[Solved] Hydrocracking feedstock

Precautions for blending catalytic diesel: (1) Catalytic diesel is rich in aromatics, and it releases a large amount of heat during hydrocracking; therefore, when blending catalytic diesel, the process must be carried out gradually. It is absolutely not advisable to add it all at once – the catalytic diesel should be incorporated step by step. Furthermore, the operating amplitude of the adjustment device should be small (to increase the amount of catalyzed diesel blended in), and the interval between adjustments should be long; further adjustments should only be made once it is confirmed that the system is stably under control. (2) After catalytic diesel is blended into the hydrocracking unit, the temperature rise in the refining reactor increases; the reactor inlet temperature can be reduced by 5°C first to provide a buffer zone for the refining reactor. At the same time, to ensure that the cold hydrogen valve position at the inlet of the hydrocracking catalyst bed remains safe and under control, the average reaction temperature in the refining section is reduced significantly; as a result, the efficiency of hydrogenation refining of VGO feedstock declines, which may affect the optimal performance of the hydrocracking catalyst.

It mainly depends on the properties of the raw materials and the operational flexibility of the equipment; it involves control of the reaction temperature as well as quality control of the product. It’s better to use a small amount of additives for easier control, and increase the amount of additives according to the required product quality

The amount of catalyst used is restricted by the smoke point specifications of aviation fuel, according to President Hao