镧改性对催化裂化催化剂物化性能及抗氮性能的影响

Effect of lanthanum modification on physico-chemical properties and nitrogen-resistant performance of FCC catalysts

采用浸渍和成胶过程中混合引入镧的方式制备了镧改性催化剂,利用比表面测试(BET法)和吡啶吸附红外光谱(FT-IR)等手段对其物化性质和酸性进行了表征;以大庆和大港两种高氮焦化蜡油为原料,在重油微反装置上对催化剂的抗氮性能进行了评价。结果表明,镧改性明显提高了催化剂酸性和抗氮性能,且随镧引入方式或位置的不同而存在较大的差别,镧浸渍催化剂的抗氮性能最优。催化剂物化性能与抗氮性能关联结果显示,催化剂总酸量在抗氮性能中起着主要作用。

Several catalytic cracking catalysts modified with lanthanum were prepared by impregnation or blending method. The physico-chemical properiies were characterized by BET and FT-IR spectroscopy of adsorbed pyridine, and the nitrogen-resistant performance of samples were investigated on a micro-activity test unit with Daqing and Dagang coking vacuum gas oil （VGO） as feedstocks, respectively. The results show that the total acidities and nitrogen-resistant performance of FCC catalysts modified with lanthanum are apparently improved, and vary greatly with the ways of lanthanum modification. The nitrogen-resistant performance of catalyst impregnated with lanthanum is remarkably superior to that of other catalysts. Meanwhile, the results also show that the difference of nitrogen-resistant performance of catalysts mainly depends on their total acidities.