升温速率对氨基酸裂解生成含氮气体的影响研究

Effect of heating rate on the formation of nitrogenous gases from the pyrolysis of amino acids

为进一步阐明卷烟烟气中含氮有害气体的形成机理,以甘氨酸、天冬酰胺和天冬氨酸为研究对象,采用TG-FTIR技术对其在不同升温速率下热解时含氮气体的释放特性进行了研究。结果表明:(1)随着升温速率增加,三种氨基酸TG和DTG曲线各个失重阶段的起始和终止温度向高温侧移动;(2)氨基酸结构不同,HCN、NH3、HNCO的生成温度及生成量不同;(3)增加升温速率,三种氨基酸热解过程中HCN、NH3、HNCO的生成量均增加,但三种氨基酸氮转化的选择性不尽相同。甘氨酸和天冬酰胺热解过程中氮主要转化为NH3,而天冬氨酸在低升温速率下热解时,氮主要转化为HCN和NH3,在高升温速率下主要生成HNCO。

In order to elucidate the formation mechanisms of harmful nitrogenous gases further, the formation behavior of nitrogenous gases from pyrolysis of three typical amino acids including glycine, asparagine and aspartic acid at different heating rates were stud- ied by TG-FTIIL The results showed that： 1 ） As heating rate increased, the TG and DTG curve of the three amino acids shifted to high temperature zone. 2） The distinctive structures of amino acids contributed to different formation behavior of nitrogenous gaseous products. 3 ）The releasing behaviors of nitrogenous gases during pyrolysis of the three samples were similar. The formation of HCN, NH3 and HNCO were favored at high heating rate. But the N-transfer behavior of the three amino acids at different heating rates were different. The glycine-N and asparagine-N converted mainly into NH3, while the aspartie acid-N converted mainly into HCN and NH3 at low heating rate, and mainly into HNCO at high heating rate.