Hydrogen sulfide content in the fresh hydrogen used for diesel hydrogenation

Is it a control parameter or something else? The hydrogen sulfide content should depend on the properties of the raw materials, I guess.

Our level is 100-220 mg/m3, with the feedstock being a mixture of PSA-produced hydrogen and reformed hydrogen.

We keep it around 2000 ppm

I was wrong above; what I meant was the hydrogen sulfide content in the recycled hydrogen. Its content in new hydrogen is very low, less than 10 ppm. If hydrogen from reformation pre-hydrogenation is used, the concentration is around 300 ppm.

If you are new to the hydrogenation industry, it is recommended that you read the book \"Hydrogenation Refining\" carefully. If you’ve been in the industry for a long time, this question is too basic. I’m telling you that if the catalyst is in a sulfided state, it’s sufficient to maintain hydrogen sulfide levels at around 500 ppm in the recycle hydrogen; these levels should not be lower than 300 ppm. If they stay above 2000 ppm for an extended period, then a desulfurization system for the recycle hydrogen needs to be considered.

We keep the H2S content in our new hydrogen at less than 0. 5PPm。

What is the hydrogen sulfide content in the fresh hydrogen used for diesel hydrogenation? So you need to desulfurize the new hydrogen first, right? Our new hydrogen does not contain hydrogen sulfide

In diesel hydrogenation units, it is generally acceptable for the hydrogen used to have a higher hydrogen sulfide content, unless sulfur-containing catalysts are being used. For reduced states and precious metal catalysts, the hydrogen sulfide content in the fresh hydrogen is required to be no higher than 1 ppm.

The new hydrogen we use is produced by subjecting waste gas to carbon monoxide conversion followed by PSA pressure swing adsorption; its hydrogen sulfide content generally does not exceed 10 PPm, with attention being paid primarily to controlling carbon monoxide and carbon dioxide in order to prevent methanation reactions

The amount of hydrogen sulfide is determined based on the amount of recycled hydrogen; it is usually 1%. The hazards associated with too high or too low levels are well known

We use dry gas to produce hydrogen, and the hydrogen content of hydrogen sulfide is very low, to the point where it can be ignored

How can there be hydrogen sulfide in the new hydrogen? Is there a mistake?

New hydrogen can contain hydrogen sulfide; the hydrogen from chemical plants does!

The H2S content in hydrogen production products is very low, as the H2S level in the feed to the hydrogen production converter is generally less than 0.2 ppm; as a result, almost no hydrogen sulfide remains in the produced hydrogen after PSA treatment to remove H2S. In hydrogenation, the hydrogen sulfide content in the circulating hydrogen needs to be controlled and kept low; otherwise, it will react with olefins to produce higher organic sulfur compounds such as thiolates, failing to achieve the desulfurization goal and thus affecting product quality. If the amount is too low, it will cause reduction of the sulfided catalyst. Therefore, to control the hydrogen sulfide concentration in the recycled hydrogen, it is generally possible to achieve this by using amine solution desulfurization for the recycled hydrogen in hydrogenation units. It is determined based on the process requirements. It generally needs to be above 100 ppm

This post was last edited by wj821313389 on 2013-12-24 21:22. How can hydrogen sulfide be present in green hydrogen? The raw material passes through the adsorption unit in the desulfurization reactor, resulting in almost zero levels of hydrogen sulfide. It is extremely dangerous for the hydrogen production desulfurization reactor to be penetrated by sulfur, especially as it affects the conversion catalysts and the catalysts used in that process. Hydrogen sulfide undergoes chemical adsorption reactions with the nickel atoms on the surface of the conversion catalysts, thereby deactivating the active centers on the surface of those nickel crystals. Entering the medium-temperature reactor is even more dangerous, as it directly produces iron sulfide; each case of poisoning results in a 10–20% decrease in catalyst activity.

The hydrogen sulfide content in the circulating hydrogen should not be too high; otherwise, it will dissolve excessively in diesel under high pressure, resulting in a sulfur content in the refined diesel that exceeds the allowable limit. This limit is generally not supposed to exceed 1500 ppm. On the other hand, the hydrogen sulfide content in the circulating hydrogen cannot be too low either, as this will cause the catalyst in its sulfided state to lose its desulfurization capacity and thus become inactive. It is generally appropriate to keep it around 600 ppm.

The new hydrogen comes from the hydrogen production plant; it basically contains no hydrogen sulfide, as hydrogen sulfide is removed during the hydrogen production process.

Please introduce the general composition of the reformed hydrogen and its hydrogen sulfide content, as well as the approximate ratio of reformed hydrogen to PSA before mixing