烟气脱汞技术研究进展

Research advances of flue gas mercury removal technology

烟气脱汞技术包括吸附剂法、化学氧化法和利用现有设备与技术控制汞排放法3种。吸附剂法是目前最成熟的一种烟气脱汞技术,常用的脱汞吸附剂有活性炭类吸附剂、飞灰、钙基吸附剂、矿物类吸附剂以及各种新型吸附剂;化学氧化法主要包括光催化氧化、金属及金属氧化物催化氧化和选择性催化还原法等,是利用氧化剂或催化剂将烟气中的Hg0氧化成Hg2+后,再进行脱除;利用现有的袋式除尘设备能除去烟气中的HgP,静电除尘器不但能除去HgP,还能有效氧化吸附Hg0;湿法脱硫技术可去除Hg2+。

Several technologies of capturing mercury from flue gas such as adsorbent method,oxidization method,and employing existing devices and technologies to control mercury were introduced,and the developments of these technologies were also summarized.The adsorbent method is the most mature mercury removal technology at present.The common mercury removal adsorbent includes activated carbon adsorbents,fly ash,Ca-based adsorbent,mineral adsorbent and various new adsorbents.The oxidation method consists of photocatalytic oxidation,metal and metal oxide catalytic oxidation,and selective catalytic reduction,by which the Hg0in flue gas was oxidized to Hg2+by the oxidant or catalyst,thus the Hg2+was removed.The present bag filter can collect the HgP in flue gas;the electrostatic precipitator not only can collect the HgP,but also can oxidize and absorb Hg0effectively;while the Hg2+can be removed by wet desulfurization technology.The recent research progress and the problems occurred during their application of above technologies were presented.Finally,the development trend of the capturing mercury technology was proposed.