连续重整原料氮含量及再生干燥空气水含量超标原因分析及处理措施

中国石化海南炼油化工有限公司连续重整装置于2014年2月开始出现反应器温降、产氢率降低等现象,在3月10日后呈现持续下降趋势,重整生成油芳烃含量、芳烃产率大幅下降。查找分析原因,认为常减压蒸馏装置加工福蒂斯等高氮原油比例过高,造成重整原料氮含量升高;同时空压站和重整再生的空气干燥器干燥效果下降,造成重整再生烧焦空气中水含量升高,进而在重整反应-再生系统形成水、氮、氯共存环境,导致催化剂氮中毒,活性大幅降低。通过调整加工原油结构、优化原料预加氢操作、降低重整装置加工负荷和反应苛刻度、投用空压站备用空气干燥器、更换空气干燥剂等一系列措施,减少系统中氮和水等毒物的携带量,并提高重整再生注氯量等,使重整催化剂氮中毒得以有效控制并逐渐恢复活性,采取措施10天后装置运行基本恢复正常。

CAUSE ANALYSIS OF HIGHER CONTENTS OF N IN FEED AND WATER IN DRIED AIR IN CONTINUOUS REFORMING UNIT AND CORRESPONDING MEASURES

The reactor temperature and hydrogen production of continuous reforming unit in Hainan Refining Company began to drop from February 2014 followed by a significant reduction in March, the content of aromatics in reformate and aromatics yield were fallen dramatically. The analysis found that with increasing the proportion of Fotis crude oil with high nitrogen content, the nitrogen content of reforming feed increases; and that the dry efficiency decreases due to insufficient air drier capacity of air compression station and regeneration system, resulting in higher water content in regenerated air and H2O-nitrogen-chlorine coexistence environment which poisons the CCR catalyst. A series corresponding measures were adopted, including: adjusting feedstock composition, optimizing pre-hydrotreating operation, reducing the load and reaction severity of reforming unit appropriately, adding more spare air drier of air compression station, changing air desiccant of reforming regeneration system and increasing the amount of chlorine injection, to control the catalyst poisoning and recovery the activity. The plant operation is returned successfully to normal.