A new multi-component marine exhaust cleaning method using combined hydrodynamic cavitation and chlorine dioxide

Abstract

Simultaneous desulfurization and denitration of ship exhaust is a challenging problem. To solve the problem, we proposed a novel non-circulation cleaning method for removing nitrogen oxides (NOx) and sulfur dioxide (SO2) using combined hydrodynamic cavitation and chlorine dioxide (ClO2). The SO2 and NO removal mechanism was studied. Experiments were carried out to determine the efficiency of combined hydrodynamic cavitation and ClO2 for exhaust desulfurization and simultaneous desulfurization and denitration. The results showed that hydrodynamic cavitation could effectively desulfurize. The simultaneous desulfurization and denitration performance of combined hydrodynamic cavitation and ClO2 process was significantly better than that of hydrodynamic cavitation alone. The study found that the presence of SO2 would promote denitration and also competed with NOx for ClO2. The effects of pressure difference (ΔP) before and after the hydrodynamic cavitation reactor, NO gas flow rate (QNO), 600 mg/L ClO2 feeding rate (ηClO2), and NO initial concentration (CNOinitial) on the denitration efficiency were further studied. The results revealed that around 95.0 % of NOx removal efficiency was reached. This study could provide important theoretical support for the industrial application of this technology.