Oxidation of volatile organic compounds by microwave plasma at atmospheric pressure

Summary form only given. The theory of microwave excited, non-thermal plasma destruction of VOCs at atmospheric pressure is described in US Navy Patents 5,468,356 and 5,478,532. Advantages of the microwave approach as compared to DC or AC corona discharge, AC barrier dielectric discharge, and DC glow pulsed discharge have been discussed [1]. Destruction efficiency of 96% for toluene (C/sub 7/H/sub 8/) in air was obtained by the Navy using a TM/sub 010/ cavity. Power was 6 kW with 600 W coupled to the plasma. Aneptek Corporation, under a license with the US Navy, has continued this research. Improvements have been made in the cavity are stability, Q, and coupling iris. Stable operation of the plasma has been achieved at atmospheric pressure at a power of 1 kW and improved coupling of about 70%. Measured flow rates are up to 10 liter/minute with an upper limit not yet established. Tests on the destruction of isobutylene (C/sub 4/H/sub 8/) are in progress. Oxidation via the metastable oxygen molecule results in the production of CO/sub 2/ and water.