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APPENDIX Neutralization of Energetic Materials by Hydrolysis BACKG ROU N D Because most energetic materials are synthesized in acidic media (or salts of acids), they are vulnerable to hydrolysis. The hydrolysis of energetic materials, such as 2,4,6-trinitrotoluene (TNT), has been of some inter- est since the mid-1800s (Wilbrand, 1863; Hepp, 1882; Meyer, 1889~. However, the work has been sporadic and the results often inconclusive. Limited reviews of hydrolysis reactions for energetics can be found in the following general references: Urbanski, 1964, 1965, 1967,1984; Feuer, 1969, 1970. Recently, the Navy has published a review of alkaline hydrolysis of energetic materials pertinent to assembled chemical weapons (ACWs) (Newman, 1999~. Because open burning or open detonation (OB/OD) of energetic materials has become increasingly unpopu- lar, more environmentally acceptable alternative tech- nologies have been proposed. Base hydrolysis has re- cently been proposed for the demilitarization and/or destruction of some types of energetic materials. For example, several investigators have shown that base hydrolysis combined with supercritical water oxidation may be effective for neutralizing pressed explosive composites containing 1,3,5,7-tetraaza-1,3,5,7-tetra- nitrocyclooctane (HMX) (Spontarelli et al., 1994; Flesner et al., 1994; Skidmore et al., 1995; Bishop et al., 1996~. Cannizzo et al. (1995) have demonstrated base hydrolysis of a composite propellant containing HMX, ammonium perchlorate, nitrate esters, and aluminum powder. Borcherding and his coworkers (Borcherding and Wolbach, 1995; Borcherding, 1997, 1998) have performed base hydrolysis on at least three 213 types of composite propellant and have claimed, "the products of the process will be treatable in conventional waste treatment facilities." In September 1997, a 200 lb/day hydrolysis-treatment facility became operational and replaced routine OB/OD disposal of waste com- posite propellant at a site near San Jose, California. Base hydrolysis decomposes energetic materials to organic and inorganic salts, soluble organic com- pounds, and various gases. The base usually attacks all of the functional groups of the energetic material. In the past, these reactions were usually conducted at ambient conditions with dilute concentrations of ener- getic material and base. Now, however, they are con- ducted at elevated temperature (between 60C t140F] and 155C [311 F]) and often at elevated pressure (up to 14 atm) in a strong base solution (pH 2 12~. In some cases, base hydrolysis has been conducted at super- critical conditions (Larson et al., 1998~. Typically, higher temperature and pressure are used to increase the solubility of reactants and to prevent clogging of the reactor. Sodium hydroxide, potassium hydroxide, ammonium hydroxide, and sodium carbonate have been used. These reactions are exothermic and must be carefully controlled by a method that can immediately recognize the onset of a thermal excursion and prevent a runaway exothermic reaction. The reactor must also be designed to contain the maximum credible explo- sive event. Depending on the specific conditions and materials, several reaction routes are possible that may produce undesirable precipitates. Energetic materials, such as nitrate esters, nitroaromatics, and nitramines, usually decompose to form nitrates, nitrites, ammonia, nitrogen,

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214 ALTERNATIVE TECHNOLOGIES FOR DEMILITARIZATION OF ASSEMBLED CHEMICAL WEAPONS hydrogen, organic acids, and formaldehyde. Interme- diates formed during the hydrolysis of some energetic materials can provide reaction pathways to other nitro derivatives and addition products that are still ener- getic. Current work indicates this occurs preferentially with aromatic nitro compounds and usually when the energetic material is in excess. The solid particles in hydrolysis must be small enough to expose adequate surface area for expedient salvation and subsequent reaction. In most of the work on hydrolysis documented in the literature, the ener- getic material has been in the form of molding powder, small pellets, or small chunks from demilitarization operations. The energetic material has then been dis- solved, and hydrolysis has been performed well within solubility limits. For the Assembled Chemical Wean- ons Assessment (ACWA), the energetic material is still in ordnance, so the first challenge is to remove it and reduce it to an appropriate size. The second challenge is to determine safe operating parameters for hydroly- sis of a heterogeneous feedstock that may include ener- getic materials, metals, and contaminants. The third challenge is for technology providers to design process equipment and develop process-control protocols that minimize the accumulation of precipitates and mini- mize damage in the event of an accident. Finally, the technology providers must scale up a robust process that can meet the Army's requirements for various weapon types and processing rates. The scalability of operating parameters for base hydrolysis of energetic materials is not universal and will depend on the spe- cific chemical munitions being demilitarized. Base hydrolysis has been proposed by several tech- nology providers for the destruction of energetic mate- rials in the ACW inventory. These materials (which make up fuze components, leads, boosters, bursters, and rocket motors) include: of 1,3,5-triaza-1,3,5- trinitrocyclohexane (RDX); Composition B (Comp B) (a 60/40 gravimetric blend of RDX and TNT plus 1 wt. percent wax added as a desensitizer); 70/30 tetrytol (a 70/30 gravimetric blend of tetryl and TNT); and M28 double-base propellant (which contains nitrocellulose ENC] and nitroglycerin ANGUS. These materials fall into four classes: aromatic nitro compounds (such as TNT), aromatic nitramines (such as tetryl), heterocyclic nitramines (such as RDX), and nitrate esters (such as no and ng). AROMATIC NITRO COMPOUNDS Several references can provide a review of the reac- tivity of aromatic nitro compounds (Feuer, 1969; Urbanski, 1964, 1984~. It is well documented that het- erolytic substitutions occur through electrophilic and nucleophilic attacks from cations and anions, respec- tively. Homolytic substitutions involve the reaction of uncharged free radicals. Base hydrolysis is usually a heterolytic substitution as a result of a nucleophilic attack of the alkaline anion. However, there is some evidence that homolytic substitutions can occur simultaneously. The reactions of aromatic nitro compounds with bases are often accompanied by intense color changes. Violet, red, or brown colors can be observed depend- ing on the alkali system. Much of what is now known about these reactions has been attributed to Jack- son (Jackson and Gazzolo, 1900), Meisenheimer (Meisenheimer, 1902), and Janovsky (Janovsky and Erb, 1886), whose fundamental work with nitroben- zene around the turn of the century identified some of the reversible reactions that form reactive intermedi- ates. Several possible resonance structures can be quite energetic, including Jackson-Meisenheimer com- plexes, Janovsky complexes, and other sigma (~) com- plexes. Russell and others have demonstrated how nu- cleophilic attack of a strong base (B-) on aromatic nitro compounds can simultaneously produce Jackson- Meisenheimer complexes, a radial anion, and a free radical (Urbanski, 1964, 1984; Russell et al., 1964~. Obviously, these species will undergo further reaction with available substrates. Depending on the reagents used to generate the anion and the reaction conditions, several anionic sigma complexes are possible (Strauss, 1970~. one of the most common aromatic nitro compounds is TNT (molecular weight 227.13 g/mole, melting point 81C [178F]~. TNT is resistant to reaction with acids, but like all nitro compounds, it reacts easily with bases. Because the solubility of TNT in water is only about 6.0 x 10-4 M at 25C (77F) (DA, 1984), hydrolysis of TNT has often been performed in an alcohol or a co- solvent system. In 1975, Hammersley (1975) published a survey of alkali reactions with TNT that affirms the conclusions of Bernasconi (1971) and of Gold and Rochester (1964~. Hammersly was probably unaware of the work of Cuta and Beranek (1974~. Many others have also

