WO2000015306A1

WO2000015306A1 - Demilitarization of chemical munitions

Info

Publication number: WO2000015306A1
Application number: PCT/US1998/019704
Authority: WO
Inventors: Russell Ward Johnson; Francis Stephen Lupton; Brent S. Defeo; Jeffrey Chang
Original assignee: Alliedsignal Inc.
Priority date: 1998-09-14
Filing date: 1998-09-16
Publication date: 2000-03-23
Also published as: CN1286640A; AU1899599A; IL149714A0

Abstract

A chemical munitions destruction system disassembles the munitions and processes the chemical agent and energetic materials through a series of treatment processes until a preselected level of destruction is achieved. The treatment process includes a disassembly process, chemical neutralization and processing of both the chemical and energetic agents, biological treatment of the aqueous wastestreams and catalytic oxidation of the air exhaust streams. In certain cases, the energetic agent and/or the propellant components of the munitions are converted to valuable chemicals by means of catalytic hydrotreating.

Description

DEMILITARIZATION OF CHEMICAL MUNITIONS

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 60/058,988 filed September 15. 1997.

Background Of the Invention

1. Field Of The Invention This invention relates to a system for destruction of chemical munitions; and. more particularly, to a system in which the disassembly of the munitions and the processing of the agent and energetic are effected through a series of treatment processes until the desired level of destruction is achieved.

2. Description of the Prior Art

The destruction of chemical munitions is a major international concern. These weapons are now outlawed by international treaties and their safe disposal has been mandated. Disposal of chemical weapons is conventionally effected by means of incineration. Although incineration represents a technically feasible approach to the destruction of these materials it is not acceptable to the many State and local governments nor to the communities surrounding the stockpile sites. The major concerns of these groups are the perceived hazards associated with air emissions from incinerators. There is a great desire on the part of all the stakeholders, government and citizen, of the chemical munitions demilitarization process to find cost efficient alternative technologies to the baseline incineration that are both safe and effective for destruction of these weapons.

Summary of the Invention

The present invention provides a chemical munitions destruction system that disassembles the weapons and destroys the chemical agents and energetic materials contained therein. The remaining metal parts and solid wastes are decontaminated to such a degree that they are safe for disposal via conventional routes, e.g. metal smelter or landfill. Generally stated, the system provides for the disassembly of the munitions and the processing of the agent and energetic through a series of treatment processes until the desired level of destruction is achieved. The treatment process comprises a disassembly process, chemical neutralization and processing of both the chemical and energetic agents. biological treatment of the aqueous wastestreams and catalytic oxidation of the air exhaust streams. Advantageously, in certain cases the energetic and/or the propellant components - of the munitions can be converted to valuable chemicals by means of catalytic hydrotreating.

Brief Description of the Drawings

The invention will be more fully understood and further advantages will become apparent when reference is had to the following detailed description and the accompanying drawing in which:

Fig. 1 is a process flow diagram of a chemical munitions disposal system utilizing a disassembly process, chemical neutralization and processing of both the chemical and energetic agents, biological treatment of the aqueous wastestreams and catalytic oxidation of the air exhaust streams;

Fig. 2 is a process flow diagram of a dissassembly process for chemical munition projectiles and chemical neutralization of both the agent and energetic components; Fig. 3 is a process flow diagram of a dissassembly process for chemical munition rockets and chemical neutralization of the agent, energetic and propellent components:

Fig. 4 is a process flow diagram of a chemical neutralization process for both energetic and chemical agent components of munitions and subsequent biological treatment and water recovery systems; Fig. 5 is a flow sheet for the chemical neutralization, biological treatment and water recovery process for chemical agent HD (Mustard Agent);

Fig. 6 is a flow sheet for the chemical neutralization, biological treatment and water recovery process for chemical agent VX (Nerve Gas); and

Fig. 7 is a flow sheet for the chemical neutralization, biological treatment and water recovery process for chemical agent GB (Sarin); >

Description of the Preferred Embodiments

Chemical agents which can be treated in accordance with the present invention are those highly toxic chemicals stockpiled for use in warfare. Examples of these chemical agents include, but are not limited to:Nerve agents such as GA (Tabun), GB (Sarin), GD (Soman), and VX:and Blister agents such as HD (distilled mustard). H, HT, nitrogen mustards (HN-1 , HN-2. HN-3), and Lewisites (1 , 2. and 3).

