Natural pentane

Resin, Polyester, Hetron 31 a n 631-1876 Rubber, Natural Pentane m 631-2571... 

According to the nature of the solvent employed, the yields and constitutions of the asphaltenes are different. In the United States, asphaltenes are obtained by precipitation from normal pentane. 

Fig. 2.17 The adsorption of pentane on different adsorbents, (a) Effect of the nature of the adsorbent on the shape of the isotherm (each isotherm is labelled with the name of the adsorbent), (b) Dependence of ajpentane) on the value of parameter C. (Courtesy Kiselev and Eltekov. )...

Other natural gas Hquids include natural gasoline [8006-61 -9] which is composed of the pentanes and heavier components of the natural gas stream, and ethane [74-84-0]. Most recendy ethane has become the principal product of natural gas processing plants. 

Adsorption. Adsorption processes have been used to recover hydrocarbons that are heavier than ethane from natural gas. Although the adsorption process has appHcations for the recovery of pentane and heavier hydrocarbons from lean gas, the percentage recovery of LPG components in these plants usually is low compared to the normal recovery of LPG in modem turboexpander or oil-absorption plants. 

HCIO4). Refluxed with benzene (6mL/g) in a flask fitted with a Dean and Stark trap until all the water was removed azeotropically (ca 4h). The soln was cooled and diluted with dry pentane (4mL/g of AgC104). The ppted AgC104 was filtered off and dried in a desiccator over P2O5 at 1mm for 24h [Radell, Connolly and Raymond J Am Chem Soc 83 3958 1961]. It has also been recrystallised from perchloric acid. [Caution due to EXPLOSIVE nature in the presence of organic matter.]... 

Natural Gas The lightest, most volatile petroleum fractions, such as propane, pentane, etc. 

Liquefied petroleum gas (LPG) Paraffin hydrocarbon gases comprising propane, butane, and pentanes derived from natural gas wells and from the petroleum refining process that remain as liquids when stored under pressure in tanks and bottles. 

The first step in a gas processing plant is to separate the components that are to be recovered from the gas into an NGL stream. It may then be desirable to fractionate the NGL stream into various liquefied petroleum gas (LPG) components of ethane, propane, iso-butane, or normal-butane. The LPG products are defined by their vapor pressure and must meet certain criteria as shown in Table 9-1. The unfractionated natural gas liquids product (NGL) is defined by the properties in Table 9-2. NGL is made up principally of pentanes and heavier hydrocarbons although it may contain some butanes and very small amounts of propane. It cannot contain heavy components that boil at more than 375°F. 

Absorber oil then flows to a still where it is heated to a high enough temperature to drive the propanes, butanes, pentanes and other natural gas liquid components to the overhead. The still is similar to a crude oil stabilizer with reflux. The closer the bottom temperature approaches the boiling temperature of the lean oil the purer the lean oil which will be recirculated to the absorber. Temperature control on the condenser keeps lean oil from being lost with the overhead. 

Condensates are natural gas liquids, consisting mostly of pentanes and heavier hydrocarbon components. These include... 

Aumann et al. have observed an unusual formal [6S+2C] cycloaddition reaction when they performed the reaction between an alkynylcarbene complex and 1-aminobenzocyclohexenes. The solvent used in this reaction exerts a crucial influence on the reaction course and products of different nature are obtained depending on the solvent chosen. However, in pentane this process leads to cyclooctadienylcarbene complexes in a reaction which can be formally seen as a [6S+2C] cycloaddition [117] (Scheme 71). The formation of these compounds is explained by an initial [2+2] cycloaddition reaction which leads to a cy-clobutenylcarbene derivative which, under the reaction conditions, undergoes a cyclobutene ring opening to furnish the final products. 

As discussed, the cultivation of C. sativa with high content of A9-THC (drug-type) is not allowed in many coimtries. Because of this, there is no opportunity to harvest a high amoimt of the medicinally important substance A9-THC directly from plant material. In the synthesis route for semisynthetic A9-THC, natural CBD from fiber hemp plants is employed. It can be extracted with non-polar solvents such as petroleum ether and purified by recrystalUza-fion in n-pentane. This procedure avoids the formation of abnormal CBD and gives the opportunity to produce A9-THC from fiber hemp. Semisyn-fhetic A9-THC is disfinguishable from the synthetic compound because it contains, besides the major product, small amounts of A9-THC-C3 and A9-THC-C4, which are not available in the synthetic product. 

