Role of various factors affecting the photochemical treatment of N-nitrosamines related to CO2 capture. Issue 11 (11th May 2020)

• Record Type: Journal Article
• Authors: Aqeel, Afzal; Lim, Ho-Jin
• Is Part Of: Environmental technology. Volume 41:Issue 11(2020)
• Page Start: 1391
• Page End: 1400
• Publication Date: 2020-05-11
• Subjects: N-nitrosamine -- photodegradation -- hydrogen peroxide -- ozone -- CO2 capture; Environmental engineering -- Periodicals; Environmental protection -- Periodicals; 628.05
• DOI: 10.1080/09593330.2018.1536172
• Languages: English
• ISSNs: 0959-3330

Abstract

ABSTRACT: Post-combustion CO2 capture using amine solvents is the most feasible method of reducing anthropogenic CO2 emissions, which are the largest contributor to global warming. The formation of carcinogenic N -nitrosamines (i.e. by-products) can hinder the industrial application of this technology. In this study, the effects of direct UV photolysis ( N -nitrosamine concentration and amines) and advanced oxidation processes (UV/H2 O2 and UV/O3 ) on the three specific N -nitrosamines that are commonplace in amine-based CO2 capture (i.e. N -nitrosodiethylamine (NDEA), N -nitrosodiethanolamine (NDELA), and N -nitrosomorpholine (NMOR)) were examined. A significant decrease in the photodegradation rate constants was observed for NDEA (1.02 × 10 0 to 2.94 × 10 −1 min −1 ), NDELA (1.52 × 10 0 to 3.32 × 10 −1 min −1 ), and NMOR (1.93 × 10 0 to 2.20 × 10 −1 min −1 ) as their concentrations increased within 1–50 mg/L. This is the first report of a significant increase in the degradation rate constants of N -nitrosamine with an increase in amine concentrations (i.e. monoethanolamine, diethanolamine, and morpholine) within 10–200 mM. The photodegradation rate constants increased as the molar ratio of H2 O2 to N -nitrosamine increased to 20, but then decreased at molar ratios beyond this. O3 had a negligible effect on the photodegradation of N -nitrosamines. GRAPHICAL ABSTRACT: