Nitrogen Oxide Reduction Method and Nitrogen Oxide Reduction System using Selective Non-Catalytic Reduction Method

• Main Authors: KIM SE HYEON, YUN SOO WON, LIM HO, KIM RYANG GYOON, LEE SE WON
• Format: Patent
• Language: English; Korean
• Published: 12.06.2023
• Subjects: PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; TRANSPORTING

The present invention relates to a method of reducing nitrogen oxides generated in an acid recovery process by an SNCR method by applying a reducing agent to waste acid which is subject to treatment in an acid recovery process before nitrogen oxides are generated, and to a nitrogen oxide reduction system used therein. In the method of reducing nitrogen oxide, an SNCR reducing agent is added to the waste acid, the SNCR reducing agent and the waste acid are input together into the acid recovery process, and the nitrogen oxides generated at the input time are reduced by the SNCR reducing agent added to the waste acid. In the nitrogen oxide reduction system, the SNCR reducing agent is added directly to a waste acid-containing separator (113) or a fluid supply line (L3') which supplies the waste acid to a roaster (215), such that the waste acid and the SNCR reducing agent are injected into the roasters (115, 215) together. Therefore, the SNCR reducing agent is effectively introduced while minimizing equipment changes to the conventional acid recovery process system. 본 발명은 질소산화물이 발생되기 전에 산회수 공정의 처리대상이 되는 폐산에 환원제를 적용하여 산회수 공정에서 발생하는 질소산화물을 SNCR법으로 저감하는 방법 및 이에 사용되는 질소산화물 저감 시스템에 관한 것이다. 질소 산화물 저감 방법은 폐산에 SNCR 환원제를 첨가하고 SNCR 환원제와 폐산이 함께 산회수 공정에 투입되고 이때 발생하는 질소산화물은 상기 폐산에 첨가된 SNCR 환원제에 의해 환원된다. 질소산화물 저감 시스템은 폐산 함유 세퍼레이터(113) 또는 로스터(215)에 폐산을 공급하는 유체 공급라인(L3')에 직접 SNCR 환원제가 첨가되어 로스터에(115, 215)에 폐산과 SNCR 환원제가 함께 투입되도록 구성된 것으로, 종래 산회수 공정 시스템의 설비 변경을 최소화하면서 SNCR 환원제가 효과적으로 투입되도록 구성된다.