Abstract

Isobutane/olefin alkylation is an important route to obtain high-quality gasoline. There is an apparent interest to apply zeolite based catalysts for this process to eliminate large scale usage of liquid catalysts such as H₂SO₄ and HF. Solid catalysts require a specific reactor system design involving frequent catalyst regeneration and operation at low concentration of the olefin. The aim of this work was to compare different reactor types: CSTR, “once-through” fixed bed type and circulating flow reactors (CFR), which are typically considered as suitable options for industrial implementation. The experiments were done on decationated Y-zeolite catalyst. Different paraffin/olefin ratios, temperature and circulation rates were studied. Catalysts and process performance are discussed based on the catalyst lifetime and the alkylate octane number. Analysis of diffusion limitations in different reactor types and optimization of the circulation rate in CFR were done. It was found that isobutane alkylation in a circulating flow reactor shows approximately the same catalyst lifetime even at a high circulation rate not exhibiting any positive impact of back-mixing on this process. However, a circulating flow reactor has demonstrated a much better quality of alkylate with the research octane number higher by 4.9 points. Additional operational costs related to the reactor effluent recycle are fully covered by the alkylate quality improvement even at a high circulation ratio.

中文翻译：

---

Y型沸石在CSTR，固定床和循环流反应器中异丁烷/正丁烯烷基化反应的比较

摘要

异丁烷/烯烃烷基化是获得高质量汽油的重要途径。显然有兴趣将沸石基催化剂用于该方法，以消除大规模使用液体催化剂（例如H ₂ SO _4）和HF。固体催化剂需要特殊的反应器系统设计，其中涉及频繁的催化剂再生和在低烯烃浓度下的操作。这项工作的目的是比较不同的反应堆类型：CSTR，“一次通过”固定床类型和循环流反应堆（CFR），它们通常被认为是工业实施的合适选择。实验是在阳离子Y型沸石催化剂上进行的。研究了不同的石蜡/烯烃比，温度和循环速率。基于催化剂寿命和烷基化辛烷值讨论了催化剂和工艺性能。分析了不同反应器类型中的扩散限制，并优化了CFR中的循环速率。已经发现，即使在高循环速率下，在循环流反应器中的异丁烷烷基化也显示出大致相同的催化剂寿命，而没有显示出反混对该方法的任何积极影响。但是，循环流反应器已证明烷基化物的质量更好，研究辛烷值提高了4.9点。即使在高循环比的情况下，烷基化物质量的改善也完全弥补了与反应器废水再循环相关的额外运营成本。