Plasma-assisted CO2 conversion in a gliding arc discharge: Improving performance by optimizing the reactor design
Plasma-assisted CO2 conversion in a gliding arc discharge: Improving performance by optimizing the reactor design
复制标题
滑动电弧放电中的等离子体辅助 CO2 转化：通过优化反应器设计提高性能
DOI：
10.1016/j.jcou.2018.12.019
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发表时间：
2019-01-01
影响因子：
7.7
通讯作者：
Tu, Xin
中科院分区：
文献类型：
--
作者：
Li, Li;Zhang, Hao;Tu, Xin
本文研究了滑动弧光放电(GAD)分解CO2的性能，旨在通过优化反应器设计来提高GAD的性能。考察了气体流量、喷嘴结构、石英罩结构等参数对CO2转化率和能量效率的影响。结果表明，CO2转化率随流量升高的变化曲线可以明显地分为两种模式：A型随出口烟气温度&Gt；440℃；B型随出口烟气温度<；440℃；随着流量的增加，CO2转化率呈A型上升，B型下降。模式A中相对较高的温度与CO2转化率呈负相关，因为它可以刺激CO和O的复合，从而导致CO2转化率随着流量的增加(和气体温度的降低)而增加。在所研究的大多数条件下，喷嘴直径较小(1.0 mm)的喷嘴具有较好的CO2转化性能和能量效率，在较高的流速(~gt；=4 L/min)下，较长的喷嘴与电极之间的距离有利于CO2的转化。结果表明，四边形反应器罩具有更好的空间利用率和更高的等离子体气体处理比例，可以确保注入气体与等离子体之间更充分的接触，从而获得更好的性能。最佳工艺条件为：流量为3 L/min，喷嘴直径为1 mm，喷嘴与电极之间的距离为5 mm，加盖为四边形，此时CO2转化率可达11.1%，能效可达20.7%。与其他典型的非热等离子体，如介质阻挡放电和电晕放电相比，GAD显示出显著更高的能量效率和高出一个数量级的流量。
In this paper, a gliding arc discharge (GAD) is investigated for CO2 decomposition, with particular efforts directed toward improving the performance by optimizing the reactor design. The effects of various parameters, e.g., gas flow rate, configuration of the injector nozzle, and structure of the quartz cover, on the CO2 conversion and energy efficiency are investigated. The results indicate that the variation profiles of CO2 conversion upon rising flow rate can be clearly be divided into two patterns: Pattern A with outlet gas temperature>440 degrees C and Pattern B with outlet gas temperature< 440 degrees C. The CO2 conversion rises in Pattern A but decreases in Pattern B with the increase in flow rate. The relatively high temperature in Pattern A is negatively correlated with CO2 conversion because it can stimulate the recombination of CO and O, which leads to the increase in CO2 conversion with increasing flow rate (and decreasing gas temperature). A smaller injector nozzle diameter (1.0 mm) exhibits a better performance in terms of both CO2 conversion and energy efficiency under most of the conditions studied, and a longer distance between the injector nozzle and electrodes is beneficial to the CO2 conversion at relatively high flow rates (>= 4 L/min). A quadrangular reactor cover was proved to have a better space utilization and a higher fraction of gas treatment by plasma, which can ensure a more adequate contact between the injected gas and plasma, and thus a better performance. The optimum conditions are: flow rate=3 L/min, nozzle diameter=1.0 mm, distance between injector nozzle and electrodes=5.0 mm, and a quadrangular cover, under which CO2 conversion and energy efficiency up to 11.1% and 20.7% can be achieved. Compared to other typical non-thermal plasmas, such as dielectric barrier discharge and corona discharge, GAD shows a significantly higher energy efficiency along with a flow rate that is an order of magnitude higher.