REMOVAL TECHNOLGIES OF POLLUTANT GASES AND TOXIC HEAVY METALS BY FINE PARTICULATE SORBENTS

在日本，填埋场的减少导致最终废物量的减少。减少二恶英的排放造成高温燃烧或气化条件。此外，通过燃气涡轮机的联合循环发电来提高效率需要高温条件。然而，其条件导致有毒金属排放，影响人类健康。除非这些金属排放物能够通过烟气处理系统或带有热气过滤器的粉尘分离工艺得到充分控制，否则燃气轮机的使用寿命将会缩短。本研究的目的是通过细颗粒吸附剂在高温下捕获污染气体，如盐酸（HCl）和/或有毒重金属镉（Cd）。在第一步实验中，以石灰石中的氧化钙（CaO）作为HCl的吸附剂。HCl连续测定装置的结果表明，在750℃以下，HCl向CaCl_2的转化率随温度的升高而增加， ...更多信息 在更高温度下，CaCl_2的熔融使其降低。颗粒大小影响其熔融行为，即使在相同的反应温度下也会产生不同的转化率。当混合SO_2时，由于CaSO_4的快速生成，HCl的转化率降低。CaCl_2遇水放出HCl。在第二阶段矿物捕集镉的实验中，选用高岭石作为实验材料。通过批式实验，我们已经证实高岭石作为吸附剂的候选物对Pb和Cd的吸附效果更好，具有相似层状结构的埃洛石、地开石也是有效的。在这项研究中，通过使用流动实验，镉作为气溶胶蒸汽供应。结果表明，镉的捕获率由两个过滤的高岭土增加与时间长达40分钟，并在60分钟的任何浓度的镉下降。高岭石给出了约40%的最大产率，但它似乎是独立的浓度。相当于300μg镉对1.0 g高岭土吸附剂。在60分钟时捕获产率的降低可以通过金属离开吸附剂进入硅胶纸并离开这些过滤器来解释。在800℃下也得到类似的结果。这表明，烟气中的金属浓度是一个更重要的参数，以及温度和时间。此外，颗粒大小和物理和化学吸附的影响进行了测量，并在本报告中进行了描述。少

Decrease of landfill place in Japan gives rise to decrease of volume of final waste. Reduction of the emission of dioxins causes high temperature combustion or gasification condition. Also, increase in efficiency by combined cycle power generation with gas turbine needs the high temperature condition. However, its condition causes the toxic metal emissions, which affect human health. Unless such metal emissions could be enough to controlled by flue gas treatment system or dust separation process with hot gas filters, the service life of the gas turbines should be decreased. Objectives of this research is to capture pollutant gases such as hydrochloric acid (HCl) and/or toxic heavy metals as cadmium (Cd) at high temperature by fine particulate sorbent. In first-step experiment focusing on HCl calcium oxide (CaO) of limestone was used as a sorbent. Results by a continuous measurement equipment for HCl showed that conversion of HCl into CaCl_2 is increased with temperature up to 750℃ but … More it is decreased at much higher temperature by melting CaCl_2. Particle size affects on its melting behavior and gives different conversion even at the same reaction temperature. When SO_2 is mixed, the conversion of HCl is decreased by fast formation of CaSO_4. With water, CaCl_2 emits HCl. It suggests that water content in fuel is an important factor to capture Cl by CaO.In second-step experiment on capturing Cd by minerals, kaolinite was used. We already confirmed that as candidates of sorbent to capture Pb and Cd kaolinite could be much effective and halloysite, dickite with similar layer structure are also effective by a batch experiment. In this study by using flow experiment, Cd was supplied as aerozol vapor. Results suggested that the capture yields of cadmium by both filtering of kaolinite are increased with time up to 40 min and decreased at 60 min for any concentration of cadmium. Kaolinite gave a maximum yield of around 40% but it appeared to be independent of the concentration. It is equivalent to the 300μg of cadmium to 1.0g of kaolinite sorbent. Decrease of captured yields at 60 min could be explained by metal leaving sorbent into silica paper and out of these filter. Similar results were also obtained at 800℃. It suggests that metal concentration in flue gases is one of more important parameters as well as temperature and time. Furthermore, effects of particle size and physical and chemical adsorption were measured and described in this report. Less