Ind. Eng. Chem. Res. 1989,28, 1055-1059
r = reduced property
Literature Cited Adachi, Y.; Sugie, H. A New Mixing Rule-Modified Conventional Mixing Rule. Fluid Phase Equilib. 1986,28,103-118. Chang, E.; Calado, J. C.; Street, W. B. Vapor-Liquid Equilibrium in the System Dimethyl Ether/Methanol from 0 t o 180 OC and at Pressures to 6.7 MPa. J. Chem. Eng. Data 1982,27,293-298. Fredenslund, A.; Gmehling, J.; Rasmussen, P. Vapor-liquid Equilibria Using UNIFAC; Elsevier: New York, 1977. Gmehling, J.; Onken, U. DECHEMA Chemistry Data Series; DECHEMA: Frankfurt/M., 1977;Vol. I. Gmehling, J.; Rasmussen, P.; Fredenslund, A. Vapor-Liquid Equilibria by UNIFAC Group Contribution. 2. Revision and Extension. Ind. Eng. Chem. Process Des. Deu. 1982,21, 118-127. Gupte, P. A,; Daubed, T. E. Extension of UNIFAC to High Pressure VLE using Vidal Mixing Rules. Fluid Phase Equilib. 1986,28, 155-170. Gupte, P. A,; Rasmussen, P.; Fredenslund, A. A New Group-Contribution Equation of State for Vapor-Liquid Equilibria. Fluid Phase Equilib. 1986a,29,485-494. Gupte, P. A.; Rasmussen, P.; Fredenslund, A. Equation of State Mixing Rules from Excess Free-Energy Models. Ind. Eng. Chem. Fundam. 1986b,25,636-645. Hirata, M.; Ohe, S.; Nagahama, K. Computer-Aided Data Book for Vapour-Liquid Equilibria; Kodansha: Tokyo, 1975. Huron, M. J.; Vidal, J. New Mixing Rules in Simple Equations of State for Representing Vapour-Liquid Equilibria of Strongly Non-Ideal Mixtures. Fluid Phase Equilib. 1979,3, 255-271. Knapp, H.; Doring, R.; Plocker, U.; Prausnitz, J. M. DECHEMA Chemistry Data Series; DECHEMA: Frankfurt/M., 1982;Vol. VI. Larsen, B. L.; Rasmussen, P.; Fredenslund, Aa. A Modified UNIFAC Group-Contribution Model for Prediction of Phase Equilibria and Heats of Mixing. Ind. Eng. Chem. Res. 1987, 26, 2274-2286. Macedo, E. A.; Weidlich, U.; Gmehling, J.; Rasmussen, P. VaporLiquid Equilibria by UNIFAC Group-Contribution. 3. Revision and Extension. Ind. Eng. Chem. Process Des. Deu. 1983,22, 676-678. Maher, P. J.; Smith, B. D. Vapor-Liquid Equilibrium Data for Binary Systems with Acetone, Acetonitrile, Chlorobenzene, Metha-
1055
nol, and 1-Pentene. J. Chem. Eng. Data 1980,25,61-68. Mathias, P. M. A Versatile Phase Equilibrium Equation of State. Ind. Eng. Chem. Process Des. Dev. 1983,22,385-391. Panagiotoupoulos, A. Z.; Reid, M. C. A New Mixing Rule for Cubic Equations of State for Highly Polar, Asymetric Mixtures. ACS Symp. Ser. 1986,300,571-582. Schwartzentruber, J.; Ponce-Ramirez, L.; Renon, H. Prediction of Binary Parameters from a Cubic Equation of State from a Group-Contribution Method. Ind. Eng. Chem. Process Des. Deu. 1986,25,804-809. Schwartzentruber, J.; Galivel-Sloastiouk, F.; Renon, H. Representation of the Vapor-Liquid Equilibrium of the Ternary System Carbon Dioxide-Propane-Methanol and its Binaries with a Cubic Equation of State: A New Mixing Rule. Fluid Phase Equilib. 1987,38,217-226. Schwartzentruber, J.; Watanasiri, S.; Renon, H. Development of a New Cubic Equation of State for Phase Equilibrium Calculations in Process Engineering. Submitted for publication in Chem. Eng. 1988. Skjold-Jsrgensen, S. Gas Solubility Calculations. 11. Application of a New Group-Contribution Equation of State. Fluid Phase Equilib. 1984,16, 317-351. Skjold-Jsrgensen, S. Group-Contribution Equation of State (GCEOS): A Predictive Method for Phase Equilibrium Computations over Wide Ranges of Temperatures and Pressures up to 300 MPa. Ind. Eng. Chem. Res. 1988,27,110-118. Stryjek, R.; Vera, J. H. Vapor-Liquid Equilibrium of Hydrochloric Acid Solutions with the PRSV Equation of State. Fluid Phase Equilib. 1986,25, 279-290. Tiegs, D.; Gmehling, J. Vapor-Liquid Equilibria by UNIFAC Group Contribution. 4. Revision and Extension. Ind. Eng. Chem. Res. 1987,26,159-161. Verhoeye, L.; de Schepper, H. The Vapour-Liquid Equilibria of the Binary, Ternary and Quaternary Systems Formed by Acetone, Methanol, Propan-2-01, and Water. J . Applied Chem. Biotechnol. 1973,23,607. Willock, J. M.; Van Winkle, M. Binary and Ternary Equilibria of Methanol-acetone-2,3-Dimethylbutane. J . Chem. Eng. Data 1970,15, 281-286. Received for review September 19, 1988 Accepted February 21, 1989
