Butane/butene

Secondary butyl alcohol, methylethyl car-binol, 2-butanol, CH3CH2CH(Me)OH. B.p. I00°C. Manufactured from the butane-butene fraction of the gas from the cracking of petroleum. Used to prepare butanone. 

Definition (in vol %) Mainly butanes/butenes < 19% propane/propylene 90% approx, propane/propylene 10% ethane/ethylene/butanes/butenes Mainly propane, butanes and propylene/butenes/pentanes/pentenes... 

Liquefied gas fractions (propane, propylene, butanes, butenes) that will be able to provide feedstocks to units of MTBE, ETBE, alkylation, dimerization, polymerization after sweetening and/or selective hydrogenation. 

Butadiene could also be produced by the catalytic dehydrogenation of butanes or a butane/butene mixture. 

In a similar study, Zhang and Wang (1997) studied the reaction of zero-valent iron powder and palladium-coated iron particles with trichloroethylene and PCBs. In the batch scale experiments, 50 mL of 20 mg/L trichloroethylene solution and 1.0 g of iron or palladium-coated iron were placed into a 50 mL vial. The vial was placed on a rotary shaker (30 rpm) at room temperature. Trichloroethylene was completely degraded by palladium/commercial iron powders (<2 h), by nanoscale iron powder (<1.7 h), and nanoscale palladium/iron bimetallic powders (<30 min). Degradation products included ethane, ethylene, propane, propene, butane, butene, and pentane. The investigators concluded that nanoscale iron powder was more reactive than commercial iron powders due to the high specific surface area and less surface area of the iron oxide layer. In addition, air-dried nanoscale iron powder was not effective in the dechlorination process because of the formation of iron oxide. 

With A in kcal/mol, a few examples are (experimental values are given in parentheses) propane/propene, 860.1 (858.56) butane/butene, 1154.2 (1154.5) pentane/pentene, 1448.2 (1447.6) cyclohexane/cyclohexene, 1616.8 (1616.1) methylcyclohexane/l-methylcyclohexene, 1913.1 (1913.2) cyclohexane/1,4-cyclo-hexadiene, 1472.8 (1472.8), and butane/butadiene, 1010.2 (1010.1). (Where appropriate, the averages of the various alkene isomers were used.)... 

Precise rate expressions are difficult to obtain because of the existence of reaction networks in which the secondary reactions take place with ease. Sometimes, the relative rate constants in a reaction network are reported and presented as the mechanism of a reaction. For example, butane > butene > furan - > 7 -butyllactone --> maleic anhydride. This is incorrect, as a different... 

Following a variation of the well-known Horiuti-Polanyi mechanism, we consider the following steps as possible for the system -butane- -butenes-hydrogen over chromia alumina catalyst ... 

Most butenes are produced in the cracking process in refineries along with other C-4 fractions such as the butanes. Butenes are separated from other compounds and each other by several methods. Isobutene is separated from normal butanes by absorption in a sulfuric acid solution. Normal butenes can be separated from butanes by fractionation. The close boiling points of butanes and butenes make straight fractional distillation an inadequate separation... 

Butadiene and Isoprene. Butane may be transformed directly to 1,3-buta-diene on chromia-alumina (Houdry Catadiene process).144-146 172 The most significant condition is operation under subatmospheric pressure (0.1-0.4 atm), which provides an improved yield of 1,3-butadiene. Operating at about 600°C, the process produces a mixture of butenes and 1,3-butadiene. After the removal of the latter, the remaining butane-butenes mixture is mixed with fresh butane and recycled. Extensive coke formation requires regeneration of the catalyst after a few minutes of operation. 1,3-Butadiene yields up to 63% are obtained at a conversion level of 30 40%. 

As for the fate of butyl bromide, 1.1 mmole of a gaseous product was evolved for the reaction of the starting material (4.6 mmole) after 12 min of milling. The main component of that gas was butane. Butene was a minor product. The residue was a viscous and dark brown material. Bromide ion (4.6 equivalents) was detected in the residue. The residue was a mixture of aluminum bromide and a polymerized matter. The reaction with aluminum activated by vibromilling may be described with these equations ... 

In Chapter 9, the butane/butene alkylation for isooctane production is discussed. The reactions can be represented by the following stoichiometry. 

Proof that radicals are formed by treatment of an alkyl halide with an alkyllithium was first presented in 1956 45 The degenerate exchange between BuBr and BuLi in cumene over an extended period was found to be accompanied not only by the formation of butane, butene and (in 43% yield) octane but also considerable quantities of the cumene dimer 32. 

It is known that methyl and ethyl radicals are formed in a primaiy process. Association reactions of CHj, C2H5, f-CjH7, C H6 can, therefore, explain the production of ethane, propane (obscured by parent), n-butane, i-butane, butene-1, i-pentane, as well as higher hydrocarbons for which analyses were not performed. The CH2 formed in primary process (144) undoubtedly contributes to the n-butane and i-butane. 

Figure 3. Cloud-point curves for EAA3 9 in butane, butene, and dimethyl ether (DME) [3],...

ABB Lummus Global Butadiene extraction Butanes/butenes/ butadienes/acetylenes Uses extraction distillation with NMP solvent and conventional distillation 26 2000... 

A consecutive reaction mechanism was also proposed by Cleaves and Centi (11). This mechanism was based on experimental work to back up the theoretical calculations of Schitt and Jorgensen. Although the proposed intermediates were not detected under reaction conditions, they have been observed with fuel-rich gas feeds and under conditions of transient reactor operation. Using a TAP (temporal analysis of products) reactor, the researchers detected products in the following order of formation butane —> butene butadiene furan. However, the... 

Extractive distillation is commercially used for separating mixtures of butanes, butenes, butadienes, and various acetylenes with four carbon atoms (13). Separating these multicomponent mixtures by fractional distillation is very difficult because the natural volatilities pf the various components, paraffinic as well as olefinic, overlap considerably. For instance, n-butane is less volatile than 1-butene but more volatile than cis-and trans-2-butenes. Thus, separation of butanes from butenes is more difficult by fractional distillation than by extractive distillation where the solvent increases the volatilities of all the butanes to make them greater than the butene volatilities. For 1,3-butadiene recovery extractive distillation is also more attractive than ordinary distillation because the large polarizability of the conjugated double bonds interacts strongly with the polar solvent. Also, in C4 hydrocarbon separations the solvent often only enhances and does not reverse the natural relative volatility for many of the components however, even for those components for which the rela-... 

The Polybutenes, random isobutene-butene copolymers predominantly composed of isobutene units, manufactured directly from the butanes-butenes C4 refinery stream, with low molar masses (MM) ranging from light to highly viscous liquids. 

Applications of POMs to catalysis have been periodically reviewed [33 0]. Several industrial processes were developed and commercialized, mainly in Japan. Examples include liquid-phase hydration ofpropene to isopropanol in 1972, vapor-phase oxidation of methacrolein to methacrylic acid in 1982, liquid-phase hydration of isobutene for its separation from butane-butene fractions in 1984, biphasic polymerization of THE to polymeric diol in 1985 and hydration of -butene to 2-butanol in 1989. In 1997 direct oxidation of ethylene to acetic acid was industrialized by Showa Denko and in 2001 production of ethyl acetate by BP Amoco. 

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