摘要
某公司芳烃项目的 3.2 Mt/a连续重整装置因第四反应器(简称四反)压降急剧升高造成非计划停工。对四反压降持续上升、紧急停工后还原段和缓冲段的料位不能正常建立及催化剂粉尘淘析不理想等异常工况进行了分析。停工卸剂后,对反应器内催化剂分布、反应器内件、催化剂物性、焦炭特性等进行了检测,分析了焦炭的生成、催化剂粉尘大、催化剂强度和比表面积下降快、反应器内中心筒网隙和扇形筒空隙堵塞、四反压降急剧升高及扇形筒向内凹陷并开裂的原因,提出了改进措施。当紧急停工时适时开启催化剂冷态循环,以保护反应器内件;以循环氢中H_2S的含量为基准,调整重整注硫量;以淘析出催化剂粉尘中整颗粒催化剂的数量为基准,调整催化剂粉尘淘析操作;采用固相脱氯技术替换Chlorsorb~(TM)氯吸收技术,避免待生催化剂与高含水再生放空气接触,改善催化剂的强度和比表面积。
3.2 Mt/a continuous catalytic reforming unit of the aromatics project of a company had caused the unplanned shutdown due to sharp increase of the 4~(th) reactor pressure drop.The abnormal working conditions such as the continuous rise of the 4~(th) reactor pressure drop,abnormal material level of reduction zone and surge zone after emergency shutdown,and unsatisfactory elutriation of catalyst dust were analyzed.After unloading,the catalyst distribution,reactor internals,catalyst properties and coke characteristics were tested.The causes of coke formation,large catalyst dust,rapid decrease of catalyst strength and specific surface area,blockage of central cylinder gap and scallops voids,sharp increase of the 4~(th) reactor pressure drop,and inward depression and cracking of the scallops were analyzed.The improvement measures were put forward.When the emergency shutdown occurs,the catalyst cooldown mode can be turned on timely to protect reactor internals.Sulfur injection in reforming process can be adjusted based on the content of H_2S in recycle hydrogen.The operation of catalyst dust elutriation can be adjusted based on the number of solid particles.Chlorsorb~(TM) chlorine absorption technology can be replaced by solid phase dechlorination technology to avoid contacting the catalyst with high water content vent gas and improve the strength and specific surface area of the catalyst.
引文
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