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 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 temperaturmultistage 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%.