多级孔Hβ分子筛用于催化裂化轻汽油醚化反应性能的研究

Study on etherification performance of FCC light gasoline on the hierarchical porous Hβ zeolite

关键词:  Hβ分子筛  多级孔  催化裂化轻汽油  醚化  碱处理 

Key words:  Hβ zeolite  hierarchical porous  FCC light gasoline  etherification  alkali treatment

摘要:

采用NaOH溶液对Hβ分子筛进行碱处理,得到了含有多级孔的Hβ分子筛,并用XRD、SEM、N₂吸附脱附、NH₃-TPD、Py-IR等手段对处理前后的分子筛进行表征,在小型固定床反应器上进行了醚化反应研究,考察了反应工艺条件对其醚化性能的影响。实验结果表明,碱处理可以在保持Hβ分子筛晶体结构的同时,增加介孔体积和比表面积,增加中强酸和B酸酸量,因而提高了醚化活性。在温度为70 ℃、空速为1 h-1、醇烯物质的量比为1.1、反应压力为0.9 MPa条件下,催化裂化轻汽油的叔碳烯烃转化率可达67.49%,比商业Hβ分子筛提高11.7%。 

Abstract:

The hierarchical porous Hβ zeolite was prepared by the alkaline treatment of Hβ zeolite with NaOH solution, and the zeolite of before and after processing were characterized by XRD, SEM, N₂ adsorption-desorption, NH₃-TPD and Py-IR. The etherification reaction for FCC light gasoline on hierarchical porous Hβ zeolite was carried out in a fixed bed reactor. The effect of reaction temperature, space velocity, mole ratio of methanol and tert-olefin and pressure on the etherification reaction were studied. The results showed that alkali treatment could maintain Hβ zeolite crystal structure, and meanwhile increase the specific surface area and mesopore volume, and the amount of dium-strong acid and acid B, thus increase the etherification activity. In optimum conditions (temperature of 70 ℃, the space velocity of 1 h-1, MeOH/tert-olefins molar ratio of 1.1, the reaction pressure of 0.9 MPa), the tert-olefins conversion of 67.49% was received, which was higher than commercial Hβ zeolite by 11.7%.