Carbon tetrachloride production

Table 4. U.S. Carbon Tetrachloride Production and Price Statistics...

Carbon tetrachloride is produced by exhaustive chlorination of a variety of low molecular weight hydrocarbons such as carbon disulfide, methanol, methane, propane, and ethylene dichloride (CEH 1985 lARC 1979). It is also produced by thermal chlorination in the production of tetrachloroethylene. Since the U.S. Food and Drug Administration banned the sale of carbon tetrachloride in any product used in the home, its production initially declined at approximately 8% a year from 1974 to 1981 (HSDB 1992). From 1981 to 1988 the United States consistently produced between 573-761 million pounds (260,000-350,000 metric tons) of carbon tetrachloride per year (C EN 1992 SRI 1988 USITC 1986). Carbon tetrachloride production dropped to 413 million pounds (187,000 metric tons) per year in 1990, and to 315 million pounds (143,000 metric tons) in 1991 (C EN 1992, 1993 USITC 1986, 1991). Carbon tetrachloride is currently manufactured at five facilities in the United States Akzo Chemical, Inc., New York, New York Dow Chemical Company, Midland, Michigan Vulcan Materials Company, Birmingham, Alabama Occidental Chemical Corporation, Dallas, Texas and LCP Chemicals, West Virginia Inc., Moundsville, West Virginia (USITC 1991 HSDB 1992). 

The magnitude of the effect of this scheduled phaseout on total carbon tetrachloride production is uncertain, since the Halogenated Solvents Industry Alliance estimates that only about 3% of the chemical manufactured in the U.S. is used in nonfeedstock applications (EPA 1991). Nevertheless, since the major current use of carbon tetrachloride is in the production of chlorofluorocarbons (see Section 4.3), and production of these chemicals has dropped significantly in recent years (C EN 1993) and is also scheduled for phase-out by 1996, a significant reduction in carbon tetrachloride production is expected during this decade. 

Carbon tetrachloride is a stable chemical that is degraded very slowly, so there has been a gradual accumulation of carbon tetrachloride in the environment as a consequence of releases from human activities. Until 1986, the largest source of release was from the use of carbon tetrachloride as a grain fumigant, but this practice has now been stopped. Other releases of carbon tetrachloride may occur during carbon tetrachloride production or during the use of carbon tetrachloride in the manufacture of chlorofluorocarbons and other chemical products. 

Relatively small amounts of carbon tetrachloride are released to water. The total in 1978 was estimated to be 2.5 metric tons, due almost entirely to discharges from carbon tetrachloride production facilities (Rams et al. 1979). Analysis of data from ERA S Storage and Retrieval (STORET) database for the early 1980s indicate that carbon tetrachloride was detectable in 5.5% of 1,343 industrial effluent samples (Staples et al. 1985). The median concentration of all samples was <5 og/L. Carbon tetrachloride was also detected in leachates from industrial landfills at concentrations ranging from <10 to 92 pg/L (Brown and Donnelly 1988). 

Another principal industrial use for carbon disulfide has been as a feedstock for carbon tetrachloride production (Mannsville Chemical Products Corp. 1985 NIOSH 1977 Timmerman 1978). While only 10% of U.S. carbon disulfide production was used to produce carbon tetrachloride in 1960, this increased to 32% in 1974, largely because of a rapid increase in the demand for carbon tetrachloride for the production of fluorocarbon propellants and refrigerants (Timmerman 1978). Although most chemical manufacturers have switched to methanol as a raw material for carbon tetrachloride, beginning in 1985, Akzo America, Inc., continued to use carbon disulfide for this purpose (Mannsville Chemical Products Corp. 1985). Beginning in 1989, 38% of the carbon disulfide produced was used to manufacture carbon tetrachloride (HSDB 1995). 

In 1989, the estimated distribution of carbon disulfide utilization was as follows 34% of production went to manufacture viscose rayon, 6% to produce cellophane, 38% to produce carbon tetrachloride, 7% to produce rubber chemicals, and 15% to produce pesticides and to solubilize waxes and oils (HSDB 1995). Future use patterns remain uncertain, although it is expected that less may be used to produce viscose rayon, cellulose, and carbon tetrachloride, products for which the demand has declined and for which alternate production processes may be found (HSDB 1995 Mannsville Chemical Products Corp. 1985 Timmerman 1978). Unless substitutes for carbon disulfide are found, its use levels may depend largely on relative import and export levels of textiles and apparel (Mannsville Chemical Products Corp. 1985). Carbon disulfide use for many other specialty industrial purposes is expected to continue (HSDB 1995 Timmerman 1978). 

