How “Green” are microwave drying systems?
Very few drying technologies can approach microwave systems for positive environmental impact. In fact, in most cases environmental permitting is not required. Let’s consider the common types of possible emissions and examine how microwave system measure up.
Combustion Products such as NOx and COx: This is simple. There is no combustion in a microwave system so there are no combustion products.
Particulates: Most microwave dryers carry material peacefully through the oven on a conveyor belt. There is no agitation, blowing, circulation, or any other movement of the material, so there are virtually no particulates.
Volatile Organic Compounds (VOCs): This depends on the material being processed. If it does not contain VOCs, there is obviously no problem. If there is some quantity of VOCs, the drying temperature is almost always below their boiling point, so they are not evaporated. Most of the time microwave dryers are also odor-free.
So what comes out of the exhaust? Almost 100% water vapor. If you really want to ultra-Green, just set up a wind turbine out back and you will have a zero CO2 impact processing system.