Is advanced PSA or advanced hydrogen production more suitable for the light gas from reforming hydrogen and hydrogenation units?
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This post was last edited by fengdingwen on 2010-6-30 at 12:28. Dear experts: The low-pressure gas from hydrogen reformation and hydrogenation units contains a significant amount of methane. From the perspective of overall plant optimization, is it more appropriate to send this gas to a PSA unit or to use it for hydrogen production?
Additionally, can the hydrogen production off-gases be used as vent gas?
It depends on whether the dry gas can enter the PSA
What is the maximum hydrogen content allowed to enter PSA?
Reformed hydrogen can be used directly; why go through the process of producing hydrogen at all? The hydrogen-rich hydrodesorption light gas can be directly fed into the PSA.
We have studied this issue at the Luoyang Design Institute: 1. The hydrogen-rich gas obtained from reprocessing can be fed into a separate PSA unit, but it cannot be fed directly into the PSA unit used for hydrogen production, as it contains a high amount of C3+ components. 2. If there is a significant amount of saturated dry gas from hydrocracking, membrane separation can be used, and it yields good results. 3. The above two types of gases can be used as raw materials for hydrogen production, but care should be taken when selecting the hydrogenation catalyst for the hydrogen production equipment; it is recommended to use the T201 type, as it is less prone to resulfidation.
Generally, people go to PSA. For example, our device
Reformed hydrogen and hydrotreated light gas can be used directly as hydrogen production feedstocks, or they can first pass through PSA. In most refineries, the reforming hydrogen and hydrogenated light gases go directly into PSA units. Has anyone studied this? By using PSA first to separate the hydrogen, what are the advantages compared to first carrying out steam reforming and then producing hydrogen?
The purity of the hydrogen obtained through reformation can exceed 90%, so there is no need to use a hydrogen production unit. For low-pressure hydrogenation applications such as diesel hydrogenation, jet fuel hydrogenation, and gasoline hydrogenation, a PSA unit is not required; the hydrogen can be used directly； If it is to be used for high-pressure hydrogenation (such as hydrocracking, residue hydrogenation, and lubricant hydrogenation), it must be purified via PSA before being fed into the plant. The low-pressure gas from hydrogenation units contains a significant amount of methane as well as hydrogen sulfide. If this gas is reused, the hydrogen purity can generally exceed 95% after desulfurization; however, this leads to substantial desulfurization efforts in the hydrogen production process, resulting in waste of resources.
The method of treatment for hydrogen that will achieve the best utilization is determined based on its purity and pressure. If the gas contains a high proportion of hydrocarbon components, membrane separation can be used to concentrate hydrogen, which can basically meet the usage requirements. By using a membrane to concentrate hydrogen before feeding it into the PSA unit, it is possible to **increase the production capacity of the hydrogen production plant and reduce the unnecessary work done by hydrogen within the entire system. Dalian Hai’ao Membrane Technology Co., Ltd. is the specialized company that has developed this technology; if any of you have applications in mind, feel free to get in touch. QQ: 896846850 Mobile: 13804098969
Does Haiao have a brief introduction to the technical features of your *membrane separation technology? Please share it so everyone can learn from it