Method for processing a gas and a device for performing the method

摘要

A method and device for processing a gas by forming a non-thermal microwave plasma of the gas. The gas that is to be processed is caused two follow a two or three co-axial vortex flow 202, 203, 204 inside the device 200 and is exposed to a standing wave microwave field from a microwave chamber 207 to form the plasma 209 in the inner co­axial vortex flow204. This is subsequently expelled as a plasma afterglow 205 through an outlet/exit channel of the device. The device is provided with a microwave field choking effect by the exit channel having a diameter, D, larger than zero but smaller than 1/16 of the wavelength of the standing wave microwave and a length, E, being larger than zero but smaller than (n+1/8), of the wavelength of the standing wave microwave, wherein n = {0, 1, 2, 3}.