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APPENDIX E performed relevant work in this area (Blake et al., 1966; Caldin and Long, 1955; Shipp and Kaplan, 1966; Shipp et al., 1972; Schaal and Lambert, 1962~. Most of the investigations attempt to identify species that cause color changes or verify the formation of specific prod- ucts. However, all of these investigations were per- formed to study the "pink-water" problems at produc- tion facilities. Their main focus was to find ways to precipitate TNT from dilute solution and prevent the discharge of the pink contaminants to the environment. Because destruction of TNT was not the goal, the quan- titative chemical reaction kinetics for the alkaline de- composition of TNT were not determined. The base hydrolysis of TNT is probably an ex- tremely complex series of reactions (Newman, 1999~. A plausible overall mechanism for the alkaline decom- position of TNT can be constructed from the work cited above. The reaction pathways and products differ if either the base or the TNT is in excess. With excess base, the general mechanism is: TNT + RO- ~ TNT TNT- ~ A + NO2 TNT- ~ B + C + NO2 B ~ NH3 ~ + HCN ~ + HNO2 C ~ D A ~ E ~ With excess TNT, the general mechanism is: TNT + RO- ~ TNT TNT + TNT- ~ JC TNT + JC- ~ Addition Compounds where. TNT = MC- = JC family of MC- resonance structures known as an anion of TNT Jackson-Meisenheimer complex Janovsky complex alkali salts of dinitrocresol (these may precipitate) B = picric acid C = isomers of dinitrophenol (these may precipitate) alkali salts of phenols alkali nitronate salts (precipitate) D = E = iWater on military bases was sometimes contaminated with trace amounts of TNT, which caused the water to take on a pink color. 215 Quantitative characterizations and prioritizations of the reaction pathways (or determination of the branch- ing ratios) have not been completed. However, the cur- rent level of qualitative understanding is perhaps suffi- cient to realize that engineering practices can probably restrict the domain of possible products. The use of excess strong base is probably the most efficient means of ensuring that hydrolysis is driven to completion. However, elevated temperature and pressure must be carefully monitored to prevent spontaneous and vio- lent exothermic reactions. A careful review of process- ing procedures is also warranted to safeguard person- nel who may have to handle precipitates and other products of incomplete hydrolysis. This is especially true during emergency shutdowns and restart proce- dures. The ACWA technology providers should iden- tify and demonstrate these engineering practices be- fore full-scale hydrolysis of TNT is deemed safe and effective. AROMATIC NITRAMINES One of the most common aromatic nitramines is tetryl (2,4,6-trinitrophenylmethylnitramine) (Urbanski, 1967; DA, 1984; DA, 1991; Kaye end Herman, 1980~. Tetryl is not very soluble in water. The molecular weight of tetryl is 287.1 g/mole, and its melting point is about 130C (266F). Tetryl forms a eutectic mix- ture at 58.3C (137F) with 57.9 wt. percent TNT (Urbanski, 1964~. Tetryl is resistant to attack by weak acids but will react with concentrated acid or any alkaline solution. As early as the 1880s, van Romburgh, Mertens, and Franchimont established a mechanism for the hydroly- sis of tetryl (van Romburgh, 1889; Mertens, 1886; Franchimont and Backer, 1913~. The nitramino group is hydrolyzed when tetryl is boiled in a dilute solution (2 wt. percent) of sodium carbonate, sodium hydrox- ide, or potassium hydroxide. The products are 2,4,6- trinitrophenol (picric acid), methylamine, and nitrous acid. The kinetics for the hydrolysis of tetryl have not been documented. However, the rate of hydrolysis of tetryl is slower than that of TNT (Newman, l 999~. The actual mechanism involved with complete alkaline de- composition is not known either but is probably very similar to those that occur in the hydrolysis of TNT. An

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216 . ALTERNATIVE TECHNOLOGIES FOR DEMILITARIZATION OF ASSEMBLED CHEMICAL WEAPONS anion resonance complex should be expected. This an- ion complex should be the result of a fast intermediate step, and its formation may complicate the family of possible hydrolysis products. If the tetryl is in excess, hydrolysis should yield insoluble Janovsky complexes and addition products that are potentially energetic. An excess of strong base should, however, drive hydroly- sis to completion. A plausible overall mechanism for the alkaline de- composition of tetryl can be hypothesized from the work previously cited for TNT. With excess base, the mechanism should be: tetryl + RO- ~ tetryl~ tetryl~ ~ A + NO2- tetryl~ ~ B + C ~ + NO2- B ~ NH3 ~ + HCN ~ + HNO2 A ~ D ~ With excess tetryl, the expected mechanism is: tetryl + RO- ~ tetryl~ tetryl + tetryl~ ~ JC- tetryl + JC- ~ Addition Compounds where, tetryl~ = hypothetical resonance structures that behave as an anion of tetryl JC- = Janovsky complexes of tetryl A = intermediate alkali salts (these may B = C D precipitate) . . plcrlc aclcl methyl amine alkali nitronate salts (precipitate) TABLE E-1 Hydrolysis Rates Obtained at Laboratory Scale More work is necessary to determine the reaction pathways and the branching ratios. However, as with TNT hydrolysis, the current level of understanding is perhaps sufficient to realize that engineering practices can probably restrict the domain of possible products. A feasibility study has been performed by the Naval Air Warfare Center, Weapons Division, at China Lake, California, to measure the hydrolysis rates with excess NaOH of TNT and tetryl residue in simulated burster sections (GA, 1998~. The NaOH concentration was varied from 12 wt. percent to 20 wt. percent (or from 3.4 M to 6.1 M). The results were reported as linear hydrolysis rates in millimeters per hour (mm/hr) as a function of temperature. The linear hydrolysis rate is a strong function of temperature. One set of experiments was conducted in laboratory glassware, and the results are given in Table E- 1. These data show that the hydrolysis rate for alkaline decom- position of tetryl increases with temperature and con- centration of NaOH solution, as expected. However, the rate is only 16 grams per hour (g/hr) for tetryl in 6.1 M NaOH at 105C (221F). In similar tests at 95C (203F) in 3.4 M NaOH, the hydrolysis rate of TNT is at least 2.7 times faster. The second set of experiments were performed in a simulated rotary hydrolyzer (see Chapter 6) in which the energetic materials were immersed in caustic 66 percent of the total test time. The results for these bench-scale rotary hydrolyzer tests are shown in Table E-2. In general, the hydrolysis rates are lower than those reported in Table E-1 for the laboratory-scale experiments. It was concluded that the mixing action for the laboratory-scale experiments was better than for NaOH Concentration Linear Hydrolysis Gravimetric Hydrolysis Test# (M) Explosive T (C) Rate (mm~hr) Rate (g~hr) Comments 2 3.4 tetryl 89 1.5 0.48 vigorous agitation ga 3.4 tetryl 95 5 to 6 1.6 to 1.9 gentle agitation 1 3.4 tetryl 100 27 8.7 moderate agitation 11 6.1 tetryl 100 34 11 gentle agitation 8 6.1 tetryl 105 50 16 gentle agitation 6a 3.4 TNT 95 5.3 gentle agitation 5 3.4 TNT 95 40 vigorous agitation aTests 9 and 6 can be compared to assess relative hydrolysis rates for tetryl and TNT in 3.4 M NaOH. Source: GA, 1998.