CH2CI2. A colourless liquid with a chloroform-like odour b.p. 4I°C. Prepared by heating chloroform with zinc, alcohol and hydrochloric acid manufactured by the direct chlorination of methane. Decomposed by water at 200°C to give methanoic and hydrochloric acids. Largely used as a solvent for polar and non-polar substances, particularly for paint removal (30%), dissolving cellulose acetate and degreasing (10%). It is more stable than carbon tetrachloride or chloroform especially towards moisture or alkali. It is somewhat toxic. U.S. production 1981 280000 tonnes. 

The substitution is best carried out by boiling A -bromosuccinimide with the olefine in carbon tetrachloride. Succinimide crystallises out from the carbon tetrachloride on cooling w hereas the brominated product remains dissolved in the carbon tetrachloride. 

Cinnamic acid can be readily esterified by the Fischer-Speier method without any risk of the addition of hydrogen chloride at the double bond. Proceed precisely as for the preparation of ethyl benzoate (p. 104), using 20 g. of cinnamic acid and 20 ml. of rectified spirit. When the crude product is poured into water, a sharp separation of the ester is not readily obtained, and hence the addition of about 10 ml. of carbon tetrachloride is particularly desirable. Finally distil off the carbon... 

Methylene chloride CHjCl, b.p. 41°, is obtained as a by product in the com mercial preparation of chloroform by the reduction of carbon tetrachloride with moist iron and also as one of the products in the chlorination of methane it is a useful extraction solvent completely immiscible with water. 

Add 1 ml. of the alcohol-free ether to 0-1-0-15 g. of finely-powdered anhydrous zinc chloride and 0 5 g. of pure 3 5-dinitrobenzoyl chloride (Section 111,27,1) contained in a test-tube attach a small water condenser and reflux gently for 1 hour. Treat the reaction product with 10 ml. of 1-5N sodium carbonate solution, heat and stir the mixture for 1 minute upon a boiling water bath, allow to cool, and filter at the pump. Wash the precipitate with 5 ml. of 1 5N sodium carbonate solution and twice with 6 ml. of ether. Dry on a porous tile or upon a pad of filter paper. Transfer the crude ester to a test-tube and boil it with 10 ml. of chloroform or carbon tetrachloride filter the hot solution, if necessary. If the ester does not separate on cooling, evaporate to dryness on a water bath, and recrystallise the residue from 2-3 ml. of either of the above solvents. Determine the melting point of the resulting 3 5 dinitro benzoate (Section 111,27). 

To obtain a maximum yield of the acid it is necessary to hydrolyse the by-product, iaoamyl iaovalerate this is most economically effected with methyl alcoholic sodium hydroxide. Place a mixture of 20 g. of sodium hydroxide pellets, 25 ml. of water and 225 ml. of methyl alcohol in a 500 ml. round-bottomed flask fitted with a reflux (double surface) condenser, warm until the sodium hydroxide dissolves, add the ester layer and reflux the mixture for a period of 15 minutes. Rearrange the flask for distillation (Fig. II, 13, 3) and distil off the methyl alcohol until the residue becomes pasty. Then add about 200 ml. of water and continue the distfllation until the temperature reaches 98-100°. Pour the residue in the flask, consisting of an aqueous solution of sodium iaovalerate, into a 600 ml. beaker and add sufficient water to dissolve any solid which separates. Add slowly, with stirring, a solution of 15 ml. of concentrated sulphuric acid in 50 ml. of water, and extract the hberated acid with 25 ml. of carbon tetrachloride. Combine this extract with extract (A), dry with a httle anhydrous magnesium or calcium sulphate, and distil off the carbon tetrachloride (Fig. II, 13, 4 150 ml. distiUing or Claisen flask), and then distil the residue. Collect the wovaleric acid 172-176°. The yield is 56 g. 

Undecylenic acid (or 10-undecenoic acid) (I), a comparatively inexpensive commercial product obtained from castor oil, reacts with bromine in dry carbon tetrachloride to give 10 11-dibromoundecoic acid (II), which upon heating with a concentrated solution of potassium hydroxide yields 10-niidecynoic acid (III) ... 

I) Dry carbon tetrachloride may be prepared by distillation of the commercial product and rejection of the first 20 per cent, of the distillation. 

