摘要
研究了在550℃长时间深度水蒸汽处理再生对HZSM-5催化剂的酸性和正十六烷裂解性能的影响,并将不同再生次数的催化剂与无铝源合成的沸石进行了对比。结果表明,一次再生的催化剂仍能保持正十六烷裂解所需的酸中心数,不影响转化率,但选择性有变化,产物中烯烃含量高,几乎没有芳烃生成;三次再生后,正十六烷转化率略有下降,产物中虽有较多的C_(10)～C_(15)组分,但气相产物仍在60％左右,C_3～C_4也仍占气相产物的95％左右,C_3～C_4中含有大量烯烃;无铝源合成的催化剂只有弱酸中心存在,其正十六烷的转化率小于60％,芳烃含量小于1％,烯烃含量明显高于含铝沸石。
The effects of the deep regeneration of HZSM-5 catalyst by steam at 550℃ and the regeneration of the deactivated HZSM-5 by air-steam on the acidity and activity for w-hexadecane were studied. It was found that a large amount of framework Al was removed by steam in the initial 10 h, and then the removal of Al decreased with the extension of treatment time. After the first regeneration of the deactivated HZSM-5 catalyst by air-steam, the number of acid sites remained could still satisfy the needs for the n-hexadecane cracking, the conversion did not decrease, but the selectivity changed obviously,the content of olefins in the product increased and the aromatics was very low. After the third regeneration, the conversion decreased slightly, and there were more C10-C15 n-alkanes in the product, but the content of gas product was still around 60%, in which there were 95% C3-C4 and a lot of C3-C4 olefins. For the HZSM-5 synthesized without Al sourse, only weak acid sites were observed, and the conversion of n-bexadecane was lower than 60%, the content of aromatics in the product was <1% and the content of olefins was obviously higher than that of the zeolites synthesized with aluminium source.
基金
国家自然科学基金
石化总公司基金