Energetic materials which can be treated in accordance with the present invention include those chemicals which are used for explosive or propellant purposes. Such energetic materials include, but are not limited to: TNT. RDX. HMX. Tetryl, Lead Azide, nitrocellulose, nitroglycerine, triacetin. dimethyl phthalate. lead stearate. 2- nitrodiphenylamine. and combination energetic materials, including Tetrytol. Comp B and B-4, Comp A-5. M-28 double-base propellant. and Propellants AX/S. NH. WIS 1212 and CYH.

Referring to Fig. l of the drawings, the disassembly of the chemical munitions is carried out by means of a reverse assembly process using a punch and drain process for removal of agent and a water jet cutting process to remove energetics and propellant 1. The remaining metal parts are transferred to a parts washout process that consists of a sealed vessel 2 where the parts will be subjected to heating where in the preferred embodiment, this heating is done with steam, typically to temperatures between 600°F and 1600°F. and preferably from about 800°F to about 1.250°F and more preferably from about 1000° F to

1200° F for a period typically ranging from about 0 to 60 minutes and preferably from about 15 to 20 mins. The steam from the parts washout is condensed and utilized in the base hydrolysis step for agent and energetics.

The recovered chemical agent is subjected to the base hydrolysis step 3, along with the condensate from the parts washout process. Hydrolysis of the agent takes place at a temperature typically ranging from about 60°C to 150°C. and preferably from about 80°C to about 100°C. Base may be added during hydrolysis to catalyze the neutralization or may be added following neutralization to adjust pH to a value between pH 6 and pH 9. and preferably between pH 7 and pH 8. depending upon the chemical agent being processed. Suitable bases include but are not limited to: sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium oxides and hydroxides, magnesium hydroxide, and aqueous ammonia. The neutralized agent hydrolysate can be pretreated 4 using suitable technologies which include but are not limited to lime precipitation, ion exchange, sulfϊde precipitation or oxidative precipitation such as the Fenton^"s reaction by ferrous sulfate and peroxide to remove metals from the hydrolysate which include but not limited to arsenic, lead. mercury, chromium . zinc, copper and cadmium. The neutralized agent hydrolystate is diluted with recycle water from the end of the process and is fed to an immobilized cell - bioreactor (1CB) system 5. The 1CB system degrades and removes the organophosphate and organosulfur compounds produced during hydrolysis of the chemical agents. The 1CB system also degrades some of the organic compounds, including volatile organic compounds (VOCs) and chlorinated volatile organic compounds produced in the agent hydrolysate. The remaining VOCs are stripped from the bioreactor and are destroyed in a catalytic oxidation system 6 on the exhaust air line of the bioreactor vessel.

The recovered energetic materials are subjected to a base hydrolysis process. Hydrolysis is carried out in the presence of base at a temperature typically ranging from about 60°C to 150°C. and preferably from about 80 to 100°C. The neutralized energetics are transferred to the same bioreactor system as used for the agent hydrolysate destruction. Whereas the agent hydrolysate is rich in organophosphate and organosulfur compounds but lacks nitrogen and in some cases organic substrates, the energetics hydrolysate is rich in nitrogen and organic substrates but lacks phosphorous and sulfur nutrients. The combination of both agent and energetics hydrolysate creates an ideal matrix for complete biodegradation of the constituents.

Optionally, if the energetic materials can be converted to valuable chemicals, the recovered energetics are sent to a catalytic hydrotreating process 7. The burster and/or the propellant components of the munitions are readily converted to these valuable chemicals by means of catalytic hydrotreating. The energetics are dissolved in a suitable solvent and reduced in the catalytic hydrotreating reactor. The valuable chemical products are separated from the solvent by means of distillation or other separation technology and the solvent recycled to the front of the process 8.

The effluent stream from the bioreactor system is sent to a water purification system 9 that will use either a reverse osmosis (RO) membrane system or an evaporator system to recover clean water for recycling to the parts washout, base hydrolysis or bioreactor dilution water. The brine or salt cake 10 produced from this process is tested and then disposed of in accordance with all local, state and federal regulations.

