Desulfurization of hydrogen in gasoline hydrogenation cycle
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Which method is better for hydrogen sulfide removal from the recycle hydrogen in gasoline hydrogenation units? Ethanolamine does not provide good desulfurization effects; I’m not sure what the reason for this is I would like to ask the fellow sailors.
Our desulfurization using grade A diethanolamine has consistently delivered good results. I’m not aware of any other desulfurization methods; please list a few, OP.
Check the quality of the lean DEA coming from upstream, and then skim the oil from your desulfurization tower to see the desulfurization effect
This is easy to do, using MDEA from a reputable manufacturer!
Control the feed temperature and the temperature of the amine solution fed in, especially the temperature difference between the two
The quality of the amine solution, as well as the temperature and pressure of the desulfurization tower – after all, it’s an absorption tower; isn’t low temperature and high pressure favorable for absorption?
Generally, temperature has a significant impact, but you can also try adjusting the flow rate
There is a clear relationship between the effectiveness of ethanolamine desulfurization and the quality of lean liquid regeneration; if the regeneration is poor, the desulfurization performance will be very poor as well. However, the lack of quality can only be compensated for by increasing the dosage
The circulation volume has remained largely unchanged compared to before, but the hydrogen sulfide content in the recycled hydrogen has increased by 10 times, now at 500 ppm. Ethanolamine causes foaming, and there is severe liquid carryover in the recycled hydrogen.
The foaming phenomenon of ethanolamine may be due to the degradation of the monoamine solution, as well as the high content of heavy hydrocarbons (such as components with carbon numbers above 3) in the recycled hydrogen. If there is foaming, the absorption effect will not be good.
To address the foaming issue, we added a small amount of defoamer, and the effect was very noticeable. However, the hydrogen sulfide content in the recycled hydrogen remains very high. The ethanolamine we use for gasoline hydrogenation comes from the ethanolamine system in the catalytic unit; this ethanolamine is also sometimes used for desulfurizing coker liquefied gas. Previously, when the three units shared the ethanolamine system, hydrogen sulfide in the gasoline hydrogenation cycle hydrogen could be reduced to below 40 ppm; now it cannot be lowered any further.