Carbon monoxide CAS

Poly(vinyl ketones) such as poly(ethylene-a//-carbon monoxide) CAS 111190-67-1, poly(methyl vinyl ketone) CAS 25038-87-3, and poly(methyl isopropenyl ketone) CAS 25988-32-3, also have practical applications. For example, poly(ethylene-a/f-carbon monoxide) is used in photodegradable plastics and in various copolymers. Several studies were reported regarding the thermal stability of these polymers. It has been shown that poly(ethylene-a/f-carbon monoxide) decomposes upon heating with chain scission generating small molecular weight alkenes and ketones. Some literature reports discussing the thermal decomposition of poly(vinyl ketones) are summarized in Table 6.5.5 [13]. 

This alternative to the Friedel-Crafts reaction, extensively developed by Stille and coworkers, is particularly important, since the reaction conditions are essentially neutral, and so provides a method for acylation of compounds containing an acid-sensitive functionality which would preclude the use of the Friedel-Crafts reaction. Reaction temperatures are often below 100 C, and high (1000-fold) turnovers of the catalyst have been achieved. Solvents employed include chloroform, toluene, and, on occasions, HMPA. Some reactions have been carried out under an atmosphere of carbon monoxide to prevent excessive decarbonylation of the acyl palladium intermediate. Indeed, carbonylative coupling of alkenylstannanes with allyl halides in the presence of carbon monoxide ca. 3 atm or greater 1 atm =101 kPa) offers an alternative to the Friedel-Crafts acylation, ketones being formed by the reaction of the stannane with the acyl species formed by carbon monoxide insertion into the allyl palladium intermediate. ... 

The absorber tail gas contains about 20 mol % hydrogen and has a higher heating value of ca 2420 kj/m (65 Btu/SCF). With increased fuel costs and increased attention to the environment, tail gas is burned for the twofold purpose of generating steam and eliminating organic and carbon monoxide emissions. 

The estimated capacity of formamide was approximately 100,000 t/yr worldwide in 1990. In 1993, there are only three significant producers BASE in Germany is the leading manufacturer. Smaller quantities of formamide are produced in the former Czechoslovakia (Sokolov) and Japan (Nitto) by direct synthesis from carbon monoxide and ammonia. Most of the formamide produced is utilized direcdy by the manufacturers. The market price for formamide (ca 1993) is about 2.00/kg. 

The conversion of coal to gas on an industrial scale dates to the early nineteenth century (14). The gas, often referred to as manufactured gas, was produced in coke ovens or similar types of retorts by simply heating coal to vaporize the volatile constituents. Estimates based on modem data indicate that the gas mixture probably contained hydrogen (qv) (ca 50%), methane (ca 30%), carbon monoxide (qv) and carbon dioxide (qv) (ca 15%), and some inert material, such as nitrogen (qv), from which a heating value of approximately 20.5 MJ/m (550 Btu/fT) can be estimated (6). 

The first gas producer making low heat-value gas was built in 1832. (The product was a combustible carbon monoxide—hydrogen mixture containing ca 50 vol % nitrogen). The open-hearth or Siemens-Martin process, built in 1861 for pig iron refining, increased low heat-value gas use (see Iron). The use of producer gas as a fuel for heating furnaces continued to increase until the turn of the century when natural gas began to supplant manufactured fuel gas (see Furnaces, fuel-fired). 

Ethane. Ethane VPO occurs at lower temperatures than methane oxidation but requires higher temperatures than the higher hydrocarbons (121). This is a transition case with mixed characteristics. Low temperature VPO, cool flames, oscillations, and a NTC region do occur. At low temperatures and pressures, the main products are formaldehyde, acetaldehyde (HCHOiCH CHO ca 5) (121—123), and carbon monoxide. These products arise mainly through ethylperoxy and ethoxy radicals (see eqs. 2 and 12—16 and Fig. 1). 

A diagram for one implementation of this process (61,62) is shown in Eigure 11. Recovered potassium sulfate is converted to potassium formate [590-29 ] by reaction with calcium formate [544-17-2] which is made by reacting hydrated lime, Ca(OH)2, and carbon monoxide. The potassium formate (mp 167°C), in hquid form, is recycled to the combustor at about 170°C. Sulfur is removed as soHd calcium sulfate by filtration and then disposed of (see... 

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). 

