大气压微波等离子体炬驱动Boudouard反应实现CO_(2)转化的研究

Study of CO_(2) Conversion in Boudouard Reaction Driven by Atmospheric-pressure Microwave Plasma Torch

利用大气压CO_(2)微波等离子体放电的余辉和固态碳源相互作用进行布多阿尔反应,把CO_(2)转化为CO实现温室气体的资源化利用。通过发射光谱测量观察到微波等离子体炬驱动的布多阿尔反应中化学荧光复合过程的发生,测量了采用实心石墨棒时布多阿尔反应中CO_(2)转化效果随着功率的变化规律,进一步提出了以空心石墨棒作为布多阿尔反应的碳源,发现转化效果得到明显提高,并获得了随着功率、气体流量、石墨棒尺寸和组分变化的规律。另外,讨论了以不同种类的碳源作为反应物进行布多阿尔反应的实际对比效果及其相应的物理原因。实验结果表明CO_(2)等离子体余辉喷射到石墨棒表面发生的布多阿尔反应是实现CO_(2)到CO转化的重要过程;随着所使用的空心石墨棒内孔直径增加,生成的CO浓度也随之增大;在CO_(2)载气中以一定比例分别添加Ar或N2会增加CO的生成量。

An atmospheric-pressure microwave plasma torch(APMPT)is employed to drive Boudouard reaction to con-vert CO_(2) into CO for the purpose of resource utilization.The process of Boudouard reaction driven by APMPT is diagnosed by optical emission spectroscopy(OES)and the chemiluminescence occurrence is observed experimentally.The variation of CO concentration is measured with respect to the microwave power when the graphite rod is placed in the downstream of the afterglow of CO_(2) APMPT by means of gas chromatograph(GC).Furthermore,a hollow graphite rod is proposed,thereby the conversion rate is enhanced,and the variation of conversion with the microwave power,gas flow rate,geometric sizes of rod,and composition of working gas is investigated.Furthermore,the conversion effects by Boudouard reaction with use of various carbon materials are compared and the discussion of mechanism is delivered.The experimental results indicate that the Boudouard reaction occurring on the surface of graphite rod plays the pivotal role in CO_(2) conversion into CO,and the concentration of the generated CO increases with diameter of the hollow graphite rod;meanwhile,the addition of Ar or N2 into carrier gas CO_(2),respectively,will improve the CO concentration.