Complete Destruction of Chlorofluorocarbons by Reductive Dehalogenation Using Sodium Naphthalenide Akira Oku,* Kenji Kimura, and Masaya Sat0 Department of Chemistry, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606, Japan
Halogen atoms (C1 and F) of 1,1,2-trichloro-1,2,2-trifluoroethane (Freon 113)were efficiently (>99%) removed as sodium chloride and fluoride ions by treatment with sodium naphthalenide (1.5 equiv per halogen atom) in THF a t 150 "C for 50 min in the presence of 10 vol % tetraethyleneglycol dimethyl ether. Similar treatment was also efficacious in the dehalogenation of Freon 22 and Freon 12. Many volatile organohalogen compounds which have been manufactured in commercial scales and widely used in industries are now realized to be harmful to human beings not only in our vicinal environments but also on a global scale. Until some years ago, chlorofluorocarbons (CFCs), whose annual gross production in the world is now inflated to a scale of several hundred million tons, had not been regarded with necessity for their safe destruction in view of environmental protection because of their chemical and physical stabilities. However, they are now strongly suspected to deplete the ozone layer in the stratosphere. Therefore, the United Nations Environmental Protection (UNEP) Protocol for CFC regulation was adopted in Montreal, Canada, in Sept 1987. With a provision for solving this problem, not only the recovery technology but 0888-5885/89/2628-1055$01.50/0
also the safe and complete destruction methods of used CFCs must be urgently established. We proposed (Oku et al., 1983b,1985) that the reductive transformation of organic halogen atoms into halide ions is more reliable and secure than the oxidative incineration process (Olie et al., 1985;Miyata et al., 1988),for safety's sake, of the treatment of environmentally harmful organohalogen compounds. For this reason, in fact, a reductive treatment process was practically adopted in US industries (e.g., Goodyear Tire and Rubber Co., 1980;Naruse and Kawagishi, 1983) for polychlorinated biphenyls (PCBs) destruction on the basis of the naphthalenide method (Oku et al., 1978a). In the present paper, sodium naphthalenide, which was once proved to be the most efficient for the reductive 0 1989 American Chemical Society
1056 Ind. Eng. Chem. Res., Vol. 28, No. 7, 1989 Table I. Dehalogenation of Freon 113 by Sodium Naphthalenide in THF Solution"
dehalogenation? entrv 1 2 3 4
5 6 7 8 9 10 11 12 13 14 15 16 17 18 18' 19 20
amt of reductant per halogen Freon 113 1.0 6 1.0 6 1.0 6 2.0 12 2.0 12 2.0 12 1.0 6 1.5 9 2.0 12 2.0 12 2.0 12 1.5 9 1.5 9 1.5 9 2.0 12 1.5 9 2.0 12 1.5 9 1.5 9 1.5 9 1.5 9
reductant concn, M
%
additiveb (vol % )
temp, "C 0 0 0 0 0 0 40 40 40 40 40
0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4
1.2 1.2 0.4 0.4 1.2 1.2 1.2
1.2 1.2 1.2
time, min 10 100 400 10 100 400 100 200 100 200 400 50 50 50 50 50 50 50 50 50 50
100 ME-4(10)
100
100 100 100 100 150 150 150 150
ME-4(10) ME-4(10) HMTA(lO)c
c198 96 98 97 100 100 100 100 99 100 99 99 100
F46
58 67 51 76 93 71 81 88 92 99 81 89 79 85 83 93 98 100 97 86
100
100 100 100 100 99 99 100
"Reaction scale: 0.937 g (0.005 mol) of Freon 113 in 20 mL of T H F was added to the T H F solution of the reductant. Reactions were carried out in T H F solutions except entries 16 and 17 where ME-2 (diglyme) was used. *ME-4: tetraglyme. HMTA: hexamethylenetetramine. Mol '70. C1- and F- ions were determined by the ion chromatographic analysis using electroconductivity detector.
