In principle, DSI can be used in combination with all existing FGT processes, including wet or all dry processes. Such combined processes usually have two main purposes:
Removing a “new” pollutant that cannot be handled by an existing FGT process, such as:
- Sorbacal® SPS injection for selective HF removal in a waste-to-energy plant, using sodium bicarbonate for SO2 and HCl control.
- Sorbacal® SP injection for HCl removal downstream from a coal or residue derived fuel fired CFB boiler using limestone for in situ SO2 removal.
- Sorbacal® SP injection upstream of a wet scrubber in a coal-fired power plant, for selective SO3 and/or HF removal to reduce air preheater fouling, corrosion and “blue plume” (sulfuric acid aerosol emission).
Increasing the removal performance of an existing FGT process, such as:
- Sorbacal® SPS injection at multiple locations in the process for optimized SO2 removal.
- Sorbacal® SPS injection in the boiler (FSI) in waste-to-energy plants, for additional SO2 control before the existing FGT installation (DSI/SDA).
- Sorbacal® SP injection before or after the SDA process for HCl and SO2 removal. This widely used combination is often called 3/4 dry or modified, conditioned dry sorption.
- Sorbacal® SP injected downstream for increased SO2 removal in a coal-fired CFB boiler using limestone for in situ SO2 removal.