Investigation of production mechanism of unintentional substance by modeling virtual waste incinerator

虽然在像日本这样的土地状况下，废物的焚烧是必不可少的，但是已经要求充分控制其中无意地产生有毒物质如二恶英的化学物质。由于二恶英等有毒焚烧产物种类繁多，焚烧炉工艺条件与特定有毒物质排放的相关性主要在宏观水平上进行研究，而在微观和/或分子水平上的理论检验则被决定性地推迟。本研究的最终目的是建立虚拟焚烧炉模型，以便从微观和分子理论的角度更好地理解燃烧过程。在实际的焚烧炉中，各种固体废物只是以混合状态燃烧。因此，在这项研究中，在特定的条件下，个别废物的燃烧进行了检查，并尝试识别燃烧气体中的化合物。以氧气含量和温度为燃烧条件，改变废气的组成，用GC和GC-MS对废气进行定性和定量分析，结果表明：随着塑料样品加入量的增加，塑料样品在实验炉中的热分解反应除产生CO_2外，还产生CH_4、C_2H_4和CO。在塑料燃烧中，证明了即使在不含苯环的聚乙烯中也能检测到废气中的苯（C_6H_6），并且证明了当燃烧塑料样品时，它会发生反应生成这种更复杂的化合物，该塑料样品比估计完全燃烧时的氧含量更丰富。这种反应被认为是无意物质的产物。

Though the incineration of wastes are indispensable in the land situation like Japan, it has been required that the chemical substance in which toxic substances such as dioxin are produced unintentionally is sufficiently controlled. Since the toxic incinerated products such as dioxin are very various, the correlation of process condition of the incinerator and emission of specified toxic substance has been mainly studied at the macro level, and the theoretical examination at the micro and/or molecular level has decisively been retarded. For the macro research information is complemented, and it is a final purpose of this study to construct the virtual incinerator model in order to understand the combustion process at the microscopic and molecule-theoretical standpoint more. In actual incinerator, various solid wastes in mixed state just bum. So, in this study, the combustion of an individual waste under specified conditions was examined and the identification of the chemical compound in combustion gas was tried. As a combustion condition, the composition of the exhaust gas was changed by oxygen content and temperature, and the gas was qualitatively and quantitatively analyzed by using GC and GC-MS. In addition to CO_2, CH_4, C_2H_4 and CO were produced by the thermal decomposition reaction of the plastic samples when amounts of the samples increased in the experimental incinerator. In the plastic combustion, it was proven that benzene (C_6H_6) in the exhaust gas was detected even in polyethylene without benzene ring and that it generates the reaction into such more complex compound, when plastic sample, which is more abounding than the oxygen content in which estimated complete combustion corresponding to those chemical composition, was incinerated. Such reaction was considered to product the unintentional substance.