热解半焦与褐煤掺烧及气体污染物排放特性TG-FTIR研究

Study on co-combustion and gaseous pollutants emission characteristics of pyrolysis semi-coke and lignite by TG-FTIR

采用热重-傅里叶红外(TG-FTIR)联用技术对较高升温速率(100~250℃/min)下热解半焦与褐煤的掺烧特性和气体污染物排放特性进行了研究。结果表明,加入褐煤可有效降低混合燃料的着火温度,缩短燃尽时间。随褐煤掺烧比例的增加,混合燃料的着火指数、燃尽指数和综合燃烧特性指数均显著增大。提高热重试验升温速率会增大混合燃料的着火温度和最大失重速率温度,但同时也会加快燃烧速率,提高综合燃烧特性。掺烧过程中气体污染物的排放温度区间与其主要的热失重阶段基本对应。随褐煤掺烧比例的增加,CO2排放量逐渐降低,NO和NO2排放量总体增大,SO2和CO排放量呈波动趋势,掺烧对NOx排放具有一定抑制作用。

The co-combustion and gaseous pollutants emission characteristics of pyrolysis semi-coke and lignite under high heating rates(100-250℃/min)were investigated by thermogravimetric analyzer coupled with Fourier transform infrared spectrometer(TG-FTIR).Results showed that adding lignite into blends could lower the ignition temperature and shorten the burnout time of the blends.All of the index for ignition,burnout and comprehensive combustion performance increased significantly with the increment of lignite blending ratio.Higher heating rates in TG experiments would lead to a higher ignition temperature and temperature at maximum weight loss rate.Meanwhile,the burning rates would also accelerated,which resulted in improved comprehensive combustion performance.The release temperature range of gaseous pollutants was consistent with the main weight loss stages.With the increase of lignite blending ratios,CO2 emission gradually decreased,while NO and NO2 emission generally increased,and the SO2 and CO emission fluctuated.In conclusion,cocombustion exerted certain suppression effect on NOx emission.