removal of chlorine atoms from organochlorine compounds (Oku et al., 197913, 1980), is shown again to be efficacious in the complete defluorination of CFCs.
Results and Discussion Because of the high C-F bond energy and their spacially well-packed structure, which protects the molecule from reagent attack (Ishikawa and Kobayashi, 1979; Negishi, 1988), perfluoroalkanes or chlorofluorocarbons have been regarded as strongly resistant to chemical transformation. However, the coloring of poly(tetrafluoroethylene), PTFE, in some organometallic solutions indicates that C-F bonds are not necessarily unreactive to all chemicals. While the reductive treatment of P T F E powder with sodium naphthalenide eliminates fluoride slowly (Yoshino et al., 1982), poly(chlorotrifluoroethylene),PCTFE, reacts with the same reagent smoothly (Oku et al., 1988). We thought the rate acceleration was due to the presence of C-Cl bonds which act as the trigger of the defluorination. A rational rate acceleration mechanism is shown in Scheme I, choosing PCTFE as a model. This facile defluorination of PCTFE was recalled and superimposed to the CFC molecules because of their structural similarity. 1 . Defluorination of 1,1,2-Trichloro-1,2,2-trifluoroethane (Freon 113) with Sodium Naphthalenide in Solution. The dehalogenation of Freon 113 at 0 "C was examined in tetrahydrofuran (THF), and the results are shown in Table I (entries 1-6). Freon 113 reacted exothermally with the reductant sodium naphthalenide, and the rate of dechlorination was very fast as shown in Table I. The dechlorination reached 98% within 10 min a t 0 "C (entry 1) with an stoichiometric amount of the reagent (reductant/halogen molar/atom ratio = 1.0, Le., reductant/Freon 113 molar ratio = 6.0 because a molecule of Freon 113 consists of three chlorine and three fluorine atoms). A plausible reaction sequence of the dehalogenation is shown in Scheme 11: chlorines are removed in the earlier stage of the reduction, and thereafter the elimination of fluorines follows, being facilitated by the formation of unsaturated carbon bonds. According to the scheme, the overall amount of reductant required for the reductive removal of six halogen atoms is 6 mol.
Scheme I
!&-L4wd+L source
c1
1
Naph'
F
%-
,
(nucleophile)
-..
