Non-Aromatic Hydrocarbons

Poro-xylene is an industrially important petrochemical. It is the precursor chemical for polyester and polyethylene terephthalate. It usually is found in mixtures containing all three isomers of xylene (ortho-, meta-, para-) as well as ethylbenzene. The isomers are very difficult to separate from each other by conventional distillation because the boiling points are very close. Certain zeoHtes or mol sieves can be used to preferentially adsorb one isomer from a mixture. Suitable desorbents exist which have boiling points much higher or lower than the xylene and displace the adsorbed species. The boihng point difference then allows easy recovery of the xylene isomer from the desorbent by distillation. Because of the basic electronic structure of the benzene ring, adsorptive separations can be used to separate the isomers of famihes of substituted aromatics as weU as substituted naphthalenes. 

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Organoperoxysulfonic acids and their salts have been prepared by the reaction of arenesulfonyl chlorides with calcium, silver, or sodium peroxide treatment of metal salts of organosulfonic acids with hydrogen peroxide hydrolysis of di(organosulfonyl) peroxides, RS(0)2—OO—S(02)R, with hydrogen peroxide and sulfoxidation of saturated, non aromatic hydrocarbons, eg, cyclohexane (44,181). 

Low temperature tars contain 30—35 wt % non aromatic hydrocarbons, ca 30% of caustic-extractable phenols in the distillate oils, and 40—50% of aromatic hydrocarbons. The latter usually contain one or more alkyl substituent groups. On atmospheric distillation, coke-oven tars yield 55—60% pitch, whereas CVR tars give 40—50% pitch. The pitch yield from low temperature tars is in the 26—30% range. 

Marcanoa V. et al. (2002). Growth of a lower eukaryote in non-aromatic hydrocarbon media C12 and its exobiological significance. Planetary and Space Science 50(7-8) 693-709. 

In addition to the species Pn+ and Pn+ M, one must consider the complexes formed by the carbenium ions with other n- or n-donors in the system, in particular the polymers formed from monomers containing aromatic groups or hetero-atoms. This means that the polymers formed from non-aromatic hydrocarbons, e.g., isobutene, form a distinct class of noncomplexing polymers we will call these the Class A polymers. It is likely that the internal double-bonds in, for example, poly-(cyclopentadiene) are such poor complexors for steric reasons, that polymers containing them can be placed into the same class. 

Non-aromatic hydrocarbons separation (e.g., olefin/paraffin, -paraffin/ non-n-paraffin) ... 

Table 5.2 Survey of liquid separations using crystalline materials non-aromatic hydrocarbon applications.

This chapter reviews the adsorptive separations of various classes of non-aromatic hydrocarbons. It covers three different normal paraffin molecular weight separations from feedstocks that range from naphtha to kerosene, the separation of mono-methyl paraffins from kerosene and the separation of mono-olefins both from a mixed C4 stream and from a kerosene stream. In addition, we also review the separation of olefins from a C10-16 stream and review simple carbohydrate separations and various acid separations. 

Yao, J., Kimble, J.B., and Drake, C.A. (2000) A method of making such improved zeolite material and the use thereof the conversion of non-aromatic hydrocarbon to aromatics and light olefins. U.S. Patent 6, 048,815. 

The second part of the book covers zeolite adsorptive separation, adsorption mechanisms, zeolite membranes and mixed matrix membranes in Chapters 5-11. Chapter 5 summarizes the literature and reports adsorptive separation work on specific separation applications organized around the types of molecular species being separated. A series of tables provide groupings for (i) aromatics and derivatives, (ii) non-aromatic hydrocarbons, (iii) carbohydrates and organic acids, (iv) fine chemical and pharmaceuticals, (v) trace impurities removed from bulk materials. Zeolite adsorptive separation mechanisms are theorized in Chapter 6. 

Fraser MR Gass GR, Simoneit BRT, Rasmussen RA, Air quality model evaluation data for organics 4. G2 to G3g non-aromatic hydrocarbons. Environ Sci Technol 31 2356-2367, 1997. 