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APPENDIX E TABLE E-2 Hydrolysis Using a Bench-Scale Rotary Hydrolyzer 217 NaOH Concentration Linear Hydrolysis Gravimetric Hydrolysis Test# (M) Explosive T (C) Rate (mimer) Rate (gear) Length of Tube (in) 3 3.4 tetryl 87 2.1 0.68 2 3 3.4 tetryl 87 1.85 0.60 4 3 3.4 tetryl 87 1.82 0.59 4 4 3.4 tetryl 95 7.4 2.4 2 4 3.4 tetryl 95 6 1.9 4 4 3.4 tetryl 95 7-8 2.3-2.6 10 4 3.4 tetryl 95 7-8 2.3-2.6 14 7 6.1 tetryl 101 18 5.8 10 13 6.1 tetryl 101 20 6.5 10 7 6.1 tetryl 101 19 6.1 14 13a 6.1 tetryl 101 20 6.5 14 2a 6.1 TNT 101 54 14 aTests 13 and 12 can be compared to assess relative hydrolysis rates for tetryl and TNT in 6.1 M NaOH. Source: GA, 1998. the bench-scale rotary hydrolyzer sections (GA, 1998~. This result may have ramifications for process design and scale up. No attempts were made during this feasi- bility study to identify the hydrolysis products for ei- ther tetryl or TNT. In summary, the hydrolysis of tetryl pellets is not rapid, even in excess base and at reasonably high tem- peratures. The hydrolysis rate of tetryl is also much slower than that of TNT, which may prompt technol- ogy providers to raise the operating temperatures. How- ever, tetryl will start to decompose to picric acid above 120C (248F) (Urbanski, 1967; DA, 1984), so at- tempts to increase the alkaline decomposition rate by performing base hydrolysis at temperatures above 120C should be avoided, because these reactions may be difficult to control. Because hydrolysis is mass- transfer limited, reducing the chunk size of the tetryl feedstock and inducing vigorous agitation in excess base are probably better ways to increase the rate of hydrolysis once a threshold temperature and base con- centration have been achieved. In any case, the tech- nology providers must identify and demonstrate pro- cessing conditions for the base hydrolysis of tetryl before it is deemed safe and effective at full scale. HETEROCYCLIC NITRAMINES The most common heterocyclic nitramines are RDX and HMX (DA, 1984; Kaye and Herman, 1980; Meyers, 1981; DA, 1996a; DA 1996b). The molecular weight of RDX is 222.1 g/mole, and its melting point is about 1 90C (374F); the molecular weight of HMX is ~ ____ O 296.2, and it melts at about 277C (531F). Because none of the munitions in the ACW inventory contains HMX, this discussion focuses on the hydrolysis of RDX. RDX is manufactured in the United States by the Bachmann process, which produces high quality RDX that may contain from 4 to 17 wt. percent HMX as a by-product (Urbanski, 1967; DA, 1996a). RDX is prac- tically insoluble in water. In 1940, Somlo performed a feasibility study to de- termine if RDX could be decomposed by alkali hy- drolysis (Urbanski, 1967; Somlo, 1940~. He reported that the heterogeneous decomposition of RDX in 1 M solution of NaOH could be accomplished in about 10 hours at 60C (140F). He also reported that increasing the concentration of the sodium hydroxide solution to 10 M and using intense stirring could reduce the time to about four hours. The decomposition products were nitrates, nitrites, organic acids, ammonia, nitrogen, formaldehyde, and hexamethylenetetramine. A mechanism for the homogeneous alkaline decom- position of RDX has been reported by Epstein and Winkler ~ 1951), Jones ~ 1954), Hoffsommer et al. (1977), and Croce and Okamoto (1979~. The detailed mechanism, a series of four reactions, was derived from base hydrolysis of RDX (3 x 10-5 to 6 x 10-4 M) in sodium methoxylate (< 0.5 M) between 19C and 45C (66F and 113F):

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218 ALTERNATIVE TECHNOLOGIES FOR DEMILITARIZATION OF ASSEMBLED CHEMICAL WEAPONS RDX + RO- ~ A + ROH + NO2 A + RO- ~ B- + ROH B- + RO- ~ C 2- + ROH r'2- 3D-+NO2 ~ - where R = CH3 W. H. Jones (1954) suggested that A was the product of HNO2 elimination and might be 1,3,5-triaza-3,5-dinitrocyclohexene-1. He also suggested structures for the other hypothetical intermediates B. C, and D, which are all various resonance structures. Jones also proposed the following equation for the rate of alkaline decomposition (dx/dt), which depends on the rate constants for the first and fourth reactions: dx/dt = k7 ~ a - 3x7 )(b - x ~ + k2 ~ x - x2 where, a = initial molarity of RO- b = initial molarity of RDX kit = the rate constant for the first reaction k2 = the rate constant for the fourth reaction x' = molarity of nitrite from the first reaction x2 = molarity of nitrite from the fourth reaction Jones also proposed the following expressions to de- termine the disappearance of RDX and RO-: - dR/dt = A, R ~ a - 3b + 3R) where R = tRDX] where Z = tRO-] -dG/dt = kit ~ (fib-a + ~ J TABLE E-3 Observed First-Order Rate Constants for Hydrolysis in Excess NaOH Solution (8.048 x 10-2 M) at 25 C % Completion Time (min) RDX Concentration x 1Os (M) Ax 104 ( I! )a o.o 15.8 17.1 28.9 36.8 40.7 42.1 48.7 52.6 76.3 82.9 alOOb 0.00 7.98 11.88 16.05 19.96 27.91 31.97 35.99 40.05 80.06 99.96 232.80b 7.6 6.4 6.3 5.4 4.8 4.5 4.4 3.9 3.6 1.8 1.3 o.lb 3.5 2.6 3.5 3.8 3.1 2.8 3.1 3.1 3.0 2.9 3.1 3.1 ak1 = 1/t in ([RDX]ol[RDx]t) bCalculated using the average first order rate constant from this experiment, kl=3.1. Source: Hoffsommer et al., 1977. Epstein and Winkler (1951), Hoffsommer et al. (1977), and Croce and Okamoto (1979) have offered and verified a simplified expression for the reaction kinetics for RDX hydrolysis. The initial reaction is a proton abstraction from the acidic methylene hydro- gens located between two adjacent nitramine groups, whereby nitrous acid is liberated. This initial second- order reaction is the rate-limiting step. Epstein and Winkler reported second-order rate constants for base hydrolysis of RDX in acetone with aoueous NaOH 1 t~ u.o in). fine relative concentrations of the solute and solvent comprising these solutions were chosen to pre- vent the precipitation of solids and ensure the miscibil- ity of the alkaline solution with acetone. Hoffsommer et al. also reported second-order rate constants for hydrolysis of RDX (< 2 x 10-4 M) in NaOH solutions (from 0.02 to 0.5 M) at temperatures of 25C,35C, and 45C (77F,95F, and 113F). The reaction kinetics were pseudo first order with excess hydroxyl ion: - dERDX]/dt = k2 [NaOH] [RDX] ~ A, [RDX] The observed first-order rate constants for the aque- ous, homogeneous, alkaline hydrolysis of RDX in ex- cess base are provided in Table E-3. Second-order rate constants were calculated from the first-order rate con- stants using the expression k2 = kit / [OHS. Second- order rate constants are given in Table E-4. The forma- tion rate of nitrite ion during the alkaline hydrolysis of RDX at 45C (113F) is presented in Table E-5. The variation in hydrolysis products as a function of hydroxide-ion concentration is given in Table E-6. Hoffsommer et al. (1977) stated that the formation of both the formate ion (HCOO-) and formaldehyde (CH2O) indicated a ring opening of RDX-h-5 by hy- droxide-ion attack on carbon followed by a series of TABLE E-4 Second-Order Rate Constants for Hydrolysis of RDX in NaOH Solutions from 0.02 to 0.25 M Temperature (C) Number of Kinetic Experiments k2x 103 ( M -I s -I ) 25.0 35.0 45.0 6 6 s 3.9+0.2 14+ 1 48+3 Source: Hoffsommer et al., 1977.

