常压、脉冲微波强化丝光等离子体作用下甲烷与二氧化碳的反应研究

采用脉冲微波强化丝光等离子体反应装置，研究了甲烷氧化偶联与二氧化碳重 整制合成气(CO+H_2)副产乙炔、乙烯的反应。常压下，当CH_4和CO_2流量分别为 120，80mL/min，微波峰值功率120W，脉冲通断比为100/100ms时，CH_4和CO_2转化 率分别为70.8%，68.8%;CO, C_2H_2,C_2H_4选择性分别为75%，17.8%和4.1%，产物 中没有积炭。H_2/CO摩尔比值随原料气中甲烷比例的增加而增大，当CH_4/CO_2摩 尔比为2：1时，H_2/CO摩尔比达到2，这种比例的合成气能方便地用于下一步的 Fischer-Tropsch反应和其他化学品的合成。与其他等离子体反应相比，采用脉冲 强化常规丝光等离子体进行CH_4脱氢偶联与CO_2重整反应，能量效率明显提高，这 对于促进微波等离子体技术在C1化学中的应用具有重要的意义。

Study on the Conversion of CH_4 and CO_2 Using a Pulsed Microwave Plasma under Atmospheric Pressure

A conventional wire-like plasma enhanced and spread by pulsed microwave was used to study the oxidative coupling and reforming of CH_4 with CO_2 to CO, C_2H_2, C_2H_4 and H_2. Under the conditions of atmospheric pressure, flow rate of 200 mL/min (CH_4/CO_2 = 1.5:1), peak microwave power of 120 W and pulse duty factor of 100/100 ms, conversions of CH_4 and CO_2 were 70.8% and 68.8%, respectively; selectivities of CO, C_2H_2, C_2H_4 were 75%, 17.8% and 4.1%, respectively, and there was no carbon deposits. Ratio of H_2/CO increased with increasing CH_4 concentration in the feed gas, and a H_2/CO ratio of 2 could be obtained at a ratio 2:1 of CH_4 to CO_2, which is acceptable for Fischer-Tropsch and other synthesis processes. The energy efficiency of the pulsed microwave plasma was obviously improved. We suggested that this enhanced pulsed plasma is useful for oxidative coupling and reforming of CH_4 with CO_2 in C1 chemistry.