One of plasma gasification's key advantages is that, as well as producing a useful gaseous product, it does not produce either bottom or fly ash. The combustion of both waste and non gaseous fuels always results in the production of ash, and in some cases this can be as much as 30% of the input mass. Whilst some use can be made of bottom ash, as aggregate for building materials, fly ash always has to be disposed of to landfill. The disposal of ash can be a major cost for some operators. The obsidian like silicate produced in plasma gasification is non leachable and non toxic, and therefore has re-saleable value. It can be used as road fill, concrete aggregate, abrasive, and when re-cast, even used as construction tiles. Even if markets can not be initially found for the silicate, it can be safely stored without special facilities because of its properties. With plasma gasification, converted ash becomes a material with potential as an income source, rather than a material that can be a financial liability.

Molten silicate ready for casting

Metals are easily recovered from the plasma gasification process, due to the fact that they principally melt in the converter and sink to the bottom of the vessel. When they are poured of into a quench they can be collected and recovered to be sent to a metal recycling agent.

Sulphur recovered through Plasma Gasification

If a waste or fuel has a high sulphur content, it can be cost effective to consider sulphur recovery. Hydrogen sulphide in the plasma converted gas, formed from the decomposition of sulphur compounds in the waste or fuel, can be extracted from the gas. Concentrated hydrogen sulphide can then be converted to elemental sulphur using the well established Claus process.

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