Pamphlet 121 - Explosive Properties - Ed. 3 - 01-2009

 

 

Table of Contents  Contents   1.  INTRODUCTIO INTRODUCTION N .............. ............................ ........................... ........................... ........................... ........................... ............................ ........................... ....................1 .......1 

1.1 1.2

SCOPE ............. ........................... ............................ ............................ ........................... ........................... ............................ ............................ ............................ ................ ..1 1 CHLORINE INSTITUTE STEWARDSHIP PROGRAM............. ........................... ............................ ............................ .........................1 ...........1

1.3 1.4 1.5 1.6 1.7

HISTORY ............ .......................... ............................ ............................ ............................ ........................... ........................... ............................ ............................1 ..............1 DISCLAIMER .............. ............................ ............................ ........................... ........................... ............................ ............................ ............................ .....................2 .......2 APPROVAL ............ .......................... ............................ ............................ ............................ ............................ ............................ ........................... .........................2 ............2 REVISIONS .............. ............................ ........................... ........................... ............................ ............................ ............................ ............................ .......................2 .........2 REPRODUCTION............. ........................... ............................ ............................ ............................ ............................ ........................... ........................... ................. ...2 2

PART A:  

" REACTIONS REACTIONS OF CHLORIN CHLORINE E AND HYDROG HYDROGEN: EN: A BIBL IOGRAPHY" IOGRAPHY" .... ........ ........ .......3 ...3 

2.  SUMMARY ............................ ......................................... ........................... ........................... ........................... ............................ ........................... ........................ ................3 .....3  

2.1 2.2 2.3

CHAIN REACTIONS .............. ............................ ............................ ........................... ........................... ............................ ............................ ..........................3 ............3 METHODS OF INITIATING THE REACTION OF HYDROGEN AND CHLORINE ..............................3 EXPLOSIVE LIMITS .............. ............................ ............................ ........................... ........................... ............................ ............................ ..........................6 ............6

3.  SELECTED REFERENCES........................ REFERENCES..................................... ........................... ........................... .......................... ........................... ......................6 ........6  4.   AB STRACTS STRA CTS ..................... .......... ..................... ..................... ...................... ..................... ..................... ...................... ...................... ..................... ..................... ............. ..11 11  PART B:  

" REACTION CHARACTERISTICS OF HYDROGEN HYDROGEN ADMIXED WITH CHLORINE, OXYGEN AND A ND INERT GASES" ......................... ....................................... ........................... ..................22 .....22  

5.  SUMMARY ............................ ......................................... ........................... ........................... ........................... ............................ ........................... ........................ .............. ...22 22  6.  DISCUSSIO DISCUSSION N .......................... ....................................... ........................... ........................... ........................... ............................ ........................... ....................... ............ ..22 22  7.  IGNITION LIMITS............. LIMITS .......................... ........................... ............................ ........................... ........................... ........................... ........................... ...................24 .....24  8.  EXPLOSIONS A ND DETONATIONS ............. .......................... ........................... ........................... ........................... ............................ ................ 26  9.  SELECTED REFERENCES........................ REFERENCES..................................... ........................... ........................... .......................... ........................... ....................30 ......30   APPENDIX  APPEND IX A ........... ...................... ...................... ..................... ..................... ...................... ..................... ..................... ...................... ...................... ........................ .................. ..... 31 

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EXPLOSIVE PROPERTIES OF GASEOUS MIXTURES CONTAINING HYDROGEN AND CHLORINE

1.

INTRODUCTION

1.1

SCOPE 

1 

This pamphlet is presented in two parts: Part A: Reactions of Chlorine and Hydrogen: A Bibliography, aims to bring together in a single source all known pertinent, published references on explosive properties of gaseous mixtures containing hydrogen and chlorine. References for each of those published reports are found in Section 3 of this pamphlet. In addition, a number of selected abstracts are included (See Section 4). The availability of an abstract will be indicated by a number in parenthesis [e.g. (46-1)] following the document’s citation in the text. Part B: Reaction Characteristics of Hydrogen Admixed with Chlorine, Oxygen and Inert Gases, is based on the literature review of reaction characteristics of hydrogen with chlorine and with mixtures of chlorine and oxygen, and represents an attempt to graphically show ignition and detonation zones for the systems hydrogen-chlorineoxygen and hydrogen-chlorine-air. In addition of inertlimits gases, water vapor, hydrogen chloride and carbon dioxidethe oneffects the ignition of nitrogen, the hydrogenchlorine system are illustrated. 1.2

CHLORINE INSTITUTE STEWARDSHIP PROGRAM  The Chlorine Institute, Inc. (CI) exists to support the chlor-alkali industry and serve the public by fostering continuous improvements to safety and the protection of human health and the environment connected with the production, distribution and use of chlorine, sodium and potassium hydroxides, and sodium hypochlorite; and the distribution and use of hydrogen chloride. This support extends to giving continued attention to the security of chlorine handling operations. Chlorine Institute members are committed to adopting CI safety and stewardship initiatives, including pamphlets, checklists, and incident sharing, that will assist members in achieving achieving measurable improvement. For more information on the the Institute’s stewardship program, visit the CI website at www.chlorineinstitute.org www.chlorineinstitute.org..

1.3

HISTORY   A predecessor group of the Institute's Properties, Analysis and Specifications Specifications Committee (PAS) met in September, 1968, to discuss a proposal for a study to be sponsored by the Institute made by D.S. Rosenberg in a memorandum of February 1, 1968 entitled, "Hydrogen Explosion Hazards in Chlorine Storage Tanks". The conferees agreed to the desirability of exploring the subject further, and requested that the Institute obtain any additional data which might be available.

 

 

2 

PAMPHLET 121

Part A of this pamphlet is based on a review of the literature by D.S. Rosenberg in April, 1969, updated through mid-1977 by L.E. Tufts and other members of the PAS, and again through mid-1989 by H.J. Hoenes, Jr. It includes information on availability of published papers on the subject, with abstracts where available. Part B of this pamphlet was originally prepared by L.E. Tufts of the Institute's Properties,  Analysis and Specifications Committee. This edition has included some minor revisions. 1.4

DISCLAIMER   The information in this pamphlet is drawn from sources believed to be reliable. The Institute and its members, jointly and severally, make no guarantee, and assume no liability, in connection with any of this information. Moreover, it should not be assumed that every acceptable procedure is included, or that special circumstances may not warrant modified or additional procedures. The user should be aware that changing technology or regulations may require a change in the recommendations herein.  Appropriate steps should be taken to ensure that the information is current when used. These suggestions should not be confused with federal, state, provincial, municipal or insurance requirements, or with national safety codes.

1.5

APPROVAL  The Institute's Health, Environment, Safety and Security (HESS) Issue Team approved Edition 3 of this pamphlet on January 23, 2009.

1.6

REVISIONS   Suggested additions and/or revisions should be directed to the Secretary of the Institute.

1.6.1

Significant Revisions in Current Edition This edition is the pamphlet’s first update since July 1992. A new literature search was not conducted. If you are aware of new research on this this topic please submit copies of documents and/or references to the Secretary Secretary of the Instit Institute. ute. Significant updates to this revision as approved include:

1.7

• 

Deletion of Section 2.4 – Plant Operations, and Section 2.5 – Hydrogen Control in Plant Design. Portions of the informat information ion found in Sections Sections 2.4 and 2.5 have been inserted into CI Pamphlet 86.

• 

Section 5 was amended to note that pressures above 1 atmosphere can impact the explosivity of the Cl 2/H2/O2 mixtures.

REPRODUCTION  The contents of this pamphlet are not to be copied for publication, in whole or in part, without Institute permission.

 

 

4 

2.2.1

PAMPHLET 121

Thermal Ignition In any purely adiabatic system the heat from an exothermic reaction, no matter how slow, will cause an acceleration acceleration of both rate of reaction and temperature increase. Only at low concentrations of one of the components is the heat capacity of the hydrogenchlorine system sufficient to absorb the heat of reaction without massive increases in both temperature and pressure. For mixtures with low concentrations of hydrogen or of chlorine the maximum temperature reached and the fraction of minor reactant consumed will depend on the initiating conditions, the initial composition, and on the conditions promoting chain termination. In cases where the potential for reaction of large amounts of hydrogenchlorine mixtures exist, particularly near the equivalence point, strong explosions and violent detonations accompanied by temperatures as high as 4532 °F (2500°K) result upon adiabatic reaction. Reaction under such conditions is essentially complete. When the chlorine is considerably in excess of the hydrogen the temperature reached by rapid adiabatic reaction is significantly reduced because of the energy absorbed in dissociation of the excess chlorine. The thermal reaction of hydrogen and chlorine has been studied in considerable detail by Pease and his associates. In their system, the reaction was quite slow at temperatures as high as 680°F (360°C). The data was was explained in terms of a Nernst chain (See Section 2.1) starting and ending on the walls, with an estimated chain length of 104 for stoichiometric proportions of the pure reactants. Thermal initiation of the hydrogen-chorine reaction was also studied by Kunin and Serdyukov (46-1) using a platinum coil to which a thermo-couple was fastened. The maximum coil temperature of 2192°F (1200°C) was needed to produce an explosive reaction with 7% H2  in a H2-Cl2  mixture. As the H2  content was increased, the coil temperature needed to produce an explosion dropped to 440 °F (227°C) at 19% H2. The difference in thermal reaction behavior in these experiments as compared to those of Pease can be attributed to the nature and locus of the surface on which the free radicals are formed for initiating the reaction. The thermal reaction reaction in a flame front is very rapid. Flames have been studied in considerable detail in various types of equipment by Kunin and Serdyukov (46-1) and by Bartholome (49-1). Flame velocities m measured easured by Bartholome are higher than those of Serdyukov, but in both cases are significantly lower than for H2-air systems. The data indicate that detonation waves are less severe for H2-Cl2 than for H2-O2 systems.

