In regenerable processes, the sorbent is regenerated chemically or thermally and re-used. Elemental sulphur or sulphuric acid is recovered from the SO2 removed. The revenue from these by-products can compensate partially for the higher capital costs required in such FGD systems. Regenerable processes generally require no waste disposal, produce little waste water and have low sorbent make-up requirements. However, in most such systems, a prescrubber is essential to control chlorides. Although these processes can achieve high SO2 removal efficiencies (>95%) they have in general high capital costs and power consumption.
Click on the relevant text below for other FGD technologies: