物理化学学报 >> 2014, Vol. 30 >> Issue (4): 738-744.doi: 10.3866/PKU.WHXB201402141

光化学和辐射化学 上一篇    下一篇

非平衡等离子体放电模式及反应器结构对氨气分解制氢的影响

赵越1, 王丽1, 张家良2, 郭洪臣1   

  1. 1 大连理工大学化工学院催化化学与工程系, 精细化工国家重点实验室, 辽宁大连116024;
    2 大连理工大学物理与光电工程学院, 辽宁大连116024
  • 收稿日期:2013-12-04 修回日期:2014-02-13 发布日期:2014-03-31
  • 通讯作者: 郭洪臣 E-mail:hongchenguo@163.com
  • 基金资助:

    国家自然科学基金(20473016,20673018)资助项目

Influence of Non-Thermal Plasma Discharge Mode and Reactor Structure on Ammonia Decomposition to Hydrogen

ZHAO Yue1, WANG Li1, ZHANG Jia-Liang2, GUO Hong-Chen1   

  1. 1 State Key Laboratory of Fine Chemicals, Department of Catalytic Chemistry and Engineering, Schol of Chemical Engineering, Dalian University of Technology, Dalian 116024, Liaoning Province, P. R. China;
    2 School of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116024, Liaoning Province, P. R. China
  • Received:2013-12-04 Revised:2014-02-13 Published:2014-03-31
  • Contact: GUO Hong-Chen E-mail:hongchenguo@163.com
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20473016, 20673018).

摘要:

在常压下研究了不同等离子体放电模式及反应器结构对氨分解制氢反应的影响. 实验中调节反应器结构分别产生了介质阻挡放电和交流弧放电两种放电模式. 通过对两种放电模式的放电图像、电压-电流波形和氨分解过程中等离子体区活性物种的发射光谱(OES)研究发现,与介质阻挡放电相比,交流弧放电为局部强放电,具有更高的电源效率和电子密度. 因此,在介质阻挡放电中氨气分子大部分通过生成电子激发态物种NH3*,再与载能电子碰撞断裂N―H键进行氨分解反应;而在交流弧放电中载能电子具有更高的平均电子能量,可直接断裂氨气分子的N―H键生成NH2和NH等高活性物种,促进氨分解反应的进行. 结果表明,交流弧放电的氨分解效果要明显优于介质阻挡放电. 在交流弧放电模式下不同类型反应器对氨气分解转化率由高到低的顺序为:管-管> 管-板> 针-板> 板-板. 在输入功率为30 W,气隙间距为6 mm时,管-管交流弧放电的氨气转化率达到60%左右,而板-板介质阻挡放电的氨气转化率仅为4%.

关键词: 介质阻挡放电, 交流弧放电, 氢气, 氨气, 发射光谱

Abstract:

At ambient pressure, the effect of plasma discharge mode and reactor structure on ammonia decomposition to hydrogen was investigated. Dielectric barrier discharge (DBD) and alternating current (AC) arc discharge were produced upon adjusting the structure of the plasma reactor. By studying the discharge images, the voltage-current waveforms and the optical emission spectra in two discharge modes, we found that the AC arc discharge was a spatially partially stronger discharge compared with DBD. The AC arc discharge had a higher power efficiency and higher electron density than the dielectric barrier discharge. The ammonia molecules were mainly transformed into NH3* in an electronic excited state, and the N―H bond ruptured upon collision with a high-energy electron in DBD. However, electrons with a high average electron energy upon AC arc discharge can rupture the N―H bond directly to form highly active NH2 and NH species, which can enhance the ammonia decomposition reaction. Results show that AC arc discharge had better performance toward ammonia decomposition than dielectric barrier discharge. The ability of different reactor structures to decompose ammonia under AC arc discharge increased in the following order: tube-tube>tube-flat>point-flat>flat-flat. The ammonia conversion can be as high as 60% under the tube-tube AC arc discharge with an input power of 30 W and a gap distance of 6 mm, while it was only 4% under the flat-flat dielectric barrier discharge.

Key words: Dielectric barrier discharge, AC arc discharge, Hydrogen, Ammonia, Optical emission spectrum

MSC2000: 

  • O646.7