天然气转化催化剂的失活特性

用化学分析、ＢＥＴ流动色谱法，Ｘ射线衍射及小角散射等方法，对天然气转化催化剂的失活特性进行研究，发现催化剂中Ｎｉ组分有流失现象，流失率约为１０％左右；失活催化剂中有ＮｉＯ、ＮｉＣ等新物相存在，比表面积增大。与新鲜催化剂对比分析可知，作为载体的α－Ａｌ２Ｏ３，失活后在（０１２）和（１０４）晶面上平均晶粒度减小；Ｎｉ在（１１１）晶面上的晶粒度变化不大，但在晶面（２００）上的晶粒度增大。失活催化剂的孔径分布改变较多，小孔的比率相对增加，而在孔径为２５ｎｍ附近的过渡孔减少。

Deactivation characteristics of reforming catalyst

he composition, surface area, crystallite size and porous distribution of the reforming catalysts were investigated by chemical analysis, BET method, X ray diffraction (XRD) and Small Angular X ray Scatting (SAXS) techniques, respectively. Compared with the fresh reforming catalyst, the content of active component (nickel) was reduced by about 10% in the deactive catalyst, and the surface area was increased; It was found by XRD experiments that new phases of NiO and NiC are present, the crystallite size of α Al 2O 3 (carrier in the catalyst) tends to be reduced on the crystal surface of (012) and (104). The results show that the crystal size of Ni(Ⅲ) surface does not change obviously, but it grows on the crystal surface of Ni(200). The important characteristics of the deactived catalyst was the change of porous distribution. The relative ratio of fine porous increases and the mediate porous with a diameter of 25mm decreases.