ZSM-35分子筛催化剂用于正丁烯骨架异构的反应性能及失活再生研究

Study of Activity and Regenerability of ZSM-35 Zeolite for n-Butene Skeleton Isomerization

摘要:

采用高硅铝比ZSM-35分子筛催化剂，在固定床连续反应器中进行了正丁烯骨架异构化稳定性试验，并采用氧气烧炭再生，利用TPO、BET、NH3-TPD、Py-IR等技术，对新鲜催化剂、不同反应时间后及再生的催化剂进行表征，研究了积炭对催化剂活性的影响。结果表明：正丁烯转化率为45%时，异丁烯选择性为95%，经过390 h的运行，异丁烯的收率仍能达到32%，该催化剂具有良好的稳定性及选择性，且再生性能良好。催化剂上积炭主要在反应初期形成，沉积在微孔内，且优先发生在强酸中心上，主要为难以烧除的类石墨炭。

Abstract:

Skeleton isomerization of n-butene over ZSM-35 Zeolite with high Si/Al ratio on a fixed-bed reactor was investigated. The used catalyst was regenerated by high temperature oxidation method. Information about the effect of carbon deposition was obtained by TPO、BET、NH3-TPD and Py-IR measurements.. The results indicated that the catalyst exhibits good stability and regenerability, furthermore, the conversion of butene was 45% and the selectivity of iso-butene was 95%, when increasing TOS to 390h, the yield of iso-butene was still maintained above 32%. Deposited carbon was substantially formed during the initial period in micropore preferentially on strong acid sites and was mainly graphite carbon which was difficult to be removed.