微波复合直流等离子体转化天然气制乙炔的研究MW-DCHybrid.PDFVIP

2005 年第 63 卷 化 学 学 报 Vol. 63, 2005 第 7 期, 625～630 ACTA CHIMICA SINICA No. 7, 625～630 ·研究论文· 微波复合直流等离子体转化天然气制乙炔的研究 徐兴祥 杨永进 孙家言 张劲松* ( 中国科学院金属研究所 沈阳 110016) 摘要 利用微波复合直流等离子体对天然气转化制乙炔反应进行了研究. 考察了氢烷比、气体流量、功率等参数对装 置的能量利用率以及天然气转化反应的影响, 并考核了微波复合直流等离子体转化天然气制乙炔工艺的稳定性. 实验 结果表明: 微波复合直流等离子体装置的能量利用率随等离子体工作气体的流量的增加而提高; 由于微波的作用使传 统直流柱状等离子体分化为多根丝状等离子体, 从而使得电极的烧蚀方式由传统的点烧蚀变为面烧蚀, 并大幅度提高 等离子体转化天然气工艺的稳定性和电极寿命; 甲烷的转化率和乙炔的收率随功率的增加而提高, 随 CH4/H2 比和气体 流量的增加而降低, 在氢烷比为 0.9、总气体流量为 760 L/min、微波源输出电功率 6 kW、直流电源输出功率 90 kW 时, 甲烷转化率可达 84.4%, 乙炔选择性为 75.6%, 乙炔收率为 63.8%, 乙炔能耗达 10.8 kWh•kg－1; 电极寿命超过 200 h. 关键词 微波复合直流等离子体; 天然气; 乙炔; 长电极寿命 MW-DC Hybrid Plasma Conversion of Natural Gas to Acetylene XU, Xing-Xiang YANG, Yong-Jin SUN, Jia-Yan ZHANG, Jin-Song* (Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016) Abstract The conversion of methane to acetylene in MW (microwave)-DC (direct current) hybrid plasma was studied. The effects of H /CH ratio, flow rate and power on the reaction and the stability of the device 2 4 were investigated. The energy efficiency of the MW-DC hybrid plasma device was increased with the in- crease of the flow rate. The conventional DC plasma column was split into tens of plasma filaments, which changed the erosion mode of the electrode from point erosion to face erosion. The conversion of methane and the yield of acetylene are increased with the