I’m thinking of “bombardement” and the “double-alkali method” for wet flue gas desulfurization

The double-alkali method has the following advantages: (1) NaOH is used for desulfurization, and the circulating water is essentially an aqueous solution of NaOH; thus, there is no corrosion or clogging of pumps, pipes, or equipment during circulation, which facilitates the operation and maintenance of such equipment； (2) The regeneration of the absorbent and the precipitation of desulfurization slag occur outside the tower, which prevents blockages and wear inside the tower, improves operational reliability, and reduces operating costs ； At the same time, efficient plate towers or packed towers can be used in place of empty towers, making the system more compact and improving the desulfurization efficiency ； (3) Sodium-based absorption solutions can absorb SO2 rapidly; therefore, a lower liquid-to-gas ratio can be used to achieve a high desulfurization efficiency, generally above 90% ； (4) For the integrated desulfurization and dust removal technology, it can improve the utilization rate of lime. The disadvantage is that Na2SO4, the by-product of the oxidation reaction using NaSO3, is difficult to regenerate, requiring continuous addition of NaOH or Na2CO3 and thus increasing alkali consumption. Furthermore, the presence of Na2SO4 will also reduce the quality of gypsum.