Abstract:

The semi-regenerative reforming unit of a refinery enterprise was shut down due to the decline in activity of the reforming catalysts, and the catalysts in the first and second reactors were replaced. After analyzing the old catalysts, it was found that the mass fraction of silicon dioxide reached a maximum of 20.4%, indicating that the reforming catalysts had been poisoned by silicon. During the silicon poisoning period, the temperature drop of the first reactor decreased from 73.7 ℃ in the initial stage to 20.12 ℃ in the final stage, and the reforming reaction was moved to the second reactor. The hydrogen volume fraction in recycle hydrogen increased to 90%, and the pure hydrogen yield decreased to 2.17%; The research octane number(RON) of stable gasoline has dropped to 83.7. Silicon poisoning of reforming catalysts is relatively rare, and the phenomenon is similar to nitrogen poisoning, making it easy to be misidentified as catalyst nitrogen poisoning. Trace the source of silicon and confirm that it is carried by crude oil. The analysis suggests that the pre-hydrogenation silicon trap agent cannot fully capture all silicon, resulting in some silicon penetrating the pre-hydrogenation system. The effect of silicon on the pre-hydrogenation catalyst is less than that on the reforming catalyst. Silicon poisoning can lead to the loss of chlorine from the catalyst, requiring an increase in the amount of chlorine injected.

Key words: semi-regenerative reforming unit, catalyst, silicon poisoning, reaction temperature drop, recycle hydrogen composition, stable gasoline, raw material silicon content

摘要：

某炼油企业的半再生重整装置因重整催化剂活性下降而停工，更换了第一反应器和第二反应器的催化剂。对旧催化剂进行分析后发现，第一反应器催化剂二氧化硅质量分数高达20.40%,因此判断重整催化剂发生了硅中毒。在硅中毒期间：第一反应器的温降由初期的73.70℃下降到末期的20.12℃,重整反应后移到第二反应器；循环氢的氢气纯度上升到90%,纯氢产率下降到2.17%;稳定汽油RON(研究法辛烷值)下降到83.7。重整催化剂硅中毒较为罕见，其表现与氮中毒相似，容易误判为催化剂氮中毒。对硅进行溯源，确认是原油携带。分析认为：重整预加氢捕硅剂无法完全捕获所有硅，导致部分硅穿透预加氢系统；硅对预加氢催化剂的影响小于对重整催化剂的影响；硅中毒会导致催化剂的氯流失，需要加大注氯量。

关键词: 半再生重整装置, 催化剂, 硅中毒, 反应温降, 循环氢组分, 稳定汽油, 原料硅含量