Waste is fed into the top of the gasifier while oxygen and steam are injected into the bottom. The injection of oxygen and steam is one of Sierra Energy’s patented innovations.
The waste descends, by gravity, inside the gasifier passing through four reaction zones:
Drying occurs when the hot syngas produced at the bottom of the gasifier rises and passes through the waste in the top zone of the unit, drying the waste as it passes.
Devolatization is where the majority of the organic matter is driven off into syngas.
Partial oxidation occurs when carbon-containing materials in the waste react with the injectors. This reaction creates high temperatures in the range of 4,000°F allowing for the thorough conversion of remaining carbon into syngas.
Melting of inorganic compounds results from the high temperatures occuring in the partial oxidation zone. These compounds collect at the bottom of the unit and are continuously removed as inert stone (slag) and recycled metals.
The simple design of our FastOx gasifier enables all of these steps to occur in a single unit, giving us an advantage over other conversion technologies that require complex systems and units to accomplish each of these steps.
http://www.sierraenergycorp.com/innovation/technology-overview/