柴油加氢裂化装置保护剂上杂质沉积分析

针对某炼油厂柴油加氢裂化装置停工换剂时发现精制反应器床层顶部的催化剂表面覆盖垢物的现象,对保护剂取样分析。对所取保护剂进行甲苯抽提处理后采用X射线荧光光谱仪（XRF）、扫描电子显微镜（SEM）、等离子体光谱仪（ICP-OES）等手段进行检测。结果表明：保护剂上主要沉积含铁、磷、硅、钙、钛（Fe、P、Si、Ca、Ti）元素的杂质;保护剂表面更多地沉积含铁、磷、硅（Fe、P、Si）元素的杂质;含钾、钙（K、Ca）等元素的杂质均匀地沉积在保护剂上;保护剂上未出现其他物相结构。对此,建议炼油厂一方面要严格控制原料油中含磷、硅（P、Si）等元素的杂质的携带,另一方面要装填部分捕硅剂来优化保护剂的级配装填,实现装置的平稳运行。

Analysis of impurity deposition on guard catalyst for diesel hydrocracking device

In view of the phenomenon that the catalyst on the top of hydrofining reactor was covered with scale when the diesel hydrocracking unit in a refinery was shut down,accompanied by replacing catalyst,the sampling analysis of guard catalyst was conducted at the same time.The X-ray fluorescence spectrometer（XRF）,scanning electron microscope（SEM）,inductively coupled plasma spectrometer（ICP-OES） and other analysis were carried out to analyze guard catalyst after toluene extraction.The results showed that the main impurities depositing on guard catalyst were inorganic componentes containing Fe,P,Si,Ca and Ti elements,and impurities containing Fe,P,and Si elements were mostly deposited on the surface of guard catalyst,while impurities containing K,Ca and other elements were uniformly deposited on the guard catalyst,without other phase structures on the guard catalyst.In this regard,it is suggested that the refinery should strictly control the carrying of impurities containing P,Si and other elements in the raw oil,and on the other hand it is necessary to load some silicon trap catalyst to optimize the grading and loading of guard catalyst,so as to realize the smooth operation of the device.