Heptane fraction

Use a sample of purified n-heptane fraction from petroleum (1), b.p. 90-100° this consists of a mixture of hydrocarbons in which the heptanes predominate. Carry out the following tests. 

At 180° and 40 atmospheres pressure, other investigators obtained a 65% yield of polymer hydrogenation of whieh yielded a liquid containing 54% of heptane fraction consisting of approximately 20% of 2,2-dimethylpentane and 80% of 2,3-dimethylpentane (Hoog et al., 34). 

The atactic amorphous portion (9-16% of the total) contained in the obtained polypropylene has been separated by treating the raw polymer with n-heptane at room temperature. When operating in such a way, we have not separated the stereoblock fraction (extractable in boiling n-hep-tane) from the isotactic (not extractable in boiling n-heptane) fraction of polymer. The results reported in this paper are generally referred to the crystalline fraction, named non-atactic, which contains also some stereoblock polymers (at the considered polymerization temperatures, the latter generally correspond only to 5-7 % of the total) (9)... 

Heptane Isomerization—It is not expected that isomerization of a heptane fraction per se will be commercially feasible since straight run heptanes are a choice stock for catalytic reforming. The estimated equilibrium octane number (RON clear) for C7 paraffins at 98°F is only about 82 using Rossini s equilibrium data. [These data have been checked experimentally at 98.2°F by G. M. Kramer and A. Schriesheim (44). Good agreement was obtained except for the 2,2-DMP and 3,3-DMP which underwent side reactions.]... 

A mixture of glacial acetic acid (4 p.a., 0.70 mol), camphene (5 95%, 0.70 mol) and acetic anhydride p.a., 9.05 mmol) was mechanically stirred (1500 rpm) overnight at 328 K under a N2 atmosphere. Subsequently, 2.5 g of catalyst was quickly suspended in the reaction mixture. The composition of the soluble fraction of the reaction mixture was analyzed by capillary GC as a function of reaction time samples were prepared as follows 1.00 mL of the reaction mixture was added to water (25.00 mL) followed by an extraction with -heptane (25.00 mL). 1.00 mL of the -heptane fraction was diluted with n-heptane... 

CATALYST COMONOMER l-HEXENC IN FEED FRACTION I. S0CU8LE IN COOL HEPTANE FRACTION II SOLUBLE IN eolLINQ HEPTANE FRACTION I] INSOLUBLE INBOILINO HEPTANE... 

C Acetone Ether Pentane Hexane Heptane fraction polymer... 

Figure A3.6.13. Density dependence of die photolytic cage effect of iodine in compressed liquid n-pentane (circles), n-hexane (triangles), and n-heptane (squares) [38], The solid curves represent calculations using the diffusion model [37], the dotted and dashed curves are from static caging models using Camahan-Starling packing fractions and calculated radial distribution fiinctions, respectively [38],...

Petroleum ether fractions free from aromatic hydrocarbons are marketed, as are also n-hexane and n-heptane from petroleum. 

Data relating to polymer fractions insoluble in / -heptane. 

Asphaltenes seem to be relatively constant in composition in residual asphalts, despite the source, as deterrnined by elemental analysis (6). Deterrnination of asphaltenes is relatively standard, and the fractions are termed / -pentane, / -hexane, / -heptane, or naphtha-insoluble, depending upon the precipitant used (5,6,49). After the asphaltenes are removed, resinous fractions are removed from the maltenes-petrolenes usually by adsorption on activated gels or clays. Recovery of the resin fraction by desorbtion is usually nearly quantitative. 

FIG. 14-37 Overall column efficiency of 25-mm Oldersbaw column compared with point efficiency of 1,22-m-diameter-sieve sieve-plate column of Fractionation Research, Inc, System = cyclohexane-n-heptane, [(Fair, Null, and Bolles, Ind, Eng, Chem, Process Des, Dev, 22, 53 (i.982),]... 

Testing of plates and other devices is carried out by Fractionation Research, Inc. for industrial sponsors. Some of the test data for sieve plates have been published for the cyclohexane//i-heptane and isobu-tane//i-butane systems. Representative data are shown in Fig. 14-43. These are taken from Sakata and Yanagi Jn.stn. Chem. Engis. Symp. See. No. 56, 3.2/21 (1979)] and Yanagi and Sakata [Jnd. Eng. Chem. Proc. Des. Devel, 21, 712 (1982)]. The column diameter was 1.2 m, tray spacing was 600 mm, and weir height was 50 mm. 

FIG. 14-74 HETP values for Max-Pak structured packing,. 35 kPa (5 psia), two column diameters. Cyclohexane/n-heptane system, total reflux. For 0.4.3 m (1.4 ft) column perforated pipe distributor, 400 streams/m2, 3.05 m (10 ft) bed height. For 1.2 m (4.0 ft) column tubed drip pan distributor, 100 streams/m ,. 3.7 m (12 ft) bed height. Smaller column data. University of Texas/Austin Larger column data. Fractionation Research, Inc. To convert (ft/s)(lb/ft ) to (m/s)(kg/m ) , multiply by 1.2199. (Couiiesy Jaeger Troducts, Inc., Housion, Texas.)... 

Methoxynaphthalene [93-04-9] M 158.2, m 73.0-73.6°, b 273°/760mm. Fractionally distd under vacuum. Crystd from absolute EtOH, aqueous EtOH, benzene or n-heptane, and dried under vacuum in an Abderhalden pistol or distd in vacuo. [Kikuchi et al. J Phys Chem 91 574 1987.]... 

Nitronaphthalene [86-57-7] M 173.2, m 57.3-58.3 , b 30-40 /0.01mm. Fractionally distd under reduced pressure, then crystd from EtOH, aqueous EtOH or heptane. Chromatographed on alumina from benzene/pet ether. Sublimes in vacuo. 

Katz et al. tested the theory further and measured the distribution coefficient of n-pentanol between mixtures of carbon tetrachloride and toluene and pure water and mixtures of n-heptane and n-chloroheptane and pure water. The results they obtained are shown in Figure 17. The linear relationship between the distribution coefficient and the volume fraction of the respective solvent was again confirmed. It is seen that the distribution coefficient of -pentanol between water and pure carbon tetrachloride is about 2.2 and that an equivalent value for the distribution coefficient of n-pentanol was obtained between water and a mixture containing 82%v/v chloroheptane and 18%v/v of n-heptane. The experiment with toluene was repeated using a mixture of 82 %v/v chloroheptane and 18% n-heptane mixture in place of carbon tetrachloride which was, in fact, a ternary mixture comprising of toluene, chloroheptane and n-heptane. The chloroheptane and n-heptane was always in the ratio of 82/18 by volume to simulate the interactive character of carbon tetrachloride. 

Figure 18. Graphs Relating the Reciprocal of the Corrected Retention Volume to the Volume Fraction of the Polar Solvent in n-Heptane.

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