Vent air from multiple sources will treated by catalytic oxidation in order to remove those trace contaminants in the air amenable to oxidation, including organic compounds containing phosphorus, sulfur, or chlorine, and chemical agents. The vent air can originate from the biological treatment systems, the punch-and-drain system, the hydrolysis reaction - systems, agent storage areas, and other areas where airborne pollutants can be generated. The vent air from different sources can be manifolded together to be treated by a single catalytic unit, or in the preferred embodiment, multiple catalytic treaters will be used to treat differing vent air streams. The preferred embodiment will allow more precise catalyst sizing and monitoring of vent air streams.

The catalytic oxidation system not only removes VOCs but also removes any unhydrolyzed chemical agent that enters into the vent air from the punch and drain operation for agent removal in the reverse assembly area as well as from leaking munitions in the storage areas.

The chemical munitions disposal process described herein destroys chemical weapons using a reverse assembly system combined with chemical neutralization and processing of both the chemical and energetic agents, biological treatment of the aqueous waste streams and catalytic oxidation of the air exhaust streams as well as a catalytic hydrotreating and product recovery system to convert some energetic components to valuable chemical by-products, and a water recovery step for recycling and reuse of the process water.

The following examples are presented to provide a more complete understanding of the invention. The specific techniques, conditions, materials, proportions and reported data set forth to illustrate the principles and practice of the invention are exemplary and should not be construed as limiting the scope of the invention.

Example 1

The disassembly stage for chemical projectiles is illustrated in Fig.2. The first step involves removing the fuse from the munitions 1. The fuses are shipped off-site for reuse 2. The burster tube component 3 is removed and the energetic component within is removed by in water jet washout stage4. The water wash-energetics slurry is transferred to the energetics hydrolyzer stage 5. Following removal of the burster well, the chemical agent is removed by the punch and drain process 6. The agent is sent to the agent hydrolyzer stage 7. The remaining metal parts are then sent to the decon stage 8 where they are washed with an aqueous caustic decon solution. The spent decon solution is then transferred to the agent hydrolyzer stage 7 . The decontaminated metal parts are sent to the metal parts treater 9. -

Example 2

The disassembly stage for chemical rockets is demonstrated in Fig. 3. The first step is removal of the firing tube and securing of the rocket fins l . This is followed by removal of the igniter assembly 2. The igniters are shipped off site to a US Military facility for possible reuse or disposal 3. The next step is punch and draining of agent from the warhead 4. The agent is drained to the agent hydrolyzer stage 5. The warhead is then flushed with decon solution 6 ( aqueous caustic). The spent solution is sent to the agent hydrolyzer stage. The section of the warhead containing the fuse will then be severed and the burster components will be washed out 7. The washout energetics slurry is then transferred to the energetics hydrolyzer stage 8. The casings are transferred to the metals part treater 9. The remainder of the warhead is severed and the metal parts decontaminated 10. The spent decon solution is also sent to the energetics hydrolyzer. The decontaminated metal parts are sent to the metal parts treater. Likewise the rocket motor section is cut in two. The front and back sections are washed out by water jet and the sluπv is sent to the energetics hydrolyzer. The motor casings are sent to the metal parts treater.

Example 3 The treatment module for treatment for components from the disassembly of both projectiles and rockets is demonstrated in Fig.4. The treatment module consists of a metal parts treater 1. an agent hydrolyzer 2. an energetics hydrolyzer 3. a bioreactor 4. a catalytic oxidizer 5 and a water recovery stage 6.

The metal parts treater consists of a vessel in which metal components can be placed. The vessel is then flooded with superheated steam and the metal parts held at a temperature ranging from 800°F to 1.250 . preferabh 1.000 to 1.250 . for a minimum period of 15 minutes. The condensate from the treater is collected and sent to the agent hydrolyzser. The treated metal parts are disposed of as scrap.

