Simplified method for calculating SNCR system efficiency

Abstract

Abstract. SNCR (Selective Non-Catalytic Reduction) technology is aimed at reducing NOx emissions. SNCR efficiency is appropriately high only for the reaction temperature range called 'the SNCR temperature window'. It is a narrow temperature range defined in various ways in the literature, which makes it difficult to evaluate the DeNOx system's efficiency. Therefore, this study attempts to approximate the relationship between SNCR system efficiency and the flue gas temperature. The approximation was performed on the basis of literature data and verified using data from an experiment. Measurements were performed in a Polish boiler with a maximum continuous rating of 230 t/h. The verified, evaluated function could be used to forecast efficiency of SNCR systems in existing units that use urea or ammonia as a reagent. The approximation results are polynomial functions that depend on flue gas temperature, which fit the literature data with the coefficient of determination R 2 = 0.83-0.86. Therefore, these equations could be used by the designer or operator of the boiler for preliminary determination of current SNCR system efficiency.

Measurement of the NOx reduction effect on food wastewater during waste incineration

“…The operating temperature ranges from 870°C to 1000°C for the NH 3 reducing agent and from 900°C to 1050°C for the urea reducing agent; in general, the optimal temperature is 950°C‒1000°C. When urea is used as the reducing agent instead of NH 3 , the temperature range is higher by approximately 50°C (Pronobis et al, 2017). Additives such as hydrocarbons, alcohols, H 2 and CO are used when the flue gas temperature is lower than the temperature range (Caton and Siebers, 1990; Wenli et al, 1990).…”