FeCl_3存在时六六六热解生成PCDD/Fs的研究  

FOMATION OF POLYCHLORINATED DIBENZO-p-DIOXINS AND DIBENZOFURANS BY HEATING HEXACHLOROCYCLOHEXANE IN THE PRESENCE OF FeCi_3

作　　者：郑明辉[1] 包志成[1] 王克欧[1] 徐晓白[1] 

机构地区：[1]中国科学院生态环境研究中心,北京100085

出　　处：《环境化学》1995年第3期179-186,共8页Environmental Chemistry

基　　金：国家自然科学基金资助项目

摘　　要：在开管体系中,于280℃时研究了六六六无效体在Fe,理体制FeCl_3存在时的热解,以及影响热解产物中PCDD/Fs生成量的因素.PCDD/Fs的生成主要取决于FeCl_3,而Fe的存在并不增加体系中PCDD/Fs的生成量.在封管体系中,研究结果表明PCSS/Fs的生成量随FeCl_3用量、反应时间和反应温度的增加而增加,但温度影响最大.实验还表明,氯苯、氨酚对PCDD/Fs的生成起决定作用.在250─280℃,PCDD/Fs的生成主要在于二者之间的缩合,而单独氯酚间的缩合则居次要地位.氯化对生成PCDD/Fs的种类及量影响很大.250─280℃时,低氯苯、氨酚在FeCl_3作用下氯代成高氯产物,进而缩合成 OCDD/F;但在 350℃以上时,氯酚反应活性增加,故低氯PCDD/Fs生成量增加,OCDD/F生成量相对降低.PCDD/Fs are formed by pyrolysis of HCH in the presence of FeCl3. The operation condition is varied to effect different regimes of FeCl3 concentration,temperature and residence time. A possible pathway for the formation of PCDD/Fs is found. Chlorobenzenes and chlorophenols, which are the main products of HCH on heating above 220℃mplay an important role in formation of PCDD/Fs. The condensation reaction of chlorophenols with Chlorobenzenes is readily compared with the condensation of chlorophenols at temperature of 250-280℃- The quantity and pattern of PCDD/Fs are influenced to a great extent by chlorination. The chlorination of lower chlorinated benzenes and phenols by FeCl3 leads to higher chlorinated PCDD/Fs, mainly OCDD/F. The activity of lower chlorinated phenols increases at temperature above 350℃ .and the yield of lower chlorinated PCDD/Fs is greater than that of OCDD/F.

关 键 词：二恶英 多氯二苯并呋喃 六六六 热解 FeCI3 

分 类 号：TQ453.21[化学工程—农药化工]