A question regarding the presulfurization of hydrocracking catalysts
Thread Content
When performing catalyst presulfurization, we require the use of low-nitrogen oil as the sulfurizing oil. Can hydrogenation tail oil be used as the sulfurizing oil? The specifications for hydrogenated tail oil are also low in nitrogen content (nitrogen level ≯5PPm). Is it possible to use hydrogenated tail oil as a sulfurizing agent? ? ?
Hydrogenated tail oil has a heavy boiling range, and there is no precedent for its use as vulcanization oil.
Generally, diesel or kerosene is used as a vulcanizing agent, while hydrogenated tail oil is used as mentioned above
As mentioned above, hydrogenated tail oil has a high boiling point, making it difficult to vaporize for pre-sulfurization; when used as a sulfurizing agent, the catalyst used for sulfuration does not exhibit very good activity
Well, I think the same way. However, recently the hydrocracking unit at Shanghai Petrochemical came online, using the latest catalysts FF-46 and FC-32 developed by Fuyan Research Institute; hydrogenated tail oil is being used as the sulfurization oil, with a very low nitrogen content of only 5 ppm. The unit is still in operation, and it’s not yet clear what the results will be. To be continued, I guess
Are you sure they’re using hydrogenated tail oil? What is their vulcanization temperature?
Our workshop started operations in 2011. The catalyst is the same as mentioned on the 5th floor; direct-current diesel is used for vulcanization, the vulcanization temperature is 175°C, and the waste oil is too viscous
The final boiling point of hydrogenated tail oil is too high; it tends to form carbon deposits during the sulfidation process, so it should be used with caution
Well, I’ve learned something – we use straight-run diesel here for pre-sulfurization, and we didn’t pay attention to the distillation range at that time.
Well, for sure and absolutely, they do use hydrogenated tail oil, with a sulfidation temperature of 230°C maintained for 8 hours
It mainly depends on the boiling range of their tail oil; it is not recommended to use tail oil. The higher the molecular weight, the easier it is to react. Under the initial activity conditions of the catalyst, its activity is very high, leading to rapid carbon deposition, which affects the hydrogenation performance of the metal.