双介质阻挡放电部分氧化甲烷关键参数研究  

Study on key parameters of partial oxidation of methane in double dielectric barrier discharge

作　　者：纪宇飞 彭丹婷 李瑞洁 罗颖鸿 赵彩悦 叶代启 吴军良 JI Yufei;PENG Danting;LI Ruijie;LUO Yinghong;ZHAO Caiyue;YE Daiqi;WU Junliang(School of Environment and Energy,South China University of Technology,Guangzhou 510006;National Engineering Laboratory for Volatile Organic Compounds Pollution Control Technology and Equipment,Guangzhou 510006;Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control,Guangzhou 510006)

机构地区：[1]华南理工大学环境与能源学院,广州510006 [2]挥发性有机物污染治理技术与装备国家工程实验室,广州510006 [3]广东省大气环境与污染控制重点实验室,广州510006

出　　处：《环境科学学报》2024年第12期282-294,共13页Acta Scientiae Circumstantiae

基　　金：广东省自然科学基金(No.2023A1515010193);国家重点研发计划(No.2022YFB4101500)。

摘　　要：低温等离子体可在常温常压条件下将温室气体甲烷部分氧化生产绿色甲醇.双介质阻挡放电(DDBD)由于其弥散均匀的放电特性,在活化甲烷的同时减少甲醇被过度氧化为CO和CO_(2)的几率,提升固碳减排效果.本研究通过调节反应器接地极循环盐水温度、CH_(4)/O_(2)比例及高压电极材质,探究了DDBD用于甲烷制甲醇的最佳反应参数,发现最优的反应参数为循环盐水温度45℃、CH_(4)/O_(2)进料比4∶1、高压电极材质铜.本工作实现了良好的甲醇选择性和产率,甲醇选择性最高为38.9%,甲醇产率最高为5552μmol·h^(-1).进一步通过等离子体电学特性及光学诊断方法,对DDBD活化甲烷制甲醇的反应机理进行了探究,结果表明,电子密度及活性氧物种(ROS)浓度是造成反应性能差异的主要原因.电子密度提高有利于甲烷转化率升高;适当的ROS浓度对甲醇生成十分必要,但过高的ROS浓度会使甲醇被进一步氧化为HCHO和CO、CO_(2).Low-temperature plasma can partially oxidize the greenhouse gas methane to produce green methanol under normal temperature and pressure conditions.Due to its uniform and diffuse discharge characteristics,double dielectric barrier discharge(DDBD)activates methane while reducing the probability of methanol being over-oxidized to CO and CO_(2),thus improving the carbon fixation and emission reduction effects.This study explored the optimal reaction parameters for the DDBD to be used to produce methanol from methane by adjusting the reactor circulating brine temperature,CH_(4)/O_(2)ratio,and high-voltage electrode material.The optimal reaction parameters were circulating brine temperature of 45℃,CH_(4)/O_(2) feed ratio of 4∶1,high voltage electrode made of Cu.Good methanol selectivity and yield were achieved in this work,with methanol selectivity up to 38.9%and methanol yield up to 5552μmol·h^(-1).Further,through plasma electrical characteristics and optical diagnostic methods,the reaction mechanism of DDBD-activated methane to methanol was explored:Electron density and reactive oxygen species(ROS)concentration are the main reasons for the difference in reaction performance.A higher electron density favors higher methane conversion;a proper ROS concentration is necessary for methanol production,but excessive ROS concentration causes methanol to be further oxidized to HCHO and CO and CO_(2).

关 键 词：双介质阻挡放电 甲烷减排 增值转化 甲醇 等离子体 

分 类 号：X701[环境科学与工程—环境工程]