Ca.rbonylProcess. Cmde nickel also can be refined to very pure nickel by the carbonyl process. The cmde nickel and carbon monoxide (qv) react at ca 100°C to form nickel carbonyl [13463-39-3] Ni(CO)4, which upon further heating to ca 200—300°C, decomposes to nickel metal and carbon monoxide. The process is highly selective because, under the operating conditions of temperature and atmospheric pressure, carbonyls of other elements that are present, eg, iron and cobalt, are not readily formed. 

In the carbonyl process, the Hquid is purified, vaporized, and rapidly heated to ca 300°C which results in the decomposition of the vapor to carbon monoxide and a fine high purity nickel powder of particle sizes <10 fim. This product is useflil for powder metallurgical appHcations (see Metallurgy, powder). Nickel carbonyl can also be decomposed in the presence of nickel powder, upon which the nickel is deposited. This process yields nickel pellets, typically about 0.8 cm dia and of >99.9 wt% purity. 

Pyrrohdinone (2-pyrrohdone, butyrolactam or 2-Pyrol) (27) was first reported in 1889 as a product of the dehydration of 4-aminobutanoic acid (49). The synthesis used for commercial manufacture, ie, condensation of butyrolactone with ammonia at high temperatures, was first described in 1936 (50). Other synthetic routes include carbon monoxide insertion into allylamine (51,52), hydrolytic hydrogenation of succinonitnle (53,54), and hydrogenation of ammoniacal solutions of maleic or succinic acids (55—57). Properties of 2-pyrrohdinone are Hsted in Table 2. 2-Pyrrohdinone is completely miscible with water, lower alcohols, lower ketones, ether, ethyl acetate, chloroform, and benzene. It is soluble to ca 1 wt % in aUphatic hydrocarbons. 

Chemica.1 Properties. Reviews of carbonyl sulfide chemistry are available (18,23,24). Carbonyl sulfide is a stable compound and can be stored under pressure ia steel cylinders as compressed gas ia equiUbrium with Hquid. At ca 600°C carbonyl sulfide disproportionates to carbon dioxide and carbon disulfide at ca 900°C it dissociates to carbon monoxide and sulfur. It bums with a blue flame to carbon dioxide and sulfur dioxide. Carbonyl sulfide reacts... 

When the Claus reaction is carried out in aqueous solution, the chemistry is complex and involves polythionic acid intermediates (105,211). A modification of the Claus process (by Shell) uses hydrogen or a mixture of hydrogen and carbon monoxide to reduce sulfur dioxide, carbonyl sulfide, carbon disulfide, and sulfur mixtures that occur in Claus process off-gases to hydrogen sulfide over a cobalt molybdate catalyst at ca 300°C (230). 

Titanium carbide may also be made by the reaction at high temperature of titanium with carbon titanium tetrachloride with organic compounds such as methane, chloroform, or poly(vinyl chloride) titanium disulfide [12039-13-3] with carbon organotitanates with carbon precursor polymers (31) and titanium tetrachloride with hydrogen and carbon monoxide. Much of this work is directed toward the production of ultrafine (<1 jim) powders. The reaction of titanium tetrachloride with a hydrocarbon-hydrogen mixture at ca 1000°C is used for the chemical vapor deposition (CVD) of thin carbide films used in wear-resistant coatings. 

Further down, ca 75 cm below the electrode tips, the mix is hot enough (2200—2500°C) to allow the lime to melt. The coke does not melt and the hquid lime percolates downward through the relatively fixed bed of coke forming calcium carbide, which is Hquid at this temperature. Both Hquids erode coke particles as they flow downward. The weak carbide first formed is converted to richer material by continued contact and reaction with coke particles. The carbon monoxide gas produced in this area must be released by flowing back up through the charge. The process continues down to the taphole level. Material in this area consists of soHd coke wetted in a pool of Hquid lime and Hquid calcium carbide at the furnace bottom. 

Sodium Ca.rhona.te Process. This process of recoveriag pure carboa dioxide from gas containing other dHueats, such as nitrogea and carbon monoxide, is based on the reversibHity of the foUowiag reaction ... 

Commercial production of these acids essentially follows the mechanistic steps given. This is most clearly seen in the Exxon process of Figure 1 (32). In the reactor, catalyst, olefin, and CO react to give the complex. After degassing, hydrolysis of this complex takes place. The acid and catalyst are then separated, and the trialkylacetic acid is purified in the distillation section. The process postulated to be used by Shell (Fig. 2) is similar, with additional steps prior to distillation being used. In 1980, the conditions used were described as ca 40—70°C and 7—10 MPa (70—100 bar) carbon monoxide pressure with H PO —BF —H2O in the ratio 1 1 1 (Shell) or with BF (Enjay) as catalyst (33). 

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