泡沫金属微反应器内富氢重整气中CO选择性甲烷化

在微反应器中,用泡沫金属镍为载体负载4Ni-2Ru/ZrO2双金属催化剂,用于选择性甲烷化去除富氢重整气中的CO。考察了催化剂负载方法、焙烧温度和空速等对CO选择性甲烷化的影响,借助X射线衍射(XRD)、程序升温还原(H2-TPR)等手段对催化剂制备方法与催化性能的关系进行了探讨。结果表明,直接将4Ni-2Ru/ZrO2催化剂涂布在泡沫镍片上,350℃下焙烧,反应温度为260℃,空速为2 000 h-1~6 000 h-1,可将富氢转化气中CO降至30×10-6以下,其中空速为5 000 h-1,可将CO出口浓度降至7×10-6,CO2的转化率低于1.5%。反应温度在260℃~300℃,CO的转化率在99.6%以上,CO出口浓度在50×10-6以下。

Selective catalytic methanation of CO in hydrogen-rich gas with a metal foam microreactor

For the purpose of removing CO to less than 100×10^－6 to meet the demand of the proton exchange membrane fuel cells (PEMFC), a bimetallic catalyst 4Ni-2Ru/ZrO₂ for CO selective methanation was prepared by homogeneously coating on the foam niekel. The effect of space velocity of feedstock, coating methods and calcination temperature on CO selective methanation was investigated in a microreactor.The relationship between the preparation method and activity of the 4Ni-2Ru/ZrO₂ catalyst was also explored by means of X-ray diffraction (XRD) and temperature programmed reduction (TPR). The results indicate that the outlet concentration of CO can be reduced to less than 30×10^－6 at 260℃ and the space velocity from 2000h^-1 to 6000h^-1, with the calcination temperature of 350℃. The outlet concentration of CO can be reduced to 7×10^－6 and the CO2 conversion is less than 1.5% as the space velocity is 5000h^-1.Because of excellent heat transfer and mass transfer ability, the CO conversion can reach a high level more than 99.6% with the outlet concentration below 50×10－6 even at a high reaction temperature of 300℃.