Data obtained during previously (project WP-2614) demonstrated electrochemical degradation of both 1,3,5-hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and several of its breakdown products including 4-nitro-2,4-diazabutanal (NDAB), nitrite, and nitrate using several types of electrodes in divided and undivided electrochemical cell (EC) configurations. Efficient cathodic alkaline hydrolysis of nitrocellulose (NC), with concomitant degradation of resulting products, nitrite, nitrate, and organic carbon, was also demonstrated using a mixed metal oxide (MMO) electrode in the divided EC configuration.

The key objective of this project is to more-fully evaluate the electrochemical degradation of explosives and propellants. Specific attention will be given to i) determining degradation mechanisms and identifying final end products; ii) closing carbon and nitrogen mass balances; iii) examining degradation of mixtures of energetics, including degradation of solid phase energetics and propellants, and; iv) integrating the electrochemical processes with existing demilitarization efforts within the Department of Defense research community.  Initial assessment of scale-up and energy usage will also be performed.

The technical objectives of this project will be achieved through the following technical tasks:

• Task 1. Perform mechanistic studies.
• Task 2. Evaluate electrochemical treatment of  insensitive high explosives (IHE) and energetic mixtures.
• Task 3. Scale up the treatment of solid energetics.
• Task 4. Evaluate integration of NC treatment with existing demilitarization efforts.

This project will concentrate on legacy energetics, 1,3,5,7-tetranitro-1,3,5,7-tetrazocane; newer IHE including 2,4-dinitroanisole, 3-nitro1,2,4-triazol-5-one, and nitroguanidine; and propellants including NC.

The electrochemical technology that will be evaluated during this project will have the following key benefits:

• Allow efficient and cost-effective demilitarization of a range of energetic compounds (legacy and new insensitive high explosives, propellants) and associated breakdown products.
• Provide an added level of worker safety, as bulk chemicals (e.g., caustics) do not need to be stored or handled.
• Applicable as a scalable standalone process, or integrated with existing demilitarization procedures.
• Adaptable to allow reuse and/or recycling of final end products as value-added feedstocks (e.g., nitrogen source for algal biofuel production). (Anticipated Project Completion – 2025)