反应条件对甲烷化法去除重整氢气中CO的影响

Influence of reaction conditions on removal of CO in reformate by methanation method

研究了在采用甲烷化法去除重整氢气中CO的过程中,反应温度、CO浓度和CO2浓度对3个竞争反应即CO甲烷化反应、CO2甲烷化反应、逆变换反应(RWGS)的影响。实验结果表明,随着温度升高,CO、CO2甲烷化反应速率均增大,但CO甲烷化的选择性降低。CO浓度对CO甲烷化反应速率的影响在高温时较为明显,反应速率随CO浓度的升高而增大;CO对CO2甲烷化反应的影响在较低温度下较为显著,CO2甲烷化反应速率随CO浓度的升高而减小,表明CO对CO2的甲烷化具有抑制作用,因而随着CO浓度的升高,选择性增大。另一方面,CO2浓度对CO甲烷化反应几乎没有影响,而CO2甲烷化反应速率和RWGS反应速率均随CO2浓度的升高而增大,该趋势在高温下更加显著,并对3个竞争反应的宏观动力学进行了初步研究。

There are three competitive reactions in the removal of CO in reformate by rnethanation, including CO methanation, CO2 methanation and reverse water-gas shift （RWGS）. Influence of several parameters such as reaction temperature, CO concentration and CO2 concentration on these reactions is studied. Results showed that both the CO and CO2 methanation rate increased with increasing temperature, while the selectivity for CO methanation decreased. With higher CO concentration, the CO methanation appeared remarkably faster at higher temperature, and the CO2 methanation was notably depressed at lower temperature. The selectivity for CO rnethanation increased with increasing CO concentration. On the other hand, the concentration of CO2 appeared no effect on the CO methanation, while both the CO2 rnethanation rate and the RWGS reaction rate increased when increasing the CO2 concentration, especially at higher temperature. The rnacro-kinetics of these three competitive reactions was also studied.