RN-1催化剂再生性能的研究

STUDIES ON REGENERATION OF RN-1 CATALYST

用X射线荧光法(XRF)、X射线衍射(XRD)及低温氮吸附(BET)等手段研究了RN-1催化剂在水蒸气及氮气再生过程中的化学组成、物理性质及结构变化,并在小型加氢装置上考察了不同再生气氛对再生催化剂活性的影响。结果表明,水蒸气-空气法再生使催化剂活性组分间相互作用增强,导致WO_3晶粒增大,并生成NiWO_4结晶,催化剂压碎强度显著下降,催化剂的脱氮活性也只能恢复至新鲜催化剂的75～80％;采用氮气-空气法再生,催化剂的金属组分及结构未发生明显的变化,脱氮活性恢复至95％以上,脱硫活性恢复至95～99％,RN-1催化剂表现出了优良的再生性能。因此,对于工业装置RN-1催化剂的再生,推荐采用氮气-空气法。

The effects of the two regeneration methods,using steam with air or nitrogen with air, on the properties of RN-1 catalyst were studied. Several means including XRF, XRD, BET and XPS were used to characterize the changes in the chemical composition,physical properties and struc- ture of the catalyst before and after regeneration. The catalytic activities of the fresh and regenerated catalysts were evaluated and compared with a bench scale hydrogenation unit. It was shown that for the catalyst regenerated in the presence of nitregen and air,there are hardly any changes in the struc- ture and composition. Both the HDN and HDS activities could be restored to over 95% of the initial level. However,remarkable changes in the structure and composition were observed for the catalyst re- generated in the presence of steam and air. The HDN activity could only be restored to 75～80% of that of the fresh catalyst,while the HDS activity to 91～97%. Thus,for the regeneration of RN-1 ca- talyst in commercial units,the nitrogen-air method is preferred.