Different process schemes for converting light straight run and fluid catalytic cracking naphthas in a FCC unit for maximum propylene production
Different process schemes for converting light straight run and fluid catalytic cracking naphthas in a FCC unit for maximum propylene production
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DOI：
10.1016/j.apcata.2004.01.020
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发表时间：
2004-07
影响因子：
5.5
通讯作者：
A. Corma;F. Melo;L. Sauvanaud;F. Ortega
中科院分区：
文献类型：
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作者：
A. Corma;F. Melo;L. Sauvanaud;F. Ortega
轻质直馏 (LSR) 和流化床催化裂化 (FCCN) 石脑油在输送床反应器 (MicroDowner) 和固定床反应器 (MAT) 中使用商用 Y 沸石基催化剂、商用 ZSM-5 沸石基添加剂以及两者的混合物在选定条件下进行裂化。根据石脑油烃的转化机制，我们评估了加工这些物流以生产轻质烯烃和/或降低商业汽油中烯烃含量的最佳替代方案。实验装置使我们能够通过不同的加工方案模拟流化催化裂化 (FCC) 装置中不同石脑油流的裂化行为。结果表明，LSR 仅在严重程度较高时才会破裂，并产生大量干燥气体。尽管其烯烃含量较高，但 FCCN 在与瓦斯油原料一起加入时实际上不会裂化。当在典型的瓦斯油裂化条件下单独裂化FCCN时，烯烃优先转化为石脑油范围的异链烷烃和芳烃，而当在高强度裂化FCCN时，烯烃优先转化为丙烯和丁烯。最后，在汽提塔中裂化石脑油产生一些丙烯并增加剩余汽油中的芳烃。
Light straight run (LSR) and fluid catalytic cracking (FCCN) naphthas were cracked in a transported bed reactor (MicroDowner) and in a fixed bed reactor (MAT) over a commercial Y zeolite based catalyst, over a commercial ZSM-5 zeolite based additive, and over a mixture of both at selected conditions. Based on the mechanisms through which naphtha hydrocarbons are converted, we evaluated the best alternatives for processing these streams to produce light olefins and/or to reduce olefins content in commercial gasoline. The experimental set-up allowed us to simulate the cracking behaviour of the different naphtha streams in a fluid catalytic cracking (FCC) unit by different processing schemes. Results indicate that LSR only cracks at high severity, yielding large amounts of dry gas. Despite its high olefins content, FCCN practically does not crack when it is fed together with gas oil feed. When cracking FCCN alone at typical gas oil cracking conditions, olefins are transformed preferentially into naphtha-range isoparaffins and aromatics, and when cracking FCCN at high severity, olefins are transformed preferentially into propylene and butylenes. Finally, cracking naphtha in the stripper produces some propylene and increases the aromatics in the remaining gasoline.