文档介绍：钙基吸附剂对烟气中气态汞的吸附特性研究
摘要
燃煤燃烧后会产生大量的汞蒸气,汞是一种有剧毒,易挥发,能长久的存在于大气中而对环境造成严重破坏的物质。汞蒸气中的汞主要以零价汞,二价氧化汞和固态颗粒汞的形态存在。其中零价汞具有很高的挥发性和较低水溶性,是及其难于控制的污染物,目前在环保领域越来越受到关注。
文章介绍了目前科学领域对汞蒸气的控制技术,并着重介绍钙基类吸附剂的研究进展,提出了改性钙基吸附剂对零价汞的吸附特性思路。本文采用固定床吸附的实验方法研究钙基吸附剂对汞蒸气的脱除性能。利用汞渗透管产生的气态单质汞和N2作为模拟气体,在固定床实验台上进行了以氧化钙、氢氧化钙及其分别用不同添加量的高锰酸钾改性后的物质作为吸附剂吸附单质汞的实验研究。实验结果表明,氧化钙对汞的吸附为物理吸附和化学吸附,而氢氧化钙对汞的吸附主要是物理吸附,低温有利于吸附;高锰酸钾改性后的钙基吸附剂在模拟气体中可以将大部分的零价汞氧化为二价汞,高锰酸钾添加量越大,吸附效果越好;改性氢氧化钙的吸附以化学吸附为主,80℃时的吸附效率最好。
关键词:汞蒸气;氧化钙;氢氧化钙;高锰酸钾;吸附
Calcium-based Sorbents on the Adsorption Characteristics of Gaseous Mercury in the Flue Gas
Abstract:Coal-bustion will produce large amounts of mercury vapor, mercury is a toxic, volatile, long-term existence of the substances in the atmosphere and cause serious damage to the environment. In the vapor mercury, it mainly includes zero price of mercury, the presence of divalent mercury oxide and solid particles of Mercury. Zero valent mercury has a high volatility and low water solubility, and it is difficult to control pollutants, more and more attention in the field of environmental protection.
This paper introduced current control technology of mercury vapor in the scientific field, and focused on the research progress of the calcium-based adsorbents. We proposed an idea that the adsorption characteristics of modified calcium-based sorbents adsorb vapor mercury. In this paper, we used the method of fixed bed adsorption experiments to study the calcium -based sorbents for removal of vapor mercury. Mercury ration of the tube to produce gaseous elemental mercury and N2 as the simulation of gas, we used calcium oxide, calcium hydroxide and their modified materials that were treated with different amounts of potassium permanganate as adsorbents, studied the adsorption of elemental mercury in the fixed bed experimental stage. The results showed that the adsorption of CaO to Hg0 was controlled by physical and chemiadsorption mechanisms, but Ca (OH) 2 was controlled by physical mechanisms, a