 

 

EXPLOSIVE PROPERTIES OF GASEOUS MIXTURES CONTAINING HYDROGEN AND CHLORINE

2.2.2

5 

Chain Ignition In studies of the explosive characteristics of the H 2-Cl2 reaction the reaction is initiated by formation of chlorine free radicals, although an excellent study of academic interest by Martin and Diskowski Diskowski (56-4) employed thermally excited hydrogen atoms. Reaction initiation thus precedes any thermal effects. The behavior of a given reaction mixture, i.e. the rate at which the reaction proceeds and the fraction of limiting reactant consumed are functions of the concentration of free radicals generated by the initiating source. The most effective method of initiating chlorine free radicals is by irradiation with light of wave length less than 4,850 o A. Selected regions of the mercury arc spectrum are usually employed, such as filtered light of wave length 3,650 ° A and 4,060° A. An excellent study of the oxygen-free system system is given by Ritchie and Taylor (42-1). The reaction has also been used to reduce the concentration of hydrogen in electrolytic cell gas (67-1). It is greatly inhibited by O2. The reaction chain length of a stoichiometric mixture can be as high as 106, but can be reduced to 10 3 with 1% O2. The usual method of reaction initiation for study of explosive limits is with a high-voltage spark. This procedure was used by Lindeijer (37-2), Weissweiler (36-1), Umland (54-1), Eichelberger, Smura and Bergenn (61-1), Davies (58-1), Suzuki and Fukunaga (56-1), van Diest and DeGraff (65-1), and Kunin and Serdyukov (46-1). Only two major studies have employed heated wires. Rozlovskiy (56-2, 56-3) used a platinum spiral to give a maximum temperature of 2192°F (1200°C). Grelecki and Mann (68-1) heated a Parr Parr wire to fusion. fusion. Explosive limits are narrower for hot wire ignition than for spark ignition. The nature of the ignition source source is very important in the study of detonations. In order for a reaction in a flammable mixture to degenerate from a deflagration to a detonation, the flame front must travel a certain distance, termed the run-up distance. This distance is greater for hot wire ignition than for spark ignition. Thus, in studies carried out by Grelecki and Mann (68-1) with hot wire ignition in a 6 foot stainless steel tube, no detonations were observed until the H2 content reached 29% to 39%, while Davies (581) observed detonations at H2 concentrations as low as 12% in a 3 foot tube with spark ignition. It should be noted, however, that the the experimental techniques similar to those of Grelecki and Mann were much more sophisticat sophisticated ed than those of Davies. Davies. In the work of Eichelberger, et. al. spark ignition was used with experimental techniques similar to those of Grelecki and Mann, giving detonation limits somewhat lower than with hot wire ignition. The reaction tube tube was 20 feet long. In studies by Weissweiler (36-1), who carried out the major definitive investigation in this field, a transition from an explosion to detonation was observed with about 18% H2 using pure, dry reactants. His studies were carried out in a glass flask or bomb, using spark ignition.

 

 

6 

PAMPHLET 121

2.3

EXPLOSIVE LIMITS  The definition of the explosive limit as the lowest concentration of hydrogen that will give an appreciable pressure rise when the reaction is initiated has been accepted by major investigators in this field. It is the definition used for the extensiv extensive e studies of Weissweiler (36-1) and Umland (54-1). J. Van Diest and DeGraff DeGraff (65-1) use temperature rise. Other investigators have attempted to define the limit as that at which a flame front appears. This definition was used by Lindeijer and gives much higher values values (8% to 10% H2). Moreover, the H2-Cl2 flame is difficult to observe. With great care, Weissweiler observed a flame at H2 concentrations as low as 7%. 7 %.

3.

SELECTED REFERENCES

 All references in this Section 3 are related rela ted to explosion and detonation limits in the Cl2H2  system. The number at the left of the reference reference indicates the availability of an abstract in Section 4 of this pamphlet. The following references are directly referenced in Part A of this pamphlet. #

Abstract

49-1

Bartholome, E. Zur Methodik der Messung von Flammengeschwindigkeit. Flammengeschwindigkeit. Zeit Electrochemie, Electrochem ie, 53, 191-196 (1949); [German]

58-1

Davis, I.P.W. Hydrogen-Chlorine Hydrogen-Ch lorine Explosions in Tail Gas, B.P. Chemicals Ltd., Murgatroyds Works, Oct. 30, 1958

67-1

Eichelberger, W.C. and Hartford, W.H. The Photochemical Photochemical Reaction of Hydrogen and Chlorine in Electrolytic Electrolytic Cell Gas, Elect. Technology, Technology, 5, 104-107 (1967)

61-1

Eichelberger, Eichelberg er, W.C., Smura, B.B. and Bergenn, W.R. Explosions and Detonation Detonations s in Chlorine Production. Production. Chem Engrg. Prog., Prog., 57:8, 94-97 (1961) (1961)

68-1

Grelecki, C.J. and Mann, D.J. Flammability Flammab ility Studies on Mixtures of Hydrogen with Chlorine Residual Gases. Gases. RMD Report 2298, Thiokol Thiokol Chem. Corp. (1968)

46-1

Kunin, T.I. and Serdyukov, J. Chlorine and Hydrogen Explosion Temperatures and Limits in Hydrogen Chloride. Chloride. Zhur. Obshchey Khimii, Khimii, 16:9, 1421-1430 (1946 (1946)) [Russian, English Translation by Foreign Technology Division.] WP-AFB (Astia AD 292616)

   

 

EXPLOSIVE PROPERTIES OF GASEOUS MIXTURES CONTAINING HYDROGEN AND CHLORINE

7 

37-2

Lindeijer, E. W. Explosive Limits of Hydrogen and Chlorine with Oxygen, Carbon Monoxide and Nitrous Oxide Oxide etc. Rec. Trav. Chem., Chem., 56, 97 (1937) and 56, 105-118 (1937)

56-4

Martin, H. and Diskowski, H. Der Vorgang H + Cl2 -- HCl + Cl als Molekularstrahlreaktion. Molekularstrah lreaktion. Zeit Elecktrochemie, Elecktrochemie, 60, 964-970 (1956) [German] [German]

42-1

Ritchie, M. and Taylor, D. The Photocombination Photocombination of Hydrogen and Chlorine. Proc. Roy. Soc., 180, 423-451 (1942)

56-2

Part III. Normal Combustion of Chlorine Hydrogen Mixtures. ZFK 30, 2489 (1956)

56-3

Part IV. Kinetics and Mechanism of Reaction in Flame ZFK 30, 2713 (1956)

56-1

Suzuki, O. and Fukunaga, T. Explosion Limits of Ternary Mixtures of HydrogenChlorine-Air. J. Elec. Soc. Japan, Japan, 24, 104-108 (1956) [Japanese with Engl English ish abstract]

54-1

Umland, A.W. Explosive Limits of Hydrogen-Ch Hydrogen-Chlorine lorine Mixtures. J. Elec. Soc., 101:12, 626-631 (1954)

65-1

Van Diest, J. and DeGraff, R. Methode nouvelle de determinati determination on des limits d'inflammabilite d'inflammabil ite de melanges gazeux de chlore et d'hydrog d'hydrogene. ene. Industrie Chimique Chimique Belge 30:11, 1195-1203 (1965) [French]

36-1

Weissweiler, A. Versuche zur Bestimmung Bestimmung der Explosionsgrenzen Explosionsgrenzen von ChlorWasserstoffgemischen. Wasserstoff gemischen. Zeit Elektrochemie, Elektrochemie, 42, 499-503 (1936), [German]

Other references dealing with the subject matter of Part A are: #

Abstract  Angel, G.,  Angel, G., L Lunde unden, n, T., T., Brannl Brannland, and, R. and Dahler Dahlerus, us, S. Influence Influence of Impuri Impurities ties in the the Electrolyte in Chlorine-Caustic Chlorine-Causti c Electrolysis by the Mercury Cell Process. S. Elect, Soc., 99, 435 (1952); 100, 39 (1953); 102, 124 (1955); 104, 167 (1957)

74-1

Antonov, V.N., Frolor, Yu E., Rozlovski, A.I. Maltseva, A.S. Explosion Hazard of Hydrogen and Chlorine Mixture. U.S.S.R.O. Kim Prom. 3, 205-208 (1974) [Moscow]  Antweiler  Antw eiler,, et. et. al. al. ChemieChemie-Ing. Ing. Tech Techn., n., 34, 387 (1962) (1962)

 

 

8 

PAMPHLET 121

53-2

Ashmore, P.G. Explosions in Mixtures of Hydrogen, Chlorine and Nitrogen Trichloride. Nature, 172, 449-450 (9/5/53). (9/5/53). (Abs. in Chem. Abs. Abs. 48, 1784 (2/25/54) (2/25/54)  Ashmore, P.G.  Ashmore, P.G. Sensit Sensitized ized ignitions ignitions in M Mixtu ixtures res of Hydrog Hydrogen en and and Chlori Chlorine. ne. 5th Symposium on Combustion, New York (1955) p. 700

50-1

Bartholeme, E. Die Flammengeschwindigkeit Flammengeschwindigkeit in sehr heissen Flammen. Zeit Electrochemie, Electrochem ie, 54, 169-172 (1950), [German] Bartkowiak, A. and Zabetakis, M.G. Flammability Flammabilit y Limits of Methane and Ethane in Chlorine at Ambient and Elevated Temperatures and Elevated Temperatures and Pressures. U.S. Bu. Mines Rept. 5610 (1960) Becker, R. Uber Detonationen. Detonationen. Zeit Electrochemie, Electrochemie, 42, 457 (1936) [German] Bodenstein, M. Hundert Jahre Photochemie Photochemie de Chlorknallgases. Ber. dtsch. Chem. Ges. 75, 119 (1942) [German] Bodenstein, M. Abschlussarbeiten Abschlussarbeiten am Chlorknallgases. Chlorknallgases. Z. Phys. Chemie, 48, 239 (1940-41) [German] Bodenstein, M. Die Reaktionskinetischen Grundlagen der Verbrenn ung suorgange. Zeit Elektrochemie, 42, 439 (1936) [German]

78-1

Casson, H.V. and Loftfield, R.E. Electrolytic Cell. U.S. Patent US 4087344, 2 May 1978, 7pp. Coward, H.F. and Jones, G.W., Limits of Flammability of Gases and Vapors. U.S. Bureau of Mines Bull 503, 19-23 (1952) Cowley, et. al. Trans. Inst. Chem. Engrs., 41, 372 (1963) Cummings, D. and Leighton, J. Separations Separation s of Gases. S. African Patent ZA 73/9427, 27 Sep 1974, 15pp.

