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Butane-butene fraction

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. [Pg.71]

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. [Pg.568]

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. [Pg.385]

Polymers account for about 3—4% of the total butylene consumption and about 30% of nonfuels use. Homopolymerization of butylene isomers is relatively unimportant commercially. Only stereoregular poly(l-butene) [9003-29-6] and a small volume of polyisobutylene [25038-49-7] are produced in this manner. High molecular weight polyisobutylenes have found limited use because they cannot be vulcanized. To overcome this deficiency a butyl mbber copolymer of isobutylene with isoprene has been developed. Low molecular weight viscous Hquid polymers of isobutylene are not manufactured because of the high price of purified isobutylene. Copolymerization from relatively inexpensive refinery butane—butylene fractions containing all the butylene isomers yields a range of viscous polymers that satisfy most commercial needs (see Olefin polymers Elastomers, synthetic-butylrubber). [Pg.374]

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... [Pg.49]

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-... [Pg.42]

The composition of the butane-butene (B-B) fraction resulting from mixed phase cracking has been reported by Snow (73) and may be compared with a similar analysis of the B-B fraction from Houdry cracking presented by Sachanen (71). The Houdry product is richer in isobutane (53% vs. 11%), poorer in isobutene (6% vs. 10%), and poorer in butadiene (none vs. 0.9%). [Pg.331]

Azeotropic Distillation. Methanol may be used to separate toluene from cracked motor fuel fractions (51), and the use of sulfur dioxide in butane-butene separation has been reported by Matuszak and Frey (54). [Pg.335]

The overhead oil is fractionated into fuel gas (ethane and lower-molecular-weight gases), propane-propylene, butane-butene, naphtha, light gas oil, and heavy gas oil. Yields and product quality vary widely because of the broad range of feedstock types charged to delayed coking. The function of the coke drum is to provide the residence time required for the coking reactions and to accumulate the coke. Hydraulic cutters are used to remove coke from the drum. [Pg.55]

In the butene isomerization section (1), raffinate-2 feed from OSBL is mixed with butene recycle from the butene distillation section and is vaporized, preheated and fed to the butene isomerization reactor, where butene-2 is isomerized to butene-1 over a fixed bed of proprietary isomerization catalyst. Reactor effluent Is cooled and condensed and flows to the butene distillation section (2) where it is separated into butene-1 product and recycle butene-2 in a butene fractionator. Butene-1 is separated overhead and recycle butene-2 Is produced from the bottom. The column uses a heat-pump system to efficiently separate butene-1 from butene-2 and butane, with no external heat Input. A portion of the bottoms is purged to remove butane before it is recycled to the isomerization reactor. [Pg.92]

Butene Butane C5 fraction C6"Cg nonaromatics Benzene Toluene Cg fraction Styrene C9 fraction (Final boiling point 200 °C) Pyrolysis tar Total... [Pg.78]

Analysis of the butene fraction obtained in reactions between 2-halogeno-butanes and the alkoxides CHa-CHj ONa and CFs-CHg-ONa at 25 C in dipolar aprotic solvents (DMF and DMSO, to minimize solvation effects) has revealed that in each case change from ethoxide to 2,2,2-trifluoroethoxide results in a decrease in the tendency for but-l-ene to be formed. This demonstrates that base strength and not size is of prime importance in determining orientation in elimination reactions between 2-halogenoalkanes and alkoxides of modest proportions. ... [Pg.144]

Butylenes are C Hg mono-olefin isomers 1-butene, <7j -2-butene, trans-2-huX.en.e and isobutylene (2-methylpropene). These isomers are usually coproduced as a mixture and are commonly referred to as the fraction. These fractions are usually obtained as by-products from petroleum refinery and petrochemical complexes that crack petroleum fractions and natural gas Hquids. Since the fractions almost always contain butanes, it is also known as the B—B stream. The linear isomers are referred to as butenes. [Pg.361]

Thermal Cracking. Heavy petroleum fractions such as resid are thermally cracked in delayed cokers or flexicokers (44,56,57). The main products from the process are petroleum coke and off-gas which contain light olefins and butylenes. This stream also contains a considerable amount of butane. Process conditions for the flexicoker are more severe than for the delayed coker, about 550°C versus 450°C. Both are operated at low pressures, around 300—600 kPa (43—87 psi). Flexicokers produce much more linear butenes, particularly 2-butene, than delayed cokers and about half the amount of isobutylene (Table 7). This is attributed to high severity of operation for the flexicoker (43). [Pg.367]

The principal components of the cut are butene-1, butene-2, isobutylene and butadiene-1,3. Methyl, ethyl, and vinyl acetylenes, butane and butadiene-1,2 are present in small quantities. Butadiene is recovered from the C4 fraction by extraction with cuprous ammonium acetate (CAA) solution, or by extractive distillation with aqueous acetonitrile (ACN). The former process is a liquid-liquid separation, and the latter a vapor-liquid separation. Both take advantage of differences in structure and reactivity of the various C4 components to bring about the desired separation. [Pg.107]

Acetonitrile serves to greatly enlarge the spread of relative volatilities so that reasonably sized distillation equipment can be used to separate butadiene from the other components in the C4 fraction. The polar ACN acts as a very heavy component and is separated from the product without much difficulty.The feed stream is carefully hydrogenated to reduce the acetylene level rerun, and then fed to the single stage extractive distillation unit. Feed enters near the middle of the extractive distillation tower, while (lean) aqueous ACN is added near but not at the top. Butenes and butanes go overhead as distillate, with some being refluxed to the tower and the rest water washed for removal of entrained ACN. [Pg.108]

