to 20 wt % of Ti. After the deposition of chromium species onto the support, the catalyst is first oxidised by an oxygen—air mixture and then reduced at increased temperatures with carbon monoxide. The catalyst systems used for ethylene copolymerisation consist of sohd catalysts and co-catalysts, ie, triaLkylboron or trialkyl aluminum compounds. Ethylene—a-olefin copolymers produced with these catalysts have very broad molecular weight distributions, characterised by M.Jin the 12—35 and MER in the 80—200 range. 

Nitric acid oxidation is used where carbohydrates, ethylene glycol, and propylene are the starting materials. The diaLkyl oxalate process is the newest, where diaLkyl oxalate is synthesized from carbon monoxide and alcohol, then hydrolyzed to oxahc acid. This process has been developed by UBE Industries in Japan as a CO coupling technology in the course of exploring C-1 chemistry. 

Miscellaneous Reactions. Ethylene oxide is considered an environmental pollutant. A study has determined the half-life of ethylene oxide ia the atmosphere (82,83). Autodecomposition of ethylene oxide vapor occurs at - 500° C at 101.3 kPa (1 atm) to give methane, carbon monoxide, hydrogen, and ethane (84—86). 

The mechanism of poisoning automobile exhaust catalysts has been identified (71). Upon combustion in the cylinder tetraethyllead (TEL) produces lead oxide which would accumulate in the combustion chamber except that ethylene dibromide [106-93-4] or other similar haUde compounds were added to the gasoline along with TEL to form volatile lead haUde compounds. Thus lead deposits in the cylinder and on the spark plugs are minimized. Volatile lead hahdes (bromides or chlorides) would then exit the combustion chamber, and such volatile compounds would diffuse to catalyst surfaces by the same mechanisms as do carbon monoxide compounds. When adsorbed on the precious metal catalyst site, lead haUde renders the catalytic site inactive. 

Compounds considered carcinogenic that may be present in air emissions include benzene, butadiene, 1,2-dichloroethane, and vinyl chloride. A typical naphtha cracker at a petrochemical complex may release annually about 2,500 metric tons of alkenes, such as propylenes and ethylene, in producing 500,000 metric tons of ethylene. Boilers, process heaters, flares, and other process equipment (which in some cases may include catalyst regenerators) are responsible for the emission of PM (particulate matter), carbon monoxide, nitrogen oxides (200 tpy), based on 500,000 tpy of ethylene capacity, and sulfur oxides (600 tpy). 

As an alternate to LNG, natural gas can be chemically converted to methanol, chemical feedstocks (such as ethylene), gasoline, or diesel fuel. Most processes start with the conversion of methane to synthesis gas, a mixture of carbon monoxide and hydrogen. This can be done partial oxidation, an exothermic reaction ... 

The catalyst is similar to that of the Wacker reaction for ethylene oxidation to acetaldehyde, however, this reaction occurs in presence of carbon monoxide. 

From the results of other authors should be mentioned the observation of a similar effect, e.g. in the oxidation of olefins on nickel oxide (118), where the retardation of the reaction of 1-butene by cis-2-butene was greater than the effect of 1-butene on the reaction of m-2-butene the ratio of the adsorption coefficients Kcia h/Kwas 1.45. In a study on hydrogenation over C03O4 it was reported (109) that the reactivities of ethylene and propylene were nearly the same (1.17 in favor of propylene), when measured separately, whereas the ratio of adsorption coefficients was 8.4 in favor of ethylene. This led in the competitive arrangement to preferential hydrogenation of ethylene. A similar phenomenon occurs in the catalytic reduction of nitric oxide and sulfur dioxide by carbon monoxide (120a). 

Thermal Decomposition. The therm decompn was studied betw 380 and 430° and found to be homogeneous and apparently 1st order. The products were complex and included nitric oxide, methane, carbon monoxide, and w plus small amts of ethane, ethylene, and nitrous oxide (Ref 23)... 

Ethylene is selectively oxidized to ethylene oxide using a silver-based catalyst in a fixed-bed reactor. Ethylene and oxygen are supplied from the gas phase and ethylene oxide is removed by it. The catalyst is stationary. Undesired, kinetically determined by-products include carbon monoxide and water. Ideally, a pure reactant is converted to one product with no by-products. 

Violent reactions have occurred between ozone and many chemicals, a small selection being acetylene, alkenes, dialkyl zincs, benzene/rubber solution, bromine, carbon monoxide and ethylene, diethyl ether, hydrogen bromide, and nitrogen oxide. 

Carbon monoxide and ethylene admitted into contact with ozone via an aluminium tip ignited and burned smoothly, while normal contact of carbon monoxide, nitrogen oxide, ammonia or phosphine causes immediate explosion at 0° or —78°C [1], At pressures below 10 mbar, contact with ethylene is explosive at —150°C [2], See Nitrogen oxide, below... 

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