The carbon tetrachloride may bo dried by distilling the commercial product and rejecting the first 10 per cent, of the distillate. 

A more active product is obtained by the following slight modification of the above procedure. Dissolve the succinimide in a slight molar excess of sodium hydroxide solution and add the bromine dissolved in an equal volume of carbon tetrachloride rapidly and with vigorous stirring. A finely crystalline white product is obtained. Filter with suction and dry thoroughly the crude product can be used directly. It may be recrystallised from acetic acid. 

Place a mixture of 30 g. of 3 5-dinitrobenzoic acid (Section IV,168 and 33 g. of phosphorus pentachloride in a Claisen flask fit a reflux condenser into the short neck and cork the other neck and side arm (compare Fig. Ill, 31, 1). Heat the mixture in an oil bath at 120-130° for 75 minutes. Allow to cool. Remove the phosphorus oxychloride by distillation under reduced pressure (25°/20 mm.) raise the temperature of the bath to 110°. The residual 3 5-dinitrobenzoyl chloride solidifies on cooling to a brown mass the yield is quantitative. Recrystallise from carbon tetrachloride the yield is 25 g., m.p. 67-68° and this is satisfactory for most purposes. Further recrystallisation from a large volume of light petroleum b.p. 40-60°, gives a perfectly pure product, m.p. 69 -6°. 

Much of the early work was inconclusive confusion sprang from the production by the reaction of water, which generally reduced the rate, and in some cases by production of nitrous acid which led to autocatalysis in the reactions of activated compounds. The most extensive kinetic studies have used nitromethane,acetic acid, sulpholan,i and carbon tetrachloride as solvents. 

Because of the chemical similarity between benzoyl nitrate and the acetyl nitrate which is formed in solutions of nitric acid in acetic anhydride, it is tempting to draw analogies between the mechanisms of nitration in such solutions and in solutions of benzoyl nitrate in carbon tetrachloride. Similarities do exist, such as the production by these reagents of higher proportions of o-substituted products from some substrates than are produced by nitronium ions, as already mentioned and further discussed below. Further, in solutions in carbon tetrachloride of acetyl nitrate or benzoyl nitrate, the addition of acetic anhydride and benzoic anhydride respectively reduces the rate of reaction, implying that dinitrogen pentoxide may also be involved in nitration in acetic anhydride. However, for solutions in which acetic anhydride is also the solvent, the analogy should be drawn with caution, for in many ways the conditions are not comparable. Thus, carbon tetrachloride is a non-polar solvent, in which, as has been shown above,... 

The products of these reactions are called vicinal dihalides Two substituents m this case the halogens are vicinal if they are attached to adjacent carbons The word is derived from the Latin vicinalis which means neighboring The halogen is either chlorine (CI2) or bromine (Br2) and addition takes place rapidly at room temperature and below m a variety of solvents mcludmg acetic acid carbon tetrachloride chloroform and dichloromethane... 

Allylic brommations are normally carried out using one of a number of special ized reagents developed for that purpose N Bromosuccimmide (NBS) is the most fre quently used of these reagents An alkene is dissolved m carbon tetrachloride N bromo succimmide is added and the reaction mixture is heated illuminated with a sunlamp or both The products are an allylic halide and succimmide... 

In 1976 the United States banned the use of CFCs as aerosol propellants. No further steps were taken until 1987 when the United States and some 50 other countries adopted the Montreal Protocol, specifing a 50% reduction of fully halogenated CFCs by 1999. In 1990, an agreement was reached among 93 nations to accelerate the discontinuation of CFCs and completely eliminate production by the year 2000. The 1990 Clean Air Act Amendments contain a phaseout schedule for CFCs, halons, carbon tetrachloride, and methylchloroform. Such steps should stop the iacrease of CFCs ia the atmosphere but, because of the long lifetimes, CFCs will remain ia the atmosphere for centuries. 

Chlorine reacts with saturated hydrocarbons either by substitution or by addition to form chlorinated hydrocarbons and HCl. Thus methanol or methane is chlorinated to produce CH Cl, which can be further chlorinated to form methylene chloride, chloroform, and carbon tetrachloride. Reaction of CI2 with unsaturated hydrocarbons results in the destmction of the double or triple bond. This is a very important reaction during the production of ethylene dichloride, which is an intermediate in the manufacture of vinyl chloride ... 

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