非平衡等离子体重整CO2-CH4制合成气是实现2种温室气体资源化利用的新兴技术途径。综合采用发射光谱分析、反应动力学计算和连续质谱对常温常压介质阻挡放电（DBD）非热等离子体重整CO2-CH4反应途径进行探索。比功率SEI为52 J/cm3时，可得到CH4和CO2转化率最大分别为22.8%和9.4%。稳态气相产物连续质谱在线分析表明，C2H4为C2烃生成重要中间体，CH4比例越高C2烃生成量越大，且按C2H6<C2H4<C2H2顺序升高。发射光谱检测到·CH、·C2自由基和CO、CO+2特征谱线，·CH相对强度随比功率增加明显降低，CO+2相对强度变化较小。通过动力学计算分析C2和C3产物生成消耗途径，发现89.2% C2H6来自复合反应CH3+CH3(+M)C2H6(+M)，78.9% C2H4主要由CH4+CHC2H4+H和C2H3+H(+M)C2H4(+M)反应生成，61.1% C2H2受电子碰撞反应影响形成，C2产物形成遵循路径：CH4→C2H6→C2H4→C2H2。电子碰撞离解CO2反应e+CO2CO+O-是CO重要形成途径，而CH3+CH4C2H+5+H2反应和电子碰撞解离CH4是H2关键生成路径。研究表明，动力学模拟结合发射光谱可为合理揭示DBD重整CO2-CH4过程复杂反应机理提供有力工具。

CO2-CH4 reforming by non-equilibrium plasma to syngas is an important emerging technology pathway to realize the resource utilization for the two greenhouse gases. The reaction pathway of CO2-CH4 reforming by non-thermal plasma in a dielectric barrier discharge (DBD) reactor at ambient temperature and pressure was thoroughly investigated by combing emission spectrometry analysis, reaction kinetics simulation and continuous mass spectrometry measurements. A maximum conversion of CH4 and CO2 of 25.8% and 9.6% respectively, can be achieved under a specific energy input (SEI) of 52 J/cm3. The continuous mass spectrometry online analysis of the stable gaseous products shows that C2H4 acts as a key intermediate in the formation of C2 hydrocarbons. The higher the proportion of CH4, the greater the generation of C2 hydrocarbons, and it increases in the order of C2H6<C2H4<C2H2.·CH, ·C2 radicals and characteristic spectral lines of CO and CO+2 are detected in the emission spectrum. The relative intensity of ·CH decreases significantly with the increase of specific power, and the relative intensity of CO+2 changes little. The generation and consumption pathways of C2 and C3 products are analyzed by kinetic calculation, and it is found that 89.2% of C2H6 comes from the combination reaction CH3+CH3(+M)C2H6(+M), 78.9% of C2H4 is mainly formed by CH4+CHC2H4+H and C2H3+H(+M)C2H4(+M) reaction, 61.1% of C2H2 is formed by electron collision reaction, and the formation of C2 product follows the path: CH4→C2H6→C2H4→C2H2. The reaction of electron collision dissociation e+CO2CO+O-of CO2 is an  important formation pathway of CO, while the reaction CH3+CH4C2H+5+H2 and electron collision dissociation of CH4 are the key generation pathway of H2. Integration of emission spectroscopy and kinetic calculation provides a useful tool to uncover the reaction mechanism of plasma-enhanced CO2-CH4 reforming process.

0 引言

1 试验

2 化学动力学反应机理模型

3 结果与讨论

   3.1 产物分布规律

   3.2 原料转化率

   3.3 C2、C3烃生成规律

   3.4 CO2-CH4等离子体发射光谱

   3.5 动力学模拟分析

4 结论