城市煤气甲烷化低镍催化剂的研究

Low Ni-Containing Catalyst for Town Gas Methanation

使用活性评价装置和TPR、XRD、TEM等技术研究了活性组分Ni含量和助剂MgO、La_2O_3、MnO_2对 Ni 基城市煤气甲烷化催化剂性能的影响。结果表明 NiO 的含量可以在较大范围内变化,最低允许含量为6%(wt),MgO 与 NiO 能形成MgNiO_2,它的形成提高了催化剂的热稳定性。随 MgO 含量的增加热稳定性能增强,而且 MgO 含量影响催化剂表面酸度和积碳迷度,当其含量为1%(wt)时,催化剂无积碳出现。La_2O_3不与其它组分发生化学作用,稳定地分散于载体表面,可起到均化 Ni 晶粒度作用,它的存在对催化剂的活性和还原性能均有影响。实验研究出一种 Ni 含量低、活性高、热稳定性好、抗积碳能力强的城市煤气甲烷化催化剂。

The effects of Ni content and promoters such as MgO,La_2O_3 and MnO_2 on the performance of Ni-based methanation catalyst were studied by means of TPR, XRD,TEM and activity evaluation.It was found that,the NiO content in acce-ptable catalyst could be decreased to as low as 6% (wt).The combination of MgO and NiO can form MgNiO_2 and increase the catalyst thermal stability.These effects are more obvious when MgO content is increased.Promoter MgO can also influe- nee the surface acidity and carbon deposition rate.Promoter La_2O_3 is well-dispersed on the catalyst surface without any interac-tion with other components Introducing cf La_2O_3 limits the Ni crystallite size wi-thin a narrow range and affects the catalyst activity and reducibility.A new Ni-based town gas methanation catalyst with low Ni content and high activity,high cardon deposition resistivity is successfully developed in our la-boratory.