Question regarding the rich liquid tank in the semi-deprotection process of tannin

Personal opinion: The traditional concept of desulfurization involves merely a pure desulfurization reaction; therefore, descriptions of this reaction emphasize that it is a rapid process, without taking into account the residence time of the feed gas inside the desulfurization tower. However, once the desulfurization method advanced to the use of catalysts, since the catalysts carry oxygen and participate in the reaction, the entire desulfurization process in the desulfurization tower should be a reaction process of \"desulfurization + regeneration\". And since the regeneration reaction takes time, the desulfurization reaction inside the desulfurization tower, or the \"desulfurization + regeneration\" reaction, also requires time. The rich liquid tank is used to increase the residence time, specifically that within the desulfurization tower, so that sulfur in its reduced form can further aggregate into stable elemental sulfur before entering the regeneration tank. The stable form of sulfur is S8; other forms are in reduced states, such as HS-, S2, S4, S6, etc. I personally think a residence time of 30 minutes in the regeneration tank is a bit long; once the foam has already formed, such a long time will cause it to shrink, become smaller, or even break apart ； At this point, the elemental sulfur particles attached to the sulfur foam may settle. This post was last edited by ypff on 2008-7-2 12:56.]

In my opinion, a rich liquid tank should be installed to increase the residence time; for a plant designed to produce 100,000 tons of synthetic ammonia, allowing the rich liquid to stay in the tank for 5–8 minutes is beneficial for the stable formation of elemental sulfur.

In my opinion, a rich liquid tank should be installed to ensure that the total residence time of the rich liquid in both the desulfurization tower bottom and the rich liquid tank meets a certain value.

It’s not necessary; it’s sufficient for the rich liquid to stay in the regeneration tank for over 20 minutes

If the solution volume in the desulfurization tower is large enough and the residence time is sufficient, it may not be necessary to install one. However, it is not convenient to clean the accumulated sulfur paste.

The function of the rich liquid tank is to increase the residence time of the desulfurization rich liquid, providing sufficient time for HS-1 and S-2 ions to be converted into elemental sulfur. This reduces the formation of by-product substances such as thiosulfates, thereby lowering the material consumption in the desulfurization process as well as a range of problems associated with by-products. A large volume of the regeneration tank is beneficial for regeneration, but it cannot completely replace the function of the rich liquid tank! ! ! ! ! !

A rich liquid tank is required; I often have a residence time involved. Desulfurization is carried out using desulfurization liquid in two-stage desulfurization towers. The process involves feeding sulfur-containing biogas from the digester into the first-stage desulfurization tower through gas pipes, with this gas rising from the bottom of the tower to its top. Sprayers located in the upper part of the tower spray the desulfurization liquid from above downward. Hydrogen sulfide present in the sulfur-containing biogas reacts with the desulfurization liquid under the action of catalysts and co-catalysts, resulting in initially purified biogas. This initially purified biogas is then discharged from the top of the first-stage desulfurization tower through gas pipes and enters the bottom of the second-stage desulfurization tower, where it rises from the bottom to the top for secondary desulfurization. The biogas after secondary desulfurization becomes further purified, and it is discharged from the top of the second-stage desulfurization tower and sent out through pipes； The rich liquid that has absorbed hydrogen sulfide in said absorption reaction is discharged from the primary desulfurization tower and from the bottom of the same tower, and enters a rich liquid tank through liquid pipelines. This rich liquid is then pressurized in the tank and sent to the ejector device, where it mixes thoroughly with the air drawn in. Subsequently, it enters a regeneration tank, where the mixture of rich liquid and air reacts to form regenerated desulfurization liquid. This regenerated desulfurization liquid goes into a lean liquid tank, where it is pressurized before being sent back through liquid pipelines to the sprayers at the upper part of the desulfurization tower for reuse. 　

There should be no problem as long as the regeneration is large enough. The sulfur content in altered pyrite is generally very low, so it does not cause any major problems. .

Reply 1# zhuqingsong Expert, please help!

In semi-discharge mode, it is necessary to have a rich liquid tank: 1. This allows for an extended residence time, enabling the S ions produced in the desulfurization reaction to be converted into elemental sulfur. 2. When the pressure difference in the desulfurization tower is high, the flow rate of the desulfurization liquid can be increased to flush the sulfur sludge inside the tower into the rich liquid tank. 3. It allows for easy adjustment of the pressure in the regeneration tank, facilitating the cleaning of the injector.