秸秆含氮模型化合物热解氮转化规律的实验研究

采用TG-FTIR联用实验系统,在氩气氛围下研究了含氮模型化合物甘氨酸酐热解失重特性以及NO_x前驱物的释放特性;研究了K、Ca、Fe金属盐对甘氨酸酐热解氮转化的影响。结果表明,在20、40、60℃/min升温速率下,NH₃、HCN、HNCO为甘氨酸酐热解的主要气相含氮产物,其中,NH₃产率最大,HCN次之,HNCO生成量最小;随升温速率增加,TG失重曲线右移,热解剩余物减少;且HCN和HNCO的产率增加,NH₃产率降低;K、Ca、Fe盐均对甘氨酸酐热解氮转化具有催化作用,其中,K、Ca有利于促进NH₃、HCN的生成,Fe对HCN的生成具有促进作用,但对NH₃的生成起到抑制作用。

TG-FTIR analysis of nitrogen conversion during straw pyrolysis:A model compound study

2,5-diketopiperazine (DKPs) was selected as N-containing model compound to investigate fuel-N conversion pathway during straw pyrolysis. The experiments were conducted using a thermogravimetric analyzer coupled with a Fourier transform infrared spectrometer (TG-FTIR) in Ar atmosphere. The results show that NH₃, HCN and HNCO are the major N-containing species during DKPs pyrolysis at 20, 40 and 60℃/min. The yield of NH₃ is the largest, followed by HCN and the amount of HNCO is the lowest. With increase of heating rate, the weight loss curve moves to right and the yields of HNCO and HCN increase, while that of NH₃ decreases. K, Ca and Fe have a catalytic effect on nitrogen conversion during DKPs pyrolysis. In the presence of K and Ca, the formation of NH₃ and HCN is enhanced. Fe can promote the formation of NH₃, but inhibit the formation HCN.