A hybrid catalytic membrane reactor for destruction of a chemical warfare simulant

• A hybrid system is developed that combines the FTCMR with a SFMS.
• It results in the continuous destruction of CWA for extended time periods.
• The hybrid system shows superior performance to that of a sole FTCMR.

The possibility of use of chemical weapons has increased in recent years, both as a result of potential terrorist attacks as well as of ongoing international conflicts. The successful application of a flow-through catalytic membrane reactor (FTCMR) as an individual protection system for the destruction of dimethyl methylphosphonate (DMMP), which is known as a chemical precursor (and used to simulate its characteristics) for Sarin (GB), a toxic chemical warfare agent (CWA) was previously investigated and reported by this group. As part of the study, the effect of the DMMP concentration in the feed on its complete combustion in the FTCMR was investigated. The studies indicate that the protection (complete conversion) time is a function of the DMMP concentration, with longer times observed for the lower concentrations, and shorter protection times associated with the higher concentrations. In this study a novel hybrid system is being developed that combines the FTCMR with a surface-flow membrane system (SFMS). Preliminary experimental results presented here manifest the main advantage of this hybrid system, combining the SFMS, capable of the physical removal of a large fraction of the CWA from contaminated air streams, and the FTCMR which completely oxidizes the remaining amount, which is the continuous CWA destruction for extended time periods which are appropriate for both individual and collective protection applications. The study investigates the impact on performance of the membrane characteristics, the transmembrane pressure gradient and the sweep ratio. Hybrid system performance is also compared with that of a sole FTCMR showing the superiority of the hybrid system in terms of offering higher destruction rates for DMMP and prolonged protection times.