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

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