Undercovering the role of physicochemical properties of amides in two-phase absorbent systems for ship exhaust pollutant removals

Abstract

The use of two-phase absorbents containing amides to treat ship pollutants is a new research solution that can achieve high NO oxidation rates and NO2 absorption rates. This paper studies the physicochemical properties of five different amides and their relationship with the desulfurization and denitrification processes. It was found that nitrous acid molecules undergo an isomerization rearrangement in the amide and combine in a more stable form during the NOx absorption process. The polarity and viscosity of the amide are more critical than the min ESP value in removing pollutants. The high polarity and low viscosity of DBA (N,N-Dibutylacetamide) provide dual advantages, facilitating the interaction between the organic and aqueous phases, as well as enhancing the mass transfer process and the combination of an inorganic acid. The system containing DBA achieved removal efficiencies of 99.6% for SO2, 86.33% for NO, and 86.3% for NOx in 10 min. Overall, this study provides valuable insights into the use of organic-containing two-phase absorbents to reducing ship exhaust pollution.