Because of the high pyrolysis temperature, the C4-fraction contains quantities of vinyl acetylene and ethyl acetylene, the removal of which prior to the recovery of butadiene is necessary in certain cases, particularly if butadiene of low acetylene content is desired. Similar considerations apply to effractions obtained by the dehydrogenation of n-butane and n-butenes. [Pg.74]

Extractive distillation is used to remove butadiene from a C4 stream fractionation can be used to separate out butene-1 adsorption is also sometimes used to separate out butene-1 polymerization is sometimes used to pull out the isobutylene dehydrogenation can be used to convert some of the butylenes and normal butane to butadiene and alkylation is used to convert the butylenes to alkylate. [Pg.423]

Raffinate-II typically consists of40 % 1-butene, 40 % 2-butene and 20 % butane isomers. [RhH(CO)(TPPTS)3] does not catalyze the hydroformylation of internal olefins, neither their isomerization to terminal alkenes. It follows, that in addition to the 20 % butane in the feed, the 2-butene content will not react either. Following separation of the aqueous catalyts phase and the organic phase of aldehydes, the latter is freed from dissolved 2-butene and butane with a counter flow of synthesis gas. The crude aldehyde mixture is fractionated to yield n-valeraldehyde (95 %) and isovaleraldehyde (5 %) which are then oxidized to valeric add. Esters of n-valeric acid are used as lubricants. Unreacted butenes (mostly 2-butene) are hydroformylated and hydrogenated in a high pressure cobalt-catalyzed process to a mixture of isomeric amyl alcohols, while the remaining unreactive components (mostly butane) are used for power generation. Production of valeraldehydes was 12.000 t in 1995 [8] and was expected to increase later. [Pg.112]

The crude C4 fraction is extracted with acetone, furfural, or other solvents to remove alkanes such as -butane, isobutane, and small amounts of pentanes, leaving only 1- and 2-butenes and isobutene. The isobutene is removed by reaction with sulfuric acid and water because it reacts more easily, being able to form a tertiary carbocation. [Pg.125]

Because of their very similar boiling points and azeotrope formation, the components of the C4 fraction cannot be separated by distillation. Instead, other physical and chemical methods must be used. 1,3-Butadiene is recovered by complex formation or by extractive distillation.143-146 Since the reactivity of isobutylene is higher than that of n-butenes, it is separated next by chemical transformations. It is converted with water or methyl alcohol to form, respectively, tert-butyl alcohol and tert-butyl methyl ether, or by oligomerization and polymerization. The remaining n-butenes may be isomerized to yield additional isobutylene. Alternatively, 1-butene in the butadiene-free C4 fraction is isomerized to 2-butenes. The difference between the boiling points of 2-butenes and isobutylene is sufficient to separate them by distillation. n-Butenes and butane may also be separated by extractive distillation.147... [Pg.46]

In the process based on n-butane feedstock, vanadium phosphorous oxides (V-P-O) catalysts are mainly used.1010-1012 Processes for the oxidation of low-cost C4 fraction from naphtha cracker consisting mainly of butenes have also been developed.1013,1014 In contrast with benzene oxidation where two carbon atoms are lost in the form of ethylene no carbon is lost in the oxidation of C4 hydrocarbons ... [Pg.516]

C4 Hydrorefining. The main components of typical C4 raw cuts of steam crackers are butanes (4-6%), butenes (40-65%), and 1,3-butadiene (30-50%). Additionally, they contain vinylacetylene and 1-butyne (up to 5%) and also some methylacetylene and propadiene. Selective hydrogenations are applied to transform vinylacetylene to 1,3-butadiene in the C4 raw cut or the acetylenic cut (which is a fraction recovered by solvent extraction containing 20-40% vinylacetylene), and to hydrogenate residual 1,3-butadiene in butene cuts. Hydrogenating vinylacetylene in these cracked products increases 1,3-butadiene recovery ratio and improves purity necessary for polymerization.308... [Pg.664]

We have tested the above hypothesis by investigating the activation of the C-H bonds of /z-butane and iso-butane and the C=C bonds of 1,3-butadiene, 1-butene and iso-butene on clean V(110) and on VC/V(110) surfaces by using HREELS and TDS.5 Figure 24.6 shows the TDS results following the reaction of/j-butane from clean and carbide-modified V(110) surfaces. For each set of TDS experiments, the clean and carbon-modified V(110) surfaces were exposed to identical exposures of /z-butane at 80 K. Desorption peaks from both parent molecules and the decomposition product (hydrogen) are compared. As shown in Figure 24.6, the adsorption of /z-butane on clean V(110) is completely reversible, as indicated by the absence of any H2 desorption peak. On the carbide-modified surfaces, the peak area of molecularly desorbed /z-butane decreases, which is accompanied by an increase in the peak area of H2 at approximately 500 K. Both observations indicate that the fraction of n-butane undergoing decomposition is increased on the carbide-modified surfaces. [Pg.515]

The reaction for making methyl-r-butyl ether proceeds quickly and highly selectively by reacting a mixed butene-butane fraction with methyl alcohol in the liquid phase on a fixed bed of an acidic ion-exchange resin catalyst (Fig. 1). [Pg.331]


See other pages where Butane-butene fraction is mentioned: [Pg.190]    [Pg.128]    [Pg.182]    [Pg.645]    [Pg.364]    [Pg.71]    [Pg.57]    [Pg.147]    [Pg.225]    [Pg.8]    [Pg.9]    [Pg.95]    [Pg.11]    [Pg.225]    [Pg.502]    [Pg.95]    [Pg.8]    [Pg.9]   
See also in sourсe #XX -- [ Pg.568 ]




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