[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.