63-1

Farbwerke - Hoechst Process for Complete Liquefaction of Chlorine. Chem. Ing. Tech., 35, 41-43 (1963) Follows, A.G. A.G. Reaction of Hydrogen Hydrogen with Chlorine in Cell Gas in the Presence of Ultraviolet Light. Chlorine Institute Institute Proceedings, 9th Meeting Meeting of Chlorine Plant Managers (2/2/66) 6pp, 8 figures

76-1

Frolov, Y., Mal'tseva, A.S., Serdechki, V.M., Fedotov, K.E., and Rozolovskii, A.I. Certain Features of the Combustion of Lean Mixtures of Hydrogen with Chlorine. Khim. Prom-st. (Moscow), (5), 358-60 (1976)

 

 

EXPLOSIVE PROPERTIES OF GASEOUS MIXTURES CONTAINING HYDROGEN AND CHLORINE

9 

Guy, Charles A. Continuous Analysis Analysis of Hydrogen in Chlorine Gas. Chlorine Institute Proceedings, 9th Meeting Meeting of Chlorine Plant Managers Managers (2/2/66) 1Opp. 7 figures Hikata, T. and Urano, I. J. Chem. Soc. Japan 60, 48 (1957) [Japanese] [Japanese] Jones, G.W. Inflammation Limits Limits and Their Practical Application Application in Hazardous Industrial Operations, Operations, Chem. Rev. 22, 1 (1938) Jost, W. Explosion and Combustion Processes in Gases. McGraw Hill, New York (1946) Jost, W. Flammenreaktionen Flammenreaktionen and Detonationen. Detonationen. Zeit Elektrochemie, Elektrochemie, 61, 559 (1957) [German] Kandiner, H.J. and Brinkely, S.R. Jr. Ind. Engrg. Chem., 42, 850-855 (1950) Kistlakowsky, G.B. Initiation of Detonations in Gases. Ind. Engrg Chem., 43, 2794 (1951) Laffite, P. Explosits 17, 14 (1964) Lewis, B. and Von Elbe, G. Combustion, Flames and Explosion of Gases. Cambridge University Press (1938); New York (1951) 74-2

Mal'tseva, A.S., Rozlovskii, A.I., and Frolov, Y.E., Explosion Hazard of Systems Containing Free and Bound Chlorine. Chlorine. Zh. Vses. Khim. O-va., O-va., 19(5), 542-51 (1974)

53-1

Mason, E.A., Bauer, W.C. and Quincy, R.R. Explosions in Chlorine Absorption Systems.. Tappi, 36:6, 274-278 (1953) Systems Mathieu, P. J. Physique, 7, 166-172, (1917) Maude, A.H. A.H. Anhydrous H Hydrogen ydrogen Chloride. Chloride. Chem. Ind., Ind., 51, 348 (1942) (1942) McGill, P.L. and Luker, J.A. Syracuse Univ. Res. Inst. Rept. No. Ch. E. 273-5611 Mellor, J.W. J.W. Comprehensive Comprehensive Treatise on Inorganic and Theoretical Chemistry, Chemistry, Vol. II, Sup. 1, 373-397, 402. 402. London (1956)

39-1

Morris, J.C. and Pease, R.N. The Thermal Hydrogen - Chlorine Reaction I Experimentall Kinetics. J. Am. Chem. Soc., 61, 391-396 (1939) Experimenta

39-2

Morris, J.C. and Pease, R.N. The Thermal Hydrogen - Chlorine Reaction II Relation to the Theory of Chain Reactions. J. Am Chem. Soc., 61, 396-401 (1939)

 

 

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PAMPHLET 121

74-3

Munke, K. Explosive Properties of the System Chlorine-Hydrogen Chlorine-H ydrogen and its  Admixtur  Admi xtures. es. Chem. Chem. Tech. Tech. (Leipzig) (Leipzig) 20:5, 292-295 292-295 (1974) (1974) Myers, John C. Explosive Mixtures Mixtures of Chlorine and Hydrogen in Production Production and Processing of Chlorine. Chlorine. Chlorine Institu Institute, te, Proceedings, 9th 9th Meeting of Chlorine Plant Managers, (Feb 2, 1966) 13pp Olsen, N.B. Small Scale Research. Three Experiments with Explosions. Dan. Kemi, 63(10), 283 (1982)

34-1

Pease, R. Kinetics of The Thermal Hydrogen Chlorine Reaction. J. Am. Chem. Soc., 56, 2388-2391 (1934) Rozlovskiy, A.I. Kinetics of the Dark Reactions of the Chlorine-Hydrogen Chlorine- Hydrogen Mixture. Zhurnal Fizicheskey Khimii, by Foreign Technology Divn., WP-AFB [Russian-ET] Part I: ZFK 28, 28, 51 (1954) (1954) Part II. ZFK 29, 3 (1955) Sanders and Gardner. Gardner. Ind. & Eng. C Chem., hem., 45, 1824 (1953) (1953) Sconce, J.S. J.S. Chlorine, Its Manufacture, Manufacture, Properties and Us Uses es (ACS Monograph 154). New York; Reinho Reinhold ld Publishing Co. (pp 139-163) (1962) Semenov, N. N. Spontaneous Ignition and Chain Chain Reactions. Reactions. Russian Chemical Chemical Reviews, 36:1 (1967) [Russian] Shilov, E.A. On the Catalytic Inflammation Inflammatio n of Mixtures of Chlorine with Ethylene and With Other Combustible Combustible Gases. Zurnel Obshchey Chimii, Chimii, 15, 133 (1945) Smirnov, N.I., Radun, D.V., Genin, L.S., and Lomakin, I.L. Condensation Condensati on of Chlorine. Khim. Prom. (Moscow), 46(9), 680-4 (1970)

73-1

Stephens, T.J.R. and Livingston, C.B. Explosion of a Chlorine Distillate Tower. Chem. Eng. Prog., 69(4), 45-7 (1973)

87-1

Tabata, Y., Kodama, T., and Kotoyori, T. Explosion Explosio n Hazards of Chlorine Drying Towers. J. Hazard. Mater., Mater., 17(1), 47-59 47-59 (1987)

 

 

EXPLOSIVE PROPERTIES OF GASEOUS MIXTURES CONTAINING HYDROGEN AND CHLORINE

4.

11 

ABSTRACTS

# 34-1

Abstract Pease, Robert N. Kinetics of the Thermal Hydrogen-Chlorine Reaction, J. Amer. Chem. Soc., 56, 2388-2391 (1934) The thermal reaction of hydrogen and chlorine was studied in a Pyrex glass tube at temperatures of 250° and 360°C. Retention times varied from 24-150 seconds. In the absence of oxygen, the reaction reaction is second order. Oxygen is a stro strong ng inhibitor (as it is in the photochemical photochemical reaction). reaction). Hydrogen chloride is not an inhibitor. inhibitor. (Note:  Additiona  Addi tionall stud studies ies were carried carried out in a static static system system and repor reported ted by Morris Morris and Pease; See Abstract 39-1 and 39-2).

36-1

Weissweiler, A. Versuche zur Bestimmung der Explosiongrenzen Explosiongrenzen von Chlor-Wasserstoffgemisc Chlor-Wasserstoffgemischen, hen, Zeit Elektrochemie, 42, 499-503 (1936) [German] Two series of studies were carried carried out in the laboratories of I.G I.G.. Farben. In the first, 3 a glass vessel of 14 cm  capacity was used containing 2 Pt electrodes with a 5 mm gap. All glass w was as brown or lacquered lacquered in black to to exclude actinic actinic light. Studies were were carried out in a darkened room with with very low illumination. illumination. The impulse produced produced by the reaction was observed by the movement of mercury in a glass tube connected to the reaction vessel. With dry chlorine there was no visible visible flame at the lower lower explosive limit of 3.5% H2. A flame was observed at 7% H2  and an audible detonation at 17.5% H2. With moist chlorine (87% relative humidity) the lower explosive limit was observed at 4% H 2, a flame at 7% H2, and a detonation at 24% H2. Further studies were carried out in a steel bomb having a heavy glass window sealed in the bottom. Pressure changes were were observed by mounting a mirror on a coil spring attached to a diaphragm sealed sealed to the vessel. A light beam was directed on the mirror and the deflection recorded photographically at 1/4 second intervals, giving a time-pressure curve. curve. Various internal confi configurations gurations were used to give a volume of 3 550-810 cm . Initial pres pressure sure was varied from 1-7 atmospheres atmospheres gauge. The lower explosive limit was 6% H2 and the upper was 84.5% H2. As the H2 content was increased from 6% there was a gradual transition from a mild pressure increase to a detonation. In some cases, an abrupt detonation detonation occurred; in others, there was an induction period with a transition from a moderate pressure increase to a sharp pressure burst of 3-4 times the initial pressure. In the pressure range studied, the explosive limits were were independent of initial pressure. A similar study was carr carried ied out with H2-O2 and H2-air mixtures, with comparable behavior observed.

