Chlorine gaseous sources

Chlorinated dielectric products Chlorine (gaseous liquefied) Chromium sulfate Coal tar (by sources)... 

Both the Toth and Alcoa processes provide aluminum chloride for subsequent reduction to aluminum. Pilot-plant tests of these processes have shown difficulties exist in producing aluminum chloride of the purity needed. In the Toth process for the production of aluminum chloride, kaolin [1332-58-7] clay is used as the source of alumina (5). The clay is mixed with sulfur and carbon, and the mixture is ground together, pelletized, and calcined at 700°C. The calcined mixture is chlorinated at 800°C and gaseous aluminum chloride is evolved. The clay used contains considerable amounts of silica, titania, and iron oxides, which chlorinate and must be separated. Silicon tetrachloride and titanium tetrachloride are separated by distillation. Resublimation of aluminum chloride is requited to reduce contamination from iron chloride. 

The gases used in the CVD reactor may be either commercially available gases in tanks, such as Ar, N2, WF, SiH, B2H, H2, and NH Hquids such as chlorides and carbonyls or soflds such as Mo carbonyl, which has a vapor pressure of 10 Pa (75 mtorr) at 20°C and decomposes at >150° C. Vapor may also come from reactive-bed sources where a flowing haUde, such as chlorine, reacts with a hot-bed material, such as chromium or tantalum, to give a gaseous species. 

Homogeneous reactions. Homogeneous noncatalytic reactions are normally carried out in a fluidized bed to achieve mixing of the gases and temperature control. The sohds of the bed act as a heat sink or source and facihtate heat transfer from or to the gas or from or to heat-exchange surfaces. Reaclious of this type include chlorination of hydrocarbons or oxidation of gaseous fuels. 

If nitration under acidic conditions could only be used for the nitration of the weakest of amine bases its use for the synthesis of secondary nitramines would be severely limited. An important discovery by Wright and co-workers " found that the nitrations of the more basic amines are strongly catalyzed by chloride ion. This is explained by the fact that chloride ion, in the form of anhydrous zinc chloride, the hydrochloride salt of the amine, or dissolved gaseous hydrogen chloride, is a source of electropositive chlorine under the oxidizing conditions of nitration and this can react with the free amine to form an intermediate chloramine. The corresponding chloramines are readily nitrated with the loss of electropositive chlorine and the formation of the secondary nitramine in a catalytic cycle (Equations 5.2, 5.3 and 5.4). The mechanism of this reaction is proposed to involve chlorine acetate as the source of electropositive chlorine but other species may play a role. The success of the reaction appears to be due to the chloramines being weaker bases than the parent amines. 

In a hood, through a rapidly stirred suspension of 76 gm (0.396 mole) of cyclohexanoneazine in 300 ml of petroleum ether (b.p. 60°-90°C) cooled to —60°C is passed a slow stream of gaseous chlorine until a slight excess of the gas is noted. The excess of chlorine is removed by ventilation at the water aspirator. Then the solution is concentrated to half-volume by gentle evaporation at reduced pressure. The reaction system is filtered free from tarry impurities and the filtrate is allowed to stand for 24 hr at room temperature. The product gradually separates out and is isolated by filtration. Evaporation of the mother liquor may afford another crop of product. The total yield is 81.5 gm (78 %). The product, after recrystallization from petroleum ether, has a melting point of 66°C. (NOTE Since aliphatic azo compounds are inherently unstable and may serve as free radical sources, the stability of the product should always be checked with due precautions, and excessive exposure to heat should always be avoided.)... 

In redox electrodes an inert metal conductor acts as a source or sink for electrons. The components of the half-reaction are the two oxidation states of a constituent of the electrolytic phase. Examples of this type of system include the ferric/ferrous electrode where the active components are cations, the ferricyanide/ferrocyanide electrode where they are anionic complexes, the hydrogen electrode, the chlorine electrode, etc. In the gaseous electrodes equilibrium exists between electrons in the metal, ions in solution and dissolved gas molecules. For the half-reaction... 

