Fecha de publicación: 13/07/2021 Fuente: WIPO Food Portada The present invention relates to an apparatus for reducing nitrogen oxides in a cement kiln, and more specifically, to an apparatus and a method for reducing nitrogen oxides in a cement kiln using acid-fermented food wastewater and methane-fermented wastewater. The apparatus for reducing nitrogen oxides in a cement kiln comprises: a food wastewater supply tank (10) for collecting and supplying food wastewater generated from a feed production facility using food waste and a composting facility using food waste and having minimal solids while passing through a pretreatment process; a food wastewater acid-fermentation tank (20) for acid-fermenting food wastewater supplied from the food wastewater supply tank (10); an acid-fermented food wastewater storage tank (40) for storing acid-fermented food wastewater fermented in the food wastewater acid-fermentation tank (20); and a spray device capable of spraying a reducing agent, in which the acid-fermented food wastewater supplied from the acid-fermented food wastewater storage tank (40), urea water, and compressed air are mixed, to a section of a cement raw material input duct (80) of a cement kiln (87), wherein one or a plurality of spray devices (50) are installed on the cement raw material input duct (80). The apparatus and the method for reducing nitrogen oxides in a cement kiln using acid-fermented food wastewater and methane-fermented wastewater are configured to: collect food wastewater with minimal solids; acid-ferment the collected food wastewater; and introduce the acid-fermented food wastewater with the maximized ammonium concentration as a reducing agent for a selective non-catalytic reduction (SNCR) process designed to remove nitrogen oxides moving through the raw material input duct of the cement kiln so as to reduce the amount of urea water used in a conventional case and improve the efficiency of removing nitrogen oxides. Accordingly, discarded food wastewater is recycled so as to prevent environmental pollution and to be used as an auxiliary agent for urea water. COPYRIGHT KIPO 2022