/
Scheme I1
CF2Cl-CFCl'
naph-
CF2CI-C FC 1CF,=CFClCF2=CF' FC=CF
CF,Cl-CFCl-
-CT
naph-, -Cl-
C Fz=C FC 1 CF2=CF'
naph-, -F-
FCsCF
nsph-, -F
FCsC'
nsph-, -F
FC=C' C coupling of free radicals coupling by nucleophilic substitution hydrogen atom abstraction from solvents
F
Ind. Eng. Chem. Res., Vol. 28, No. 7 , 1989 1057 Table 11. Absorption and Dehalogenation of Gaseous Freon 113 in THF Solution of Sodium Naphthalenide" amt of bubbling dehalogenareductant,b rate of N P , bubbling tion, % remaining Freon 113 not entry e-/ halogen mL/min time: min c1Forg C1, % absorbed, 70 1 2 3 4 5 6
1.3 1.9 1.1 1.9 1.1 1.9
50 50 100 100 200 200
3.2 2.3 2.0 1.3 1.0 0.7
95 98 95 96 96 96
45 49 45 44 52 49
0.13 0.41 1.32 0.00 1.40 0.65
0.3 0.1 0.7 1.2 1.3 1.6
Gaseous Freon 113 was absorbed in 80 mL of the THF solution of naphthalenide (0.4 M) a t 0 "C. Actually the amount of Freon per a constant amount of naphthalenide was changed depending on the e-/Freon 113 ratio. CTemperatureof the vaporizer was 30 "C, and the reaction time was 5 min in addition to the bubbling time.
The rate of defluorination is puzzling because about 50% of the fluorine atoms was removed almost as easily as the chlorine atoms but, thereafter, the removal of the remaining fluorines became difficult. Presumably, besides the reactions shown in Scheme I1 (eq 1-81, which facilitate the elimination of fluorines, other reactions, such as coupling of intermediately generated free radicals, hydrogen abstraction by free radicals from solvents, and coupling via nucleophilic substitution of reduction intermediates (eq 9-11), are taking place to produce saturated fluoroalkyl compounds whose electron affinities are generally much smaller than those of unsaturated systems. Prolonged treatment with 2 equiv of the reductant a t 0 "C for 400 min attained 93% defluorination (Table I, entry 6). Of two ethereal solvents, T H F and diethyleneglycol dimethyl ether (diglyme, ME-2), the latter seems somewhat efficient, although the former is a better solvent of naphthalenide. A t 40 "C, defluorination rate was accelerated significantly, and a prolonged treatment for 400 min with 1.5 equiv of the reductant finally attained the expected defluorination over 99% (entry ll). Thus, one of the prerequisites for realizing the naphthalenide method as a practical CFC destruction technology, i.e., complete removal of all organic halogen atoms, was satisfied. With the purpose of shortening the time of defluorination within 50 min, the temperature was raised to 100 and 150 "C (entries 12-20). The effects of the reductant amount and additives which are expected to increase the reduction power by facilitating the dissociation of the reductant ion pairs were also examined. At 100 "C, the maximum defluorination was 93% when 2 equiv of the reductant was used (entry 17). When diglyme was used as solvent in place of THF, the reaction was accelerated to some extent, and this observation was extended to the use of tetraethyleneglycol dimethyl ether (tetraglyme) as an additive in the following experiments. At 150 "C in T H F with 1.5 equiv of the reductant in the presence of 10 vol % tetraglyme, the defluorination finally reached 99% (entry 18'). Hexamethylenetetramine (HMTA) was also proven to be an effective additive (entry 19). Thus, the reaction time was shortened enough for practical application of the present method. The conditions used in entries 18 and 19 are probably the most effective for CFC destruction hitherto reported. 2. Defluorination of Gaseous Freon 113. On the assumption that waste CFCs will be supplied sometimes as gases, we examined their absorption into sodium naphthalenide solution and the consecutive dehalogenation that follows. For this purpose, a simple set of glassware for gas absorption was assembled (Figure 1;for details, see the Experimental Section). Under the gas-liquid treatment conditions shown in Table 11, the amount of unreacted Freon 113 and volatile reduction intermediates trapped in D was very small. This
vacuum
J
mL I
W
7
I-
!
