摘要
制备了负载硅溶胶的Ca SO4载氧体,并对其与CH4、CO和H2的反应特性进行了研究表征。采用管式炉实验系统,对PVC在基于Ca SO4载氧体的化学链燃烧和空气燃烧两种方式下,二噁英的生成特性进行了实验研究。结果表明,负载了硅溶胶的Ca SO4载氧体与CH4、CO和H2反应均接近完全转化,其中,与CH4和H2的反应时间显著短于CO。采用化学链燃烧方式可有效抑制PVC燃烧过程二噁英的生成,其生成量和毒性当量分别由空气燃烧中的34 172.5 pg/g及732.8 pg(ITEQ)/g降到化学链燃烧的2 270.9 pg/g及290.2 pg(I-TEQ)/g,这主要是因为化学链燃烧过程中燃料与O2不直接接触,显著减少了大分子碳结构的氧化断裂以及HCl向Cl2的转化,从而抑制了二噁英的低温从头合成反应和前驱物生成反应。
CaSO4 oxygen carders with silica sol were prepared and their reaction performances with CH4, CO and Hz were experimentally investigated. The formation characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans （PCDD/Fs） in PVC combustion by means of chemical looping combustion （CLC） based on CaSO4 oxygen carder and air were studied in a tube furnace system. The results show that CaSO4 oxygen carriers with silica sol can be completely reduced by CH4, CO and H2. The reaction time of CH4 and H2 is much shorter than CO. The chemical looping combustion of PVC can effectively inhibit the formation of PCDD/Fs. The yield and International Toxicity Equivalent Quantity （I-TEQ） of PCDD/Fs produced in CLC are 2 270.9 pg/g and 290.2 pg（I-TEQ）/g, much lower than those in air combustion which are 34 172.5 pg/g and 732.8 pg（I-TEQ）/g. It is mainly because fuel doesn＇t directly contact with O5 in CLC, the oxidative cleavage of large carbon molecule and the conversion from HCI to C12 are significantly reduced which will inhibit the low temperature de novo synthesis and precursors reaction of PCDD/Fs.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2015年第7期884-889,共6页
Journal of Fuel Chemistry and Technology
基金
国家重点基础研究发展规划(973计划
2011CB201502)
中国博士后科学基金(2014M551978)
关键词
化学链燃烧
二噁英
PVC
载氧体
CASO4
chemical looping combustion
PCDD/Fs
PVC
oxygen carder
calcium sulfate
