소형 석탄-암모니아 혼소시스템에서의 NOx 발생 및 slip 암모니아 처리기술에 관한 실험적 연구
Experimental Study on NOx Generation and Slip NH3 Treatment in a Small Scale Coal-ammonia Co-firing System
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Ammonia, along with hydrogen, is a representative CO2 free energy and co-firing of coal and ammonia is a direct means of suppressing greenhouse gas emissions. As an energy source, excessive generation of NOx, including NO, and the risk of air emissions of ammonia slip are important issues in the use of ammonia fuel. By analyzing the nitrogen oxide emission characteristics from a 5 kW lab. scale co-firing furnaces and deriving a stable treatment function for slip ammonia, we aim to provide basic data necessary for practical design. For this purpose, the NOx generation was checked according to various experimental factors such as ammonia co-firing ratio, air flowrate, ammonia injection point and oxidizer supply technique. There is no doubt that the increase of ammonia co-firing ratio is a factor in the increase of NO emission. However, NO can be stably controlled by combustion engineering methods such as air ratio, multi-stage supply of fuel and oxidizer. And separate supply of ammonia can suppress the generation of NO by inducing effects such as heat load reduction and high-temperature air combustion. Ammonia slip cannot occur in normal operation, but rather slip may occur due to the SCR reductant. In preparation for unexpected ammonia leakage, the installation of an ammonia oxidation catalyst was reviewed.
Abstract
Ammonia, along with hydrogen, is a representative CO2 free energy and co-firing of coal and ammonia is a direct means of suppressing greenhouse gas emissions. As an energy source, excessive generation of NOx, including NO, and the risk of air emissions of ammonia slip are important issues in the use of ammonia fuel. By analyzing the nitrogen oxide emission characteristics from a 5 kW lab. scale co-firing furnaces and deriving a stable treatment function for slip ammonia, we aim to provide basic data necessary for practical design. For this purpose, the NOx generation was checked according to various experimental factors such as ammonia co-firing ratio, air flowrate, ammonia injection point and oxidizer supply technique. There is no doubt that the increase of ammonia co-firing ratio is a factor in the increase of NO emission. However, NO can be stably controlled by combustion engineering methods such as air ratio, multi-stage supply of fuel and oxidizer. And separate supply of ammonia can suppress the generation of NO by inducing effects such as heat load reduction and high-temperature air combustion. Ammonia slip cannot occur in normal operation, but rather slip may occur due to the SCR reductant. In preparation for unexpected ammonia leakage, the installation of an ammonia oxidation catalyst was reviewed.
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