Aliphatic hydrocarbons residues

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. 

The results of more recent investigations by Blicke with Maxwell and with Kaplan covering a wide range of basic components and of acyl residues, do not lend themselves to a simple generalisation. The basic components were mainly dialkylamino-derivatives of aliphatic hydrocarbons from ethane to pentane, e.g.,. CHj. CHj. NMcj to. CHj. CMcj. CHj. NEtj, and similar but shorter series of derivatives of piperidine (CgHjoN), morpholine, e.g.,. CHj. CHj. NC HgO, and methylcj/clohexylamine... 

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. 

LEDA [Low energy de-asphalting] A process for removing the asphalt fraction from petroleum residues by liquid-liquid extraction in a special rotating disc contactor. The extractant is a C3-C6 aliphatic hydrocarbon or a mixture of such hydrocarbons. Developed in 1955 by Foster Wheeler USA Corporation and still widely used 42 units were operating in 1996. 

Pignatello, J. J. (1990) Slow reversible sorption of aliphatic hydrocarbons in soils I. Formation of residual fractions. Environ. Toxicol. Chem. 9, 1107-1115. 

Character of Center Nucleus.—As was stated in connection with anthracene itself we can not say positively as to the character of the center nucleus in either the hydrocarbon or the quinone. In anthracene the aliphatic character of this center nucleus is indicated by its formation from an ethane residue, by the tetra-brom ethane synthesis. This does not, however, preclude the possibility of its becoming a true benzene nucleus when condensed with two benzene rings, for benzene itself may be made from aliphatic hydrocarbons, from acetylene by polymerization (p. 478), and from hexane through hexa-methylene with the loss of hydrogen after the formation of the cyclo-paraffin (p. 469). Also naphthalene, in which there is no doubt of the benzene character of the two nuclei, may have one nucleus formed from an aliphatic chain as in the syntheses given (p. 767) from phenyl butylene bromide, from phenyl vinyl acetic acid and from tetra-carboxy ethane. In the same way the facts in regard to anthraquinone do not prove... 

In helium quantitative yield of HCI. remainder residue and hydrocarbons, benzene is major volatile hydrocarbons product aliphatic hydrocarbons, benzene (major product), toluene, ethylbenzene, o-xyiene, monochlorobenzene styrene, vinyl tcriuerre. p-dichlorobenzene, o-dichlorobenzene, indene, 1,3.5-trichlorobenzene 1.2.4. richlorobenzene. naphthalene, u-methylnaphthalene. p-methylnaphthatene effect of ZnO. SnOj, and Ab03 on the yields of products Is also recorded HCI. CO2. ethene. ethane, propane, 1-butene. 2-butene. 1-pentene. cydopentene, n-pentane, 2-methylbulane, 1,3-pentadiene. 2-methyl-1,3-pentadiene, complex series (60 Identlfled) of aromatic and polyaromatic species including benzene, styrene, methylstyrenes, toluene, o-xytene, m-xylene, p-xylene, biphenyl, naphthalene, anthracene, phenanthrene. pyrene, etc. 

Particulates are another source of respiratory irritation when inhaled. In urban environments, diesel exhaust particles and fly ash residue from power plant oil combustion are the main contributors of respirable particulates of less than 10 pm diameter (PM 10). These contain mixtures of lipo-philes and hydrophiles including various metals, acid salts, aliphatic hydrocarbons, PAHs, quinones, nitroaromatic hydrocarbons, andaldehydes. 151 Diesel combustion particulates contain large surface areas that can adsorb large quantities of organic compounds and deliver these to respiratory tract tissue. Other inhaled particulates can adhere to lung surfaces and adsorb and bond other vapors that are inhaled, thereby increasing their toxicities. PM2.5 particulates (those with diameters of less than 2.5 pm) that reach the lower respiratory tract as far as the alveoli are more toxic than PM 10 particulates of the same composition. 16 ... 

Chemically, paraffin wax is a mixture of saturated aliphatic hydrocarbons (with the general formula C H2 +2). Wax is the residue extracted when lubricant oils are dewaxed and it has a crystalline structure with a carbon number greater than 12. The main characteristics of wax are (1) absence of color, (2) absence of odor, (3) translucence, and (4) a melting point above 45°C (113°F). 

Because of its nonpolar and hydrophobic character, the mercury-water may serve as a good model interface for the adsorption study and determination of the organic substances that are adsorbed primarily because of hydrophobic expulsion. There is generally a proportionality of adsorbability (free energy of adsorption) found at the mercury electrode to a number of -CH2 groups in paraffinic hydrocarbon residues in nonpolar surfactants and a similar relation between the octanol water partition coefficient and chain length. This was recently also illustrated in the case of adsorption of aliphatic fatty acids (Ulrich ct al., 1988). 

In the absence of molybdenum, the blank dehydrated zeolites showed no CO hydrogenation activity even up to 400°C. In contrast, measurable quantities of aliphatic hydrocarbons were detected over the molybdenum-zeolite catalysts at 300°C and above. Figs. 1-2 show the time dependence of CO conversion over MOii g HY and Mo g CsY at 300°C. The conversion and product distribution were dependent on the reaction conditions, a typical set of results is illustrated in Table 1. The molybdenum-zeolites prepared by adsorption and decomposition of Mo(C0)g resembled closely the alumina-supported molybdenum catalysts prepared by decomposing Mo(C0)g on alumina (ref. 13). The results obtained presently could not match the figures reported by Brenner et aK (ref. 8), but this could be due to the significant differences in the reaction conditions used by the above authors. However, a comparison with the silica-molybdena catalyst (prepared by impregnation of ammonium molybdate) clearly indicates that the molybdenum-zeolites were more active on per molybdenum basis. The improved activity is due to the presence of zerovalent molybdenum (for LaY and HY, residual zerovalent molybdenum were responsible for the activity). 

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