 

 

12 

PAMPHLET 121

37-2

Lindeijer, E.W. Explosion Limits of Hydrogen and Chlorine with Oxygen, Carbon Monoxide and Nitrous Oxide and of Carbon Monoxide and Oxygen with Chlorine and Nitrogen, Also of Carbon Monoxide with Nitrous Oxide, Rec. Trav. Chim. 56. 105-118 (1937) Explosive limits were determined determined using an explosion burette 30 cm long x 1.5 cm diameter shielded shielded from light. light. The gas ignited ignited at the top top by a spark. spark. A gas mixture mixture was considered explosive when the reaction initiated by the spark propagated the length of the burette. The spark intensity was adjusted adjusted to be just above the minimum ignition intensity. intensity. In this system the explosion explosion limits for hydrogen and chlorine were at 10.4 and 83.9% H2. Addition of up to 80% oxygen had no significant significant effect on on the lower explosive limit. limit. Lindeijer attributed this behav behavior ior to the chain reaction phenomenon first described by N. Semenov in 1932.

39-1 and 39-2

Morris, J.C. and Pease, R.N. The Thermal Hydrogen-Chlorine Hydrogen-Chlorine Reaction, I Experimental Kinetics, J. Am Chem. Soc. 61, 391-396 (1939) II Relation to the Theory of Chain Reactions ibid, 396-401 (1939) Studies of the thermal reaction of hydrogen and chlorine were carried out in a static system using three three Pyrex tubes and one tube coated coated with potassium chloride. chloride. The tubes were 3.5 cm cm in diameter and 22 c cm m long, giving a vol volume ume of 200 cc. The reaction temperature was 184°C. Most of the data were explained explained by treating treating the reaction as a Nernst Nernst chain starting starting and ending on the walls. The estimated estimated chain 4 6 length is about 10   as compared to as high a 10   for a photochemical reaction in which the chains are started started in the gas phase. The inhibiting effe effect ct of oxygen is much less for thermal than a photochemical reaction, reduci reducing ng the chain length by 10 as compared compared to a thousand-fold reduction for a photochemical reaction. An unexplained phenomenon in these studies was the drop in the initial reaction rate to a fairly steady-state reaction in two of the Pyrex tubes. Data obtained are compared with those of other investigators and with rate constants calculated by collision collision theory and by statistical therm thermodynamics. odynamics. Reasons for the wide variations are discussed in terms of chain-reaction theory.

42-1

Ritchie, M. and Taylor, D. The Photocombination of Hydrogen and Chlorine in Oxygen-Free Systems, Proc. Roy. Soc., A180, 423-51 (1942) The photochemical reaction of hydrogen and chlorine at 25°C was studied in silica reaction vessels of 31.3 cc and 178.0 cc capacity irradiated with light of wave length 3,650° A and and 4,060 4,060° A. A 500-fo 500-fold ld v variat ariation ion in intens intensity ity of incid incident ent light was studied. studied.

 

 

EXPLOSIVE PROPERTIES OF GASEOUS MIXTURES CONTAINING HYDROGEN AND CHLORINE

13 

Data were interpreted interpreted in terms of a Nernst chain chain mechanism. mechanism. The quantum efficiency is normally proportional to the hydrogen pressure, since the only reactions involving H2 atoms are: Cl + H2  ⇒  HCl + H H + Cl2  ⇒  HCl + Cl With increasing partial pressure of chlorine and of diluents such as nitrogen and argon the quantum efficiency shows a maximum at intermediate partial pressures. With increasing pressure pressure of HCl the quantum efficiency dec decreases reases continually. continually. The n change in intensity exponent 1  increased with increasing pressure, reaching about 0.5 at the higher pressures studied (1 atm total pressure). 46-1

Kunin, T.I. and Serdyukov, V.I. Chlorine and Hydrogen Explosion Temperatures and Limits in Hydrogen Chloride, Zhur Obshehey Khimii, 16, 1421-1430 (1946) [Russian] Translation by Foreign Technology Division, WP-AFB, FTO-TT-62-1415/1+2 The reaction chambers for these studies were glass vessels with a diameter up to 40 mm and a volume up to 500 ml. ml. The vessels were were shielded from light by by wrapping with black paper. All tests were conducted at atmospheric pressure. The gas mixture could be ignited by a spark discharge or a platinum heating coil with a platinum-rhodium thermocouple attached. After reaction, the gas mixture was analyzed. Since the apparatus did not provide for complete mixing of the reactant gases, there was some scatter in the data. Data for the H2-Cl2  system with spark ignition are reasonably consistent with later studies by Umland, showing a lower explosive limit of 5.5% as compared to 4.1% reported by Umland. With hot wire igniti ignition on at a coil temperature of 1200°C the lower explosive limit is reported at a hydrogen content of 7%. As the hydrogen content content is raised above 7% the temperature temperature needed to initiate initiate an explosion drops gradually to 227°C with a H2-Cl2  mixture containing 19% hydrogen. Considerable studies were were made with systems containing containing HCl as a diluent. These studies are not considered pertinent to the problem under consideration.

49-1 and 50-1

Bartholome, E. Zur Methodik der Messung von Flammengeschwindigkeit, Zeit Electrochemie 53, 191-196 (1949) [German] Die Flammengeschwindigkeit Flammengeschwindigkeit in sehr heissen Flammen, ibid 54, 169-172 (1950)

 

 

14 

PAMPHLET 121

Burner nozzles from 1-8 mm diameter were fabricated with a proper configuration to give a flame having the the desired conical form. These nozzles were were used to observe observe various combustible combustible gas mixtures mixtures using various various ratios of reactants. With H2-Cl2  mixtures the maximum flame velocity was 410 cm/sec as compared to 1,180 cm/sec for H2-O2 mixtures. The maximum velocity for a H2-Cl2 flame is obtained with a feed mixture containing 73% hydrogen having a calculated flame temperature of 2,402 °K. With equimolar proportions the calculated flame temperature is 2,500°K and the measured flame velocity is 350 cm/sec. 53-1

Mason, E.A., Bauer, W.C. and Quincy, R.R. Explosions in Chlorine Absorption Systems, Systems, Tappi, 36, 274-278 (1953) During a study of explosions occurring in absorption systems used for the preparation of chlorine bleaching solutions from cell gas, the lower explosive limits for mixtures of hydrogen, chlorine, chlorine, and air were determined. The presence of explosiv explosive e mixtures of these gases in the absorption towers was established and traced to the stripping of chlorine from the feed gas. gas. Ignition may have been due to static electricity. The use of an air bleed into the system and of an anti-foaming agent in the spray water has been successful in eliminating serous explosions.

53-2

Ashmore, P.G. Explosions in Mixtures of Hydrogen, Chlorine, and Nitrogen Trichloride, Nature, 172, 449-450 (1953) The behavior of the systems hydrogen, chlorine, nitrogen trichloride and nitrogen, chlorine, nitrogen trichloride trichloride was stud studied. ied. The concentration concentration of NCl3 was varied from 0.1% to 2.0 %. Explosions resulting resulting from branched-chain branched-chain decomposition decomposition of NCl3  occurred in both systems when the total pressure was reduced below an upper limit. The pressure of the upper limit increases with temperature, and is nearly the same for both systems. The rate of decomposition decompositi on rises rapidly following a typical S-curve as the pressure is reduced below the upper limit, giving an explosive reaction after an induction period. The explosion explosion can be prevented prevented by introduction introduction of of trace quantities of a chain stopper such as nitrosyl chloride.

54-1

Umland, A.W. Explosive Limits of Hydrogen-Chlorine Mixtures, J. Elec. Soc., 101, 626-631 (1954) Explosive limits for hydrogen in mixtures of chlorine containing oxygen, nitrogen, and carbon dioxide were determined determined at pressure of 0 to 1 135 35 psig. The definition used is is the lowest concentration concentration of hydrogen that will give an appreciable pressure rise. The apparatus employed a stainless steel bomb having an inner diameter of 5 cm and a length of 20 cm with a volume of 432 ml. A sight glass was mount mounted ed in

 

 

EXPLOSIVE PROPERTIES OF GASEOUS MIXTURES CONTAINING HYDROGEN AND CHLORINE

15 

one end and brass rupture disc in the other end. Gases were mixe mixed d with a magnetic stirrer. A recording recording pressure gauge was used. A spark plug in the lower section provided ignition with upward flame propagation. With pure Cl2, the explosive limit dropped from 4.1% to 3.2% H2 as the pressure was raised from atmospheric atmospheric to 103 psig. With the various oxygen-containing oxygen-containing mixtures the explosive limit was higher than for pure Cl2, but the effect of pressure was unpredictable. 56-1

Suzuki, Osamu and Fukunaga, Tomio Explosion limits of Ternary Mixtures of Hydrogen-Chlorine-Air, Denki Kagakur 24: 104-108 (1956) [Japanese] J. Elec. Soc. Japan The authors of this paper were acquainted with the extensive studies of Umland (541) relating to mixtures simulating tail gases from chlorine liquefaction systems. Suzuki and Fukunaga decided to extend the range of compositions to lower limits of oxygen concentration concentration than studied by Umland. Such composit compositions ions may occur in cell gas. The chlorine-hydrogen mixtures studied were diluted with air. The compositions studied contained contained 5, 10, 15, 20, 30, 50, 70, and 90% air. H2- air mixtures were also tested. The apparatus contained a brown glass explosion chamber of inside diameter 4.2 cm, 10 cm long with a volume of 145 cc. Ignition was provided by a spark across a gap of 2.5 mm between two platinum wires sealed to the bottom of the chamber. The chamber top was covere covered d with a glass plate weighing 20 g. All studies were made at room tempe temperature rature and atmospheric pressure. An explosion was considered considered to occur when the reaction developed sufficient pressure pressure to raise the glass plate. Both lower and higher explosive limits limits were studied. For the lower limit, the minimum hydrogen content of 4.3% was obtained with a mixture containing 15%, rising to 5.8% with no air present and to 5.0% with 90% air. Due to the limitations of the experimental experimental technique, the data are not conclusive, although they are reasonably consistent with the data of Umland.

