Waste Processing Using a Packed Bed Electrolysis Reactor with Thermal Pretreatment at High Pressure

The recovery of resources for reuse from the processing of diverse waste materials produced by a crew in space-based closed life support systems is essential for the success of long duration space missions. Lynntech, Inc. is investigating and developing a waste processor that uses thermal solubilization and wet oxidation at elevated pressure and an electrochemical process for solid waste processing for closed life support systems. The electrochemical process uses a packed bed anode that oxidizes waste at temperatures <100°C and operates at atmospheric pressure. This approach offers an alternative to high temperature thermal processes for solid waste treatment. Incorporated into the packed bed reactor design is a method that shows potential for regenerating a liquid electrolyte enabling the electrochemical process to operate for long periods without having to be replaced. The paper describes scale-up of the packed bed reactor to a multicell stack, the testing of different electrode materials and the treatment of different waste materials. The solubilization and wet oxidation used to render waste materials to a soluble form before being processed in the electrochemical reactor is also described. A breadboard system will be delivered and installed in NASA-JSC's regenerative waste processing test bed facility in June 1995 for evaluation and comparison with other candidate technologies.