金属改性SAPO-34分子筛的合成及其催化裂解丁烯性能的研究

Synthesis of SAPO-34 molecular sieve modified with metal and study on catalytic properties of 1-butene catalytic cracking reaction

以石脑油裂解副产混合C4中的丁烯为原料,以金属改性的SAPO-34分子筛为催化剂,经催化裂解合成了丙烯。分别采用浸渍法和水热合成法对SAPO-34分子筛进行了金属改性,改性金属为铈与锰,以XRD、NH3-TPD等表征手段对改性后的试样进行了表征。将改性后的催化剂试样应用于丁烯催化裂解反应中,考察了改性方式、改性金属种类对SAPO-34分子筛酸性及丁烯裂解性能的影响,并与未改性SAPO-34分子筛进行了比较。结果表明:铈元素对延长催化剂的寿命有积极作用,而锰元素更适合用于提高丙烯选择性;采用水热合成法可以有效提高催化剂的丁烯转化率,减缓积炭速率,延长催化剂的寿命;用Ce改性时,浸渍法可得到更高的丙烯选择性;用Mn改性时,水热合成法可得到更高的丙烯选择性。

Propylene is prepared by catalytic cracking using 1？butene from naphtha cracking byproduct mixture C4 as rawmaterial, and SAPO？34 molecular sieve modified with metal as catalyst. SAPO-34 molecular sieve is modified with metals of cerium andmanganese by impregnation method and hydrothermal synthesis method, respectively, and the modified catalysts are characterized byXRD and NH3 -TPD. The modified catalysts are applied in 1-butene catalytic cracking reaction, and the effects of modifying mode andmetal kinds on the acidity of catalyst and 1-butene catalytic cracking properties are investigated, and the unmodified catalyst is taken ascontrast. The results show that cerium is beneficial to lengthening the lifetime of catalyst, while manganese is suitable for enhancing theselectivity of propylene. The catalyst prepared by hydrothermal synthesis method can effectively increase the conversion rate of 1-bu-tene, retard the carbon deposition speed, and lengthen the lifetime of catalyst. The selectivity of propylene can be enhanced by usingthe catalyst modified by cerium and prepared by impregnation, or modified by manganese and prepared by hydrothermal synthesis.