The present study investigates the effects of the changes of the catalyst to feedstock ratio (C/O) on FCC cracking using a Y-zeolite-based catalyst. Experiments are developed in a CREC Riser Simulator. This bench-scale mini-fluidized batch unit mimics the operating conditions of large-scale FCC units as follows: It uses temperatures ranging from 510 to 550 °C and reaction times from 3 7 s. For every experiment, 0.2 g of 1,3,5-TIPB is contacted with a 0.12–1g catalyst amount. This is done to achieve a C/O ratio in the range of 0.6–5. Experiments show the effects of increasing the C/O ratio on 1,3,5-TIPB conversion, coke formation, and product selectivity. On this basis, a mechanism involving single catalyst sites for cracking and two sites for coke formation is considered. Coke formation is postulated as an additive process involving coke precursor species, which are either adsorbed on sites in the same particle or adsorbed in close sites in different particles. The proposed mechanism helps explain the results obtained, introducing a rationale for the selection of optimum C/O ratios to yield the highest possible 1,3,5-TIPB conversions with controlled amounts of coke formation. It is anticipated that the findings of this study will have a significant influence on the selection of an optimum C/O ratio for the design and operation of the most advanced FCC risers and downers.

中文翻译：

---

使用基于Y沸石的催化剂在CREC提升管模拟器中催化裂化碳氢化合物：评估催化剂/油比的影响

本研究调查了催化剂/原料比（C / O）的变化对使用Y型沸石基催化剂催化裂化裂化的影响。实验是在CREC Riser Simulator中开发的。这种台式微型流化间歇式装置模仿了大型FCC装置的操作条件，如下所示：它使用的温度范围为510至550°C，反应时间为3 7 s。对于每个实验，将0.2 g的1,3,5-TIPB与0.12-1g的催化剂接触。这样做是为了实现0.6 / 5的C / O比。实验表明，提高C / O比对1,3,5-TIPB转化率，焦炭形成和产物选择性具有影响。在此基础上，考虑了一种机制，该机制涉及单个催化剂裂化位点和两个焦炭形成位点。焦炭的形成被认为是涉及焦炭前体物质的加成过程，这些物质要么吸附在同一颗粒的位点上，要么吸附在不同颗粒的近位点上。所提出的机制有助于解释所获得的结果，为选择最佳C / O比提供了依据，以在控制焦炭形成量的情况下产生最高的1,3,5-TIPB转化率。可以预料，这项研究的结果将对最先进的FCC立管和立管的设计和操作的最佳C / O比的选择产生重大影响。介绍了选择最佳C / O比的原理，以在可控制的焦炭形成量下实现最高的1,3,5-TIPB转化率。可以预料，这项研究的结果将对最先进的FCC立管和立管的设计和操作的最佳C / O比的选择产生重大影响。介绍了选择最佳C / O比的原理，以在可控制的焦炭形成量下实现最高的1,3,5-TIPB转化率。可以预料，这项研究的结果将对最先进的FCC立管和立管的设计和操作的最佳C / O比的选择产生重大影响。