医疗废弃物热解动力学及产物研究

Research on the Pyrolysis Kinetics and Products of Medical Waste

对医疗废弃物在氩气条件下,进行3种升温速率(10℃/min、20℃/min、30℃/min)下热重实验。医疗废弃物热解失重分为4个阶段:水分蒸发阶段、不发生热化学反应的平坦阶段、急剧热解失重阶段、残留大分子物质分解阶段。在惰性气氛下,其中口罩、纱布、医用脱脂棉、针筒只有一个DTG最大失重速率峰,急剧热解失重阶段与残留大分子物质分解阶段界限没有表现出来,分为3个阶段。输液器、医用一次性橡胶手套、竹棒有2个DTG最大失重速率峰,经历4个阶段,动物组织因水分、挥发分含量高,失重阶段发生重叠,不易区分。除了动物组织以外,升温速率越快,医疗废弃物分解开始温度和反应终止温度越高。同时,对模化医疗废弃物的有关的热解动力学参数进行分析,采用Caots-Redfern推导的近似积分方程建立动力学模型,得到指前因子、活化能等参数。通过通入管式炉氮气,利用气相色谱仪对医疗废弃物200~800℃产生的尾气进行分析。同时,对不同温度下医疗废弃物热解固体残留物进行扫描电镜。

The thermogravimetric experiments of medical waste at three heating rates(10 ℃/min、20 ℃/min、30 ℃/min) were carried out under the condition of argon.The pyrolysis weight loss of medical waste is divided into four stages:water evaporation stage,flat stage without thermochemical reaction,rapid pyrolysis weight loss stage,and residual macromolecular material decomposition stage.In the inert atmosphere,there is only one peak of DTG maximum weight-loss rate for masks,gauze,medical absorbent cotton and needle cartridges,and the boundary between the rapid pyrolysis weight-loss stage and the decomposition stage of residual macromolecules is not shown,which is divided into three stages.The infusion set,disposable medical rubber gloves and bamboo stick have two DTG maximum weightlessness rate peaks,which go through four stages.Because of the high content of water and volatile matter in animal tissues,the weightlessness stages overlap and are difficult to distinguish.In addition to animal tissues,the faster the heating rate is,the higher the decomposition start temperature and reaction end temperature of medical waste are.Simultaneously,the relevant pyrolysis kinetics parameters of modeled medical waste were analyzed,and a kinetic model was established using the approximate integral equation derived by Caots-Redfern,obtaining parameters such as pre exponential factor and activation energy.This paper analyzes the tail gas generated by medical waste at 200~800 ℃ by introducing nitrogen into the tubular furnace.At the same time,the solid residue of medical waste pyrolysis at different temperatures was examined by scanning electron microscopy.