Abstract: Due to the unplanned shutdown of the original diesel hydrogenation unit due to low purified air pressure, this set of diesel hydrotreating unit is started to ensure the material balance of the whole plant. Cause analysis and countermeasures for the problems occurred during the start-up of diesel hydrotreating unit: (1)After the feed pump is started and low nitrogen diesel oil is introduced for 22 min, the liquid level of hot high-pressure separator is established and continuously increased to 65%, which is significantly shorter than the previous start-up time (90 min), and can maintain the delivery flow of 20~30 t/h. After feeding, the sulfur content of refined diesel oil fluctuates between 3.2~50.0 mg/kg, resulting in the product quality exceeding the standard. By checking the oil storage in the equipment pipeline, oil vaporization and internal leakage of the high-pressure heat exchanger, it is judged that the reason is the internal leakage of the high-pressure heat exchanger in the low-temperature stage, and the internal leakage is reduced by appropriately increasing the temperature. (2)It is judged that the sulfur dioxide in the flue gas of the heating furnace exceeds the standard due to the low molecular mercaptan produced in the vulcanization process entering the low separation gas. The environmental protection problem is solved through the reverse purging of the pipeline, which can provide reference for the commencement of similar units.

Key words: diesel hydrotreating unit, start-up, sulfur content of product, the liquid level of hot high-pressure separator, flue gas of heating furnace

摘要： 由于原有柴油加氢装置因净化风压力低导致装置非计划停工，为保证全厂物料平衡，开启本套柴油加氢装置。针对柴油加氢装置开工过程中出现的问题进行原因分析并采取应对措施：①在进料泵开启、引低氮柴油 22 min 后，热高压分离器建立液位且持续升高至65%，较历次开工时间（90 min）明显缩短，并且能保持20~30 t/h外送流量，投料后，产品精制柴油硫质量分数在3.2～50.0 μg/g波动，导致产品质量不合格，通过排查设备管线存油、油品汽化和高压换热器内漏情况，判断原因是低温阶段高压换热器存在内漏，通过适当提高温度来减少内漏量；②针对低分气并网导致加热炉烟气二氧化硫含量超标的问题，判断是硫化过程中生成的低分子硫醇进入低分气造成，通过管线反向吹扫解决了该问题，可为同类装置开工提供借鉴。

关键词: 柴油加氢装置, 开工, 产品硫含量, 热高压分离器液位, 加热炉烟气