Requirements for oil used in catalyst sulfidation for diesel upgrading
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Dear sea friends, those who have used Topso diesel modification catalysts – why is the nitrogen content in the sulfurizing oil required during pre-sulfurization? Also, what are the requirements for the nitrogen content of the feedstock in the modification reactor during normal production? Why? Thank you! !
Catalyst sulfidation is the process of converting the metallic state to a sulfided state. When nitrogen is present in the raw materials, it reacts with hydrogen to form ammonia, and ammonia can inhibit the sulfidation reaction of the catalyst; therefore, ammonia needs to be injected only when the catalyst temperature rises too high to prevent its sulfidation.
The modified catalyst contains molecular sieves; if it contains excessive nitrogen, especially basic nitrides, this will reduce the acidity of the molecular sieves and thereby decrease the overall activity of the catalyst.
A level of 150 PPm is required to prevent the catalyst from reacting too rapidly, especially for pour-point depressant catalysts
To prevent a sharp rise in temperature during the sulfidation process, low-nitrogen straight-run diesel is introduced for pre-sulfidation. Additionally, to prevent excessive ammonia from reacting with sulfides and reduce the progress of sulfidation reactions. We require less than 20 ppm