Theoretical Study on Sulfur Dioxide Absorption with Citrate Solution

The citrate absorption of SO2 is currently one of the most successful and economic methods to harness sulfur dioxide pollution.In order to theoretically elucidate the mechanism of SO2 absorption by citrate solution and provide theoretical instruction for experiments and industrial process, the theory of multi-buffer solution, combined with computer numerical calculation methods, was applied to study the distribution parameters of the components of the citrate solution in the process of SO2 absorption and the following results were obtained: (1) HCi2- and H2Ci- in the citrate solution played the dominant role in the absorption and desorption processes; (2) Through the calculation for the buffer capacity of citrate solution, it was found that the pH of the absorption and desorption solution should be in the range of 2～8, while at pH=4.5 the buffer capacity reached its maximum. Some valuable parameters were obtained, which are instructive to the ensuing experiments and industrial design.