Non-aromatic Hydrocarbons, Heterocyclic Analogs and Derivatives , A. F. Cameron, in Molecular Structure by Diffraction Methods , ed. G. A. Sim and L. E. Sutton, Royal Society of Chemistry, London, 1975, vol. 3, pp. 128-162. 

There are several potentials for hydrocarbons in the literature. One of the most widely used potentials among these is that due to Williams and Cox [19]. This has been derived by fitting to about 30 different aromatic and non-aromatic hydrocarbons. It is an atom-atom potential with 22 sites on each of the C and H atoms and has the following form ... 

Simple distillation cannot separate aromatics from noD -aromatic, because the relative volatilities are very low, and many azeotropes are formed. Azeotropic distillation is based on the formation of an azeotrope betu een the non-aromatic hydrocarbons and a low boiling polar solveat It is select among the hrst terms of the series of alcohols, ketones, aldehydes and nitriles, and is employed pure or mixed with water. If the solvent forms a hetero-azeotrope, its recovery is accordbgly facilitated. The )aeld is not limited in principle. The impurity content of the feedstock and the composition of the azeotrope determine the amount of solvent required. Cuts rich in aromatics can be treated in this way fairly economically. However, any variation in the type of impurity to be removed, and consequently in the composition of the azeotrope, may lead to less perfect purification. Furthermore, this method can be applied only to a narrow cut which contains... 

Okamoto K, Wang H, Ijyuin T, Fujiwara S, Tanaka K, and Kita H. Pervaporation of aromatic/non-aromatic hydrocarbon mixtures through crosslinked membranes of polyimide with pendant phosphonate ester groups. J Membr Sci 1999 157 97-105. 

Fang J, Tanaka K, Kita H, and Okamoto K. Pervaporation properties of ethynyl-containing copolyimide membranes to aromatic/non-aromatic hydrocarbon mixtures. Polymer 1999 40 3051-3059. 

Ruckenstein E. Emulsion pathways to composite pol3mieric membranes for separation processes. Colloid Polym Sci 1989 267 192-191. Park JS and Ruckenstein E. Selective permeation through hydrophobic-hydrophihc membranes. J Appl Pol Sci 1989 38 453 61. Wang Y, Hirakawa S, Wang H, Tanaka K, Kita H, and Okamoto K. Pervaporation properties to aromatic/non-aromatic hydrocarbon mixtures of cross-linked membranes of copoly(methacrylates) with pendant phosphate and carbamoylphosphonate groups. J Membr Sci 2002 199 13-27. 

Gmehling J, Krummen M (to Carl v. Ossietzky University Oldenburg), DE10154052 Separation of aromatic hydrocarbons from non-aromatic hydrocarbons, comprises using a selective solvent selected from liquid onium salts publication date 2003-07-10... 

Table III. Gravimetric and gas chromatographic data on unbound and non-aromatic hydrocarbon fractions, DSDP Site 603B lower continental rise, U.S, east coast.

The prime purpose of reforming is to make aromatics from each class of non-aromatic hydrocarbons in naphtha. The core reaction of alkane dehy-drocyclisation in reforming is complex and its optimisation has driven catalyst science and reforming technology since the 1960s. 

Figure 2 shows the effect of temperature and benzene concentration on the kinetics of carbon deposition on a nickel foil. The temperature behavior follows a pattern that has been previously observed in the catalytic carbon formation from non-aromatic hydrocarbons (1 ,2). There are three regions in the Arrhenius plot. At low temperatures, the rate increases with increasing temperature and, thus, a negative slope-line is obtained in the Arrhenius plot. This low temperature region is denoted as Region I. 

Zsolnay (1973b) reported the existence of a significant linear correlation (r = 0.63 P 0.001) between the non-aromatic hydrocarbons and the chlorophyll a content in the euphotic zone of the water off West Africa during a short period (six days) of high biological activity in March 1972. It was suggested, therefore, that the non-aromatic hydrocarbons present resulted essentially from phytoplankton activity. 

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