Both the agent and energetics hydrolyzer consist of glass or plastic lined vessels with a high speed mechanical mixer. Agent, base solution and dilution water are added to the vessel and the temperature is raised to 90°C. Suitable bases include but are not limited to: sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium oxides and - hydroxides, magnesium hydroxide, and aqueous ammonia. The reaction is carried out for sufficient time so that >99.9999% of the chemical agent and >99.999% of the energetic material is neutralized. Following neutralization, the hydrolysate is treated in a bioreactor. The

Immobilized Cell Bioreactor (1CB) system is the preferred bioreactor system to use for Treatment of HD Hydrolysate. For the treatment of VX and GB hydrolysates the preferred embodiment is a two bioreactor system consisting of 1CB and a Continuously Stirred Tank Bioreactor (CSTR). This bioreactor system removes >80% of the soluble COD. >95% of the soluble BOD, >80% of the organophosphate and >95% of the organosulfur compounds present in the hydrolysates.

From the bioreactor the effluent is sent to a sludge clarification and dewatering step. The dewatered sludge cake is sent off-site for disposal according to all local. State and Federal regulations. The clarified water is transferred to a water recovery process utilizing either an evaporation and condensation system or a UV/peroxide oxidation, carbon polishing, microfiltration and RO membrane system to produce fresh, clean water for recycle and reuse as decon solution, water jet cutting and hydrolysis and bioreactor dilution water.

The vent gas from the bioreactor, the vent gas from the agent and energetic hydrolyzers as well as the metal parts treater and munitions disassembly processes are all sent to a catalytic oxidizer which destroys odor. VOCs as well as any unreacted chemical agents.

Example 4 The process flow for agent HD hydrolysis and biotreatment is demonstrated in Fig.

5. FID is hydrolysed with hot water at 90°C for 6 hours 1 . Following hydrolysis, the solution is brought to a neutral pH using a sodium hydroxide solution 2. One kg of mustard agent requires 6.7 kg of water 3 and 0.49 kg of sodium hydroxide for neutralization. The treatment of the hydrolysate in the bioreactor 4 requires about 70 kg of recycled .desalinated water 5 and fresh make up 6 water for dilution, about 0.02 kg of phosphoric acid and 1 kg of sodium hydroxide for pH control 7. The bioreactor consumes about 14 kg of oxygen 8 and produces about 1 kg of carbon dioxide. The catalytic oxidizer 9 on the - vent gas from the bioreactor produces about 0.006 kg of HCL from chlorinated VOCs. About 0.15 kg of biological solids 10 are generated from the clarifier 1 and the water recovery system 12 produces about 1.5 kg of salt cake 13. About 60 kg of water are available for recycle and reuse 14

Example 5

The process flow for agent VX hydrolysis and biotreatment is demonstrated in Fig. 6. One kg of VX is hydrolyzed with 2.7 kg of water and 0.4 kg of sodium hydroxide 1. The hydrolysate is diluted with about 75 kg of water 2 and about 0.015 kg of KCL and 15 kg of either isopropanol or dextrose are added for nutrients 3. The bioreactors 4 consume about 14 kg of oxygen 5. The clarifier 6 following the bioreactors produces about 1.2 kg of biological sludge 7. The water recovery system 8 system following the clarifier produces about 2 kg of salt cake 9 and provides about 70 kg of water for recycle and reuse 10.

Example 6 The process flow for agent GB neutralization and biotreatment is demonstrated in Fig. 7. One kg of agent GB is hydrolyzed with 3 kg of water and 0.6 kg of sodium hydroxide 1. Following neutralization, the hydrolysate is diluted with 70 kg of water 2 and 0.015 kg of KCL and 15 kg of isopropanol or dextrose 3 are added as nutrients.. The bioreactors 4 consume about 14 kg of oxygen 5 and the clarifier 6 generates about 1.2 kg of biological sludge 7. About 1.1 kg of salt cake 9 is generated from the water recovery system 8 and about 67 kg of water is generated for recycle and reuse 10.

