Zhang Yingyi, Ge Xinlei, Liu Lili, Wang Xidong, Zhang Zuotai
Beijing Key Laboratory for Solid Waste Utilization and Management and Department of Energy and Resource Engineering, College of Engineering, Peking University, Beijing, 100871, People's Republic of China.
Environ Sci Pollut Res Int. 2015 May;22(9):7139-46. doi: 10.1007/s11356-014-3890-8. Epub 2014 Dec 13.
The pollution emission during the widespread utilization of coal gangue in construction industry has long been neglected. In present study, the NO x release behaviors in a simulation experiment of coal gangue calcination in construction industry were systematically investigated. The corresponding evolution of nitrogen functionalities in coal gangue was also discussed. Results showed that pyrrolic (N-5) and pyridine N-oxide (N-6-O) forms nitrogen were relatively abundant in the raw gangue. During calcination, the N-5 and N-6-O form nitrogen greatly decreased and converted to quaternary nitrogen (N-Q). It was found that NO2 was formed under slowly heating-up condition and at 600 °C under isothermal condition, while only NO was detected with further increase of temperature. From 600 to 1000 °C, the conversion ratio of fuel nitrogen to NO x increased from 8 to 12 %. The char nitrogen was found greatly contribute to NO formation, which may bring difficulty to the abatement of NO x emission during coal gangue calcination.
煤矸石在建筑行业广泛利用过程中的污染排放长期以来一直被忽视。在本研究中，系统地研究了建筑行业煤矸石煅烧模拟实验中NOx的释放行为。还讨论了煤矸石中氮官能团的相应演变。结果表明，原生煤矸石中吡咯型（N-5）和吡啶-N-氧化物型（N-6-O）氮相对丰富。煅烧过程中，N-5和N-6-O型氮大幅减少并转化为季氮（N-Q）。研究发现，在缓慢升温条件下以及在600℃等温条件下会形成NO2，而随着温度进一步升高仅检测到NO。在600至1000℃范围内，燃料氮向NOx的转化率从8%提高到12%。发现焦炭氮对NO的形成有很大贡献，这可能给煤矸石煅烧过程中NOx排放的减排带来困难。
