4. Effects of co-firing

4.1 Combustion quality

Controlling the aerodynamics of the flame is essential for good combustion. Typically, a recirculation zone is created near the burner to maintain a high-temperature zone, with good mixing and sufficient residence time for the fuel. It is in this zone that volatile matter is emitted. If the moisture content of the biomass added is reasonable, as is its particle size, the range of combustion stability (flame retention) can be extended by increasing the volatile matter content. This has a positive effect on plant operation.

However, depending on the coal/biomass pair chosen and their respective proportions, burner behavior can vary greatly. A combination of lean coal (low volatile content) and biomass with a high volatile content is preferred,...