Figure 1. Dehalogenation apparatus for gaseous CFCs. A, N z flowmeter; B, Freon 113 vaporizer; C, reactor; D, liquid N2 trap; E, balloon; F, Freons 12 and 22; G, gas buret; H, pressure gauge; I, drying tube; J, K, and L, valves.
indicates that Freon 113 in the nitrogen stream was efficiently absorbed in the reductant solution probably due to a very rapid, almost diffusion-controlled reaction of the C-C1 bonds (Oku et al., 1983a). A small amount of Freon 113 detected in D may be due to a little imperfect absorption. In Table 11, some results of the gas-liquid treatment are shown. Within a short time (5-8.2 min) below ambient temperatures, the defluorination reached 44-52%, while dechlorination was over 95%. For further and higher defluorination, the procedure described in the preceding section for liquid Freon 113 can be applied. 3. Defluorination of Freon 22 and Freon 12 in Gas-Liquid Reaction Systems. The effects of the amount of reductant and additives on the dehalogenation of chlorodifluoromethane (Freon 22) and dichlorodifluoromethane (Freon 12) were examined using the gasliquid absorption apparatus of Figure 1 (see also the Experimental Section). The results are shown in Table 111. As for the treatment of Freon 22 with 1.1 equiv of the reductant at 0-10 "C for 10 min, the defluorination reached 4090, though the dechlorination was 99%. The inefficacy of defluorination was gradually improved by raising the treatment temperature, lengthening the time of treatment, and increasing the amount of reductant. Finally, when 20 vol 70 of tetraglyme was added together with 2 equiv of the reductant, the defluorination was almost complete (entry 6). Similarly, in the treatment of Freon 12 with 2 equiv of the reductant at 150 "C for 50 min in the presence of 10 vol % of tetraglyme, 97% of defluorination was attained (entry 9). It is of interest that the reactivity of Freon 1 2 in this reductive treatment is higher than that of Freon 22, while it is reversed in the atmosphere.
1058 Ind. Eng. Chem. Res., Vol. 28, No. 7, 1989 Table 111. AbsorDtion and Dehalogenation of Freons 22 and 12 in THF Solution of Sodium Naohthalenide
dehalogenation, entry
amt of reductant, e-/ halogen 1.1 2.1 1.0 2.0 2.0 2.0
1
2 3 4 5
6
%
reductant concn, M
additiven (vol % ) temp,* "C Freon 22-CHC1F2 0-10
0.4
time, min
c1-
F-
10
100 100
40 47
99 99
66 81 89
0.4
0-10
60
1.2 1.2 1.2 1.2
20-150 20-150 20-150 20-150
50 50 50 50
100 100
20-150 20-150 20-150
50 50 50
100 100 100
ME-4(10) Me-4(10)
100
Freon 12-CCl2F2 n
1.5 1.5 2.0
8 9 (I
1.2 1.2 1.2
ME-4( 10) ME-4( 10)
73 84
97
ME-4: tetraglyme. *Freon gas was bubbled in the reductant solution a t 20 "C, and thereafter, the temperature was raised to 150 "C. NG
,?3
temp
0 - 150°C
23 a) ( -waste
water
which may not deplete the ozone layer. However, we must face a problem of these partially dehalogenated substances someday.
Np
--+
oil
washing - s a l t s
Figure 2. Small-scale destruction scheme of volatile organohalogen compounds.
Concluding Remarks A prototype of the present destruction procedure for practical purposes is illustrated in Figure 2. Solvent THF and naphthalene can be recovered by distillation and the distillation residue is dissolved in low-grade or waste hydrocarbon oils to remove sodium fluoride and chloride by washing with water. Thereafter, the oil which does not contain any halogen compounds can be incinerated by the ordinary method, thus rendering us a safe and simple method for the destruction of CFCs. Despite some economical disadvantages such as the stoichiometric consumption of sodium metal compared with direct incineration, the characteristic advantages of the present method are (1)safety, (2) easy applicability to rapid and on-site small-scale destruction where the treatment cost is not a serious problem for users, and (3) no involvement of hazardous H F or F2in the destruction process. When Freon 113 is used repeatedly with the aid of a recovery system, the destruction cost per price of Freon 113 can be reduced considerably. Furthermore, the destruction cost can also be reduced by the recycle of the reductant solution removing separated salts and naphthalene from the reactor. A question arises that the economical problem of the method can be solved by the use of a partial dehalogenation procedure, Le., the dehalogenation at ambient temperature for a short period with a minimum amount of reductant to accomplish almost complete removal of chlorine atoms but approximately 50% removal of fluorine. The reason is that such a process is economical and products are chlorine-free organofluorine compounds