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APPENDIX E TABLE E-5 Formation of Nitrite Ion during Hydrolysis of RDX (7.07 x 10-5 M) at 45C (113F) with Excess NaOH Solution (6.82 x 10-2 M) Time (min) % RDX Hydrolysis + [NO2-] x 105 (M) Mole Ratio +[NO2-] /-[RDX] 1.38 2.93 4.32 6.17 8.17 41.00 23.4 43.3 56.7 69.8 79.4 100 1.61 3.32 4.59 5.70 6.54 8.35 0.97 1.08 1.14 1.16 1.17 1.18 Source: Hoffsommer et al., 1977. bond cleavages to form NH3, N2, and N2O. The forma- tion of some H2 is probably due to OH- attack on CH2O under Cannizzo's conditions (Cannizzo et al., 1995; Walker, 1964~. No evidence of the nitrate formation observed by Somlo (1940) was found. Dell'Orco investigated the hydrolysis of Comp B (a blend of RDX and TNT) at the Los Alamos National Laboratory (LANL) under the Joint Department of DefenselDepartment of Energy (DOD/DOE) Muni- tions Technology Program (Dell' Oreo et al., 1995~. Simple experiments in alkaline decomposition were performed with 1.5 M NaOH solutions at both labora- tory and pilot scale. These results are summarized in Table E-7. Two reaction times were reported. One rep- resents the amount of time at or above 81C (178F); the other represents the total time from start to finish of the experiment. Because these experiments were 219 TABLE E-6 Analysis of RDX Hydrolysis Products with Different Hydroxide Concentrations (Mole ratio of product formed per RDX hydrolyzed) [OH-] NO2- N2 NH3 N2O HCOO- CH2O H2 Weak, 0.1 M Strong, 19 M 1.1 0.12 0.9 1.2 2.1 0.7 1.6 0.4 1.6 0.7 1.1 o 0.2 Source: Hoffsommer et al., 1977. performed beyond the solubility limits of Comp B. the hydrolysis rate was slower than expected. Color changes from orange-red to dark brown and black were observed during these experiments. A sig- nificant exotherm occurred at 81 C (178F) as the TNT in the Comp B melted and the rate of reaction increased. This event was accompanied by vigorous bubbling of off-gas. The reaction temperature was reported as self- limited because the boiling point of the solution was about 91C (196F). The reported products of reaction included precipitates, gases, and liquid-phase species. Precipitates included unreacted RDX and HMX. The gas contained nitrous oxide (N2O) and ammonia (NH3~. The organic products found in the aqueous phase in- cluded "formate" (presumably the anion and salts or esters of formic acid) and "hexamine" (apparently hex- amethylenetetram~ne as reported in Somlo t1940] ). Ion chromatography results for anionic products from the hydrolysis of Comp B are given in Table E-8. The table TABLE E-7 Summary of Alkaline Decomposition Experiments for Comp B Performed by LANL Scale [NaOH] (M) Time of Reaction T (C) (min) Gravimetric Hydrolysis % Completion Rate (glhr) 1 g CompB in 1.5 85 15 98.5 3.9 10 ml of NaOH 1.5 33-81 27 98.5 2.2 solutiona 100 g Comp B in 1.5 >81 90 >99.9 66.7 1 liter of NaOH 1.5 33-81 210 >99.9 28.6 solutiona Two711 g billets 1.5 >81 120 95.7 676 in 14 liters of 1.5 28-83 300 95.7 270 NaOH solutiona aThe concentration of Comp B in these experiments is calculated to be 0.44 M. Source: Dell'Orco et al., 1995.

