ABSTRACT Today, many European refineries finish up with excess of low-quality thermal naphthas that are hard to be marketed and, commonly, end being absorbed by catalytic naphthas at the expense of their higher quality. In this context, we propose to investigate the suitability of co-feeding thermal naphthas, i.e. visbreaker naphtha and heavy coker, with vacuum gasoil (VGO) to the fluid catalytic cracking unit. A riser simulator reactor has been used in the experimentation and tested conditions have been: 500 and 550 °C; C/O mass ratio, 6 gcat goil−1; and, residence time, 3 − 12 s. Products have been lumped according to the fractionation made in refineries in: dry gas, liquefied petroleum gases, gasoline, light cycle oil and coke. The results reveal that the co-feeding of any of the naphthas hinders the over-cracking increasing the contents of gasoline and that it inhibits the condensation reactions that produce coke. Two main factors contribute to these results: (i) the competitive adsorption and reaction between the components of the naphthas and the VGO; and (ii) the shortening of the residence time caused by an increase of the flow when the naphtha is co-fed. It should be highlighted the variation in the composition of the gasoline produced with the blends, with overall reductions of the contents of olefins and aromatics.

中文翻译：

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利用热石脑油过剩提升催化裂化装置产品质量

摘要 今天，许多欧洲炼油厂最终生产出过多的低质量热石脑油，这些石脑油难以销售，并且通常最终被催化石脑油吸收，以牺牲其更高的质量为代价。在这种情况下，我们建议研究将热石脑油（即减粘裂化石脑油和重焦化器）与减压瓦斯油 (VGO) 共同进料到流化催化裂化装置的适用性。实验中使用了提升管模拟反应器，测试条件为：500 和 550 ℃；C/O 质量比，6 gcat goil−1；和，停留时间，3 - 12 秒。产品根据炼油厂的分馏分为：干气、液化石油气、汽油、轻循环油和焦炭。结果表明，任何石脑油的共同进料都会阻止过度裂解增加汽油含量，并抑制产生焦炭的缩合反应。两个主要因素促成了这些结果：(i) 石脑油组分与 VGO 之间的竞争吸附和反应；(ii) 当石脑油被共同进料时，由于流量增加而导致停留时间缩短。应该强调的是，用混合物生产的汽油组成的变化，烯烃和芳烃的含量总体减少。(ii) 当石脑油被共同进料时，由于流量增加而导致停留时间缩短。应该强调的是，用混合物生产的汽油组成的变化，烯烃和芳烃的含量总体减少。(ii) 当石脑油被共同进料时，由于流量增加而导致停留时间缩短。应该强调的是，用混合物生产的汽油组成的变化，烯烃和芳烃的含量总体减少。