等离子体改性活性炭纤维脱硫脱氮的研究

项目名称： 等离子体改性活性炭纤维脱硫脱氮的研究

项目编号： No.50876077

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 王祖武

作者单位： 武汉大学

项目金额： 31万元

中文摘要： 本项目通过放电等离子体改变活性炭纤维的化学官能团来强化活性炭纤维对SO2、NOx的化学吸附和催化过程，增强对NO的氧化能力。利用SEM、比表面积测定仪、FTIR及XPS对改性活性炭纤维的物理、化学特性进行表征，研究结果表明放电方式、载气种类、放电电压、改性时间等条件对改性结果有重要影响。电晕放电改性效果较弱，介质阻挡放电改性效果较强；N2和NH3等离子体中，氮元素被引入到活性炭纤维表面，O2等离子体中，氧元素被引入到活性炭纤维中，而空气等离子体中，氮元素和氧元素的含量都增加。最佳改性条件如下：N2等离子体为放电电压8kV改性20min；氧气等离子体为8kV改性8min；氨气等离子体为8kV改性5min；空气等离子体为8kV改性5min。改性后的活性炭纤维表面碱性基团含量增加，脱硫效率95%以上的时间可由14min延长至24min，硫吸附量增加45%达到173mg/g，VACF脱氮效率达65%，氮吸附量增加2.5倍，PAN-ACF脱氮效率达70%。吸附稳定后ACF上的SO42-和NO3官能团占据了吸附氧化活性位。碱性溶液解吸性能较好，解吸后的活性炭纤维表面官能团种类和含量变化较小。

中文关键词： 等离子体；活性炭纤维；改性；脱硫脱氮；化学官能团

英文摘要： The purpose of this project is to strengthen the reduction and oxidation capacity of ACF to remove SO2 and NOx by plasma modification of ACF surface properties. Several techniques were used to characterize the physical and chemical properties of these materials, including SEM、 BET、FTIR、XPS and so on. The results shows that lots of factors affect the modification results such as the discharge type, gas type, discharge voltage and treatment time. The modification effect of corona dischage is weak comparing to dielectric barrier discharge. After modified by plasma at suitable dischage voltage and treatment time, the specific surface area changes little, while the surface becomes rough and the average pore size decreases. The nitrogen atoms are introduced to the ACF surface in N2 and NH3 plasma, and oxygen atoms are introduced to the surface in O2 plasma, while both the nitrogen and oxygen atomas are introduced the surface in air plasma. The optimum modification conditons at different gases are as fellow: discharge voltage of 8 kV and treatment time of 20 min for N2 plasma, discharge voltage of 8 kV and treatment time of 8 min for O2 plasma, discharge voltage of 8 kV and treatment time of 5 min for NH3 plasma and discharge voltage of 8 kV and treatment time of 5 min for air plasma. The content of alkaline functional groups on ACF surface increased after modification. The time of desulfurization efficiency above 95% can reach to 24 min from 14 min and the ulfur adsorption increased about 45% to 173 mg/g. The nitrogen adsorption of VACF increased about 250% and denitration efficencies can reach to 65%, and to PAN-ACF is 70%. The functional groups of SO42- and NO3 were observed after the adsorption of SO2 and NO by modified ACF, which block the adsorption. Alkalin solution shows the better desorption effect in different types desorption solution and the types of functional groups and the relative contents changes little after desorption when contrast to the modified VACF.

英文关键词： plasma; activated carbon fiber; modification; desulfurization and denitrification; chemical functional group