Ammonium salt crystallization in hydrogenation heat exchangers
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Since my work is related to corrosion prevention, I have come into contact with many manufacturers’ hydrogenation heat exchangers. Among these, the corrosion caused by diesel hydrogenation and ammonium salt crystallization is the most severe; even heat exchangers made of 825 alloy have developed perforations as a result. Could anyone please explain why corrosion is so severe in the case of diesel hydrogenation?
Severe salt deposition, possibly due to insufficient water injection； Additionally, does the formation of ammonium salts after crystallization lead to under-scale corrosion?
Salt formation has no direct relation to water injection; water injection is merely used to flush out the crystallized ammonium salts. After crystallization, ammonium salts readily absorb moisture and deliquesce, forming a highly concentrated HCl solution that causes corrosion beneath the scale.
I don’t quite understand corrosion, but water injection is used to prevent the crystallization of ammonium salts; it removes those ammonium salts that have not yet crystallized, as well as the gaseous ammonium salts formed as a result of reactions.
The nitrogen content in the raw material, chlorine content, chlorine content in hydrogen, the temperature of the heat exchanger, water injection, and so on all have an impact
Is it the high chlorine content in the circulating hydrogen that causes the ammonium salts to crystallize during heat exchange, with the low operating temperature of the heat exchanger accelerating the crystallization of these ammonium salts?
Water injection is not as effective as specialized additives for ammonium salt crystallization—ammonium salt dispersants. Those who are interested can contact me at VX231883799
Yes, there are use cases for CNPC and Shandong’s local refineries
How effective is it? That company manufactures it