Developing Suppression Techniques for Dioxin (DXN)s Released from Small-scale Incinerators for Industrial Wastes by Adding Titania Particles

开发添加二氧化钛颗粒抑制小型工业废物焚烧炉释放的二恶英 (DXN) 技术

基本信息

批准号：
13555218
负责人：
EMI Hitoshi
金额：
$ 8.38万
依托单位：
Kanazawa University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

项目摘要

The present work is aimed at developing a method for suppressing the formation of dioxin (DXN)s emitted from small-scale incinerators for industrial wastes, which are difficult of operate under well controlled combustion, by adding a chemical (sulfur-contained titania) into incinerators. In the first year, the lab-scale experiments on incomplete combustion of me waste samples prepared by adding hydrated lime (Ca(OH)_2) with a given content into PVC powders were performed. The experiments revealed that the DXNs concentration in the burnt samples with 33.2wt%-added Ca(OH)_2 decreased by about 1/10 compared to that without the addition. However, we concluded that this technique adding chemicals into an incinerator is insufficient for the future regulation of tolal emission even if titania, which might be more reactive than Ca(OH)_2 is applied. Thus, we focused on the secondary heat treatment for fly ash in which DXNs arc most concentrated. In the conventional method, DXNs in the fly ash a … More re dechlorinated under reductive atmospheres below 500 deg. C. by adding some chemical since fly ash is subject to solidification above 500 deg. C. In the second year, we investigated the mechanism on solidification of fly ash at the high temperature and attempted to establish the technique of high-temperature treatment for fly ash preventing it from the solidification. Sodium hydroxide (NaOH) and mullile were chosen as an additive that can trap chlorine in fly ash, assuming that it might contribute the solidification, and then me chosen chemical was mixed with fly ash at a given ratio, followed by heating in an electric furnace at 700 deg.C. It was found that no solidification of fly ash with the additives took place after the heat treatment. Moreover, the X-ray diffractometer analyses indicated that the fly ash prior to the heating did not contain calcium chloride (CaCl_2) but CaClOH, which was a product of reaction between Ca(OH)_2 and HC1, and that sodium chloride (NaCl) was detected in the heated sample with NaOH and wadalite in the treated one with mullitc. The differential thermal analyses revealed that for the sample without additives there was an exothermic peak in ihe cooling step (around 800 deg.C). while this peak was not detected in that with additives. Furthermore, the DXNs in the samples before and after the heal treatment were analyzed. The results showed that DXNs concentration in the treated samples with additives decreased by less than 1/!05 compared to the untreated one without additives. These findings confirmed that the application of these additives has the advantages not only to prevent fly ash from the solidification but also to enhance the decomposition of DXNs. Less

目前的工作旨在开发二恶英（DXN）TE的形成，这些TE是在良好的燃烧下运行的，通过将化学物质（含硫的钛）添加到焚化炉中，这是实验室规模的实验。通过在PVDER中添加水合石灰（OH2）来制备的ME废物样品。未来的tolal排放法规，如果二氧化钛可能超过CA（OH）d。 DEG在高温下固化粉煤灰的机制，并试图建立高温治疗的技术，以防止其固化。，并以给定比率将选择的化学品与飞蝇粉一样，然后在700摄氏度的电炉中进行X射线衍射仪分析表明，在加热之前的粉煤灰未氯化钙（CACL_2）Butcacloh，它是CA（OH）之间现实的产物，在使用NaOH和NaOH和NaOH的样品中检测到HC1氯化物（NACL）。 WADALITE在没有差异的情况下，没有差分的差异分析，而没有添加剂中的dxns中的dxns，而没有检测到该峰。在分析治疗之前和之后，结果表明，与未经处理的添加剂相比，添加剂的处理样品中的DXN浓度降低了1/！05。只是防止粉煤灰凝固，也可以减少DXN的压缩。