微通道反应器内Ni-Ru/ZrO_2催化剂上CO选择性甲烷化

利用微通道反应器,对富氢重整气在Ni-Ru/ZrO2催化剂上的CO选择性甲烷化反应进行了研究;考察了反应温度、原料气中CO含量和CO2含量对Ni-Ru/ZrO2催化剂活性的影响,并考察了Ni-Ru/ZrO2催化剂的稳定性。实验结果表明,在微通道反应器中,Ni-Ru/ZrO2催化剂对CO选择性甲烷化反应具有良好的活性,当原料气中CO体积分数不大于1.0%时,在260～300℃内可将CO出口体积分数降至1×10-4以下;CO出口体积分数的最低值随原料气中CO含量的增加而增大,当原料气中CO含量增加到一定程度时,需采用温度梯级甲烷化法才能将CO出口体积分数降至1×10-4以下;120h的稳定性实验结果表明,Ni-Ru/ZrO2催化剂具有良好的稳定性,CO转化率均保持在99.50%以上。

Selective Methanation of CO over Ni-Ru/ZrO2 Catalyst in Microchannel Reactor

Selective methanation of CO in hydrogen-rich gas was studied in a special microchannel reactor.Ni-Ru/ZrO2 was taken as catalyst.Effects of reaction temperature,inlet CO and CO2 contents on activity of Ni-Ru/ZrO2 catalyst were observed.The stability of Ni-Ru/ZrO2 catalyst was also under consideration.Although the methanation of CO was strongly exothermic,in the microchannel reactor the reaction proceeded almost isothermally.So the Ni-Ru/ZrO2 catalyst displayed excellent catalytic performance in the reaction.The outlet CO volume fraction could decrease from not more than 1.0% to below 1×10-4 in temperature range of 260-300 ℃.Taking inlet CO volume fraction not more than 1.5% as upper limit,minimum outlet CO volume fraction increased with increasing inlet CO content.When inlet CO content increased to some extent,the operation mode of temperature-multistage methanation could keep outlet CO volume fraction below 1×10-4.Ni-Ru/ZrO2 catalyst had good stability during on-stream time of 120 h and could keep CO conversion at more than 99.50%.