沸石孔结构对植物油催化裂化性能的影响

制备出硅铝比相近但介孔体积逐渐增加的超稳Y（USY）沸石，进而制备成微球状催化剂。本文在固定流化床装置上，考察了两种植物油的催化裂化性能。小桐子油的评价结果表明，催化剂中USY沸石的介孔体积越大，汽柴油收率越高；汽油族组成中烯烃收率越高，芳烃收率越低，汽油辛烷值和抗爆指数也越低；采用铵交换和水热改性制备介孔体积为0.142cm³/g的USY沸石催化剂的裂化产物中，汽柴油总收率为62.21%（质量分数），焦炭收率最低，汽油研究法辛烷值达到90.5；大豆油的催化裂化反应规律与小桐子油的一致，中等介孔催化剂裂化得到的汽油研究法辛烷值达到92.2。研究结果表明，采用催化裂化工艺，利用适当介孔的USY沸石催化剂，可以将植物油高效转化为车用轻质燃料，并且得到高辛烷值的汽油。

Influence of pore structure of USY zeolite on its performance in catalytic cracking of vegetable oil

USY zeolites with similar framework SiO₂/Al₂O₃ ratio and increased mesopore volume were prepared, with which globular catalysts were prepared by spray drying. Catalytic cracking of Jatropha curcas L. seed oil (JCO) and soybean oil were performed in a constrained fluidized bed reactor. The results of JCO evaluation showed that the gasoline/diesel yields increased as the increased catalyst’s mesopore volume. The higher the yield of olefins and lower yield of aromatics in gasoline gave rise to lower octane number and the anti-explosion index. As for the product distribution of USY catalyst with mesopore volume of 0.142cm³/g, which was prepared by ammonium exchange and hydrothermal modification, the maximum yield of gasoline/diesel was 62.21% (mass fraction), the yield of coke was lowest, and the research octane number (RON) of gasoline was up to 90.5. The catalytic cracking of soybean oil gave the same reaction trend as that of JCO, and the RON of gasoline was up to 92.2 using the catalyst with moderate mesopore volume. The results showed that the catalytic cracking process, with appropriate mesoporous USY zeolite catalyst, can high-efficiently produce light vehicle fuel and high-octane gasoline from vegetable oil.