镍基催化剂用于合成气甲烷化的实验研究

实验基于工业用镍基甲烷化催化剂,分别考察了操作温度、原料气CO浓度、操作压力、空速等对合成气(CO浓度5%~25%)甲烷化反应的影响,并分析了造成催化剂失活的因素。结果表明,在300~500 ℃ CH₄的生成速率随着温度的升高、压力的增大、CO浓度的增加而增大。但CO的浓度不能过高,当H₂/CO≤3时催化剂的催化活性会逐步下降。通过XRD、EDS等分析结果得知,催化剂表面存在积炭,催化剂的失活跟积炭有关,通过进一步的对照实验和BET分析表明,积炭的速率与反应温度有关,温度越高积炭速率越快。

Study on the syngas methanation of nickel-based catalyst

The experiment was conducted based on an industrial nickel-based catalyst.The effects of operating temperature,feed ratio,and operating pressure on the methanation and the factors for the catalyst deactivation were investigated.The results indicate that the formation rate of CH4 increases with operating temperature,pressure,and CO concentration.But the concentration of CO can not be excessive,because the activity of catalyst will gradually decrease if H2/CO≤3.The carbon deposit is found on the surface of deactivated catalyst by X-Ray Diffraction(XRD) and Energy Dispersive Spectrometer(EDS) analyses.It can be concluded that the deactivation of catalyst may be related to the surface carbon deposition.The BET surface area analysis shows that the rate of carbon deposition is related to the reaction temperature,and the higher the temperature,the faster the coking.