中孔分子筛Al-MCM-41的制备及催化聚乙烯裂解反应

Preparation and Catalytic Performance for Polyethylene Pyrolysis of Al-MCM-41

采用水热合成法制备了不同硅铝比(摩尔比)的中孔分子筛Al-MCM-41,通过XRD、N_2吸附-脱附、FT-IR进行了表征,表明其具有中孔结构,并且随着骨架中铝含量的增加,Al-MCM-41孔道的长程有序性和结晶度有所减弱。将Al-MCM-41应用于高密度聚乙烯和低密度聚乙烯的催化裂解反应,通过改变硅铝摩尔比、反应温度和催化剂用量,探讨了Al-MCM-41催化聚乙烯裂解反应的规律,并比较了催化裂解及热裂解反应。实验结果表明,Al-MCM-41具有较高的催化活性和对液体产物较大的选择性。

Mesoporous Al-MCM-41 materials of different Si/Al molar ratios were synthesized under hydrothermal conditions, and characterized by XRD,FT-IR and nitrogen adsorption-desorption. The results show that the obtained materials are of the characteristics of mesoporous molecular sieves, and long-range order and crystallinity will degrade with the increase of Al content. Al-MCM-41 was used as catalyst in the pyrolysis of HDPE and LDPE. Influences of reaction conditions such as molar ratio of Si/Al, temperature and dosage of catalyst on the pyrolysis were examined, and the results of catalytic pyrolysis were compared with those obtained by thermal pyrolysis. The results show that Al-MCM-41 is of better catalytic activity and higher selectivity of liquid products.