Experimental Section General. Commercially available chemical-grade solvents were used after a single distillation. Freons were supplied from Daikin Co. Destructions of Freon 113 at 0 and 40 "C were carried out in ordinary Pyrex glass flasks and in a stainless steel autoclave for gaseous Freons at 100 and 150 "C, under nitrogen atmosphere. Sodium Naphthalenide. This reducing reagent (Holy, 1974) was prepared under N2atmosphere by simply mixing sodium metal and naphthalene in T H F or by dissolving in T H F the commercially available sodium dispersion in naphthalene. The effective concentration of the radical anion was determined according to the reported procedure (Oku et al., 1983~).A t low temperatures, the treatment with the reductant whose concentration was thicker than 1.0 M was not adequate due to the increased viscosity of the solution. Analysis of Eliminated Chloride and Fluoride Ions. After the reductive treatment was over, the solution was diluted with hexane (200 mL) followed by repeated careful washing with distilled water three times. The combined aqueous solution was diluted to 1 L and subjected to ion chromatographic analysis. The analyzing system consisted of a TOSO CCPD pump, CM-8000 electroconductivity detector, and Anion-PW column: eluent, 0.8 mM boric acid in water, 500 KL/min at 38 "C. The chromatogram was calibrated against a standard solution containing 5-20 pM sodium fluoride and chloride. Analysis of Nonvolatile Organic Chlorine and Fluorine Atoms after Destruction. After removing inorganic sodium salts, the residue was dissolved in 30 mL of benzene, and the solution was subjected to X-ray fluorescence analysis for chlorine using a Horiba SLFA-200 analyzer and trichloroethylene in naphthalene as the standard. After the X-ray analysis, solvent was removed and the residue was submitted to combustion analysis. Peculiar to us was that, in many cases where the defluorinations were around 5070,fluorine was not detected in the residue. A possible reasoning is that the imcompletely defluorinated reaction intermediates were fluoroalkyl- or fluoroalkenylsodium compounds which, on workup, were protonated to produce volatile fluorohydrocarbons. Destruction of Freon 113 at 0 and 40 "C. Two mixing methods were compared. (1) Normal Mixing. Reductant was added to Freon 113 (5 mmol) in 30 mL of T H F over 5 min at 0 "C under a N2atmosphere. (2) Inverse Mixing. Freon 113 (5 mmol) in 30 mL of T H F was added to the reductant. However, no appreciable difference in the ex-
Ind. Eng. Chem. Res., Vol. 28, No. 7, 1989 1059
tent of dehalogenation was observed. Destruction of Freon 113 at 100 and 150 "C. A stainless steel cylinder was used as a reactor. After the reductant was added to a T H F solution (20 mL) of the Freon (5 mmol) under ice cooling, the cylinder was heated at 100 or 150 "C for 50 min. Destruction of Gaseous Freon 113. As shown in Figure 1, a controlled nitrogen stream was bubbled through Freon 113 in container B, which was warmed to 30 "C. The vaporized Freon was led to a T H F solution of the reductant (80 mL) through a sintered glass bubbling ball in reactor C, which was cooled to 0-5 "C. The outlet from the reactor was led to a liquid nitrogen trap, D. The absorption rate was so fast that only a slight amount of Freon 113 was detected in the liquid nitrogen trap, D. Other conditions are listed in Table 111. Destruction of Freon 22 and Freon 12. A gas buret, shown in Figure 1, was connected to the same reactor, C. Valves K and L were closed, and the tube was evacuated. J was closed against the pump and then slowly opened toward F to fill the tube with Freon 22, and K was opened to fill G with a measured amount of Freon under a pressure of 1 atm. Again K and L were closed, and J was opened toward the pump to evacuate the tube. Then the tube was filled with N2,and under a slow N2stream, K and L were opened to lead the Freon in G slowly through a drying tube, I, into the stainless steel reactor, C, whose temperature was kept a t 5-20 "C. Then the total solution of the reaction mixture was heated a t 150 "C for 50 min. Freon 12 was also subjected to the same reaction procedure.
