不同硅铝比Al-ITQ-13分子筛的甲醇制丙烯反应催化性能

发布时间：2018-07-09 20:27

本文选题：MTP + Al-ITQ-分子筛　；参考：《燃料化学学报》2017年11期

【摘要】：采用晶种法直接合成了硅铝比(SiO_2/Al_2O_3物质的量比)为137、224和309的三种Al-ITQ-13分子筛,并采用粉末X射线衍射(XRD)、扫描电镜(SEM)、N_2吸附-脱附、固体核磁共振(MAS NMR)和NH_3-程序升温脱附(NH_3-TPD)等分析方法对不同硅铝比分子筛进行了表征,并在固定床微型反应评价装置上,考察了硅铝比对甲醇转化制丙烯反应性能的影响。结果表明,不同硅铝比Al-ITQ-13分子筛呈现出相似的织构性质,酸量及酸强度随着硅铝比的升高逐渐下降。硅铝比对甲醇转化反应的产物分布存在较大的影响;随着硅铝比的升高,氢转移反应和芳构化反应活性降低,使得乙烯选择性下降,而丙烯和丁烯的选择性升高。硅铝比由137提高到309,丙烯的选择性(质量分数)由46.04%增加到55.52%,而丙烯/乙烯比由3.39提高到6.57。
[Abstract]:Three kinds of Al-ITQ-13 molecular sieves with SiO2 / AlSn2O3 ratio of 137224 and 309were synthesized by means of crystal seeding method, and were adsorbed and desorbed by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The molecular sieves with different Si-Al ratios were characterized by solid nuclear magnetic resonance (MAS NMR) and NH _ 3-TPD. The effect of Si / Al ratio on the reaction performance of methanol to propylene was investigated in a fixed-bed micro-reactor. The results show that Al-ITQ-13 zeolites with different Si-Al ratios exhibit similar texture properties, and the acid content and strength decrease with the increase of Si-Al ratio. With the increase of the ratio of Si to Al, the activity of hydrogen transfer reaction and aromatization decreased, and the selectivity of ethylene decreased, while the selectivity of propylene and butene increased. The ratio of Si to Al was increased from 137 to 309, the selectivity (mass fraction) of propylene increased from 46.04% to 55.522%, and the ratio of propylene to ethylene increased from 3.39 to 6.57.
【作者单位】：中国石油大学(北京)化学工程学院重质油国家重点实验室;
【基金】：国家自然科学基金(U1462202) 中国石油大学(北京)科研基金(2462015YQ0309)资助~~
【分类号】：O643.36;TQ221.212

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