在温度为600 ~900℃、氮气气氛下,用管式炉实验台对医疗废物典型组分——棉花和聚丙烯(PP)进行了快速热解实验.为了研究氯的迁移规律,对物料添加了适量的盐水.结果表明,医疗废物典型组分和NaCl溶液混合热解的过程中Cl的析出随着热解温度、热解时间和物料与Cl元素质量配比的改变而改变.研究发现,Cl的析出峰在以棉花为物料时出现在800℃,而用PP为物料时出现在700℃;随着热解时间的变化,Cl的析出率呈现不规律的变化:700℃棉花热解实验中,热解时间5min时,Cl的析出率只有0.0002,在10min时,析出率达到了0.0003;而在800℃棉花的热解实验中,5min时Cl的析出率为0.00062,而随着热解时间的增加,10min时,Cl的析出率却降到了0.00045.同时还发现,随着Cl元素含量的增加,其析出率也在提高.当Cl和物料质量比值增加1倍时,Cl的析出率也随着温度的变化相应的增加2 ~4倍.
Fast pyrolysis of cotton and polypropylene (PP) , which are typical components of medical waste, was performed in a pipe stove at 600 - 900℃ under a N2 atmosphere. Selected quantities of brine were added to the materials with the goal to study the process of Cl transformation during pyrolysis. The results showed that the rate of Cl release changed along with the pyrolysis temperature, pyrolysis time and the weight ratio of Cl to the mixture of medical waste and brine. The rate of Cl release reached a maximum at 800 ℃ during cotton pyrolysis and at 700 ℃ during PP pyrolysis. It was observed that the rate of Cl release changed irregularly at different pyrolysis times. For fast pyrolysis of cotton at 700 ℃ , the rate of Cl release was 0. 0002 at a pyrolysis time of 5 rain, and increased to 0. 0003 at 10 min. In contrast, for fast pyrolysis of cotton at 800℃ , the rate of Cl release was 0. 00062 at 5 min, but it decreased to 0. 00045 at 10 rain. We also found that the rate of Cl release increased as the weight ratio of Cl to the material was raised. Thus, the rate of Cl release could increase 2 - 4 times as the temperature rose as long as the weight ratio of Cl to the material doubled.