Selective Non-Catalytic Reduction (SNCR) Technology for NOx Removal – the Past, the Present, and the Future

SNCR is a NO_x abatement technology which is considerably less expensive than SCR, though its NO_x removal efficiency is lower than that of SCR. This paper surveyed the SNCR technology in the past 20 years, including the advancement of SNCR technology in recent years. The limitations include low efficiency (25-60%), N₂O emission concern, and not applicable to large system above 200 MW. The performance improvement solutions and some suggestions for future development are provided, such as device for better gas and temperature distribution [1], new reducing agents [2], and using surfactant additives [3], etc.

References

[1] Maoqi Feng, Rijing Zhan, Jeff Harris, Selective Non-Catalytic Reduction For NOx Removal, 8,815,193 (2014).

[2] Maoqi Feng, Rijing Zhan, Ketone/water mixtures for nox removal, US 8,535,627 (2013).

[3] Muhammad Ayou, Muhammad Faisal Irfan, Kyung-Seun Yoo, Surfactants as additives for NOx reduction during SNCR process with urea solution as reducing agent, Energy Conversion and Management, 2011, 52(10), 3083–3088.