Hydrocarbons aliphatic saturated

More recently a convenient method of purification has been recommendedt which is to decant the solvent, previously treated with sulphuric acid, directly on to a basic alumina (Grade I) column using about 50 g of adsorbent for each 100 ml of solvent the first 5 per cent of eluate is discarded. The column receiver should be suitably protected from the ingress of moisture by the attachment of a calcium chloride tube. This method also removes any peroxides which may be present. 

Light petroleum fractions free from aromatic hydrocarbons are marketed, as 

Similar purification procedures apply to cyclohexane, methylcyclohexane and the decalins. 

The purity of all these hydrocarbon solvents may be checked by gas-liquid chromatography (Section 2.31) using an Apiezon, a Silicone oil or an SE-52 silicone rubber gum chromatographic column. 

---

Saturated Aliphatic Hydrocarbons, Table III, 6. Unsaturated Aliphatic Hydrocarbons, Table III, 11. Aromatic Hydrocarbons, Table IV, 9. 

Peroxides. These are formed by aerial oxidation or by autoxidation of a wide range of organic compounds, including diethyl ether, allyl ethyl ether, allyl phenyl ether, dibenzyl ether, benzyl butyl ether, n-butyl ether, iso-butyl ether, r-butyl ether, dioxane, tetrahydrofuran, olefins, and aromatic and saturated aliphatic hydrocarbons. They accumulate during distillation and can detonate violently on evaporation or distillation when their concentration becomes high. If peroxides are likely to be present materials should be tested for peroxides before distillation (for tests see entry under "Ethers", in Chapter 2). Also, distillation should be discontinued when at least one quarter of the residue is left in the distilling flask. 

Johnson, P.C., R.C. Lemon and J.M. Berty, Selective Non-Catalytic, Vapor-Phase Oxiation of Saturated Aliphatic Hydrocarbons to Olefin Oxides, 1964, US Patent 3,132,156. 

The condition defined by equation (8) is met by adjustment of (Qg(3)) nd (T(3)). The pressures at the second stripping flow inlet and that of the outlet for solute (C) must be made equal, or close to equal, to prevent cross-flow. Scott and Maggs [7] designed a three stage moving bed system, similar to that described above, to extract pure benzene from coal gas. Coal gas contains a range of saturated aliphatic hydrocarbons, alkenes, naphthenes and aromatics. In the above theory the saturated aliphatic hydrocarbons, alkenes and naphthenes are represented by solute (A). 

Paraffins (Alkanes). These saturated aliphatic hydrocarbons include normal alkanes as well as branched alkanes (isoalkanes), represented by the formula The... 

Figure 2-77 shows how the weight distributions of the different molecular types vary during the fractional distillation of a naphthenic crude oil. Saturated aliphatic hydrocarbons (i.e., paraffins and naphthenes) are the predominant constituents in the light gasoline fraction. As the boiling point is raised, the paraffin content decreases, and the NSO content increases continuously. About 75 wt% of tbe residuum is composed of aromatics and NSO compounds. 

Dispersive forces are more difficult to describe. Although electric in nature, they result from charge fluctuations rather than permanent electrical charges on the molecule. Examples of purely dispersive interactions are the molecular forces that exist between saturated aliphatic hydrocarbon molecules. Saturated aliphatic hydrocarbons are not ionic, have no permanent dipoles and are not polarizable. Yet molecular forces between hydrocarbons are strong and consequently, n-heptane is not a gas, but a liquid that boils at 100°C. This is a result of the collective effect of all the dispersive interactions that hold the molecules together as a liquid. 

It is only in a few cases that the limits of inflammability of a vapour mixture can be calculated, thanks to the limits of inflammability of the components in the pure state of a mixture. In fact, Le Chatelier s law only applies to mixtures of saturated aliphatic hydrocarbons and to two or three other mixtures of inorganic substances (CO, H2) alone or with methane. 

Reactions and characterisation of saturated aliphatic hydrocarbons 7i-Ootar e Wurtz reaction). ... 

To analyze the green contamination on the small cups, the residue was removed using a micropipette and was placed onto a glass slide prior to recording its ATR spectrum, which is shown in Figure 37. The spectrum is shown together with the optimum-quality matches, which comprise materials such as an oil, a wax, and a defoamer. At the absorbance intensity recorded, the ATR spectrum recorded has all features associated with a saturated aliphatic hydrocarbon. 

In conclusion, the yellow contamination appears to be a mixture of materials, their infrared spectra suggesting that they are primarily a vegetable oil and pullulan, with possibly a surfactant and maybe an inorganic pigment also being present. The green residue is consistent with a saturated aliphatic hydrocarbon, such as a processing aid or an oil. 

Wulff A two-stage process for making acetylene by the pyrolysis of saturated aliphatic hydrocarbons. The feed gas is first pyrolyzed at approximately 1,300°C and then passed into a refractory brick reactor at below 400°C. Developed by R. G. Wulff in California in 1927. Operated in the United States, Brazil, and Europe until the end of the 1960s. See also Ruhr Chemie. 

Paraffin (alkane) one of a series of saturated aliphatic hydrocarbons, the lowest numbers of which are methane, ethane, and propane. The higher homologs are solid waxes. 

Solvents Good to limited resistance against vegetable oils, saturated aliphatic hydrocarbons, polyglycols and ... 

---