摘要
In the current era of renewable energy prominence,the wide operational capacity of coal-fired boilers has emerged as crucial for ensuring the sustainability of power plants.However,attaining ultra-low nitrogen oxides(NO_x)emissions during periods of low-load operations presents a significant and persistent challenge for coal power enterprises.While techniques such as biomass re-burning and advanced re-burning have shown promise in enhancing NO reduction effciency above 800℃,their elevated levels of chlorine(Cl)and alkali metals pose potential risks to boiler equipment integrity.Therefore,this study proposes the utilization of biomass char derived from pyrolysis as a dual-purpose solution to enhance NO reduction efficiency while safeguarding boiler integrity during low-load operations.Findings indicate that pyrolysis treatment effectively reduces the Cl and alkali metal content of biomass.Specifically,it was determined that biomass char produced through deeply pyrolysis at 300℃achieves the highest NO reduction efficiency while minimizing the presence of harmful components.At a reduction temperature of 700℃,both re-burning and advanced re-burning techniques exhibit NO reduction efficiencies of 55.90%and 62.22%,which is already an ideal deficiency at low temperatures.The addition of water vapor at 700-800℃obviously avoids the oxidation of ammonia to NO in advanced reburning.Upon further analysis,denitrification efficiency in biomass char re-burning and advanced reburning is influenced not only by volatile content but also by physicochemical properties such as porosity and surface functional group distribution under certain reaction conditions.This study provides a theoretical framework for the industrial implementation of biomass char for NO control in coal-fired power plants,offering insights into optimizing NO reduction efficiency while mitigating potential risks to boiler equipment.
基金
supported by the Open Topics of State Key Laboratory of Clean and Efficient Coal-Fired Power Generation and Pollution Control(D2022FK103)
National Natural Science Foundation of China(22278250)
the Shanxi Province Science and Technology Cooperation and Exchange Special Program(202104041101014)
the Shanxi Province Scholarship Council。