Example 7 The following example is illustrative of the biological treatment process for HD agent. Diluted HD hydrolysate ( 1 : 10) had the following properties: thiodiglycol. 6.900 mg/L: COD. 15.000 mg/L. The efficacy of the AlliedSignal Immobilized Cell Bioreactor ICB to treat the thiodiglycol (TDG) and Chemical Oxygen Demand (COD) present in the diluted HD hydrolysate was evaluated in a small bench top glass reactor. A total of about 13.8 Liters (3.6 gallons) of diluted hydrolysate were treated in the bench top ICB vessel. The ICB vessels were operated at ambient temperature (20^U C - 25°C) at 1 atm. Diluted hydrolysate was added as both batch and continuous feed. The bench top bioreactors were - aerated by means of a glass frit at the bottom of the bioreactors through which air was fed at between 100 and 200 ml/min. The glass reactor had a liquid volume of about 740 ml. The reactor was packed with about 680 ml of a mixed media packing consisting of ! •> inch squares of carbon coated polyurethane foam and V-i inch polypropylene cylinders. The destruction efficiencies of COD and TDG were as follows:

Example 8

The following example illustrates use of the biological treatment process to treat agent VX hydrolysate. The diluted VX Flydrolysate had the following properties: sulfate. 10 mg/L: COD. 12.500 mg/L The Efficacy of the ICB to treat the organophosphorous. organosulfur and COD present in the diluted VX hydrolysate was evaluated in a small bench top glass reactor. A total of about 5.5 Liters ( 1.5 gallons) of diluted hydrolysate were treated in the bench top ICB vessel. The ICB vessels were operated at ambient temperature (20 - 25 °C) at 1 atm. Diluted hydrolysate was added as both batch and continuous feed. The bench top bioreactors were aerated by means of a glass frit at the bottom of the bioreactors through which air was fed at between 100 and 200 ml/min. The glass reactor had a liquid volume of about 740 ml. The reactor was packed with about 680 ml of a mixed media packing consisting of '/_ inch squares of carbon coated polyurethane foam and '/_ inch polypropylene cylinders. The destruction efficiency of COD. organophosphorous and organosulfur in the ICB vessel at a 15 day HRT was as follows:

Chemical oxidation of the effluent from the bioreactor was tested as a polishing step to remove undegraded organophosphorous compounds. The following results were obtained:

Having thus described the invention in rather full detail, it will be understood that such detail need not be strictly adhered to but that various changes and modifications may suggest themselves to one skilled in the art. all falling within the scope of the present invention as defined by subjoined claims.

Claims

What is claimed is:

1. A process for disposal of chemical munitions composed of chemical agents, energetic materials and metal parts, comprising the steps of:

(a) removing said chemical agents and energetic materials from the munitions;

(b) decontaminating said metal parts;

(c) neutralizing said chemical agents and said energetic materials by subjecting said chemical agents and energetic materials to hydrolysis in the presence of hot water or hot water and base to destroy said chemical agents and energetic materials and create an aqueous waste stream;

(d) biologically treating said aqueous waste stream to remove organics. including chlorinated organics, organophosphorous and organosulfur compounds;

(e) catalytically treating vent air to destroy trace contaminants such as volatile organic compounds that are amenable to oxidation;

(f) clarifying said aqueous waste stream to remove biological solids; and

(g) subjecting said aqueous waste stream to a water recovery step to produce fresh water for recycle and reuse.

2. A process for disposal of chemical munitions, as recited by claim 1. wherein said step ol removing said chemical agents and energetic materials from the munitions further comprises the steps of:

(i) removing fuses and ignitor components: (ii) removing said chemical agent using a punch and drain process; (iii)removing said energetic materials from a water slurry using a water jet washout process; and (iv) decontaminating said metal parts using dilute caustic solution.

3. A process for disposal of chemical munitions, as recited by claim 1. wherein said metal parts decontamination step further comprises the steps of:

(i) placing said metal parts in a vessel;

(ii) filling said vessel with superheated steam to heat the metal part to a temperature ranging from about 600┬░F to 1.600┬░F; and

(iii) subjecting the metal parts to the superheated steam for a time period ranging - from about 5 to 60 mins.

4. A process for disposal of chemical munitions, as recited by claim 3. wherein said metal part is heated by said superheated steam to a temperature ranging from about 800┬░F to about 1.250┬░F.

