Simultaneous reduction of NOx emission and SOx emission aided by improved efficiency of a Once-Through Benson Type Coal Boiler

Abstract

With significant contributions in global emissions of air pollutants, sustainable practices for coal-fired power generation are fundamental to mitigate global climate change, besides ensuring compliance to the local authorities, which is as critical as climate issues. Despite the importance of these issues, some gaps exist in the literature to develop practices capable of fostering emissions reduction of NOx and SOx. In this sense, the present study aimed to present a comprehensive approach to NOx emission and SOx emission reduction through improved efficiency of a once-through Benson type coal boiler in a coal-fired power plant. In improving efficiency, NOx and SOx emissions were strongly influenced by O2 concentration, coal mass flow, air/fuel ratio and coal calorific value. The optimum conditions that resulted in simultaneous reduction of NOx and SOx emissions were achieved when the O2 concentration was 3.28 vol% with the coal mass flow of 281 tonnes/hr. The results further suggested that NOx concentration was reduced by a large margin when the air/fuel ratio changed from the lean side to the rich side. The findings of this study help to establish benchmarks relating to a comprehensive assessment of SOx and NOx emissions reduction.