56-2 and 56-3

Rozlovskiy, A.I. Kinetics of the Dark Reaction of the Chlorine-Hydrogen Mixture, III and IV, Zhur Fizicheskoy Khimii, 30, 2489-2498, 2713-2723 [Russian] Translation by Foreign Technology Division, WP-AFB, ATD-TT62-1688/1+2 (April 1, 1963)

 

 

16 

PAMPHLET 121

Rozlivskiy has carried out and reported extensive studies of the thermal reaction of hydrogen and chlorine. Flame temperatures temperatures were were calculated calculated for various various H2-Cl2  mixtures, and flame flame velocities were were measure photographically. photographically. Velocities are lower lower than reported reported by Bartholome (49-1, 50-1). 50-1). The deviation deviation is not explained. explained. Flames with less than 30% chlorine were were non-luminous and could not be phot photographed. ographed. The primary apparatus was a round gas flask 100 mm in diameter with central ignition. Initial pressures pressures were varied from from 35 to 260 mm Hg. Tests in long long tubes gave detonation waves. Rozlovskiy presents considerable considerable discussion of data in terms of the chain mechanisms propounded propounded by Semenov. The reaction rate data are considered considered consistent with a reaction mechanism in which energy branching results from collisions between chlorine molecules and excited HCl molecules. 56-4

Martin, H. and Diskowski, H. Der Vorgang H + Cl2  ───> HCl + Cl als Molekularstrahlreakton, Zeit Elektrochemie 60, 964-970 (1956) [German] The reaction of chlorine at very low pressures with thermally excited hydrogen atoms was observed to determine the collision collision yield of HCl. Measurements at 2, 2,300 300°K and at 2,490°C activation temperature gave a relative activation energy of 9.4 ± 0.4 Kcal.

58-1

Davies, I.P.W. Hydrogen-Chlorine Explosions in Tail Gas, B.P. Chemicals Limited, Murgatroyds Works, October 30, 1958 The rate of flame propagation and violence of combustion as a function of hydrogen concentration in tail gas were measured in a glass tube 1 inch in diameter and 3 feet long. Gases were fed to one end of the tube through through a tee. The gas velocity velocity was 34 cm/sec. The mixture was ignited by a spark from an induction induction coil. Initial Initial combustion of the gas mixture was observed at about 4.7% H 2. The rate of flame propagation was observed visually. visually. It increased progressively progressively to about 200 cm/s cm/sec ec at 11% H2, and then rose rapidly until detonation occurred at 11.8% H2. As the hydrogen concentration was increased, the reaction became progressively more violent.  A flame flame trap was tested, tested, consisti consisting ng of a bed of grave gravell about about 20 20 cm deep attached attached to the inlet end of the tube. tube. The ignition spark was was placed in the gas feed feed tube at the base of the bed. At hydrogen contents contents below 10.5%, a steady flame burnt at the top of the gravel. A stable flame flame could not be maintained maintained below 6.4% H2. At H2  concentrations above 12.5%, detonation occurred and the flame struck back through the gravel bed to the point of mixture of the two gases. gases. At 18.1% H2, the gravel was blown from the trap. It was concluded that a trap of this ty type pe would prevent instantaneous passage of a flame in gas mixtures containing less than 10.5% hydrogen.

 

 

EXPLOSIVE PROPERTIES OF GASEOUS MIXTURES CONTAINING HYDROGEN AND CHLORINE

61-1

17 

Eichelberger, Eichelberg er, W.C., Smura, B.B. and Bergenn, W.R. Explosions and Detonations in Chlorine Production, Chem Eng. Progress 57, 94-94 (1961) (Also additional additional data from files of ADI 6809) Two reaction chambers were used to study explosions and detonation of mixtures of hydrogen with gas mixtures corresponding to tail gas from chlorine liquefaction plants. Laboratory tests were were carried out in a stainless steel bomb m made ade of 1.25 inch pipe, 14 inches long (350 cc) cc) and plant tests in a 1 inch pipe 20 feet feet long. Various packing materials in the bomb did not appear to affect the nature of the reaction. Fifty-four tests tests were made with with 51 gas mixtures. mixtures. The transition ffrom rom explosion to detonation was was detected detected audibly. Twenty-nine mixtures gave detonations detonations and twenty-five twenty-fiv e gave explosions. explosions. Pressure traces were were made with with an oscilloscope. oscilloscope. The maximum observed detonation pressure rise was about 2,400 psi occurring about 30 milliseconds after gas ignition using a mixture containing 38.02% H2, 28.0% Cl2 and 7.1% O2. The calculated pressures of the the reflected waves waves and explosion explosion waves corresponded closely to the observed observed pressures. The hydrogen concentration concentration at the boundary between explosions and detonations rises with increasing chlorine concentration from 18.6% for H2-air mixtures to 28% H2 for mixtures containing 50% chlorine.

63-1

Farbwerke - Hoechst Process for Complete Liquefaction of Chlorine, Chem. Ing. Tech. 35, 41-43 (1963) Chlorine from electrolytic cells is compressed compressed to 1.5-2 atm gauge and liquefied in a multi-stage refrigerated cooling system with a final coolant temperature of about 60°C. In the first first stage (-15 (-15 to -20°C) about 90% of the chlorine is liquefied, giving an exhaust gas having about 4% 4% hydrogen. This gas composition composition was not explosive. explosive. In the second stage, virtually all of the chlorine is liquefied, giving a gas phase containing about 16% hydrogen, hydrogen, which is in the explosive region. This zone is filled with a multitude of baffles to prevent prevent detonation waves. The system is grounded and is designed to withstand the maximum explosion pressure.

65-1

Van Diest, J. and DeGraaf, R. Methode Nouvelle de determination des limites d'inflammabilite de melanges gazeux de chlore et d'hydrogene Industrie Chimique Belge, 1195-1203 (1965) The apparatus for these experiments employed a vertical stainless steel explosion chamber 82 mm inner diameter and 1200 mm long, tested for a hydraulic pressure of 40 kg/cm2 (approximately 40 atms). The tube was jacketed and insulated to control the initial gas gas temperature. temperature. Chromel-alumel thermocouples were mounted below and above the ignition spark and a pressure tap was mounted below the rupture disc at the top. The platinum electrodes electrodes for spark igni ignition tion had a variable gap from 0-10 mm. A stirrer was mounted in the bottom of the chamber to mix the gases.

 

 

18 

PAMPHLET 121

This system was then designed to observe flammability limits is measured by an increase in temperature temperature of the reaction reaction gases rather rather than explosive limits. With measuring devices of equal sensitivity, the results will be the same by either method. In addition to the primary test chamber described above, two other chambers were used for determination of lower flammability limits, one 16 mm in diameter and 600 mm long and the other 130 mm in diameter diameter and 1800 mm long. A fourth chamber chamber 82 mm in diameter and 130 mm long was also used for the upper flammability limit. As the tube diameter is increased, the reaction approaches adiabatic conditions, giving higher terminal temperatures temperatures and pressures. However, the flammability flammability limits were the same in all chambers. The initial temperature was varied from -60°C to 100°C. The lower flammability limit for H2-Cl2  mixtures dropped from 5.0% to 3.0% H 2  as the initial temperature was raised from -60°C to 20°C, and stayed at this level up to 100°C. There was was no effect of initial pressure in the range of 0.5 - 1.6 atmospheres. In summary, the results of these studies are consistent with those of other earlier investigators, and provide no significant contribution to the bases for safe design of commercial systems. 67-1

Eichelberger, Eichelberg er, W.C. and Hartford, W.H. The Photochemical Reaction of Hydrogen and Chlorine in Electrolytic Cell Gas, Electrochem Tech., 104-107, March-April, 1967  A photoc photochemi hemical cal reaction reaction system system is is define defined d for for remova removall of 90% to 95% 95% of the the hydrogen in cell gas by irradiation with light from from a mercury-arc lamp. Liquefaction efficiency can be raised from 95% to 99% by such pretreatment.

68-1

Grelecki, C.J. and Mann, D.J. Flammability Studies on Mixtures of Hydrogen with Chlorine Residual Gases, RMD Report 2298, Thiokol Chemical Corporation, January 31, 1968 (Private) Experiments on flammability characteristics of residual gases from chlorine liquefaction units were conducted for Wyandotte Chemical Corporation by Thiokol Chemical Corporation. Residual gases were from two sources: the Hooker cell liquefaction unit and the mercury mercury cell liquefaction unit. Typical composition composition of gases from the Hooker cell system was 4.5% H2, 22% Cl2 and 18% O2 (remainder CO2, N2, CO), and from the mercury cells 6% H 2, 17% Cl2, 14% O2 (remainder CO2, N2). The test unit used a 2" diameter stainless stainless steel tube 6 feet long. The ignition source was was a Parr wire heated to fusion. Pressure and temper temperature ature were monitored by signals signals transmitted to to a Honeywell visicorder. visicorder. Liquefaction off-gas off-gas was diluted diluted with air or enriched with H2 content.

