Butane yields

Like propane, the noncatalytic oxidation of butane yields a variety of products including organic acids, alcohols, aldehydes, ketones, and olefins. Although the noncatalytic oxidation of butane produces mainly aldehydes and alcohols, the catalyzed oxidation yields predominantly acids. 

From these and similar reactions, it s possible to calculate a reactivity order toward chlorination for different sorts of hydrogen atoms in a molecule. Take the butane chlorination, for instance. Butane has six equivalent primary hydrogens (-CH3) and four equivalent secondary hydrogens (-CH2-). The fact that butane yields 30% of 1-chlorobutane product means that each one of the six primary hydrogens is responsible for 30% -e 6 = 5% of the product. Similarly, the fact that 70% of 2-chlorobutane is formed means that each of the four secondary hydrogens is responsible for 70% -e 4 = 17.5% of the product. Thus, reaction of a secondary hydrogen happens 17.5% + 5% = 3.5 times as often as reaction of a primary hydrogen. 

More recently the flash photolysis of diethyl mercury has been re-investigated by Fischer and Mains92. At 1.54 torr and 24 °C the major products are butane (36 %), ethylene (32 %), ethane (22 %), propane (6 %) and hydrogen (4 %). Only traces of methane were detected. The addition of perfluorodimethylcyclo-butane vapour did not alter the extent of photolysis, but the butane yield increased approximately 25 % while the yield of ethylene, ethane, hydrogen and propane all decreased. The change in product distribution occurred as the inert gas pres-... 

Only two alkanes have the molecular formula C4H10 butane and isobutane (2-methylpropane)— both of which give two monochlorides on free-radical chlorination. However, dehydrochlorination of one of the monochlorides derived from butane yields a mixture of alkenes. 

Isobutane Production. The importance of Isobutane domestically prompted experimentation aimed at maximizing the Iso-butane yield. Indications had been obtained from Figures 2 and 3 and discussed previously that as the catalyst aged. Isobutane yields Increased (at the expense of propane). It appeared likely that processing at less severe conditions would be beneficial towards increasing Isobutane yields. 

Photolysis of diazirine in the presence of a large excess of propane yielded n- and isobutane and in the presence of n-butane yielded n- and isopentane. From the relative rates of attack on the primaiy and secondary carbon-hydrogen bonds in these compounds, it was concluded that methylene derived from diazirine showed approximately the same discrimination as methylene formed by the photolysis of ketene. The results obtained, using methylene derived from the photolysis of diazomethane, gave a product ratio closer to the simple statistical ratio of the number of carbon-hydrogen bonds without correction factors for the type involved and indicated almost no differentiation between the types. 

The radiolysis of ethane has been studied almost exclusively in the gas phase. The products of reaction are mainly hydrogen, n-butane, ethylene, propane and methane with smaller quantities of acetylene, isobutane and isopentane - °°. When the radiolysis is conducted with NO added as a radical scavenger, the hydrogen and n-butane yields are reduced and propene and butene are observed as products > The radiolysis of ethane with iodine vapor has shown that the radicals H, C2H5, and CH3 along with smaller quantities of C3H7, C4H9 and CH2 are present . 

The reaction of a r-butyl halide with butanal yields the r-butyl propyl carbinol in a... 

Formaldehyde. Oxidation with air or oxygen of natural gas or propane and butane yields not only formaldehyde but also acetaldehyde, propionaldehyde, acetone, methyl ethyl ketone, tetrahydrofuran, methanol, propanol, butyl alcohols, and formic, acetic, and propionic acids. Such literature is covered by Walker (120, 121). Two reports on German processes for oxidation of methane to formaldehyde are given by Sherwood (254), and by Holm and Reichl (47). One of these processes indicates the almost exclusive formation of formaldehyde it is also indicated that the process was applied to ethane and propane with similar results. 

Catalysts 1 and 2, that are 0.4 and 0.8 % CoNx/y-AbOs, indicate similarly high performances in oxidative dehydrogenation of n-butane. Even at 400°C, the conversion exceeded 40 % (Fig. 1) and yield of olefins reached 25 %. The special feature of this catalyst consists of a high conversion of n-butane yielding mostly light olefins, ethylene and propylene. 90 wt% of olefins formed at 400°C and molar ratio Oj/n-butane of 1.5, were C2-C3 olefins 53 wt.% was ethylene and the rest propylene. 

The above data indicate that at a low hydrogen partial pressure and rather high butane yield aromatization is completely suppressed. This evidenced that, first of all, hydrogen influenced intermediate chemical transformations rather than butene formation. The stronger platinum hydrogenation activity found in these experiments is likely to facilitate coke precursor hydrogenation in real reaction mixtures, where the hydrogen partial pressure is rather low. 

Now we know that the hydroxylation of cis- and trans-2-butane yields two fractions of glycols with the same formula (CH3CHOHCCH3CHOH) but having different melting points. The two fractions formed must therefore be stereoisomers. Since their chemical properties (here m.p. s) are similar but not identical, they are not enantiomers of each other (which by definition differ only in optical rotation), but diastereomers. Note that the glycol contains two chiral centers, C2 and C3, which is compatible with diastereomer formation. 

Butane yields the butyl and s-butyl groups, the former by removal of a hydrogen from one of the end carbons and the latter by removal of a hydrogen from one of the inner carbons. 

In addition to more highly chlorinated products, chlorination of butane yields a mixture of compounds with the formula C4H9CI. 

Ethylene Coproduction. Historically, butadiene was first prepared in pilot plant quantities via an uneconomical electric arc process. However, the primary source of butadiene in the world today is as a by-product of thermal pyrolysis of hydrocarbon feedstocks in ethylene production. In the United States, production of coproduct butadiene exceeded that of on-purpose butadiene for the first time in 1977 and by 1990 high cost on-purpose butadiene production was essentially eliminated in the United States (Fig. 1) (46,47). In 1996, the total US production of butadiene was 1.75 million, 93% of which was co-produced (47). Steam cracking of hydrocarbons yields varying amounts of butadiene, depending on the nature of the feedstock, the volume of ethylene produced, and the severity of the cracking operations (48-50). For example, when feedstocks are switched from atmospheric gas oils and napthas to propane and butane, yields of butadiene drop by as much as 60% (51). 

Furthermore, the partial chloromethylation with SnCl4/bis-l,4-(chloromethoxy)-butane (yielding (174b)) was studied [276]. Another class of monomers containing pendant... 

For the maximum butane case, Figure 12.121 shows the steam rate reduced to 14.5. The change in butane yield caused by constraining the reflux is given by... 

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