甲烷等离子体裂解制氢制碳的影响因素研究  

Study on the Influencing Factors of Hydrogen and Carbon Production From Methane Plasma Cracking

作　　者：吴祖良 成雨莲 高尔豪 李晶[1] 朱佳丽 姚水良 王建新[2] 江捷 WU Zuliang;CHENG Yulian;GAO Erhao;LI Jing;ZHU Jiali;YAO Shuiliang;WANG Jianxin;JIANG Jie(Key Laboratory of Advanced Plasma Catalysis Engineering for China Petrochemical Industry,School of Environmental Science and Engineering,University of Changzhou,Changzhou 213164,China;Environmental Protection Design&Research Institute,Zhejiang Gongshang University,Hangzhou 310012,China)

机构地区：[1]常州大学环境科学与工程学院,石化行业先进等离子体催化技术工程实验室,江苏常州213164 [2]浙江工商大学环保设计研究院,浙江杭州310012

出　　处：《石油学报（石油加工）》2023年第5期1205-1214,共10页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：国家自然科学基金项目(12075037)资助。

摘　　要：甲烷(CH_(4))等离子体裂解是一种很有前景的制氢方法。采用针-针式纳秒脉冲火花放电方法研究了放电功率、CH_(4)含量、CH_(4)流量、反应温度以及不同背景气氛等对CH_(4)转化和产物分布的影响,并采用TEM与Raman方法对产物纳米碳的形貌和结构进行表征分析。结果表明:CH_(4)放电裂解产物主要是氢气(H_(2))、纳米碳(C)和乙炔(C_(2)H_(2)),另有少量的乙烷(C_(2)H_(6))和乙烯(C_(2)H_(4))生成;在30 mL/min的CH_(4)/Ar总气体流量和10%的CH_(4)初始体积分数下,输入60 W功率时实现了CH_(4)转化率83.56%和H_(2)选择性70.28%。放电功率的增大有助于CH_(4)的完全裂解,促进H_(2)和C的生成;而随着CH_(4)初始含量和CH_(4)气体流速的提高,CH_(4)的转化率、H_(2)和C的选择性明显下降;500℃以下的反应温度对CH_(4)转化影响不大,但当反应温度从500℃升高至800℃时,C_(2)H_(2)高温分解加快;与N_(2)相比,放电中Ar激发态更能促进CH_(4)的初步分解和C_(2)H_(2)的形成;通过TEM和Raman表征,发现N_(2)背景气氛下产生粒径更小的20~30 nm无定形碳,而在Ar背景气氛下纳米碳的石墨化程度更高。Plasma cracking of methane(CH_(4))is a promising method of hydrogen production.The effects of discharge power,CH_(4)content,CH_(4)gas flow rate,reaction temperature and different background gas on CH_(4)conversion and product distribution were studied using the needle-needle nanosecond pulse spark discharge,and the morphology and structure of nano-carbon were characterized and analyzed using TEM and Raman.The results show that hydrogen(H_(2)),nano-carbon(C)and acetylene(C_(2)H_(2))are the main products of CH_(4)discharge cracking,plus a small amount of ethane(C_(2)H_(6))and ethylene(C_(2)H_(4)).At a total Ar/CH_(4)gas flow rate of 30 mL/min,an initial volume concentration of 15%CH_(4),and discharge power of 60 W,83.56%CH_(4)conversion rate and 70.28%H_(2)selectivity can be achieved.The increasing discharge power contributes to complete CH_(4)cracking,and the generation of H_(2)and C.However,with the increase of the initial content and gas flow rate of CH_(4),the conversion rate of CH_(4)as well as the selectivity of H_(2)and C are decreased significantly.The reaction temperature below 500℃has little effect on CH_(4)conversion.However,as the reaction temperature is increased from 500℃to 800℃,the pyrolysis of C_(2)H_(2)can be accelerated.Compared with N_(2),Ar excited state during discharge can more obviously promote the initial decomposition of CH_(4)and the formation of C_(2)H_(2).TEM and Raman characterization results show that the amorphous carbon with a smaller size of 20-30 nm can be produced in the N_(2)background gas,and the graphitization degree of nano-carbon is higher in the Ar background gas.

关 键 词：火花放电 甲烷裂解 氢气 纳米碳 C_(2)分布 

分 类 号：TE64[石油与天然气工程—油气加工工程]