The 50.31 MHz 13C NMR spectra of the chlorinated alkanes were recorded on a Varian XL-200 NMR spectrometer. The temperature for all measurements was 50 ° C. It was necessary to record 10 scans at each sampling point as the reduction proceeded. A delay of 30 s was employed between each scan. In order to verify the quantitative nature of the NMR data, carbon-13 Tj data were recorded for all materials using the standard 1800 - r -90 ° inversion-recovery sequence. Relaxation data were obtained on (n-Bu)3SnH, (n-Bu)3SnCl, DCP, TCH, pentane, and heptane under the same solvent and temperature conditions used in the reduction experiments. In addition, relaxation measurements were carried out on partially reduced (70%) samples of DCP and TCH in order to obtain T data on 2-chloropentane, 2,4-dichloroheptane, 2,6-dichloroheptane, 4-chloroheptane, and 2-chloroheptane. The results of these measurements are presented in Table II. In the NMR analysis of the chloroalkane reductions, we measured the intensity of carbon nuclei with T values such that a delay time of 30 s represents at least 3 Tj. The only exception to this is heptane where the shortest T[ is 12.3 s (delay = 2.5 ). However, the error generated would be less than 10%, and, in addition, heptane concentration can also be obtained by product difference measurements in the TCH reduction. Measurements of the nuclear Overhauser enhancement (NOE) for carbon nuclei in the model compounds indicate uniform and full enhancements for those nuclei used in the quantitative measurements. Table II also contains the chemical... 

Drizo A variation of the glycol process for removing water vapor from natural gas, in which the water is removed from the glycol by stripping with a hydrocarbon solvent, typically a mixture of pentanes and heavier aliphatic hydrocarbons. The process also removes aromatic hydrocarbons. Last traces of water are removed from the triethylene glycol by stripping with toluene in a separate, closed loop. Invented in 1966 by J. C. Arnold, R. L. Pearce, and H. G. Scholten at the Dow Chemical Company. Twenty units were operating in 1990. U.S. Patent 3,349,544. 

Naturally occurring mixtures of hydrocarbon gases and vapors, the more important of which are methane, ethane, propane, butane, pentane and hexane. Natural Gas is lighter than air, non-toxic and contains no poisonous ingredients. Breathing natural gas is harmful when there is not an adequate supply of oxygen in the atmosphere. 

Condensate is normally considered the entrapped liquids in process or production gas streams due to temperature or pressure, in the typically in the range of C3, C4, C5 or heavier hydrocarbon liquids. It is also known as natural gasoline C5 plus and pentanes plus, and as a liquid at normal temperatures and pressures it generally consists of a mixture of the C5 (pentanes) and heavier hydrocarbons. It is normally condensed (i.e., by expansion and cooling of the gas) out of the process stream in primary separation processes, where it is then sent to other refinery processes to further separate the condensate into its primary fractions, i.e., propane, butane, and liquids constituents. 

Ethylene-propylene (30-60 mole per cent) copolymers produce substances which are rubbery in nature. They are prepared by using Ziegler catalysts based on vanadium oxychloride/aluminium trihexyl by solution process at 40°C using chlorobenzene or pentane as a solvent. These can be vulcanised with peroxides. Ethylene-propylene-hexa 1, 4-diene terpolymers are rubbers which can be vulcanised with sulphur. 

The above example illustrates the influence of the lattice on the constitution of the product. The photolysis of azobis-3-phenyl-3-pentane, 189, provides a case of influence on the product configuration (249). In this system, too, the crystal lattice favors disproportionation over combination. Two disproportionation products, the Z- and -pentenes 190 and 191, are formed in the solid, in a ratio of 1 3 the predicted equilibrium ratio is 1 1.6. While the nature of the processes determining this ratio is not clear, it was established that the Z isomer is formed under strong lattice control, whereas the E isomer is formed in a process with greater, but not complete, molecular freedom. 

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