Thermal oxidisers, using concentrated sunlight

A VOC treatment apparatus for treating substantially opaque VOCs comprising:

• a processing chamber in which VOCs are treated;
• a solar introducer having a tubular structure having, the tubular structure having a first end located externally of said processing chamber and having a first inlet configured to receive concentrated sunlight therethrough and a second inlet configured to receive a flow of substantially optically transmittant gas said tubular structure further having a second end that opens into said processing chamber and terminating in a nozzle, said nozzle providing an outlet for said substantially optically transmittant gas and said concentrated sunlight, said nozzle configured to create a jet of said optically transmittant gas to form an optically transmittant zone in the substantially opaque VOC's within the processing chamber, in which zone said sunlight can travel:
• and
• a controller configured to control the velocity of said substantially optically transmittant gas as it exits said nozzle so as to vary the depth of the optically transmittant zone within the VOC's and therefore the penetration of the concentrated sunlight, into the VOCs.