Guide for the SNCR and other deNOx measures in biomass facilities

Abstract

The paper addresses a potential problem related to biomass combustion, which is the increased emission of nitrogen oxides, especially pronounced with the usage of agricultural biomass. The paper presents: mechanisms of NOx formation and conversion of nitrogen from fuel during combustion, a brief overview of available methods for denitrification, both conventional and newer ones that have not yet come to industrial-scale application. The aim is to give an objective comparison of the available measures that correspond to the temperature range of biomass combustion. NOx emissions from biomass combustion are mainly caused by fuel-bound nitrogen, therefore the focus is on selective non-catalytic reduction, SNCR, as a secondary measure of denitrification. Main pathways of SNCR chemical reduction reactions for different reagents and reaction kinetics are given. Also, a comparison of SNCR with primary measures and other secondary measures is given, with the main advantages and disadvantages for each one of them.