Simultaneous Removal of SO₂ and NO from the Flue Gas of Marine Ships with a Gas Cyclone–Liquid Jet Absorption Separator

Abstract

SO2 and NO emitted from marine ships have seriously polluted the regional environment. However, there is a lack of high-efficiency, small-size, and cost-effective technology with which these pollutants could be purified. Here, a gas cyclone–liquid jet absorption separator (GLAS) combined with NaClO solution was developed to remove SO2 and NO simultaneously. The high-speed gas that rotates in the GLAS forms a high-gravity field and vortex flow, and SO2 and NO were removed efficiently in a small GLAS. The effect of key operating parameters was well studied through the experiment, and the total mass transfer coefficient (KGa) was calculated. It was found that the removal efficiency increased with the absorbent flow rate and concentration, while it decreased with the gas flow rate and the initial SO2 and NO concentrations. Under the experimental conditions, the maximum removal efficiency for SO2 and NO was 99% and 93%, and the maximum KGa was 0.0559 and 0.0357 kmol·m–3·kPa–1·s–1, respectively, which were 10 times higher than that of traditional devices. Semiempirical equations were also developed to predict the mass transfer performance of desulfurization and denitrification by GLAS. The study indicates that GLAS combined with NaClO solution has great potential applications for marine ships.