射频放电等离子体作用下CO_2-H_2的转化研究

Study on the conversion of carbon dioxide and hydrogen by RF-discharge plasma

在低压室温下,研究了在射频放电等离子体作用下CO2-H2体系的转化。分别考察了H2/CO2摩尔比、激发电压、原料气总流量对CO2转化的影响,分析了CO2转化的能量效率。结果表明:在射频放电等离子体作用下CO2与H2反应,得到的主要产物有CO、CH3OH和CH4。随着激发电压的增加,CO2转化率、甲烷的选择性及产率增大,CO的选择性明显下降,甲醇的选择性呈现先增大而后减小的趋势;当原料气中CO2含量不断增加时,CO2的转化率、产物甲醇和甲烷的选择性和收率显著下降,相应地CO的选择性却随之而增大。随着总流量的增加,CO2的转化率、产物甲烷和甲醇的选择性和产率减小,而CO的选择性在缓慢增加,但其产率是在不断减小的。整个反应过程中,CO2的转化率最高可达87.46%。

The conversion of CO2-H2 by RF-discharge plasma was studied under low pressure and ambient temperature. The effects of H2/CO2 molar ratio, discharge voltage, and total flow rate on the conversion of CO2 and the energy efficiency were investigated. Experimental results showed that CO2 reacted with H2 by RF-discbarge plasma to form really CO, CH3OH and CH4. The conversion of CO2 , the selectivity and yield of methane increased with the increase of discharge voltage, while the selectivity of CO reduced, the selectivity of methanol decreased at first but then increased; the conversion of CO2, the yield and selectivity of methane and methanol reduced with the increase of CO2/H2 ratio in feed gas, while the selectivity of CO increased. As total flow rate increased, he conversion of CO2, the selectivity and yield of methane and methanol reduced, but the selectivity of CO increased slowly while its yield decreased. In the whole process, the maximum conversion of CO2 was up to 87.46%.