 

 

EXPLOSIVE PROPERTIES OF GASEOUS MIXTURES CONTAINING HYDROGEN AND CHLORINE

19 

Undiluted Hooker cell gas (4.5% to 5% H 2) showed no reaction. reaction. There was a very slight reaction with un-diluted mercury cell gas with a flame propagating at a rate of about 1 ft/sec. Enrichment of the two residual gases gases with H2 showed a quite different behavior, since reaction rates for H2-Cl2 are greater as the composition approaches the stoichiometric stoichiometric reaction ratio. With Hooker cell residual residual gases enrichment to 20% H2 resulted in flame propagation rates rates of about 1.5 ft/sec. ft/sec. With mercury cell resi residual dual gases enrichment to 20% H2  gave flame flame velocities velocities of about 6 ft/sec. With both gases, enrichment to about 30% H2 produced a detonable mixture. 73-1

Stephens, T.J.R. and Livingston, C.B. Explosion of a Chlorine Distillate Distillate Tower. Chem. Eng. Prog., Prog., 69(4), 45-7 (1973) The case history of an explosive explosive failure of a pressure vessel is presented. The culprit, hydrogen, was formed in a corrosive environment where the chlorine concentration was low, and then carried to process equipment with high amounts of chlorine. While molecular hydrogen hydrogen does not appear to be generated generated in high concentrations of chlorine, it can be formed where the chlorine concentration is lower, and subsequently be carried to process equipment where explosive concentrations can can result. Other analogous incidents incidents experienced during handling of chlorine at DuPont are discussed.

74-1

V.N. Antonov, Yu E. Frolov, A.I. Rozlovskil and A.S. Maltseva Explosion Hazard of Hydrogen and Chlorine Mixture, U.S.S.R.O. Kim Prom. (Moscow), 205-208 (1974) The authors investigated hydrogen - chlorine explosions of mixtures containing up to 15% hydrogen and at initial initial pressures of 1, 2 and 3 atmospheres. atmospheres. They calculated calculated the theoretical pressure rise expected for the various hydrogen - chlorine mixtures tested (making allowance for the dissociation of excess chlorine at high temperatures).. Mixtures with temperatures) with up to 8% hydrogen were found to develo develop p far less than the theoretical pressure, while the more rapid reactions at 15% hydrogen developed pressures essentially equal to the theoretical limit for adiabatic reactions. They did not determine whether the reactions with low concentrations of hydrogen failed to reach the theoretical pressures because of incomplete reaction or because of heat losses during the relatively slow reactions. reactions. They concluded concluded that the pressures pressures developed on explosion of mixtures containing up to 8% hydrogen would not be greater than twice the initial pressure and would be insufficient to damage industrial equipment. They did not investigate the explosive explosive properties of 8% hydrogen hydrogen admixed with with gases low in chlorine chlorine and high in oxygen oxygen and nitrogen. Such compositions are more representative of the residual gases leaving the final stage of condensation in chlorine chlorine liquefaction plants. plants. The authors also did not not mention the hazards of stationary flames which might result from ignition of a flow of chlorine gas containing 8% hydrogen.

 

 

20 

PAMPHLET 121

74-2

Mal'tseva, A.S., Rozlovskii, A.I., and Frolov, Y.E. Explosion Hazard of Systems Containing Free and Bound Chlorine. Zh. Vses. Khim. O-va., 19(5), 542-51 (1974) The determination of explosion limits of binary and ternary mixtures of chlorinated hydrocarbons with oxygen and air, some combustible gases with oxygen and HCl, organic compounds with free chlorine, and explosiveness explosiveness of chlorine-hydrogen mixtures are reviewed reviewed and discussed. discussed. Includes 59 refe references. rences.

74-3

Munke, K. Explosive Properties of the System System Chlorine-Hydrogen Chlorine -Hydrogen and its Admixtures. Chem Tech. (Leipzig) 20:5, 292-295 (1974) This paper is a critical and selective review of the published data on explosive properties of hydrogen mixed with chlorine, oxygen, and various inert diluent gases. The emphasis of the paper is directed toward selection of the best values for ignition limits of the gaseous mixtures. mixtures. Effects of variations variations in temperature temperature and pressure on ignition limits also are reviewed. reviewed. Detonation limits are mentioned mentioned only briefly.

76-1

Frolov, Y., Mal'tseva, A.S., Serdechki, V.M., Fedotov, K.E., and Rozolovskii, A.I. Certain Features of the Combustion of Lean Mixtures of Hydrogen with Chlorine. Khim. Prom-st., (5), 358-60 (1976) (Moscow) The effect of O2 and CO2 on the explosion danger of hydrogen-chlorine mixtures, the completeness of combustion of lean hydrogen-chlorine mixtures, and the effect of the gas motion on the combustion stability stability were studied. In a fast gas stream, the unstable combustion of hydrogen-chlorine mixtures with a subcritical ratio becomes stable (independently of the pressure pressure increase). The inducted turbulence of the burning mixture in the fast stream stabilizes the flame, as does free convection.

78-1

Casson, H.V. and Loftfield, R.E. Electrolytic Electrolyt ic Cell. U.S. Patent US US 4087344, 2 May 1978, 7pp. The title designed cell for brine electrolysis has a removable casing dividing the cell into a separate cell chamber and a cooling and concentrating concentrating cham chamber. ber. The latter is made for circulating the electrolyte from the cell chamber to the cooling and concentrating chamber without without circulating circulating the gas between between said chambers. chambers. The gases evolved in the cell are combined and an excess over the flammability limit of hydrogen in air is avoided. This cell by virtue of iits ts construction construction uses less outside energy because the heat developed during electrolysis is utilized in concentrating and evaporation processes.

 

 

EXPLOSIVE PROPERTIES OF GASEOUS MIXTURES CONTAINING HYDROGEN AND CHLORINE

87-1

21 

Tabata, Y., Kodama, T., and Kotoyori, T. Explosion Hazards Hazards of Chlorine Drying Towers. Towers. J. Hazard. Mater. 17(1), 17(1), 47-59 (1987) Three chlorine drying towers made of PVC exploded suddenly and violently in a Mercury Amalgam Amalgam Cell Chlorine Plant. Because of failure of the elec electric tric power system, a current breaker tripped out, the Hg pumps stopped, and the steel bottom plates in the cells became exposed. exposed. The alarm did not work, since both the AC power supply to the mercury pumps and that for the alarm system were taken from the same source. Meanwhile the DC power and the brine supply to the cells cells were not interrupted. Therefore, the hydrogen generated generated at the steel plate cathode and oxygen at the anode at a mole ratio of 4:1, forming an explosive gas mixture, passed to the chlorine drying towers. Concentrated sulfuric sulfuric acid is used for drying the wet chlorine gas. The most likely source of ignition ignition in the towers was a discharged spark from an electrostatic charge charge caused by sulfuric acid drops. The actual electrostatic electrostatic charge of a PVC chlorine drying tower tower was measured. A static potential potential of minus 5 kV was detected constantly near the hole that was drilled in the side wall of the space below the Raschig ring layer. The main conclusion of the study w was as that towers should be constructed of an acid-proof conductive material so they can be maintained at ground potential to prevent electrostatic charges.

 

 

22 

PAMPHLET 121

PART B:

5.

" REACTION CHARACTERISTICS OF HYDROGEN HYDROGEN ADMIXED WITH CHLORINE, OXYGEN OXYGEN AND INERT GASES"

SUMMARY

The literature reporting reaction characteristics of hydrogen with chlorine, and with mixtures of chlorine and oxygen has been reviewed with particular attention to ignition limits and explosion and detonation conditions. Data selected from several reports were used to draw the figures found in Appendix A in which reaction characteristics for the systems hydrogen-chlorine-oxygen hydrogen-chlorine-oxygen and hydrogen-chlorine-air are summarized. A third figure shows the effects of the inert gases nitrogen, water vapor, hydrogen chloride and carbon dioxide on the ignition limits of the hydrogen-chlorine system. The apparatus for determining ignition limits has been refined over many years. Investigators, using apparatus meeting the critical criteria, report data which agree well on the location of these limits. Hence, it is felt that the ignition limits shown in the figures are andbycover adequately the conditions in influence industrial of practice. It has accurate been noted at least one organization (Euro encountered Chlor) that the pressure on the ignition limits and explosion and detonation conditions of hydrogen, chlorine, oxygen mixtures is relatively small between 0.25 and 11.5 absolute bars (3.6 and 166.8 psia). Since the effect of pressure is not known it is recommended that experimental measurements be collected and evaluated prior to operating at higher pressures. Relatively meager data on detonation limits have been reported, and the best apparatus for determining these limits limits is not y yet et clearly defined. Hence, the lines for detonation limits are located with far less confidence than than for the ignition limits. In particular, the upper detonation limits are based on only one datum point plus the assumption that consumption of equal amounts of hydrogen will reach the detonation condition for all mixtures of chlorine and oxygen and of chlorine and air. The lines which indicate the limits of compositions which on ignition will develop not more than twice the initial pressure are based on similar assumptions as discussed below. However, even with these assumptions assumptions it seems seems probable that these lines for for high hydrogen concentrations are nowhere in error by more than 2% hydrogen. Also, the lines at low hydrogen concentrations are more likely to exclude compositions which will not reach twice the initial pressure rather than to include compositions which will on ignition significantly exceed twice the initial pressure. 6.

