摘要
硒是燃煤过程排放的有毒痕量元素之一,硒在烟气中的存在形式为SeO2。在700℃左右中温范围,氧化钙(CaO)能够通过化学吸附作用脱除SeO2。本研究目的是探索在中温范围CaO脱除SO2过程中同时脱除痕量SeO2的规律。研究方法是利用热重分析仪(TGA)进行吸附反应试验,通过CaO样品重量变化确定反应速率。CaO吸附SeO2的效果在300-700℃没有明显的差别,超过740℃吸附效果明显降低,确定出CaO同时脱硫脱硒的最佳温度范围为700-740℃。脱硫形成的产物层作为单独的因素不会影响CaO吸附SeO2的效果,并且脱硫产物层的存在能抑制被吸附的硒发生解析。
Selenium is one of the trace element pollutants derived from coal combustion. It exists as selenium dioxide (SeO2) in flue gas. It can be chemically absorbed by calcium oxide (CaO) at medium temperature of about 700℃. This study relates to simultaneous removal of sulfur dioxide (SO2) and trace SeO2 gas by CaO adsorption. The experiments were conducted in a thermo-gravimetric analyzer (TGA). The reaction rates were calculated according to the sample weight changes. The ability of CaO to adsorb SeO2 is nearly uniform at 300~700℃. When the temperature is higher than 740℃, the ability becomes weaken. The best temperature range for the simultaneous removal is 700~740℃. The sulfate product layer has no obvious effect on the ability of CaO to adsorb trace SeO2 gas, and it can restrain the decomposition of the absorbed selenium.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2006年第z2期223-226,共4页
Journal of Engineering Thermophysics
基金
国家重点基础研究发展规划项目资助(No.2006CB200301)
关键词
痕量元素
中温脱硫
二氧化硒
联合脱除
trace element
medium temperature desulphurization
selenium dioxide
simultaneous removal
