2. The carbon combustion efficiency changes mainly with
moisture and ash contents in wastes, with extra air
ratio, secondary air ratio, and the secondary air injection
height. The highest carbon combustion efficiency
was found at around 30% of excess air (25% for sawdust),
20% of secondary air (30% for poultry manure)
and 0.85 m (0.65 m for poultry manure) above the distributor
plate for the secondary air injection