Acknowledgment The present work is partially supported by the Grantin-Aid for Scientific Research on Priority Areas, No. 63602013. Registry No. Freon 113,76-13-1;freon 22, 75-45-6; freon 12, 75-71-8; sodium naphthalenide, 3481-12-7; tetraethylene glycol dimethyl ether, 143-24-8.
Literature Cited Goodyear Tire & Rubber Co., A Safe, Efficient Chemical Disposal Method for Polychlorinated Biphenyls, Technical Report, Akron,
1980. Also Sunohio Co., 1981; Acurex Waste Technologies Inc., 1981. Holy, N. L. Reactions of the Radical Anions and Dianions of Aromatic Hydrocarbons. Chem. Rev. 1974, 74, 243-300. Ishikawa, N.; Kobayashi, Y. Compounds of Fluorine; Kodansha Scientifics: Tokyo, 1979; pp 69-72, 162-176. Miyata, H.; Takayama, K.; Ogaki, J.; Kashimoto, T. Formation of Polychlorinated Dibenzo-p-Dioxins (PCDDS) and Dibenzofurans in Typical Urban Incinerators in Japan. Toxicol. Enuiron. Chem. 1988,16, 203-218. Naruse, K.; Kawagishi, K. Present Situation of the PCBs Destruction Technology in the US. Gekkan Haikibutsu 1983,9(102), 61-65. Negishi, A. Chemistry of Fluorine; Maruzen: Tokyo, 1988; p 9. Oku, A.; Yasufuku, K.; Kataoka, H. A Complete Dechlorination of Polychlorinated Biphenyl by Sodium Naphthalene. Chem. Znd. (London) 1978a, 841-842. Oku, A,; Yasufuku, K.; Kato, S.; Kataoka, H. The Dechlorination of Polychlorinated Biphenyls by Alkaline Metals and Naphthalene. J. Chem. SOC.Jpn. 1978b, 1577-1582. Oku, A.; Ueda, H.; Tamatani, H. The Dechlorination of Polychlorinated Biphenyls by Alkali Metal Graphite Intercalation Compounds. J. Chem. SOC.Jpn. 1980, 1903-1906. Oku, A.; Yoshiura, N.; Okuda, T. Nonhomogeneous Phase Effect on the Generation of Carbene Radical Anions in the Birch-Type Reduction of Bidgem-dihalocyclopropyl) Compounds. J. Org. Chem. 1983a, 48, 617-619. Oku, A.; Ueda, H.; Tamatani, H.; Takai, H. The Dechlorination of Octachloronaphthalene by Naphthalene Radical Anions and Unsolvated Hydroxide Ion. J. Chem. SOC.Jpn. 198313, 738-742. Oku, A,; Harada, K.; Yagi, T.; Shirahase, Y. Cyclopropylidene Rearrangement in the Reduction of Bis(dihalomethano)tetrahydropolymethylnaphthalenes by Naphthalenides. J.Am. Chem. SOC. 1983c, 105,4400-4407. Oku, A.; Nishimura, J.; Nakagawa, S.; Yamada, K. The Defluorination of Tetrafluorobenzene with Naphthalene Radical Anion and Unsolvated Hydroxide Ion. J. Chem. SOC.Jpn. 1985,1963-1967. Oku, A.; Nakagawa, S.; Kato, H.; Taguchi, H. Dehalogenation of Poly(viny1 chloride) and poly(chlorotrifluoroethy1ene) by Naphthalene Radical Anion. J. Chem. SOC.Jpn. 1988, 2021-2025. Olie, K.; Lustenhouwer, J. W. A.; Hutzinger, 0. Polychlorinated dibenzo-p-dioxins and Related Compounds in Incinerator Effluents. In Chlorinated Dioxins and Related Compounds; Hutzinger, O., Firei, R. W., Merian, E., Pocchiari, F., Eds.; Pergamon Press: Oxford, 1982; pp 227-301. Yoshino, K.; Yanagida, S.; Sakai, T.; Azuma, T.; Inuishi, Y.; Sakurai, H. Conducting Polymer Prepared from Teflon. Jpn. J. Appl. Phys. 1982,21, L301-302.
Received f o r review August 15, 1988 Revised manuscript received March 6 , 1989 Accepted April 3, 1989
