Amine reclaimer wastes (ARW) generated in CO2 capture processes demand suitable disposal means.
Such wastes contain remaining amine, NH3 and other degradation compounds. This study investigated
the potential of using ARW as a NOx reducing agent, under laboratory conditions in a flow reactor. A
simulated flue gas containing about 500 ppm of NO and 5% O2 was injected with liquid ARW under
different stoichiometric ratios (TN/NO – total N to nitric oxide ratio) and temperatures. The ARW was
obtained from a distillation monoethanolamine reclaimer in an industrial CO2 capture facility with a coal
fired boiler. The results indicate that ARW has a significant NOx reduction potential when injected with
TN/NO ratios in excess of 1. The optimum temperature is close to 950 ◦C, where 40% reduction in NOx is
recorded with a TN/NO ratio of 1.6. Increasing TN/NO to 8.5 resulted in a 96% reduction. At low TN/NO
ratios (<1.6), the NOx reduction potential of ARW is comparable to that of monoethanolamine, but lower
than that of NH3. Nevertheless, the fact that ARW is a waste product, together with its demonstrated NOx
reduction capability and its calorific value contribution, makes it attractive as an additive to combustion
processes, including cement industry kilns.
Bibliographical noteAbbreviations: ARW, amine reclaimer wastes; CCS, CO2 capture and sequestration, carbon capture and storage; EU, European union; HEEDA, N-(2-hydroxyethyl)-ethylenediamine; HEIA, 1-(2-hydroxyethyl)-2-imidazolidone; HSS,
heat stable salts; LHV, lower heating value; MEA, monoethanolamine; NTP, normal temperature and pressure; PCDD/F, polychlorinated dibenzo–p-dioxins and dibenzofurans; PTFE, polytetrafluoroethylene; SCR, selective catalytic reduction; SNCR, selective non-catalytic reduction; TN, total nitrogen; UV-RAS, ultra-violet resonant absorption spectroscopy.
- Amine reclaimer waste
- CO2 capture
- NOx reduction