DISCUSSION

In the following discussion all compositions are given in percent by volume. The terms "ignition limits", "flammable limits", and "explosive limits" have been used by several investigators to describe gaseous compositions which when ignited under optimum conditions will barely sustain sustain reaction. In the following text only the term term

 

 

EXPLOSIVE PROPERTIES OF GASEOUS MIXTURES CONTAINING HYDROGEN AND CHLORINE

23 

ignition limit is used. This is defined as a composition of gas which when ignited by an adequate point source of energy, such as strong spark, will barely continue to propagate the reaction in an upward direction to the limits of the container. Such reactions should should not be called flames or explosions, since they do not emit light and give only slight pressure surges and minor increases in temperature. The ignition limit is very dependent upon the nature of the ignition source. A composition which is at the ignition limit for strong spark ignition will not be ignited by a hot wire or a weak spark. Unpublished Hooker Chemicals & Plastics Corporation Corporation research may explain this difference: In experiments to react out traces of hydrogen in chlorine by catalysis with ultraviolet light it was found that mild explosions may occur at hydrogen contents somewhat below the 4% ignition limit shown in the Figures found in Appendix A. A flow of chlorine was passed through a transparent tubular reaction zone continuously illuminated with a strong flux of ultraviolet light. The hydrogen content of the chlorine stream entering the reaction zone was gradually increased in small increments. When the hydrogen concentration reached 3.0% to 3.5% an audible explosion occurred - often with sufficient force to blow rubber tubing from the slip-on connections. The ultraviolet light passed throughout the entire volume of the reaction chamber. Hence, the absorption of photons with the attendant generation of chlorine free radicals also extended throughout the chamber. Under such conditions it is to be expected that, that, once started, an explosion would progress rapidly throughout the entire volume rather than in an upward direction only. The explosions which resulted were, therefore, much more violent than the comparatively mild reactions at 4% hydrogen reported as the ignition limit with spark initiation. It seems evident that the very mild reaction after spark ignition of a 4% hydrogen-in-chlorine mixture must leave much of the hydrogen unreacted. Also, it seems seems that a strong flux of ultraviolet light is more effective in initiating the reaction than are the strong sparks used in most investigations. It may be that the flash of ultraviolet light from a strong spark contributes materially to initiation of the reaction. This could explain why strong sparks are more effective than hot wires in initiating the reaction of hydrogen with chlorine. The mild explosions reported above with ultraviolet initiation of 3.0% to 3.5% hydrogenin-chlorine occurred only when the system system was essentially ffree ree of oxygen. A few tenths of a percent of oxygen in the mixture prevented the explosions and increased the hydrogen content in the gas leaving the reaction zone.

 

 

24 

7.

PAMPHLET 121

IGNITION LIMITS

Several investigators have reported results obtained in experiments to determine the ignition limitsinert and gases. the explosive of mixtures of hydrogen, chlorine, oxygen, air and several From aproperties comparison of the reports it is evident that variations in apparatus can cause large differences in the values obtained for both the upper and lower ignition limits. It is now generally agreed that for acceptable accuracy the the apparatus should provide for upward upward flame propagation. A spherical test chamber should be at least 20 cm in diameter, while a vertical cylindrical chamber should be at least 5 cm in diameter with with a height of at least four times the diameter. Spark ignition is preferred with the electrodes located on the center line of the test chamber and 20% to 30% of the height from the bottom. The electrodes should be at least 5 mm apart, and the spark energy should be 10-2  joule or more. Such strong sparks are required only when the gas composition is near an ignition limit. Mixtures of hydrogen and chlorine near the equivalence point are ignited by sparks of only 10-7 joule. Since the the flames are invisible near the ignition limits, sensitive and fast response measurement of the pressure rise on ignition is the preferred means to determine if ignition has occurred. The ignition limits reported by investigators (J. Van Diest; A.W. Umland; A. Weissweiler; O. Suzuki) using apparatus meeting the above criteria are in relatively good agreement. The ignition limits shown in the Figures A-1, A-2 and A-3 were obtained with such apparatus. In general, such apparatus gives lower concentrations of hydrogen at the lower ignition limit and lower concentrations of oxidant at the upper ignition limit than have been reported by investigators using apparatus failing some aspects of the above criteria. It appears unlikely that any further modification of test test apparatus will significantly decrease the lower ignition limits or increase the upper ignition limits. Hence, it seems safe to conclude that the ignition limits drawn in Figures A-1, A-2 and A3 are essentially accurate. The data found in Table 7-1, as determined by J. Van Diest and DeGraff, shows the effect of initial temperature on the ignition limits. Except for the upper ignition limit of hydrogen - air mixtures only minor changes in the ignition limits occur within the temperature range from 140°F to 212°F (60°C to 100°C).

 

 

EXPLOSIVE PROPERTIES OF GASEOUS MIXTURES

25 

CONTAINING HYDROGEN AND CHLORINE

Ta Table ble 7-1 7-1

Effect of Initial Temperature Temperature on Ignition Limit s (H (Hydrog ydrog en Content, % by Volu me) H2 - Cl2 

H2 - Air

H2 - O2 

Temperature (°C)

Lower Limit

Upper Limit

Lower Limit

Upper Limit

Lower Limit

Upper Limit

-60

5.0*

90

4.0

69

4.0

96

-40

4.0*

90.5

4.0

71

4.0

96

-20

4.0

91.5

4.0

72

4.0

96

0

3.5

92

4.0

73

4.0

96

20 to 25*

3

92.5

4.0

75

4.0

96

50

3

93

3.7

76

4.0

96

100

3

93

3.0

80

4.0

97

*

The results reported for 20°C to 25oC check well with those reported by others (A.W. Umland; A. Weissweiler; O. Suzuki). J. Van Diest and DeGraff also reported the effects of inert gases on the ignition limits of hydrogen - chlorine mixtures at 212°F (100°C). Their results are shown in Figure A-3. The same apparatus, which gave accurate values for the ignition limits for hydrogen chlorine, hydrogen - air, and hydrogen - oxygen, was used for development of this data. Hence, it seems probable that Figure A-3 is an accurate presentation of the ignition limits of hydrogen - chlorine mixtures diluted with the indicated inert gases. Umland reported the small increase in hydrogen content of the lower ignition limits which maximizes at 15% to 20% chlorine. He suggests that this is due to the transition from a predominately hydrogen - oxygen reaction to a hydrogen - chlorine reaction. Umland also investigated the pressure range from 1 to 10.5 atm, finding only minor changes in the lower ignition limit. For mixtures of both hydrogen and oxygen and hydrogen and chlorine he found the lower ignition limit to change from 4% hydrogen at 1 atm to about 3% hydrogen at 7.8 atm. Some gas mixtures mixtures showed small increases in the hydrogen content at the lower ignition limit as the pressure was increase to 10.5 atm. atm. This increase usually was less than 2% hydrogen. This increase also may be associated associated with transition from a hydrogen - oxygen reaction to a hydrogen - chlorine reaction as the partial pressure of chlorine was raised with increasing total pressures.

 

 

26 

8.

PAMPHLET 121

EXPLOSIONS AND DETONATIONS

When the reaction rate in a gas system is so fast that heat is liberated more rapidly than it can be dissipated to the surroundings (by radiation, conduction or convention) the temperature pressure in the system system rise.a reaction When the rise isissignificant the reaction mayand become an explosion. Once in pressure a gas s system ystem initiated, the reaction rate may accelerate for two reasons: first, because the absolute reaction reaction rate is dependent on temperature, as defined by the Arrhenius reaction rate equation, and second, because a chain reaction with chain branching may occur, as in the hydrogen chlorine reaction. If the reaction rate is sufficiently sufficiently rapid, full adiabatic heat release may occur. If the reaction takes place uniformly throughout the reaction mass, the res resultant ultant pressure rise can be calculated. If an explosive reaction is initiated at a point in a gas system, a pressure pulse is generated which moves through the gas at the velocity of sound. However, this pressure pulse heats the gas by adiabatic compression. Since the velocity of sound increases with temperature, the pressure pulse moves more rapidly in the heated zone than through the colder zone zone ahead of it. As a result, the back of the pressure wave moves faster than the front and tends to catch up with it to form a single large abrupt pressure pulse, known as a shock wave. Shock waves also can be generated by mechanical impulse, as in shock tubes. If a very rapid and highly exothermic reaction takes place in the generated wave front, the reaction zone will move through the gas at a velocity many times that of the speed of sound, accelerating to a constant maximum velocity if the reaction path is sufficiently long. This reaction front of constant velocity is defined as a detonation detonation wave. Its speed is dependent on the composition and the properties of the gas mixture, and is relatively little influenced by the initial temperature and pressure or by the method of initiation. The front of a detonation wave is the boundary between the reacted and unreacted gases. There are extremely sharp temperature and pressure gradients across this wave wave front. When the wave front reaches a boundary surface, it strikes strikes with a force equal to the sum of the adiabatic pressure rise in the system and the force of flow of the mass of gas behind the wave front. The magnitude of this impulse impulse depends on the velocity velocity of the impact wave. For a mild shock wave, it may be only 1. 1.5 5 to 2.0 times that of the adiabatic pressure rise in the system. For a detonation wave, the impuls impulse e may be 10 to 20 times the adiabatic pressure rise. Detonation studies are usually made in long tubes with a s spark park initiator at one end. For hydrogen - air mixtures at atmospheric pressure the detonation limit is about 18.5% hydrogen. Below this concentration concentration of hydrogen, the detonation wave is not stable, and the velocity actually decreases as the wave moves down the tube. Nevertheless, a shock wave is produced in a tubular reactor at hydrogen concentrations below the lower detonation limit, although at concentrations below 10% only mild explosions are observed.

