Olefins internal

The rate of 9-BBN hydroboration of cis-2-pentene is 100 times slower than that of 1-hexene. 

One-side branching of internal olefins only moderately reduces the rate. The behavior follows from the fact that 9-BBN reacts almost exclusively at the less hindered site of the double bond. 

The branching on both sides of the double bond drops the rate of hydroboration sharply.  

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C with low conversion (10—15%) to limit dichloroalkane and trichloroalkane formation. Unreacted paraffin is recycled after distillation and the predominant monochloroalkane is dehydrochlorinated at 300°C over a catalyst such as nickel acetate [373-02-4]. The product is a linear, random, primarily internal olefin. 

Catalytic Oligomeri tion. Shell Chemical provides C —C linear internal olefin feedstock for detergent oxo alcohol production from its SHOP... 

Shell Higher Olefin Process) plant (16,17). C -C alcohols are also produced by this process. Ethylene is first oligomerized to linear, even carbon—number alpha olefins using a nickel complex catalyst. After separation of portions of the a-olefins for sale, others, particularly C g and higher, are catalyticaHy isomerized to internal olefins, which are then disproportionated over a catalyst to a broad mixture of linear internal olefins. The desired fraction is... 

The Cg—0 2 branched, odd and even, linear and internal olefins are used to produce improved flexible poly(vinyl chloride) plastics. Demand for these branched olefins, which are produced from propylene and butylene, is estimated to be increasing at a rate of 2% per year. However, the growth of the linear a-olefins is expected to slow down to a rate of 5% per year from 1992 to 1997 (3), as opposed to growth rates of 7—10% in the 1980s. 

Formation of by-products varies with each process typical by-products are paraffins, linear internal olefins, and vinyfidene (branched) olefins. 

Eig. 4. Shell a-olefin and internal olefins schematic (Geismar, La. and Stanlow, United Kingdom). 

A key portion of the SHOP process is the isomerization—disproportionation (I/D) process in which excess light (C —C q) and heavy olefins (Cjg ) are converted to detergent range odd and even linear internal olefins. Eor each pass through this system, only 10—15% of the olefins fed are... 

These detergent range (C C ) odd and even linear internal olefins are fed to oxo-alcohol plants to produce C22 C2 semilinear alcohols. Most of the alcohols are ethoxylated and sold into detergent markets (8). Shell balances carbon numbers by a combination of the ethylene oligomerization extent. 

SASOL. SASOL, South Africa, has constmcted a plant to recover 50,000 tons each of 1-pentene and 1-hexene by extractive distillation from Fischer-Tropsch hydrocarbons produced from coal-based synthesis gas. The company is marketing both products primarily as comonomers for LLDPE and HDPE (see Olefin polymers). Although there is still no developed market for 1-pentene in the mid-1990s, the 1-hexene market is well estabhshed. The Fischer-Tropsch technology produces a geometric carbon-number distribution of various odd and even, linear, branched, and alpha and internal olefins however, with additional investment, other odd and even carbon numbers can also be recovered. The Fischer-Tropsch plants were originally constmcted to produce gasoline and other hydrocarbon fuels to fill the lack of petroleum resources in South Africa. 

Wax Cracking. One or more wax-cracked a-olefin plants were operated from 1962 to 1985 Chevron had two such plants at Richmond, California, and Shell had three in Europe. The wax-cracked olefins were of limited commercial value because they contained internal olefins, branched olefins, diolefins, aromatics, and paraffins. These were satisfactory for feed to alkyl benzene plants and for certain markets, but unsatisfactory for polyethylene comonomers and several other markets. Typical distributions were C 33% C q, 7% 25% and 35%. Since both odd and... 

Chlorination and Chlorination—Dehydrochlorination of Paraffins. Linear internal olefins were produced by Shell at Geismar from 1968 to 1988, using the dehydrochlorination of chlorinated linear paraffins, a process that also yields hydrogen chloride as a by-product. To avoid the production of dichloroparaffins, which are converted to diolefins by dehydrochlorination, chlorination of paraffins is typically limited to 10% conversion. 

A few companies, eg, Enichem in Italy, Mitsubishi in Japan, and a plant under constmction at Eushun in China, separate the olefins from the paraffins to recover high purity (95—96%) linear internal olefins (LIO) for use in the production of oxo-alcohols and, in one case, in the production of polylinear internal olefins (PIO) for use in synthetic lubricants (syn lubes). In contrast, the UOP Olex process is used for the separation of olefins from paraffins in the Hquid phase over a wide carbon range. 

Linear terminal olefins are the most reactive in conventional cobalt hydroformylation. Linear internal olefins react at less than one-third that rate. A single methyl branch at the olefinic carbon of a terminal olefin reduces its reaction rate by a factor of 10 (2). For rhodium hydroformylation, linear a-olefins are again the most reactive. For example, 1-butene is about 20—40 times as reactive as the 2-butenes (3) and about 100 times as reactive as isobutylene. 

