Experiments of flue gas desulfurization were carried out using electrostatic spray. The organic acid solutions dissolving CaCO3 were used to prepare the highly reactive absorbent for desulfurization. The micro-properties of dried spent absorbents were characterized using a Raman microscope. Phosphoric acid, malonic acid, citric acid, formic acid, acetic acid and propionic acid having the different acidity degrees were selected. The phosphoric acid was easily combined with the calcium in solution and produced the insolvable solids. The solution containing Ca of malonic and citric acids considerably enhanced the SO2 absorption efficiencies because of the effect of buffered solution which consists of a mixture of a weak acid and its calcium compounds. The dissolved Ca in solution of acetic, formic and propionic acids reacted with SO2 to form CaSO4･2H2O as desulfurization product. Effects of organic acids on the desulfurization mechanism were strongly dependent on the acidities degrees of organic acids