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220 TABLE E-8 Comp B ALTERNATIVE TECHNOLOGIES FOR DEMILITARIZATION OF ASSEMBLED CHEMICAL WEAPONS Anionic Products from the Hydrolysis of Anion Shown as a Percentage of C or N in Comp B formate acetate nitrite nitrate 30% of C 1.2% of C 25% of N 0.2% of N Source: Dell'Orco et al., 1995. TABLE E-9 Product Analysis for Sodium Carbonate Hydrolysis of HMX Powdera % Total Carbon and Nitrogen in HMX (average of ten experiments) Carbon in solution Inorganic carbon Organic carbon Carbon-bearing species Formate (aqueous) Acetate (aqueous) Carbon dioxide (gaseous) lists only the aqueous-phase products and is, there- Carbon monoxide (gaseous) Carbon fore, an incomplete material balance. No effort was made to quantify gas-phase products or to specify final products. HMX is present as a contaminant in RDX manufac tured in the United States. The solubility of HMX in water is only about 5 ppm at 20C (68F). Some inves tigations have been performed to determine the chemi cal-reaction kinetics and the products of HMX alkaline decomposition (Epstein and Winkler, 1951; Croce and Okamoto, 1979; Spontarelli et al., 1994~. The rate-lim iting step is a bimolecular elimination reaction produc ing nitrous acid. The reaction kinetics are second or der, and according to Epstein and Winkler's data, the hydrolysis of HMX is more than 300 times slower than that of RDX at 15.5C (60F). Bishop et al. (1996) have developed a reaction-rate model for the hydrolysis of HMX. Their second-order rate constant for the base hydrolysis of HMX in so dium carbonate (1.01.5 M) was fit to an Arrhenius equation. The experimentally determined values for activation energy and pre-exponential factors are given below in the expression for the reaction-rate constant. in k = - (92.4 + 0.7 kJ/mol) / RT + 20.8 + 0.8 (in so) In this equation, the effect of temperature is substan tial; however, the rate constant (k) is low, and the alka line decomposition is slow. Bishop et al. claim that this model can be used in the design of reactors and in scale up to production. Because the hydrolysis of HMX is mass-transfer limited, investigators have resorted to using higher tem peratures and pressures to increase the reaction rate. Bishop et al. have recently developed a solid-liquid mass-transfer model to describe how faster rates can be achieved for the hydrolysis of HMX by using higher o.s to as about 99 44.00 2~.00 0.86 0.74 34.00 Nitrogen-bearing species Nitrite (aqueous) Nitrate (aqueous) Nitrogen (gaseous) Nitrous oxide (gaseous) Ammonia (gaseous + aqueous) 20.00 o.os 4.10 ss.oo 2s.00 aThe uncertainty in the values presented is + 15 percent. Source: Bishop et al., 1998. temperatures and vigorous agitation (Bishop et al., 1998~. The hydrolysis products are given in Table E-9. In summary, the alkaline decomposition of RDX and HMX is better understood than the alkaline decompo- sition of either TNT or tetryl. However, there are still uncertainties regarding the removal and particle-size reduction of energetic materials in the ACW inventory that will constitute the feed stream for the hydrolysis unit. Insufficient size reduction may adversely impact the effectiveness and scalability of processing param- eters and may increase safety concerns, such as clog- ging of the reactor and exothermic runaway at full scale. Therefore, the ACWA technology providers must demonstrate processing conditions for realistic feeds before the alkaline decomposition of RDX, Com- position B. or HMX can be deemed safe and effective at full scale. NITROCELLULOSE AND OTHER NITRATE ESTERS Information on nitrate esters and their use in various explosive and propellant applications is available from several sources (e.g., Miles, 1955; Urbanski, 1965, 1984; Lindner, 1980; DA, 1984; Fedoroff and Sheffield, 1962, 1972, 1974; Meyers, 1981), many of

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APPENDIX E which include substantial information about character- istics and reactivity. The physical properties of nitrate esters and their affinity to undergo base hydrolysis or alkaline decomposition are described briefly below. Nitrate esters are classified as primary, secondary, or tertiary, depending on whether they were derived from primary, secondary, or tertiary alcohols. The com- plicated base hydrolysis of nitrate esters is now reason- ably well understood. It involves the cleavage of both C-O and O-N bonds. The hydrolysis reactions can be summarized by the following set of expressions (Urbanski, 1984; Baker and Neale, 1954, 1955; Baker and Heggs, 1955; Anbar et al., 1954~: 1. Nucleophilic attack on carbon (Sol and SN21: HO- + RCH2 - O - NO RCH2 - OH + NO3 2. Nucleophilic attack on nitrogen (SN21: HO- + RCH2 - O - NO2 ~ tRCH2- O + HONO2 ~ ~ RCH2 - O - H + NO3 3. Nucleophilic attack on oc-hydrogen (Em: HO- + RCH2 - O - NO RCH = 0 + NO2- + H2O 4. Nucleophilic attack on ,8-hydrogen (E1 and Em: HO- + R CH2CH2 - O - NO RCH=CH2+NO3-+H2O The hydrolysis of both primary and secondary mononitrate esters is slow. In general, the hydrolysis of primary nitrate esters proceeds mostly by substitution reactions 1 and 2 above. However, the hydrolysis of secondary nitrate esters is dominated by the elimina- tion reactions 3 and 4. NC and NO are the two nitrate esters of greatest con- cern in the ACWA program. NC is notoriously unstable at elevated temperatures. At 125C (257F), NC de- composes to CO, CO2, H2O, N2, and NO. At 50C (122F), the rate of decomposition of NC is approxi- mately 4.5 x 106 wt. percent per hour, increasing by a factor of about 3.5 with each 10C (18F) increase in temperature. Dry NC burns very rapidly and may deto- nate when acted upon by a sufficient stimulus if the NC is present in large quantities or if it is confined. NC is a dangerous material to handle dry because of its sensi- tivity to friction, static electricity, impact, and heat. The higher the nitrogen content, the more sensitive NC tends to be. Therefore, NC is always shipped wetted 221 with water or alcohol. However, even NC with 40 per- cent (vol.) water can detonate if it is confined and acted upon by a sufficient stimulus (Lindner, 1980~. NC is not a single homogeneous product. Rather, it is a family of very similar compounds containing mono-, di-, and tri-nitrocellulose. The molecular weight of NC depends on the nitrogen content and can be calculated using the following expression. molecular weight of NC = 324.2 + t% N / 14.14] 270 Military grades of NC contain more than 12 percent N. Four grades of NC are specified for military use; however, it is often blended to meet the performance requirements of specific weapons. The cast double- base propellant grain, M28, specified for the M55 rocket contains both NC and NO. However, the actual nitrogen content for the NC is not specified (DA, 1966~. NC is soluble in acetone but insoluble in water. The higher the nitrogen content, the less soluble NC is in ether-alcohol mixtures (Sax and Lewis, 1987), and al- kaline solutions. Therefore, the residence time required for alkaline decomposition of NC (14 percent N) is expected to be longer than for NC (12 percent N). Be- cause NC is more soluble in ammonia than in aqueous alkaline solution, some researchers recommend ammo- nia hydrolysis, or "ammonolysis," for destroying NC (Cannizzo et al., 1995; Morgan et al., 1994; Melvin, 1997; GA, 1997~. The alkaline decomposition of NC in aqueous NaOH solution is mass-transfer limited. Kenyon and Gray (1936) performed a quantitative study of the alkaline decomposition of NC in which they examined the time necessary for dry NC fibers to disappear in NaOH solutions. Although their time mea- surement technique is not extremely reliable, it does indicate a relative order of magnitude required to per- form the operation on a laboratory scale. They evalu- ated the effect of base concentration and temperature on hydrolysis rate. Their data set for the alkaline de- composition of NC at 30C (86F) is given in Table E-10 and at 60C (140F) in Table E-ll. They concluded that alkaline decomposition of NC proceeds faster at higher temperature and in stronger base. They also ob- served that small amounts of carbon dioxide were prod- ucts of decomposition and that large amounts of the nitrates were reduced to nitrites. An average of about 66.6 percent of the nitrogen in NC was reduced to

