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在HZSM-5中引入金属元素进行改性,可以改变催化剂的酸性和孔结构,进而提高催化剂的抗积炭能力和选择性。选用金属铈改性前后的HZSM-5分子筛催化剂,在内径为16 mm的不锈钢管式反应器中考察反应温度、系统压力等条件对甲醇制汽油(MTG)反应的影响,并结合X射线衍射、FT-IR、低温氮吸附-脱附等对HZSM-5催化剂进行表征,分析了汽油收率、产物分布和产物组成的变化规律。结果表明,经铈改性后HZSM-5催化剂仍能保持完整的MFI结构,L酸强度增加。在反应温度为375℃,系统压力为2.0 MPa,进料空速为1.0 h~(-1)的条件下,甲醇转化率为100%,汽油的收率可达34%以上,反应效果和活性周期明显优于改性前。
HZSM-5 in the introduction of metal elements modified, you can change the acidity and pore structure of the catalyst, and thus improve the anti-carbon catalyst capacity and selectivity. The effects of reaction temperature, system pressure and other conditions on the reaction of methanol to gasoline (MTG) were investigated in a 16 mm ID stainless steel tubular reactor with HZSM-5 zeolite catalyst before and after modification with cerium. Combined with X-ray diffraction, HZSM-5 catalyst was characterized by FT-IR, low temperature nitrogen adsorption-desorption and so on. The changes of gasoline yield, product distribution and product composition were analyzed. The results show that the HZSM-5 catalyst can still maintain a complete MFI structure after the cerium modification, and the L acid strength increases. Under the conditions of reaction temperature of 375 ℃, system pressure of 2.0 MPa and feed space velocity of 1.0 h ~ (-1), the conversion of methanol was 100% and the yield of gasoline was above 34%. The reaction efficiency and activity Cycle was significantly better than before modification.