Among many processes under consideration for flue-gas desulfurization, wet scrubbers that use lime, limestone, or other carbonate materials as the reactant appear to be the most advanced. The quantity of lime, limestone, or other carbonate material required for flue-gas desulfurization for a particular plant would depend on sulfur content and the amount of fuel burned, the type of scrubber system used, and, most important, the level of sulfur oxide emissions permitted for the area.