Effect of Oxidants in the Utilization of Polysulfone Hollow Fiber Membrane Module as Bubble Reactor for Simultaneously Removal of NOx and SO2

Abstract

Air pollution has become a global issue and contributes significantly to climate change, mainly due to the massive energy consumption in industry and the transportation sector. Emissions of harmful gases from burning fuels such as NOx and SO2 are the most significant sources of environmental pollution, which have negative impacts on the environment, such as the greenhouse effect, damage to the ozone layer, photochemical smog, and acid rain, and can interfere with the respiratory system in humans. This study utilizes hollow fiber membrane modules, which act as a reactor on the shell side of the membrane module and a gas distributor by the membrane fiber to remove NOx and SO2 spontaneously. The oxidant solutions used were a pair of hydrogen peroxide and sodium hydroxide (H2O2-NaOH) solutions, a pair of sodium chlorite and sodium hydroxide (NaClO2-NaOH) solutions, and a pair of sodium chlorate and sodium hydroxide (NaClO3-NaOH) solutions. Based on the results of experiments, SO2 can be removed entirely in the process, while NOx depends on the feed gas flow rate and the concentration of the oxidant solution used. H2O2 is the most effective oxidizing agent in removing NOx and SO2 because of its higher oxidative properties than NaCLO2 and NaClO3. The increase in feed gas flow rate resulted in a decrease in the efficiency of NOx removal even though the NOx mass transfer flux and NOx loading increased. Meanwhile, an increase in the concentration of oxidants increases the efficiency of NOx removal and mass transfer flux but decreases NOx loading. Based on the experimental results, the maximum NOx removal efficiency achieved by the oxidant solutions is 93.9, 91.1, and 88.3% for H2O2-NaOH, NaClO2-NaOH, and NaClO3-NaOH, respectively.

Keywords

• climate change
• harmful gases
• nox
• removal efficiency
• so2