Bisphosphites such as (7) combine excellent reactivity, straight-chain selectivity, and high resistance to the typical phosphite degradation reactions (29). Further, the corresponding 0x0 catalysts are excellent olefin isomerization catalysts so that high normal-to-branched isomer ratios are obtained even from internal olefins, enabling, in certain instances, the use of inexpensive mixed isomer olefin feedstocks. 

Surfactants evaluated in surfactant-enhanced alkaline flooding include internal olefin sulfonates (259,261), linear alkyl xylene sulfonates (262), petroleum sulfonates (262), alcohol ethoxysulfates (258,261,263), and alcohol ethoxylates/anionic surfactants (257). Water-thickening polymers, either xanthan or polyacrylamide, can reduce injected fluid mobiHty in alkaline flooding (264) and surfactant-enhanced alkaline flooding (259,263). The combined use of alkah, surfactant, and water-thickening polymer has been termed the alkaH—surfactant—polymer (ASP) process. Cross-linked polymers have been used to increase volumetric sweep efficiency of surfactant—polymer—alkaline agent formulations (265). 

HP Alkylation Process. The most widely used technology today is based on the HE catalyst system. AH industrial units built in the free world since 1970 employ this process (78). During the mid-1960s, commercial processes were developed to selectively dehydrogenate linear paraffins to linear internal olefins (79—81). Although these linear internal olefins are of lower purity than are a olefins, they are more cost-effective because they cost less to produce. Furthermore, with improvement over the years in dehydrogenation catalysts and processes, such as selective hydrogenation of diolefins to monoolefins (82,83), the quaUty of linear internal olefins has improved. 

Several side reactions or post-cuting reactions are possible. Disproportionation reactions involving terminal hydride groups have been reported (169). Excess SiH may undergo hydrolysis and further reaction between silanols can occur (170—172). Isomerization of a terminal olefin to a less reactive internal olefin has been noted (169). Viaylsilane/hydride interchange reactions have been observed (165). 

The hydrides can also be used to form primary alcohols from either terminal or internal olefins. The olefin and hydride form an alkenyl zirconium, Cp2ZrRCl, which is oxidized to the alcohol. Protonic oxidizing agents such as peroxides and peracids form the alcohol direcdy, but dry oxygen may also be used to form the alkoxide which can be hydrolyzed (234). 

Straight-chain terminal olefins are more reactive than straight-chain internal olefins, which are more reactive than branched-chain olefins (133). 

The alkanoic acids, with the exception of formic acid, undergo typical reactions of the carboxyl group. Formic acid has reducing properties and does not form an acid chloride or an anhydride. The hydrocarbon chain of alkanoic acids undergoes the usual reactions of hydrocarbons except that the carboxyl group exerts considerable influence on the site and ease of reaction. The alkenoic acids in which the double bond is not conjugated with the carboxyl group show typical reactions of internal olefins. All three types of reactions are industrially important. 

Some generalizations that pertain are (1) Terminal olefins are more rapidly reduced than internal olefins (2) conjugated olefins are not reduced at 1 atmosphere (3) ethylene is not hydrogenated. Rates of reduction compare favorably with those obtained by heterogeneous catalysts such as Raney nickel or platinim oxide. In fact, the hydrogenation of some olefins may be so rapid that the temperature of the solution (benzene) is raised to the boiling point. 

The higher activity of the catalyst [(mall)Ni(dppmo)][SbFg] in [BMIM][PFg] (TOF = 25,425 h ) relative to the reaction under identical conditions in CFF2C12 (TOF = 7591 h ) can be explained by the fast extraction of products and side products out of the catalyst layer and into the organic phase. A high concentration of internal olefins (from oligomerization and consecutive isomerization) at the catalyst is known to reduce catalytic activity, due to the formation of fairly stable Ni-olefin complexes. 

Because of the difficulty in selling large amounts of C10 and Cl8+ olefins, these were isomerized to internal olefins followed by disproportionation. Here the important internal olefins for the synthesis of LAB are obtained (Fig. 5) [34]. Equations (4) and (5) illustrate the isomerization and disporportionation on 1-octene as an example. 

Olefin isomerization process Isomerization of internal olefins to a- 54... 

TABLE 4 Physical-Chemical Data of Internal Olefins Distributed by Shell... 

When the reaction conditions approach the thermodynamic equilibrium, isomerization follows. The distribution of the double bond is statistical. The molecular formation in the disproportionation stage is also statistical. Normally a run will produce 10-15% by weight of product, which is then suitable for LAB synthesis after distillation. The physical data of these internal olefins are shown in Table 4 [41]. 

The difference in sulfonation behavior between a-olefins (AO) and internal olefins (IO) has been a longstanding problem [14] and the literature is replete with earlier explanations [14,15] and practical solutions [16-20] to the problem of IO sulfonation. In their studies of IO sulfonation chemistry, Stapersma and colleagues [4], Radici et al. [21], Yoshimura et al. [22,23], and Roberts and Jackson [24] identified the origins of the poor sulfonatability of IO, and the process modifications required to produce good-quality IO sulfonate. 

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