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222 ALTERNATIVE TECHNOLOGIES FOR DEMILITARIZATION OF ASSEMBLED CHEMICAL WEAPONS TABLE E-10 Alkaline Decomposition of NC (12.2% N) at 30C (86F) Volume of Mass of NaOH Solution NaOH Concentration Time Required for NC (g) (cc) (%) Decomposition (hrs) 10 100 20 (or 6.09 M) 2.58 10 200 10 (or 2.77 M) 11.13 10 400 5 (or 1.32 M) 23.33 10 800 2.5 (or O.64M) 170.90 10 2000 1.0 (or O.25 M) 245.00 Source: Kenyon and Gray, 1936. either nitrates or nitrites during alkaline decomposition at 30C (86F) and about 71 percent at 60C (140F). NG is a pale yellow viscous liquid, also known as glyceryl trinitrate or trinitroglycerin, with a molecular weight of 227.1 g/mole. It is soluble in almost all or- gan~c solvents and is sufficiently soluble in water (0.18 g/ 100 g H2O at 20C [68F]) to cause a contamination problem in a process waste stream. When acid free, NG is stable, but it is very sensitive to impact. NG de- composes at temperatures above 60C (140F) to form nitric oxides that catalyze further decomposition. Mois- ture increases the rate of decomposition. Unconfined NG will burn without transitioning to a detonation; however, it will detonate if confined. Even though it is well known that NC and NG can be destroyed by alkaline decomposition in the labora- tory, the application of this method to actual propellant formulations will have to be tested further to determine its feasibility as a demilitarization technique. NG readily plasticizes NC to form a gel that will solidify and provide useful mechanical properties, making it attractive as a rocket propellant. Unfortunately, this plasticizing effect makes alkaline decomposition of double-base propellants much more difficult than merely performing base hydrolysis of its components. Preliminary experiments indicate that base hydrolysis of gun propellants under normal conditions (at stan- dard temperature and pressure) requires several hours for decomposition. During hydrolysis of a double-base propellant, NG can be expected to be hydrolyzed first via extraction from the NC. However, the conditions that favor this separation are severe. The double-base propellant must be in small pieces, and the temperature and/or pressure must be relatively high. Bunte et al. (1977) have demonstrated a more rapid chemical destruction of double-base propellants using high-pressure alkaline hydrolysis. To destroy a large quantity of obsolete ordnance in Germany, researchers were asked to identify an "environmentally friendly" technology. Bunte, Krause, and Hirth have advocated alkaline hydrolysis at about 150C (302F) and 20 aim, which they claim results in the same hydrolysate prod- ucts as under normal conditions but 8 to 10 times faster. The five actual gun and rocket propellant formulations used in their experiments are presented in Table E-12 as Pi through P5. A 180-cm3 autoclave (OD = 70 mm, ID = 48 mm) batch reactor was used to assess the products of alka- line decomposition of these propellants. The experi- mental conditions included a propellant-to-water weight ratio of 1 to 10, and a propellant-to-NaOH weight ratio of 2.3 to 1. About 120 ml of this reaction TABLE E-11 Alkaline Decomposition of NC (12.2% N) at 60C (140F) Volume of Mass of NaOH Solution NaOH Concentration Time Required for NC (g) (cc) (%) Decomposition (hrs) 10 100 20 (or 6.09 M) 0.05 10 200 10 (or 2.77 M) 0.23 10 400 5 (or 1.32 M) 0.83 10 800 2.5 (or O.64M) 8.00 Source: Kenyon and Gray, 1936.

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APPENDIX E TABLE E-12 German Propellant Formulations Used in Pressured Alkaline Decomposition Experiments NameP1 (% by wt)P2 (% by wt) P3 (% by wt)P4 (% by wt) P5 (% by wt) NC9780 57.557 56 NG 14 26.728 26 DNT 2 8.511 9 Centralite 2 2.93 2.9 DPA2 Graphite11 Potassium salt 1 Lead 1.4 Dibutylphthalate 4.5 Vaseline 11 1 NC = nitrocellulose (% N not given) NG = nitroglycerin DNT = 2,4-dinitrotoluene DPA = diphenylamine Source: Bunte et al., 1997. mixture was put into the autoclave, and the autoclave was evacuated and then filled with helium to a pressure of about 20 atm. The reactor was heated at 10C/m~n to 150C (302F) (15 minutes), and this temperature was held for one hour. The hydrolysis is exotherm~c, and small temperature increases (on the order of about 10C [18F] ) were reported. Because NC is the major component of the P1 through P5 propellants, the products of NC decompo- sition were identified. The main products are nitrite and nitrate in the aqueous phase, along with small-chain organic acids (Urbanski, 1984; Kenyon and Gray, 1936; Bunte et al., 1997~. Using ion-exclusion chroma- tography, the small-chain organic acids were identified 223 as malonic acid. succinic acid. clutaric acid. formic , , acid, acetic acid, and propionic acid. These prod- ucts are all biodegradable, and Bunte et al. recom- mend treating them with a two-step bioremediation operation, anoxic denitrification and normal aerobic treatment. The propellant samples were originally in the form of sticks and cylinders that were ground down to a par- ticle size of about 1-5 mm. The results for the decom- position of the propellant P2 are summarized in Fig- ures E- 1 through E-4. The results for all five propellants are generalized in Table E- 13. As Figure E-1 shows, more than 50 wt. percent of the nitrogen in P2 is decomposed to gaseous products, TABLE E-13 Results for the Pressured Alkaline Decomposition of Propellants P1-P5 % of the Total Carbon and Nitrogen in the Propellant Residue P1 P2 P3 P4 P5 Solid residue containing DPA, graphite, centralite, lead oxide, dibutylphth al ate Liquid residue containing NO2, NO3, DNT emulsion DPA emulsion, COD, HCO3 Gaseous residue containing N2, N2O, NO, CO2, CO, CHn 2-3 3-12 10 5-16 10 40-70 20-50 Source: Bunte et al., 1997.

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224 100 1' 80 ~ cow a' a' 60 AIL - 40 20 o ALTERNATIVE TECHNOLOGIES FOR DEMILITARIZATION OF ASSEMBLED CHEMICAL WEAPONS AIL / /, i NO3 Ngas N2 N2O NOx N sum N res N lie NO2 FIGURE E-l Conversion of nitrogen (N) during pressurized alkaline decomposition of propellant P2. which include mostly elemental nitrogen and nitrous oxide. The amount of NOX is less than 10 wt. percent. More than 40 wt. percent of the nitrogen in P2 is de- composed to liquid products, which include nitrates and nitrites. Less than 5 wt. percent of the nitrogen in P2 is decomposed to a solid residue. The material balance for the carbon in P2 is uncertain, as shown in Figure E-2. The carbon content of the P2 propellant is transformed into about 8 wt. percent CO2, less than 1 wt. percent CO, and less than 0.1 wt. percent, of methane. Depend- ing on the specific additives in the propellant, between 6 and 10 wt. percent of the carbon can be found in the solid residue. The main products in the aqueous solu- tion are carboxylic acids, carbonates, and bicarbonates. The chemical oxygen demand (COD) in the liquid phase is between 50 and 60 percent carbon. This is the so - / 70 60 50 a) c' a) ILL 40 30 20 10 O- measure of the amount of oxidizable compounds present in water. Because this value does not differen- tiate stable from unstable organic matter, it does not necessarily correlate with the biochemical oxygen-de- mand value. The formation of gaseous products is strongly influ- enced by reaction conditions. The quantity of gaseous products can be reduced if stronger alkaline solutions are used (e.g., propellant-to-NaOH weight ratio of 1: 1~. Figures E-3 and E-4 show the conversion results for nitrogen and carbon, respectively, for the alkaline de composition of propellant P5 using propellant-to- NaOH weight ratios of 2.3:1 (weaker alkaline solution) and 1:1 (stronger alkaline solution). In Figure E-3, the gaseous products are reduced from about 20.3 wt. per- cent to 2.6 wt. percent by going to the stronger alkaline ~ 7 LO A/ I mu/ I ~ //'l k ~// '~714Y ores Ccod C gas CO co2 CH n FIGURE E-2 Conversion of carbon (C) during pressurized alkaline decomposition of propellant P2. C sum

