Study on Coupling Effect of Additives on NOx Control in Coal Pyrolysis-Combustion Xianglu Kong, Song Yang, Shoujun Liu, Kaixia Zhang, Tingting Jiao and Ju Shangguan E3S Web Conf., 290 (2021) 03029 Published online: 14 July 2021 DOI: 10.1051/e3sconf/202129003029