Abstract: The processing of high-chlorine feedstock in the diesel hydrofining unit of a petrochemical plant led to the shutdown of the unit due to the excessive differential pressure of the reaction system. During the process of restarting with conventional low-chlorine diesel after maintenance, when the reaction temperature reached 180 ℃, the catalyst continuously released chloride ions, causing the pressure drop of high pressure heat exchanger to rise again. By adding temporary water injection measures to flush the high pressure heat exchanger, the differential pressure of the reaction system was reduced and the normal production of the unit was maintained. The data showed that when processing ultra-high chlorine feedstock, one ton of the diesel hydrofining catalyst absorbed about 4.7 kg chlorine. It was suggested that dechlorination should be carried out first when starting again, and dechlorination should begin when the reaction temperature reached about 180 ℃.

Key words: diesel hydrofining unit, high-chlorine feedstock, ammonium chloride, crystallization temperature, sour water of cold high pressure separator

摘要： 某石化厂柴油加氢精制装置加工一批高氯原料油导致装置因反应系统压差过大被迫停工处理。在检修后采用常规低氯柴油重新开工的过程中，当反应温度达到180 ℃时，催化剂持续释放氯离子，导致高压换热器等设备的压差再次上升。通过增加临时注水对高压换热器进行冲洗等措施，降低反应系统压差，维持了装置的正常生产。数据表明加工超高氯原料油时，柴油加氢精制装置催化剂会吸收吸附部分高氯组分，每吨催化剂吸收约4.7 kg氯。建议再开工时首先脱氯，反应温度达到180 ℃左右时即开始发生脱氯反应。

关键词: 柴油加氢精制装置, 高氯原料, 氯化铵, 结晶温度, 冷高分酸性水