Resistance reduction through wet flue gas desulfurization

What is a drag reducer? I’m hearing about it for the first time. Study hard!* Could the poster provide some more details about the situation?

From what the original poster is saying, if this tower is meant to last 20 years, then I’ll have to stay there for those 20 years; it won’t be demolished unless there are other problems? It’s a bit weird.

It’s just a joke for 20 years (if it’s a packed tower); unless the gas flow rate and load don’t match, it’s still very difficult. Perhaps he has just graduated and is not yet familiar with the industry. Additionally, the drag reducer he proposed is likely something he invented on his own; it might be a \"modified version\" of another system that was tried out, and without proper understanding of the situation, the chances of success are usually low. There are no records of surfactants yet.

I have been working in wet flue gas desulfurization for a few years now, and I really have never heard of anything called a drag reducer. I think the resistance inside the desulfurization tower is mainly determined by the structure of the tower itself; that’s probably the most important factor. Of course, there are other factors such as the flow rate and velocity of the flue gas, as well as the amount of slurry, but these are likely secondary factors. For example, changing whether to use a demister or not, or whether to use a first-stage demister or a second-stage one – such structural changes must pose much greater resistance than changes in flow rate and the like.

It can be said to be a desulfurizing agent that reduces tower resistance.

Thank you all for participating in the discussion. The drag reducer I’m referring to is a substance added to the desulfurization solution, which helps to dissociate the substances that adhere to the packing or internal components of the tower. It can’t be said that there isn’t any; rather, it has not been found yet. Since the desulfurization tower is clogged with substances other than salts, sulfur, and tar naphthalene, there must be a way to deal with it. I also hope to get some guidance from experienced seniors.

It seems that so far, no factory has been known to use the drag-reducing agent mentioned by the original poster; if such a product does exist, it would truly be a blessing for manufacturers everywhere. In fact, to address tower blockage, it is necessary to start with management by strengthening daily oversight to keep the operating conditions at their optimal level; this is the most crucial factor in delaying tower blockage. Additionally, choosing a suitable catalyst is also a very important factor, and in this regard, our company’s 888 has certain advantages. When the 888 catalyst is used, the reaction between H2S and Na2CO3, as well as the oxidation of NaHS, proceed in the same manner as other liquid-phase catalytic reactions. However, the reaction in which NaHS reacts with (X-1)S under the action of the “888” catalyst to form Na2Sx is a reaction unique to this catalyst. The formation of Na2Sx causes the sulfur originally deposited on the packing material of the desulfurization tower to quickly participate in chemical reactions with NaHS and be converted into Na2Sx, thereby loosening the deposited sulfur and facilitating the cleaning of the tower. This is why, when the “888” catalyst is used, there is no risk of tower blockage, and the sulfur previously deposited inside the tower can be removed rapidly when switching from other desulfurization methods to this one.

Tower blockage problem (reposted) Tower blockage is the main factor causing instability and disruptions in the production process. There are many complex factors that cause an increase in the resistance of the desulfurization tower, with the improper selection of desulfurization catalyst being the main factor. There are also reasons related to raw materials and equipment, such as high levels of tar and dust particles in the gas, excessive impurities in the absorbent, severe damage and deformation of the packing in the tower, low flow rate from the lean liquid pump, a low liquid-to-gas ratio, low spray density, uneven distribution of the solution inside the desulfurization tower, as well as problems with the regeneration system and sulfur recovery system. The desulfurization equipment for the wet oxidation method mainly consists of three parts: desulfurization, regeneration, and sulfur recovery. Problems with the regeneration and sulfur recovery systems can also lead to an increase in the suspended sulfur content in the solution, thereby increasing the resistance in the desulfurization tower. There are many sulfur recovery methods in China, including advanced membrane separation methods, vacuum filtration sulfur melting methods, unfiltrated sulfur melting methods, and continuous sulfur melting methods. Some small nitrogen fertilizer plants do not have filtration and sulfur melting equipment; instead, they allow the sulfur foam that rises to the surface in the regeneration oxidation tank to flow into a pool, where it is clarified before the solution is reused, while the sulfur slurry is removed. In nitrogen fertilizer plants that have sulfur melting tanks, the solution released during sulfur melting is recycled and reused by some facilities. While this can reduce raw material consumption, the sulfur melting process requires maintaining a temperature of over 120°C for 2 hours, which results in many impurities remaining in the solution; as a consequence, the levels of by-products such as Na2S2O3 increase significantly. If these solutions are recovered and reused, it is more likely to cause tower blockage. Furthermore, relying solely on simple clarification in the tank does not result in effective separation of the sulfur foam; when these solutions containing a high amount of sulfur foam are recovered and reused, it leads to an increase in the suspended sulfur content in the solution, which can easily cause tower blockages. 　　If the three components of the desulfurization system are all functioning properly yet tower blockage still occurs, it can be determined that the issue is caused by poor quality of the raw materials used for desulfurization or inappropriate process conditions. The substances causing the blockage are mainly sulfur and salts, along with catalyst components and impurities present in the system. Typically, the blockages in semi-water gas desulfurization systems are primarily composed of sulfur (sulfur blockages). However, there are exceptions; when the NaHCO3 content is too high or the levels of by-products are too high, it will also precipitate and stick to the packing inside the tower along with sulfur (salt fouling). The HCN content in coke oven gas is much higher than that in semi-water gas, ranging from 1.0 g/m3 to 2.5 g/m3. Therefore, by-products such as NaCNS and Na2S2O3 formed in the desulfurization solution must be regularly removed to prevent crystallization from occurring and blocking the tower.

Could some expert tell me how to post a thread? I want to post a few messages, but I can’t! ! Thank you, thank you, thank you!