title: Experimental investigation on NOx emission characteristics of a new solid fuel made from sewage sludge mixed with coal in combustion.
abstract: In this article, a new briquette fuel (SC), which was produced by the mixture of coal fines (25.9%), sewage sludge (60.6%), lignin (4.5%), tannic acid (4.5%) and elemental silicon (4.5%), was provided. Then, in a high temperature electric resistance tubular furnace, the total emissions of NO2 and NO, effects of combustion temperature, air flow rate and heating rate on NOx (NO, NO2) emissions of SC were studied during the combustion of SC; furthermore, effects of additives on hardness were also analysed, and the X-ray photoelectron spectroscopy was applied to investigate the reduced NOx emission mechanism. The research results showed that, compared with the characteristics of briquette fuel (SC0) produced only by the mixture of coal and sewage sludge (the ratio of coal to sewage sludge was the same as that of SC), the Meyer hardness of SC was 12.6% higher than that of SC0 and the emissions of NOx were 27.83% less than that of SC0 under the same combustion conditions. The NOx emissions of SC decreased with the adding of heating rate and increased with the rise of air flow rate. When the temperature was below 1000 °C, the emissions of NOx increased with the elevated temperature, however, further temperature extension will result in a decreasing in emissions of NOx. Furthermore, the X-ray photoelectron spectroscopy results proposed that the possible mechanism for the reduction of NOx emissions was nitrogen and silicon in SC to form the compounds of silicon and nitrogen at high temperatures.
authors: College of Environmental Science and Engineering, Hunan University, Changsha, People's Republic of China Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, People's Republic of China ybzhai@hnu.edu.cn ybzhai@163.com.
authors: Yunbo
authors: Y
authors: Zhai
authors: College of Environmental Science and Engineering, Hunan University, Changsha, People's Republic of China Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, People's Republic of China.
authors: Lu
authors: L
authors: Zhu
authors: College of Environmental Science and Engineering, Hunan University, Changsha, People's Republic of China Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, People's Republic of China.
authors: Hongmei
authors: H
authors: Chen
authors: College of Environmental Science and Engineering, Hunan University, Changsha, People's Republic of China Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, People's Republic of China.
authors: Bibo
authors: B
authors: Xu
authors: College of Environmental Science and Engineering, Hunan University, Changsha, People's Republic of China Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, People's Republic of China.
authors: Caiting
authors: C
authors: Li
authors: College of Environmental Science and Engineering, Hunan University, Changsha, People's Republic of China Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, People's Republic of China.
authors: Guangming
authors: G
authors: Zeng
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D056804:Biofuels / Q000032:analysis*; D003031:Coal; D019245:Compressive Strength; D008031:Lignin / Q000737:chemistry; D009589:Nitrogen Oxides / Q000032:analysis*; D056951:Photoelectron Spectroscopy; D012722:Sewage / Q000737:chemistry; D012825:Silicon / Q000737:chemistry; D013634:Tannins / Q000737:chemistry; D018505:Waste Management / Q000379:methods*
chemical_list: D000393:Air Pollutants; D056804:Biofuels; D003031:Coal; D009589:Nitrogen Oxides; D012722:Sewage; D013634:Tannins; D008031:Lignin; D012825:Silicon
keywords: Meyer hardness; NOx emission; Solid fuel; X-ray photoelectron spectroscopy (XPS); coal; sewage sludge