非平衡等离子体催化氧化极低浓度^(14)CH_(4)的实验研究  

Study on catalytic oxidation of low concentration ^(14)CH_(4) by non-thermal plasma

作　　者：裴鉴禄 梁书玮 林中鑫 李佳雨 陈建利[1] 韩明 侯建荣[1] 李永国[1] PEI Jianlu;LIANG Shuwei;LIN Zhongxin;LI Jiayu;CHEN Jianli;HAN Ming;HOU Jianrong;LI Yongguo(CNNC Key Laboratory of Radioactive Gas Purification Technology,China Institute for Radiation Protection,Taiyuan 030006,China)

机构地区：[1]中国辐射防护研究院中核集团放射性气体净化技术重点实验室,太原030006

出　　处：《核技术》2025年第2期83-91,共9页Nuclear Techniques

基　　金：中核集团"青年英才"项目(No.JY22040604);中国辐射防护研究院创新团队项目(No.YC22010603)资助。

摘　　要：^(14)C碳氢化合物中^(14)CH_(4)的占比最大且化学性质最稳定,本研究以与^(14)CH_(4)具有相同物化性质的^(12)CH_(4)为实验对象,通过引入催化手段,对非平衡等离子体催化氧化极低浓度^(12)CH_(4)的性能以及参数影响规律进行考察。结果表明:本研究中等离子体发生器的帕邢击穿电压为16.01 kV;引入Pd/Al_(2)O_(3)催化剂能够显著提升等离子体对CH_(4)处理性能,通过提高放电电压、降低反应温度和气体流量,CH_(4)处理效率和CO_(2)选择性可达100%和83.7%;等离子体与Pd/Al_(2)O_(3)催化剂之间具有协同效应,Pd/Al_(2)O_(3)能够降低反应壁垒、优化反应路径,显著提高等离子体的CH_(4)处理性能,同时等离子体激发的活性物种也有利于催化剂中关键反应活性相PdO的产生。现有结果表明,等离子体催化氧化技术能够在常温常压条件下实现对极低浓度^(14)C碳氢化合物的有效处理,具备极大应用潜力。[Background]^(14)C has become the largest contributor of annual effective dose to the surrounding public in radioactive effluent during normal operation of nuclear power plants whilst ^(14)CH_(4) is the largest and most chemically stable of the ^(14)C hydrocarbons.However,an effective treatment method for ^(14)C in the form of hydrocarbons has not yet been established.[Purpose]This study aims to investigate the treatment performance of a non-thermal plasma/catalytic coupling system for low concentrations of ^(14)CH_(4).[Methods]Considering the optimization of radiation protection,^(12)CH_(4),which possesses the same physicochemical properties as ^(14)CH_(4),was selected as the experimental subject.The Pd/γ-Al_(2)O_(3) catalyst were prepared by segmental heat treatment and wet impregnation.The discharge behaviors of the plasma were analyzed by the Lissajous figure.The CH_(4) treatment performance of the non-thermal plasma before and after the introduction of the catalyst under different discharge voltages,gas flow rates and temperatures were analyzed by the constructed experimental system.The microstructural changes of the catalyst were analyzed by N_(2) adsorption-desorption isotherm,X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).[Results]The introduction of Pd/Al_(2)O_(3) catalyst can significantly improve CH_(4) treatment performance in non-thermal plasma,and the CH_(4) treatment efficiency and CO_(2) selectivity can reach 100%and 83.7%by increasing the discharge voltage,lowering the reaction temperature and reasonably adjusting the gas flow.[Conclusion]The non-thermal plasma and the Pd/Al_(2)O_(3) catalyst exhibit a synergistic effect.The Pd/Al_(2)O_(3) catalyst can reduce the reaction barriers,optimise the reaction paths and significantly improve the CH_(4) treatment performance of the plasma.Furthermore,the plasma-excited reactive species are conducive to the formation of PdO,which is the key reactive phase in the catalyst.

关 键 词：碳-14 等离子体 甲烷 压水堆 

分 类 号：TL941.2[核科学技术—辐射防护及环境保护] X771[环境科学与工程—环境工程]