5. A process for disposal of chemical munitions, as recited by claim 4. wherein said temperature of said superheated steam is 1000┬░F to 1200┬░F.

6. A process for disposal of chemical munitions, as recited by claim 3. wherein said metal parts are subjected to said superheated steam for a time period ranging from about 10 to 30 min.

7. A process for disposal of chemical munitions, as recited by claim 6. wherein said time period ranges from about 15 to 20 min.

8. A process for disposal of chemical munitions, as recited by claim 1 , wherein said neutralization step for each of said chemical agents and energetic materials comprises the step of:

(i) hydrolysis at a temperature ranging from about 60┬░C to about 150┬░C in the presence or absence of a strong base

9. A process for disposal of chemical munitions, as recited by claim 8. wherein said hydrolysis step is carried out at a temperature ranging from about 80┬░C to 100┬░C.

10. A process for disposal of chemical munitions, as recited b\ claim 8. w herein said base is at least one member selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium oxides and hydroxides, magnesium hydroxide and aqueous ammonia.

1 1. A process for disposal of chemical munitions, as recited by claim 1. wherein said energetic materials, upon being recovered are subjected to a hydrotreating process comprising the steps of:

(i) dissolving the energetic materials in a suitable solvent to produce an energetic solvent mixture; and

(ii) treating the energetic solvent mixture in a reductive hydrotreating reactor containing hydrogen gas and a suitable catalyst at a temperature ranging from about 100┬░C to 600┬░C.

12. A process for disposal of chemical munitions, as recited by claim 1. wherein said biological treatment step further comprises the steps of:

(i) adjusting the pH of the hydrolysate to between pH 6 and pFI 9; (ii) adding additional supplements to support microbial growth: (iii) diluting the hydrolysate to a suitable concentration for microbial growth: (iv) contacting the diluted hydrolysate with microorganisms in the presence of air to metabolize biodegradable compounds into carbon dioxide, water, new microorganisms and energy (v) catalytically oxidizing off gas created during said biological treatment step to remove volatile organic compounds: (vi) clarifying said aqueous waste stream to remove biological solids; and

(vii) recovering water in a water recovery step.

13. A process for disposal of chemical munitions, as recited by claim 12. wherein said pFI of said hydrolysate is adjusted to between pH 7and pH 8..

14. A process for disposal of chemical munitions, as recited

claim 6. wherein said biological treatment step further comprises the step of:

(i) polishing organophosphorous and organosulfur compounds in the biological effluent using a UV/peroxide oxidation system.

15. A process for disposal of chemical munitions, as recited

claim 6. wherein said biological treatment step further comprises the steps of:

(i) pretreating said aqueous waste stream to remove metals therefrom.

16. A process for disposal of chemical munitions, as recited b> claim 15. wherein said metals include at least one member selected from the group consisting of arsenic, lead, mercury, chromium and cadmium.

17. A process for disposal of chemical munitions, as recited b> claim 15. wherein said pretreatment step is accomplished using a technology selected from the group consisting of lime precipitation, ion exchange, sulfide precipitation or oxidative precipitation.

18. A process for disposal of chemical munitions, as recited by claim 17, wherein said oxidative precipitation is carried out using the Fenton ^"s reaction by ferrous sulfate and peroxide.

19. A process for disposal of chemical munitions, as recited

claim 1. wherein said catalytic oxidation step further comprises the steps of:

(i) treating vent air. including bioreactor vent gas and vent air from reverse assembly and munitions storage in a monolith catahtic oxidizer at a temperature ranging from about 200┬░C to 600┬░C.

20. A system for disposal of chemical munitions, as recited

claim 1. wherein said clarification step further comprises the steps of: (i) treating the bioreactor effluent in a secondary clarifier or dissolved air flotation chamber to remove biological solids therefrom.

21. A process for disposal of chemical munitions, as recited by claim 1. wherein said water recovery step further comprises the step of:

(i) transferring said aqueous waste stream to a water evaporator operating at a temperature of 100┬░C.

22. A process for disposal of chemical munitions as recited by claim 1. wherein said water recovery step further comprises the steps of:

(i) transferring said aqueous waste stream to carbon adsorption, micro filtration and reverse osmosis membrane water recovery system.