关键词: font-family:-apple-system, blinkmacsystemfont, ", font-size:14px, background-color:#FFFFFF, ">催化裂化装置, 再生器, 二级旋分料腿, 结垢, 金属元素, 生焦率, 超温, 富氧再生

Abstract: By analyzing the elemental composition of the scale sample, it is demonstrated that metal elements have been enriched in the catalyst powder. Through X-ray diffraction analysis, it has been proven that the catalyst powder has undergone melting and bonding. The main reason for the scaling of the second-stage cyclone separator feed leg in the regenerator is that the enrichment of metal elements reduces the collapse temperature of the catalyst molecular sieve crystal structure. When CO and a small amount of fine powder carrying coke particles continue to burn in the second-stage cyclone separation, due to the small amount of solid particles carried by the flue gas in the second-stage cyclone separation, the heat trap effect weakens, causing a sudden increase in flue gas temperature. When the temperature reaches or even exceeds the melting point of the catalyst fine powder, the crystal structure of the fine powder breaks down and becomes a liquid phase. Under the action of high-speed centrifugation, it adheres to the top of the feed leg to form a scale layer. By comparing the number of overheating times in the regenerator with the number of "annual ring" layers in the scale sample, it is proven that the scaling of the second cyclone feed leg is directly related to the oxygen-rich regeneration environment and the tail combustion of uneven coke burning. The enriched metal elements reduce the melting temperature of the catalyst fine powder. Corresponding improvement measures and suggestions have been proposed for the causes of scaling.

Key words: font-family:-apple-system, blinkmacsystemfont, ", font-size:14px, background-color:#FFFFFF, ">FCCU, regenerator, feed leg of the second-stage cyclone separator, fouling, metallic element, coking rate, overheating, oxygen-rich regeneration