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APPENDIX E 225 100 ~ 80 ~ 60- c' a' ray 40 20 O- ~ ~ N res N liq NO2 NO 3 1:1 2.3:1 ,~ NgaS N 2 N2 o NOx N sum FIGURE E-3 Conversion of nitrogen (N) during pressurized alkaline decomposition of propellant PS under different alkaline conditions. solution. NOX formation is also virtually eliminated. In Figure E-4, the CO2 has been reduced from 4.5 wt. per- cent to less than 0.1 wt. percent. The carbon content in the solid residue is also reduced from 21.9 percent to 9.4 wt. percent. The COD value increased from 71 per- cent to 87 wt. percent, indicating more oxidizable com- ponents in the liquid phase. The products of pressurized alkaline hydrolysis for propellants P1-P5 depend on the additives in the com- positions. Components that do not completely react, such as diphenylamine (DPA) and centralite, will pre- cipitate as solid residue. However, some DPA appears as an emulsion in the liquid phase. The most problem- atic component in this evaluation is dinitrotoluene 100 ~ 80 ~ ~ 60 rip 40 20 (DNT). In additional experiments performed with pure 2,4-DNT, only 7 percent of the nitrogen was found as nitrite in the liquid phase (Bunte et al., 1997), and none was found in the solid residue. Therefore, it is believed that DNT is not completely converted and may still be present as an emulsion in the aqueous phase. Emulsi- fied components, such as DNT and DPA, must be re- moved before aerobic bioremediation can proceed. These results have been described in substantial de tail because they impact the proposed approaches for demilitarizing assembled chemical weapons. Some technology providers propose using base hydrolysis of all of the energetic materials from ACW ordnance in a single batch reactor during a demilitarization campaign 1:1 2.3:1 ,: , , , , , ~ , ' , ' , Ores C ~ jq COD HCO3 Cgas CO CO2 CH n Csum FIGURE E-4 Conversion of carbon (C) during pressurized alkaline decomposition of propellant PS under different alkaline conditions.

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226 ALTERNATIVE TECHNOLOGIES FOR DEMILITARIZATION OF ASSEMBLED CHEMICAL WEAPONS (Lockheed Martin, 1997; Parsons, 1997~. Because the M55 rockets contain both aromatic nitro compounds and nitrate esters, simultaneous hydrolysis on bursters and rocket motors could be problematic. First, the dis- sociated components of the M28 propellant could react with TNT intermediates during hydrolysis. Second, the decomposition of emulsified components or interme- diates might require very severe operating conditions or extremely long residence times. Every M55 rocket contains about 19.3 pounds of M28 propellant. Assuming that access to the grain is adequate and that particle size reduction is sufficient to obtain hydrolysis results similar to those presented for propellant P5, the NC and NG will be hydrolyzed. However, the remaining components will either be pre- cipitates or will exist as an emulsion in the aqueous or liquid phase. Lead stearate, an additive in M28 propellant, is in- soluble in water at ambient temperature but is soluble in hot alcohol (Sax and Lewis, 1987~. Hence, the com- mittee is concerned that it may dissolve in hot alkaline solution, in which case the lead cations could combine with other anionic substrates in a batch reactor and pre- cipitate out sensitive compounds. This possibility is supported by the results for propellant P3. For example, picric acid will be formed during hydrolysis of the TNT or tetryl contained in the M55 rocket bursters. If burst- ers and propellant are hydrolyzed simultaneously, lead from the propellant could either precipitate out or form lead picrate. In the hydrated form, lead picrate is not particularly sensitive. However, enough heat could be produced from this exothermic process to heat and de- hydrate the lead picrate deposited on vessel walls. As indicated in the section on TNT hydrolysis, dry lead picrate is an extremely sensitive explosive and is very dangerous to handle. Therefore, the committee believes that, to avoid forming sensitive compounds such as lead picrate, hydrolysis of bursters and propellant should be performed in separate vessels unless further testing demonstrates the process is safe. It is uncertain whether slightly soluble components are eventually decomposed or emulsified if they are allowed to undergo prolonged base hydrolysis. Bunte et al.(l997) report that alkaline hydrolysis of centralite, DPA, DNT, and TNT may require supercritical hy- drolysis and oxidation (374C t705F] and 218 aim [3204 psi]) to be completely decomposed. In any event, the technology providers will have to demonstrate that the hydrolysate product from base hydrolysis of ener- getic materials is an appropriate feedstock for the next unit operation. Some of these emulsions, such as TNT. tetryl, and 2-nitrodiphenylamine, may not be good can didates for biotreatment. SU M MARY This review of the hydrolysis of energetic materials important to the ACWA program, based on available literature, shows that the base hydrolysis of energetic materials extracted from obsolete ordnance is not a mature technology. There is relatively little experience with the alkaline decomposition of ACWA-specific energetic materials (compared to experience with chemical agents). Most of the base hydrolysis described in the literature on other energetic materials was con- ducted in dilute solutions and within solubility limits. Under these conditions, several undesirable products and precipitates can result. Data in the literature rel- evant to the hydrolysis of energetic materials from as- sembled chemical weapons indicates that hydrolysis is relatively slow unless the reaction conditions are se- vere (elevated temperature, pressure, and pH) because these materials are not very soluble in aqueous systems and the hydrolysis of solids is mass-transfer limited. To overcome this problem, investigators have resorted to using strong alkaline solutions, high temperatures, and even high pressures. In general, the relative hy- drolysis rates of the energetic materials of interest to the ACWA program are expected to be (from faster to slower): NG>TNT>tetryl2RDX>HMX>NC One of the most important unresolved issues is that the family of products is not understood well enough to support simultaneous hydrolysis of different kinds of energetic materials in the same batch reactor. This tech- nique should be disallowed until there is substantial evidence that intermediates from the hydrolysis of aro- matic nitro compounds will not combine with M28 pro- pellant additives or fuze components to form extremely sensitive explosives or other dangerous precipitates. An associated concern is that the conditions under which aromatic nitro compounds, such as TNT or picric

