The Process

The BOS process starts with untreated waste being bulk-loaded into the primary gasification chamber (PGC) through a hydraulically operated door at the top of the chamber. This occurs once per day.

Slow gasification occurs in the PGC at relatively low temperatures of 450-550°C (800-1000°F), converting the waste into gas and ash. This process is initiated by an ignition burner, situated towards the top of the chamber. Once the gasification process has commenced, this burner is turned off and the thermal process continues, controlled by the input of a small amount of air (just enough to maintain the process) from the base of the chamber.

The hot gases then pass into the secondary chamber where they are actively mixed with oxygen (taken from the ambient air) and oxidation occurs at much higher temperatures of 850 - 1200°C (1600-2200°F). This temperature ensures that the gases are totally combusted. The gases in general can support this process, however a secondary burner ensures that minimum temperatures are maintained.

The process design is simple yet clever, allowing for a robust and effective system which is easy to operate and maintain, and at the same time highly efficient in terms of energy recovery and environmental standards.