Saturated hydrocarbons, purification

A study of sonochemical treatment of chlorinated hydrocarbons in water demonstrated the homogeneous destruction of CH2CI2, CCI4, MeCCl3, and CICH = CCI2 in solution at concentrations of 100-1000 ppm by volume [29]. The method appears to be potentially quite powerful for the purification of contaminated water. In a separate study when saturated aqueous solutions of CH2CI2 (110 ppm) and MeCClj (1300 ppm) were sonicated for 20 min some 75 % of the contaminant was degraded [30]. 

D. Prepurification Of Solvents. Some solvent purification procedures call for some type of wash. For example, saturated hydrocarbons are often washed with concentrated H2S04 to remove alkenes. These washing procedures are generally done first, since they usually involve the use of an aqueous solution or a substance that contains significant amounts of water. Unlike the following procedures, washes can be done in the presence of air, since further treatment usually involves a step designed to eliminate oxygen. 

More accurate quantitative analyses can be carried out by GC or LC. A suitable internal standard is usually required it must be chemically stable and involatile under the conditions of the experiment (prior to injection into the chromatography apparatus), and must be resolved from the other signals in the chromatogram. It is usually added to the product mixture after the reaction has been completed but before any extraction, purification or analysis steps are undertaken. Saturated hydrocarbons of Cio or above are typically used as internal standards for GC [7]. Response factors are obtained for each component of... 

However, most fuel cell systems can tolerate methane concentrations up to at least 1% in the reformate, no special purification reactions are required. In contrast, hence, removing small residual amounts of carbon monoxide from pre-purifled reformate applying the methanation reaction may be considered as an alternative to the preferential oxidation of carbon monoxide, provided that the CO concentration is low enough to have no significant impact on the hydrogen yield. However, no applications of methanation for CO clean-up in micro structured devices appear to have been reported, hence the issue is not discussed in depth. Finally, during hydrocarbon reforming all hydrocarbon species (saturated and unsaturated) smaller than the feed molecule may be formed. 

Technical 1-eicosene was obtained from the Aldrich Chemical Company, Inc. and used without further purification. Analysis by quantitative catalytic hydrogenation over Pd-C and NMR spectroscopy indicated that it contained about 10% unreactive, saturated hydrocarbon material. 

The steam-methane reforming process produces ammonia by steam reforming natural or refinery gas under pressure, followed by carbon monoxide shift, purification of raw synthesis gas, and ammonia synthesis. In the process, saturated and unsaturated hydrocarbons are decomposed by steam according to the basic equation ... 

As an aside, it is worth mentioning that the study of primary radical cations in saturated hydrocarbon liquids presents a much greater purity problem than for excess electrons since many potential impurities and products of irradiation tend to have ionization potentials lower than that of the saturated hydrocarbon solvent. Rigid purification from unsaturated and even isomeric impurities, and very low accumulated doses are therefore imperative in such studies. 

H20, CO2, cyclopentanone, traces of saturated hydrocarbons, purification from water and add polymerization catalysts increases stability and decreases yield of CO2 H2O, CO2, NH3, cydic monomer, cyclopentanone. cyclopentylidenecyclopentanone, cydopentylcyclopentanone, hexylamine, hexamethyleneimine, hexamethylenediamine... 

Most olefinic gas streams obtained from refinery off-gases or from the cracking of saturated hydrocarbons contain acetylenic compounds in concentrations ranging from a few tenths of 1% to about 2%. These compounds must be removed if the olefins are to be used for the production of certain petrochemicals. Although liquid purification processes employing. selective. solvents have been developed, selective catalytic hydrogenation is usually the pre-... 

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