化工学报2016，Vol.67Issue(4)：1467-1474,8.DOI:10.11949/j.issn.0438-1157.20151368
温度和氧含量对NH4Br改性稻壳焦汞氧化吸附特性的影响
Effects of temperature and oxygen content on Hg0 oxidation and adsorption by rice husk char impregnated with NH4Br
摘要
Abstract
The mercury sorbent was prepared from raw rice husk char impregnated with 10 g·L−1 NH4Br solution. The physical-chemical characteristics of sorbents before and after modification were analyzed by surface area and porosity analyzer, scanning electron microscopy and X-ray energy dispersive spectroscope. The mercury oxidation and adsorption performance of the modified sorbents were investigated by analyzing mercury speciation (Hg0 and Hg2+) in the outlet of a fixed bed reactor system in N2 and N2+6.4%(vol)O2 atmosphere at different temperatures. No obviousHg2+ was detected in N2, N2+6.4%(vol)O2 atmosphere at 50℃ and N2 atmosphere at 150℃. Modified rice husk char exhibited a mercury removal efficiency of 90% at 50℃ and 150℃. Total mercury (HgT) removal efficiency of 98.2% was obtained in N2+6.4%(vol)O2 atmosphere at 150℃, 82.2% Hg0 was bound to the sorbent surface, the remaining was removed in the form of Hg2+ which was generated from heterogeneous oxidation by O2 at the surface of sorbent. The heterogeneous reaction between O2 and gaseous Hg0 at relatively elevated adsorption temperature promotes the Hg0 oxidation efficiency of modified sorbents. Desorption performance of adsorbed mercury was identified by analyzing HgT at the outlet of temperature programmed tube furnace. Peak mercury desorption temperature of 300℃ manifested that mercury was bound to sorbent surface in the form of Hg-Br compound most likely. Mercury desorption temperature between 220℃ and 350℃ suggested high thermal stability of adsorbed mercury. Mercury balance ratio of 100.14%—118.62% verified the accuracy of experimental results in this study.关键词
改性稻壳焦/脱汞/汞形态/氧化/吸附/脱附Key words
modified rice husk char/mercury removal/mercury speciation/oxidation/adsorption/desorption分类
化学化工引用本文复制引用
姚婷,段钰锋,朱纯,周强,佘敏,陈亚南..温度和氧含量对NH4Br改性稻壳焦汞氧化吸附特性的影响[J].化工学报,2016,67(4):1467-1474,8.基金项目
国家自然科学基金项目（51376046，51576044）；中央高校基本科研业务费专项资金项目；江苏省普通高校研究生科研创新计划资助项目（CXZZ13_0093，KYLX_0115，KYLX_0184，KYLX15_0071）；东南大学优秀博士学位论文培育基金项目（YBJJ1505）；国家科技支撑计划项目(2012BAA02B01)；江苏省产学研联合创新基金项目（BY2013073-10）。@@@@supported by the National Natural Science Foundation of China (51376046,51576044), the Fundamental Research Funds for the Central Universities, Graduate Student Research and Innovation Program of Jiangsu Province (CXZZ13_0093, KYLX_0115, KYLX_0184, KYLX15_0071), the Scientific Research Foundation of Graduate School of Southeast University (YBJJ1505), the National Science and Technology Support Program of China (2012BAA02B01) and the Jiangsu Province United Creative Subject (BY2013073-10) （2012BAA02B01）