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APPENDIX E acid, will emulsify in the aqueous phase and not be completely hydrolyzed are not understood. Any unit operation that immediately follows hydrolysis of ener- getic material should be designed to accept emulsified aromatic nitro compounds, such as TNT or picric acid, as contaminants in the aqueous feed stream. The principal problem for ACWA technology pro- viders is to develop and demonstrate a practical produc- tion process based on previously unrelated chem~cal- engineering unit operations and emerging technologies to satisfy destruction efficiency requirements. These chem~cal-engineering unit operations are: (1) section- ing of munitions to gain access to the energetic materi- als, (2) reducing the size of energetic materials ex- tracted from ordnance sections to expedite salvation and reaction, and (3) decomposing a heterogeneous feed stream consisting of energetic materials, metal, and contaminants via alkaline decomposition. The hy- drolysate produced must be an appropriate feed stream for the next unit operation, which may be another emerging technology (supercritical water oxidation and biotreatment have been proposed). An associated problem for the ACWA technology providers is to develop sound engineering and mana- gerial practices in the event of incomplete alkaline decomposition of the heterogeneous feed stream. Products and precipitates of incomplete hydrolysis of energetic materials can still be energetic and toxic, and some emergency shutdowns during processing are likely considering the overall complexity of the process. The current level of understanding is, perhaps, suffi- cient to indicate that engineering practices can prob- ably restrict the domain of possible reaction products. The use of strong base is probably the most efficient way to ensure that hydrolysis is driven to completion. Ammonia hydrolysis for the alkaline decomposition of some energetic materials could be considered. This would decrease the solubility problem and minimize the need for severe reaction conditions to increase throughput rates. REFERENCES Anbar, M., I. Dostrovsky, D. Samuel, and A.D. Yoffe. 1954. Esters of inorganic oxyacids. Part I. The mechanism of hydrolysis of alkyl esters, i8O being used as a tracer, and its relation to other reactions in alkaline media. Journal of the Chemical Society, 1954, Vol. III: 3603-3611. 227 Baker, J.W., and T.G. Heggs. 1955. Hydrolytic decomposition of esters of nitric acid. Part V. the effects of structural changes in aralphyl nitrates on the SN and ECo reactions. Journal of the Chemical Society, 1955, Part I: 616-630. Baker, J.W., and A.J. Neale. 1954. Hydrolytic decomposition of esters of nitric acid. Part III. kinetic evidence for ion exchange between anionic reagents and the solvent in the carbonyl elimi- nation reaction (ECo2~. Journal of the Chemical Society, 1954, Part III: 3225-3233. Baker, J.W., and A.J. Neale. 1955. Hydrolytic decomposition of esters of nitric acid. Part IV. acid hydrolysis, and the effects of change in the nucleophilic reagent on the SN and ECo reactions. Journal of the Chemical Society, 1955, Part I: 608-615. Bernasconi, C.F. 1971. Kinetic and spectral study of some reac- tions of 2,4,6-trinitrotoluene in basic solution. I. deprotonation and janovsky complex formation. Journal of Organic Chemistry 36 (12): 1671-1679. Bishop, R.L., C. Skidmore, R.L. Flesner, P.C. Dell'Orco, T. Spontarelli, K.J. Uher, J.F. Kramer, and D.A. Bell. 1996. Base Hydrolysis Kinetics of HMX-Based Explosives Using Sodium Carbonate. Report LA-UR-96-1818. Los Alamos, N.M.: Los Alamos National Laboratory. Bishop, R.L., R.L. Flesner, P.C. Dell'Orco, T. Spontarelli, and S.A. Larson. 1998. Modeling of the base hydrolysis of HMX powder and HMX based plastic bonded explosives using sodium hy- droxide. Pp. 320-331 in Proceedings of the Fourth Conference on the Life Cycles of Energetic Materials. Los Alamos, N.M.: Los Alamos National Laboratory. Blake, J.A., M.J.B. Evans, and K.E. Russell. 1966. Kinetic studies of proton transfer from phenols to trinitrobenzyl anion. Cana- dian Journal of Chemistry 44: 119-124. Borcherding, R. 1997. An alternative to open burning treatment of solid propellant manufacturing wastes. Waste Management 17 (2/3~: 135-141. Borcherding, R. 1998. An alternative to open burning treatment of solid propellant manufacturing waste. Pp. 87-92 in Proceedings of the Fourth Conference on the Life Cycles of Energetic Mate- rials. Los Alamos, N.M., Los Alamos National Laboratory. Borcherding, R., and D. Wolbach. 1995. Treatment of solid propel- lant manufacturing wastes, base hydrolysis as an alternative to open burning. Pp. 185-193 in Chemical Propulsion Information Agency Publication 626. Columbia, Md.: Chemical Propulsion Information Agency. Bunte, G., H. Krause, and T. Hirth. 1997. Disposal of energetic materials by alkaline pressure hydrolysis and combined tech- niques. Journal of Propellants, Explosives, and Pyrotechnics 22~3~: 160-164. Caldin, E.F., and G. Long. 1955. The Rates and Equilibria of Some Reactions of Trinitrotoluene and Related Sustances from -80 to 20C. Proceedings of the Royal Society of London 226A: 263-285. Cannizzo, L.F., G.L. Mower, L.R. Huntsman, W.R. Achatz, and W.W. Edwards. 1995. Hydrolysis of the energetic materials present in a composite modified double base solid rocket pro- pellant. Journal of Energetic Materials 13~3-4~: 331-356. Croce, M., and Y. Okamoto. 1979. Cationic micellar catalysis of the aqueous alkaline hydrolyses of 1,3,5-triaza-1,3,5-trinitro- cyclohexane and 1,3,5,7-tetraaza-1,3,5,7-tetranitrocyclooctane. Journal of Organic Chemistry 44 (13~: 2100-2103. Cuta, F., and E. Beranek. 1974. Spektrophotometrische und

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228 ALTERNATIVE TECHNOLOGIES FOR DEMILITARIZATION OF ASSEMBLED CHEMICAL WEAPONS Chromatographische Untersuchung der Reaktion von 2,4,6- Trinitrotoluol mit Natriumhydroxid. Collection of Czechoslo- vakian Chemical Communications 39: 736-741. DA (Department of the Army). 1996a. Detail Specification MIL- DTL-398D, RDX (Cyclotrimethylenetrinitramine). Dec. 12, 1996. DA.1996b. Detail Specification MIL-DTL-45444C, HMX (Cyclo- tetramethylenetetranitramine). Nov. 26, 1996. DA. 1991. Military Specification.Tetryl (Trinitrophenylmethyl- nitramine), MIL-T-339C, Notice 2. November 4, 1991. Wash- ington, D.C.: Department of the Army. DA. 1984. Military Explosives. TM 9-1300-214. September 1984. Washington, D.C.: Department of the Army. DA.1966. Military Specification. MIL-P-60071A(MU), Propellant Grain, M28. May 10, 1966, as amended by Amendment 1 of June. 15, 1966. Dell' Orco, P., R. Flesner, T. Spontarelli, J.A. Sanchez, and J.F. Kramer. 1995. 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