Reversible absorption of SO2 from simulated flue gas by aqueous calcium lactate solution

The capture of SO 2 by recyclable absorbents has drawn much attention all over the world. In this work, it was found that aqueous calcium lactate (CaL 2 ) solution can be used as a recyclable absorbent for the capture of SO 2 . The solution shows high SO 2 absorption capacities up to 24.8 g SO 2 /kg absorbent at 40 °C. The effects of temperature, excessive lactic acid and CaL 2 concentration on the absorption of SO 2 , the desorption of SO 2 , and the reuse of aqueous CaL 2 solution were systemically studied. Furthermore, the difference between CaL 2 method and traditional calcium method was discussed. Compared with traditional calcium method, there are some advantages, such as regeneration of absorbent, recovery of SO 2 and reduction of CaSO 4 . This work suggests that aqueous CaL 2 solution, which can be obtained at quite low cost, is a promising recyclable absorbent in the process of desulfurization of flue gas.