老化时间对催化裂化催化剂物性的影响

EFFECT OF AGING TIME ON PHYSICAL PROPERTIES OF CATALYTIC CRACKING CATALYST

采用固定流化床老化装置,在水热老化温度为800℃、100%水蒸气和常压条件下,对催化裂化催化剂进行2~70 h的老化试验,考察老化时间对催化裂化催化剂物性的影响。采用XRD、BET、NH3-TPD、Py-IR和微反活性等表征手段对选取的不同老化时间下的11个催化剂样品进行分析。结果表明:随着老化时间的延长,催化裂化催化剂相对结晶度、比表面积呈先快速降低后缓慢降低的趋势;弱L酸酸量与弱B酸酸量比、强L酸酸量与强B酸酸量比呈先增加后降低的趋势;催化剂微反活性宏观上表现出先快速下降后趋于平缓的趋势。

The catalytic cracking catalyst was aged for different duration from 2 h to 70 h under the conditions of 800℃,100%steam and normal pressure in a fixed fluidized bed aging apparatus to investigate the physical properties changes of the catalyst.Eleven aged catalysts with different aging periods were analyzed by XRD,BET,NH3-TPD and Py-IR and MAT.The results showed that as the aging period increased,the relative crystallinities and the specific surface areas of the catalysts decreased rapidly and then slowly;the ratio of weak L acid to B acid and the ratio of strong L acid to B acid increased first and then decreased;the MAT of the catalyst decreased rapidly and then tended to be flat.