载溴竹炭的脱汞特性研究

REMOVAL OF ELEMENTAL MERCURY BY BAMBOO CHARCOAL MODIFIED BY KBr

为获得脱汞性能高的烟气汞吸附剂,采用化学浸渍法对廉价的生物质竹炭进行溴化学改性,并在小型实验台架上考察了载溴竹炭的脱汞性能。对改性前后的样品进行了BET和XPS表征分析以研究表面官能团在改性过程中的转化规律和脱汞机理。结果表明:改性后竹炭具有超强的脱汞能力,特别是在140℃时,其脱汞效率仍保持在100%。改性后竹炭具有更多的利于脱汞的官能团,其主要靠化学吸附脱汞。烟气中低浓度的SO2与NO对汞的脱除有一定的抑制作用,在相同的实验条件下,SO2对吸附剂脱汞的抑制作用更加明显。

To develop cost-effective carbon-based sorbents used in gas-phase elemental mercury removal,the performance of commercial bamboo charcoal( BC) produced from renewable bioresource of bamboo and modified BC was investigated with a bench-scale fixed-bed reactor. The simple impregnation method was used to modify the BC using KBr. XPS was used to determine the surface chemistry characteristics of the sorbents. The characterization of sorbents in relation to Hg0 adsorption capacity provided important information on Hg0 adsorption mechanism. This suggested that the modified BCs have excellent adsorption potential for elemental mercury at a relatively higher temperature of 140 ℃. The impregnation has increased the sorbents' active sites for mercury adsorption and the specific reaction mechanism has been further analyzed.