生物质炭再燃脱汞技术的试验研究

Experimental Study on Mercury Removal Technology Using Biomass Charcoal Reburning

燃煤的汞排放控制技术是个十分重要的环保课题。采用生物质炭作为再燃燃料,并掺混一定比例的尿素或者消石灰,在某锅炉主燃烧器上方喷入炉膛,研究生物质炭再燃技术对燃煤脱汞的影响。试验结果表明:掺混不同物料的生物质炭进行再燃时,能够抑制煤燃烧时汞向烟气中的迁徙能力,促使烟气中的元素态汞(Hg0)向氧化态汞(Hg2+)或颗粒态汞(HgP)转化,有效降低了尾部烟气中总汞含量,提高了除尘器内飞灰和炉渣中的汞含量;试验还发现掺混消石灰的生物质炭对元素态汞的氧化促进作用更强,降低烟气总汞含量的作用更明显。

Controlling technology of mercury emissions for a coal-fired boiler is an important issue for environmental protection. The biomass charcoal reburning technology was researched on the coal-fired mercury removal, and biomass charcoal was sprayed into the top of furnace from a certain distance and mixed with a certain proportion of urea or slaked lime. The experimental results show that: by reburning the biomass charcoal blended with different materials,the migration ability of the mercury in the flue gas with coal combustion can be suppressed, prompting the conversion of elemental mercury (Hg0) in the flue gas to oxidation state mercury (Hg2+) or particulate mercury (HgP), so as to reduce the total content of mercury in the flue gas and to improve the content of mercury in the fly ash and slag. The experiments also discovery that the biomass charcoal blended with slaked lime has a much stronger oxidation promoting effect to the elemental mercury, and the reduction of the total mercury content in the flue gas is more obvious.