模拟医疗废物在TG-DTA-FTIR上的热失重特性研究

在热重-差热分析仪上对模拟医疗废物分别在氮气和空气气氛中不同升温速率下加热的热失重行为进行了研究,并对升温速率和不同气氛对其热失重行为的影响进行了探讨.结果表明,随升温速率的提高,模拟医疗废物在2种气氛下热失重时挥发分初析出温度（T_s）向高温方向偏移、失重速率峰值（DTG_max）显著增大;在氮气气氛下,物料热失重时有2个失重峰,前后2个峰的失重率分别为31%和59%左右,在空气气氛下,有3个失重峰,前2个峰失重率分别在44%～59%和31%～46%之间.同时,结合同步傅立叶变换红外光谱仪对各个条件下的气体产物进行了定性分析,并对其中的CO、CO₂、H₂O和CH₄进行了定量分析.实验发现,模拟医疗废物在2种气氛下热失重主要阶段的产物种类相似,都检测到了CO₂、CO、烷烃类、醛类、羧酸、醇类和烯烃的特征吸收峰.并且,结果显示升温速率和气氛条件对CO、CO₂、H₂O和CH₄的生成量都有影响.在热失重的主要阶段,水分含量随加热时间变化曲线上显示1个向下的峰,说明载气中原有水分参与了反应.

Study on Thermogravimetric Characteristics of Simulated Medical Waste by Using TG-DTA-FTIR Analysis

Thermogravimetric behavior of simulated medical waste was studied in the atmosphere of nitrogen and air at different heating rates by thermogravimetric analysis and differential thermal analysis (TG-DTA), and the influence on the thermogravimetric behavior of simulated medical waste by the atmosphere and heating rate was also discussed. The results indicate that the initial separating temperature of the volatile organic matter ( T(s)) moves toward higher temperature and the peak value of the weight loss velocity (DTGmax) has a remarkable increase with the increasing heating rate when simulated medical waste is heated at these two atmospheres. There are two weight loss peaks when the experimental material is pyrolyzed at the atmosphere of nitrogen and the corresponding weight loss rate is about 31% and 59% . There are three weight loss peaks at the atmosphere of air and the corresponding anterior two weight loss rate is about 44% - 59% and 31% - 46%. At the same time, qualitative analysis of evolved gases under different conditions was analyzed by the coupled simultaneous fourier transform infrared spectroscopy (FTIR). In addition, quantitative analysis of CO, CO2, H2O and CH4 was conducted. Experimental results show that the main thermogravimetric stages of simulated medical waste in the atmosphere of nitrogen and air have the similar products, and the typical absorbed peaks of CO2, CO, alkanes, aldehydes, carbonyl acids, alcohols and alkenes were detected. And result shows that the heating rate and atmosphere have an effect on the yield of CO, CO2, H2O and CH4. In the main stages of the process, the curves of water content changing along with the heating time show downward peaks, which count for the participation of water during the reaction.