NO emission characteristics of superfine pulverized coal combustion in the O2/CO2 atmosphere

• Published in: Energy conversion and management 2014-01, Vol.77, p.349-355
• Main Authors: Liu, Jiaxun, Gao, Shan, Jiang, Xiumin, Shen, Jun, Zhang, Hai
• Format: Article
• Language: English
• Subjects: Applied sciences; Atmospheres; Carbon dioxide; Coal; Combustion; Crude oil, natural gas and petroleum products; Energy; Exact sciences and technology; Fuel-N conversion; Fuels; Homogeneous and heterogeneous reduction; NO emission characteristics; O2/CO2 combustion; Particle size; Petroleum products, gas and fuels. Motor fuels, lubricants and asphalts; Porosity; Pulverized coal; Reduction; Superfine pulverized coal
• ISSN: 0196-8904; 1879-2227
• DOI: 10.1016/j.enconman.2013.09.048

•Superfine pulverized coal combustion in O2/CO2 atmosphere is a new promising technology.•NO emissions of superfine pulverized coal combustion in O2/CO2 mixture were focused.•Coal particle sizes have significant effects on NO emissions in O2/CO2 combustion. The combination of O2/CO2 combustion and superfine pulverized coal combustion technology can make full use of their respective merits, and solve certain inherent disadvantages of each technology. The technology of superfine pulverized coal combustion in the O2/CO2 atmosphere is easy and feasible to be retrofitted with few reconstructions on the existing devices. It will become a useful and promising method in the future. In this paper, a one-dimensional drop-tube furnace system was adopted to study the NO emission characteristics of superfine pulverized coal combustion in the O2/CO2 atmosphere. The effects of coal particle size, coal quality, furnace temperature, stoichiometric ratio, etc. were analyzed. It is important to note that coal particle sizes have significant influence on NO emissions in the O2/CO2 combustion. For the homogeneous NO reduction, smaller coal particles can inhibit the homogeneous NO formations under fuel-rich combustion conditions, while it becomes disadvantageous for fuel-lean combustion. However, under any conditions, heterogeneous reduction is always more significant for smaller coal particle sizes, which have smoother pore surfaces and simpler pore structures. The results from this fundamental research will provide technical support for better understanding and developing this new combustion process.