 

 

EXPLOSIVE PROPERTIES OF GASEOUS MIXTURES CONTAINING HYDROGEN AND CHLORINE

27 

In the oxygen - hydrogen system detonation waves with velocities over 4,000 meters per second have been observed. In the chlorine - hydrogen system system detonation wave velocities are considerably lower, with a maximum of 1,850 meters per second reported for hydrogen contents of 66% to 75% (vol). The only reported study of detonation limits in the H2  - O2  - Cl2  system is that of Eichelberger, Smura, and Bergenn. Bergenn. Studies were carried out in a 1 inch pipe 20 feet long, using spark initiation. The impulse was picked up with a pressure transducer and observed on a cathode ray oscilloscope. oscilloscope. The initial pressure of 3.4 atm was the same for all experiments. The initial temperature was not reported, but probably was near ambient. The purpose of this study study was to evaluate tthe he potential hazards in handling the residual gas from chlorine liquefaction operations. This gas is a mixture of H 2, Cl2, O2, CO2 and N2, together with other trace diluents. The gas mixtures studied initially were essentially H2  - air mixtures, with progressive additions of chlorine. The explosion detonation boundary was 18.6% H2  with no Cl 2, corresponding to data of earlier investigators of the H 2  - air system. system. As chlorine was added to the mixture the hydrogen content of this lower detonation limit rose to a maximum of about 25% at 40% chlorine. For dry mixtures of hydrogen and chlorine (no air or oxygen added). Weissweiler reported a lower detonation limit of 17.5% hydrogen and an upper detonation limit of 83% hydrogen. Both Eic Eichelberger helberger and Weissweiler Weissweiler recognized that the sharp ping sound of a detonation wave would serve to determine whether a detonation or a less violent explosion had occurred. No other data was found in the literature regarding detonation limits within the the range from 50% to 100% chlorine. Therefore, the line over over this range of the lower detonation limit in Figures A-1 and A-2 is merely a graphical interpolation connecting Weissweiler's result with data obtained by Eichelberger. Lacking any reason to suspect a sudden change in explosive properties within this region of high chlorine content, it seems probable that this interpolation is reasonably accurate. Weissweiler's report ofonly 83% hydrogen as the upper detonation limit hydrogen chlorine mixtures is the datum point available to as assist sist in locating thisinlimit. In orderto draw the upper boundary of Zone IV it was assumed that consumption of approximately equal amounts of hydrogen would occur at all points along this detonation limit. Hence, the high hydrogen boundaries between Z Zones ones III and IV in Figures A-1 and  A-2 are drawn to give oxidant equivalent to 17 to 19% hydrogen. The upper detonation limit drawn in this way is probably of relatively poor accuracy. However, the size and shape of equipment containing the explosive mixture may have quite large influence on the actual composition at the detonation limit in that equipment. In contrast to the situation with determination of ignition limits, there is relatively little information concerning the chamber size and shape which is best for determination of detonation limits. Weissweiler obtained the data he reported using the same small vertical cylindrical chamber in which he determined ignition limits. Eichelberger ran preliminary experiments in a similar chamber.

 

 

28 

PAMPHLET 121

They also packed the chamber with "lead shot, 5 mm glass beads, 0.25 inch Berl saddles, 0.25 inch Raschig rings, glass wool, steel wool and protruded stainless steel. The results of these tests showed that explosion pressure rises in the packed bomb are in almost all cases many times larger than the pressure rise when the bomb is not packed. The oscilloscope trace of a high hydrogen explosion in a packed bomb showed that the reaction was approaching a detonation. In no case did the packing appear to quench the explosion". It appears that that the packed bomb would have yielded a lower hydrogen content for the lower detonation limit than the 20 foot long 1 inch internal diameter pipe with which the results used to locate the lower detonation limit in Figure A1 and A-2 were obtained. The Farbwerke-Hoechst process for liquefaction of chlorine yields a residual gas containing about 16% hydrogen. The final stage stage of liquefaction liquefaction is at -76°F (-60°C) in equipment filled with a multitude of baffles to prevent detonation waves in the event ignition should occur. Here is a situation where the shape of equipment is deliberately designed to increase the hydrogen content which must be reached before a detonation can occur. From the foregoing discussion it is apparent that both the upper and lower detonation limits of Figures I and II must be regarded as only a rough indication of the actual situation for a given piece of industrial equipment. A great deal more information is required concerning optimum chamber shape and dimensions before upper and lower detonation limits could be drawn with confidence of accuracy comparable to the ignition limits in the attached figures. The line at 8% hydrogen in Figures A-1 and A-2 is shown as the upper boundary of low hydrogen mixtures which will develop not more than tw twice ice the initial initial pressure when ignited. This line is based on the work of Antonov, Frolov, Rozlovskii, and Malts Maltseva eva who investigated hydrogen - chlorine explosions of mixtures containing up to 15% hydrogen and at initial pressures of 1, 2 and 3 atms. They calculated the theoretical pressure rise expected for the various hydrogen - chlorine mixtures tested (making allowance for the dissociation of excess chlorine at high temperatures). temperatures). Mixtures with up to 8% hydrogen were found to develop far less than the theoretical pressure, while the more rapid reactions at 15% hydrogen developed pressures essentially equal to the theoretical limit for adiabatic reactions. They did not determine whether the reactions with with low concentrations of hydrogen failed to reach the theoretical pressures because of incomplete reaction or because of heat losses losses during the relatively slow react reactions. ions. They concluded that the pressures developed on explosion of mixtures containing up to 8% hydrogen would not be greater than twice the initial pressure and would be insufficient to damage industrial equipment. They did not investigate the explosive properties of 8% hydrogen admixed with gases low in chlorine and high in oxygen and nitrogen. Such compositions are more representative of the residual gases leaving the final stage of condensation in chlorine liquefaction plants. The 8% hydrogen line is very close to the lower ignition limit at the maximum found by Umland in the region of 15% to 20% chlorine.

 

 

EXPLOSIVE PROPERTIES OF GASEOUS MIXTURES CONTAINING HYDROGEN AND CHLORINE

29 

It therefore seems that this 8% hydrogen line should move to near 10% hydrogen in this region, since such mild explosions probably are reduced in power by the same causes which increase the lower ignition limit in this area. Hence, it appears that this 8% line represents a conservative estimate of the hydrogen content which can exist in explosive mixtures without exceeding twice the initial pressure when ignited.  Antonov recommended that chlorine liquefaction plants be designed to allow up to 8% hydrogen in the residual gas discharged from the process. This recommendation was based on the data showing that explosive mixtures of chlorine and hydrogen containing up to 8% hydrogen would not develop more than twice the initial pressure when ignited. However, they did not comment on the possibility of damage from the heat of stationary flames which might result from ignition of a flow of gas containing 8% hydrogen. The possibility of forming such standing flames and the damage which they could cause should be evaluated carefully before designing for a maximum of 8% hydrogen in residual gases from chlorine liquefaction plants. The line for the lower boundary of the high hydrogen mixtures which will develop not more than twice the initial pressure when ignited is based on the work of Suzuki and Fukunaga. They determined the upper ignition limit limit of hydrogen - chlorine - air mixtures using apparatus with a relatively insensitive pressure measuring s system. ystem. They reported results with hydrogen contents several percent lower than the upper ignition limit drawn in Figures A-1 and A-2. They also reported that the explosion rapidly became more more violent at only slightly lower hydrogen contents than they found for the ignition limits. In the light of this information the lower boundaries of Zones II in the high hydrogen areas of Figures I and II were drawn to show about one percent less hydrogen than Suzuki and Fukunaga reported from the upper ignition limit. Admittedly, this is at best a rough estimate of the location of this boundary.

   

 

30 

9.

PAMPHLET 121

SELECTED REFERENCES

The following documents are directly referenced in Part B of this pamphlet. # 1 -1A

Reference Euro Chlor – GEST 91/168 – Physical, Physical , Thermodynamic Thermod ynamic and Selected Chemical Properties of Chlorine, chapter 9 – Safety

2-1

J. Van Diest and R. DeGraff Industrie Chimique Chimique Belg., 30: 11, 1195-1203 (1965)

3-2

A. W. Umland J. Electrochem. Soc., 101: 12, 626-631 (1954)

4-3

A. Weissweiler Z. Electrochem., 42, 499-503 (1936)

5-4

O. Suzuki and t. Fukunaga J. Electrochem. Soc., 24, 101-108, (1956) (Japan)

6-5

Farbwerke - Hoechst Process for Complete Liquefaction of Chlorine Chem. Ing. Tech., 35, 41-43 (1963)

7-6

W. Eichelberger, Eichelberg er, B. Smura and W. Bergenn Chem. Eng. Prog., 57: 8, 94 (1961)

8-7

V. N. Antonov, Yu. E. Frolov, A. I. Rozlovskii, and A.S. Maltseva (U.S.S.R.) Khim. Prom. 3, 205-208 (1974) (Moscow)

Other articles dealing with the subject matter of Part B are: Reference Gosta Wrangler, Teknisk Tidckrift (Technical Journal) pages 363-370 (1969) (Swedish) K. Munke, Chem. Tech., 20: 292-295 (1974) (German) Evans, Marjorie W., and C.M. Ablow, Theories of Detonation. J. Chem. Rev., V129, 129178 (1961) Gibbs, G.J., and H.F. Calcote. Effect of Molecurlar Molecurla r Structure on Burning Velocity. J.Chem. Eng. Data, V.5, 226-237 (1959) Zabestakis, M.G., and D.S. Burgess. Research on the Hazards Associated with the Production and Handling of Liquid Liquid Hydrogen. Bumines Dept. of Inv. Inv. 5707, 50 pages, (1961)

 

 

EXPLOSIVE PROPERTIES OF GASEOUS MIXTURES CONTAINING HYDROGEN AND CHLORINE

 APPENDIX  A PPENDIX A

31 

 

 

32 

PAMPHLET 121

 

 

EXPLOSIVE PROPERTIES OF GASEOUS MIXTURES CONTAINING HYDROGEN AND CHLORINE

33 

 

 

34 

PAMPHLET 121

 

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