The cheapest source of chlorine is the hazardous, yellow-green CI2 gas, supplied under pressure as a liquid. However, the supply of chlorine bottles (cylinders), the maintenance of a chlorinator (which permits the conversion of liquid chlorine into lower pressure gaseous chlorine), and the eductor and piping system is costly. It also requires first class health and safety handling procedures. 

The addition of a gas to a reaction mixture (commonly the hydrogen halides, fluorine, chlorine, phosgene, boron trifluoride, carbon dioxide, ammonia, gaseous unsaturated hydrocarbons, ethylene oxide) requires the provision of safety precautions which may not be immediately apparent. Some of these gases may be generated in situ (e.g. diborane in hydroboration reactions), some may be commercially available in cylinders, and some may be generated by chemical or other means (e.g. carbon dioxide, ozone). An individual description of the convenient sources of these gases will be found under Section 4.2. 

Although a battery cell depending on these reactions of zinc and chlorine could be used as a source of electrical energy, it is rather obvious that a battery involving the use of gaseous chlorine would hardly be practical in everyday use. Hence, before going any further into the problem of the general characteristics of battery cells, a battery more nearly suitable for actual use is considered. 

Autoignition temperature The autoignition temperature of a substance, whether solid, liquid, or gaseous, is the minimum temperature required to initiate or cause self-sustained combustion (e.g., in air, chlorine, or other oxidant) with no other source of ignition. 

At the moment, when, due to this reaction, two electrons are consumed at the cathode an equal number of electrons is set free at the other electrode (the anode) by two chloride ions yielding one electron each whereby they are transformed into two chlorine atoms. The electrons so set free then return through the outer conductor from the electrode to the source of the current, while nascent chlorine atoms combine in pairs to form molecules of gaseous chlorine which escape into the atmosphere. The anodic reaction can thus be written as ... 

The dechlorination section of the plant consists of components which together effect release of chlorine from plastics such as PVC in the presence of coal and additives. The hot viscous waste plastic is fed from the upper end of the vessel and allowed to heat up at 220-250°C. The coal acts as a source of hydrogen required for the reaction. The released gaseous hydrochloride travels upwards through the vessel and is discharged to gaseous product recovery. 

In the first experiment we will chlorinate 1-chlorobutane because it is easier to handle in the laboratory than gaseous butane and we will use sulfuryl chloride as our source of chlorine radicals because it is easier to handle than gaseous chlorine. Instead of using light to initiate the reaction we will use a chemical initiator, 2,2 -azobis-(2-methylpropionitrile). This azo compound (R—N=N—R) decomposes at moderate temperatures (80-100°C) to give two relatively stable radicals and nitrogen gas ... 

Laser-induced breakdown spectrometry was used for the analysis of gaseous samples containing elements such as F, Cl, S, P, As and Hg in air, and hydrides of column 111 and V elements (e.g. B,H, PH,) [184-189]. The aim was to measure trace amounts of analytes in hostile environments and gas impurities for hydride work. Mercury was detected at the parts-per-billion level in air using a photodiode array detector that recorded single-shot spectra over a range of 20 nm [186]. Cremers el al. [189] reported limits of detection of 8 and 38 pg/ml for chlorine and fluorine, respectively, the source of both... 

Duce RA (1969) On the source of gaseous chlorine in marine atmosphere. J Geophys Res 74 4597 Duce RA, Unni CK, Ray BJ, Prospero JM, Merrill JT (1980) Long-range atmospheric transport of soil dust from Asia to the tropical north Pacific Temporal variability. Science 209 1522-1524 Duncan JL, Schindler LR, Roberts JT (1998) A new sulfate-mediated reaction Conversion of acetone to trimethylbenzene in the presence of liquid sulfuric acid. Geophys Res Lett 25 631-634 Duncan JL, Schindler LR, Roberts JT (1999) Chemistry at and near the surface of liquid sulfuric acid A kinetic, thermodynamic, and mechanistic analysis of heterogeneous reactions of acetone. J Phys Chem B 103 7247-7259... 

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