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

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