An efficient and economic denitration technology based on fuel pretreatment for cement cleaner production

Abstract

Nitrogen oxide (NOx) emission from cement industry has caused severe atmospheric pollution for low denitration efficiency of existing denitration technologies. To tackle down this problem, an innovative NOx reduction method exhibiting a higher denitration efficiency was developed in this study to satisfy the requirement of cleaner production. Besides, its specific mechanism was clarified in a bench scale experimental setup while its commercial viability was verified in a demonstration project. In accordance with the method, the pulverized coal was first pretreated in a specially designed pretreater where partial fuel nitrogen was in-situ reduced to N2. Subsequently, products of pretreatment that exhibited higher chemical activity were injected to the precalciner to further reduce formed NOx in the kiln gas. As revealed from the results, the denitration efficiency of the novel method can reach to 60%∼80%. Besides, it is promising in industrial application for the easy on-site implementation, high denitration efficiency and incomparable cost advantage. Under the premise of NOx that dropped largely, the costs of initial investment and operation were overly small. It is therefore revealed that the proposed approach outperforms many of the existing denitration technologies in technological and environmental indicators, as well as from the economical perspective.