电厂飞灰对烟气中汞吸附性能的试验研究

Experimental Study on Mercury in Flue Gas Absorbed by Fly Ash from Power Plant

采用美国环保署(EPA)推荐的Ontario Hydro方法,在小型模拟燃煤烟气Hg吸附和形态转化试验台上研究了几种典型燃煤电厂灰样对模拟烟气中Hg的脱除效果。结果表明:袋式除尘器(FF)灰和消石灰只能吸附氧化态汞,在135℃时,SO2的存在能促进它们对Hg的吸附;电除尘器(ESP)灰由于残碳含量较高,对零价汞也有一定的吸附能力;消石灰对Hg吸附能力的主要因素是比表面积,其吸附能力随着比表面积的增大而增强;在含有SO2的烟气体系中,ESP灰和FF灰的吸附能力基本相当,SO2的存在大大提高了FF灰的吸附能力。

A beach-scale experimental set-up was built, on which an experiments was conducted to study the ability of several typical ash from coal-fired power plant on removing mercury from simulated flue gas. The test method used here was Ontario Hydro Method, which was recommended by U. S. Environmental Protection Agency（EPA）, The conclusions are as follows. Ca（OH）2 and ash from Fabric Filter can only adsorbed Hg^2＋ , and their adsorption ability would increases with the existence of SO2 at 135℃ ; Ash from ESP was found also have adsorption ability on Hg^0 because of its high containing of unburned carbon; BET is the main factor of the adsorption ability of Ca（OH）2, with the BET increases the adsorption ability of Ca（OH）2 climbs; In the gas system containing SO2, the adsorption ability of ESP ash and FF ash are similar; SO2 can improve the adsorption ability of FF obviously.