国产活性炭喷射去除大型城市生活垃圾焚烧发电厂烟气中的二恶英

本研究针对二恶英削减及降低成本选用优质国产活性炭,对一典型城市生活垃圾焚烧发电厂(MSWI)的"活性炭喷射+布袋除尘过滤"系统优化。在实际工况条件下,对3个活性炭投加速率(5、10和15 kg/h)下所获得的二恶英的排放浓度、去除效率及去除特征进行评价。结果发现,(1)选用的活性炭对二恶英具有优越的去除效果,5 kg/h投加速率即可使去除效率达到99.0%,排放浓度下降到低于改用前的1/10,远低于欧盟排放标准;(2)3个投加实验在二恶英的排放浓度、总去除效率、去除特征上并没有表现出显著差异,综合考虑认为,5 kg/h(150 mg/Nm3)是合理的工程应用依据;(3)本研究成功的实验结果说明,选用的活性炭品质能满足工程需求,其表征特点可作为未来活性炭选用的依据,即孔径分布主要集中在2~5 nm之间,属于中孔范围中靠近微孔区域,比表面积大于500 m2/g,比孔容积大于0.2 cm3/g。

Removal of dioxin in flue gas from a large-scale MSWI by domestic activated carbon injection

To obtain better performance but lower cost of activated carbon(AC) adsorption with a bag filter system in a large-scale municipal solid waste incinerator(MSWI), one kind of domestic AC was firstly selected by its suitable physicochemical properties for dioxin abatement, then the dioxin removal efficiencies of the specific AC were evaluated via a series of dioxin absorption experiments under different AC feeding rates(5 kg/h, 10 kg/h, 15 kg/h). It was found that:(1) the selected AC was proven to have effective dioxin removal ability with high dioxin removal efficiency(99%) and low dioxin emission concentrations which were at least 10 times lower than the history data and all under the EU recommend limit(0.1 ng I-TEQ/Nm3);(2) there were no differences in dioxin emission values, dioxin removal efficiency and congener performance under different AC feeding rates, and 5 kg/h(150 mg/Nm3) could be an appropriate feeding rate for future application;(3) the chosen AC satisfied the engineering application requirement and its physicochemical properties could be used as reference for AC valuation, which has pore distribution mainly within 2-5 nm, surface area is larger than 500, and pore volume of pores is larger than 0.2 cm3/g.