摘要
采用研磨-焙烧-碱处理的方法,以偏高岭土为原料,制备了流化催化裂化(FCC)催化剂大孔基质。采用自动压汞仪和扫描电子显微镜对制备的大孔基质的孔结构和表面形貌进行了表征;考察了研磨时间和碱量对偏高岭土孔结构的影响。实验结果表明,经研磨-焙烧-碱处理后,偏高岭土中形成了100～2000nm的大孔,所形成的大孔与偏高岭土中原有的介孔构成了介孔-大孔双峰分布;研磨时间和碱量对偏高岭土的孔道结构有较大影响,在研磨时间为3h、加入NaOH的质量分数为20%时,偏高岭土的孔结构最好,以此条件下得到的偏高岭土为FCC催化剂基质与以高岭土为FCC催化剂基质相比,重油裂化的汽油收率从28.82%提高到36.14%。
Macroporous metakaolin matrix for fluid catalytic cracking（FCC） catalyst was prepared by milling-calcination-alkali treatment method. Metakaolin was first ballmilled with NaOH particles, then calcined, washed with water and finally dried. The pore size and pore distribution of modified metakaolin were determined by high-pressure mercury intrusion porosimetry. The morphology of modified metakaolin was characterized by SEM. Macropores with diameter of 100 -2 000 nm form in as-modified metakaolin. The newly-formed macropores together with original mesopores in raw metalkaolin give out bimodal pore distribution in modified metakaolin. Milling time and alkali content are major factors influencing pore structure of metakaolin. With different milling times and different alkali contents obvious disparity in pore distribution is observed. Cracking activity of catalysts improved sharply when milling time of 3 h and w（NaOH） of 20% were adopted in modification of Kaolin clay and was used as matrix of FCC catalysts. By micro-reactor activity evaluation with heavy oil as feed, gasoline yield increases from 28.82% to 36.14%.
出处
《石油化工》
EI
CAS
CSCD
北大核心
2008年第1期17-21,共5页
Petrochemical Technology
基金
国家基础研究"973"项目(2004CB217806)。
关键词
大孔材料
偏高岭土
改性
流化催化裂化
催化剂
macroporous material
metakaolin
modification
fluid catalytic cracking
catalyst
