Plasma Gasification VS Incineration
Updated: Apr 12, 2018
There is a perception in some quarters that plasma gasification is essentially incineration, since in both incineration and plasma gasification, wastes are reduced to much smaller volumes. But whereas incineration is focused on reduction of waste to ash, gasification involves conversion of waste to synthesis gas and inert slag with recovery of energy and valuable metals.
In its purest form, incineration involves burning of organics in the presence of excess oxygen, converting them to heat, particulates, and a variety of combustion gases, with all these vented to the atmosphere. Modern incinerators seek to achieve complete combustion employing temperatures in the 600 to 1,200ºC range, to capture heat generated, and to manage emissions through pollution controls. Ash is landfilled, with the content of ash requiring pretreatment as hazardous waste.
Fundamentally different than incineration, are several thermal conversion (sometimes referred to as thermal-chemical conversion) technologies. All these processes employ elevated temperatures in combination with little or no oxygen to decompose wastes. The lack of oxygen in waste decomposition prohibits combustion and clearly separates these technologies from incineration.
One form of thermal decomposition is plasma gasification. Plasma gasification employs extreme temperatures (3,000-5,000ºC) in the absence or near-absence of oxygen, with organics and other materials dissociated into constituent chemical elements that are then either collected (in the case of valuable metals), vitrified to produce an inert glass-like slag, or reformed into synthesis gas that can be used as an industrial feed-stock or converted to energy. Burning does not occur in a plasma gasification unit, and so as with other thermal conversion processes, gasification is completely different than incineration.