Wet desulfurization: PDS method and complexed iron method

The wet PDS process for removing hydrogen sulfide does indeed face the problem of high levels of by-products salts. During inspections of several coking enterprises in Yulin, Shaanxi, it was found that although their PDS processes require less capital investment, with carbon steel equipment being used (the interior of the absorption towers is lined with tetrafluoroethylene), there is a problem of pitting corrosion. Additionally, the concentration of by-product salts in the system solution is high; two units had to have their entire PDS desulfurization system solutions replaced during maintenance, which increased operating costs. However, this did not resolve the issue of high by-product salt levels, leaving the risk of excessive hydrogen sulfide levels in the exhaust gas. The wet complexation iron process for hydrogen sulfide removal does not suffer from the problem of high by-product salts, and it features high efficiency in hydrogen sulfide removal, with a single-pass removal rate of 99.99%, and a hydrogen sulfide content in the exhaust gas of ≤5 ppm.

Thank you, sir. You seem to know a lot about this craft. Have you worked in this field?

There are few complex salts in iron formed by wet method, and the complex salts that do exist have a certain positive effect on the reaction. The biggest difference between the two is probably the absence of waste generation, which is also one of the major advantages of using ferric complexes for treatment. It is known that ferric complexes are effective at removing hydrogen sulfide, and levels can even be reduced to below 1 ppm. :(

This post was last edited by sdwfsgyykai on 2019-7-24 07:48. You’re welcome! I am currently mainly engaged in the treatment of various hydrogen sulfide-containing gas mixtures; feel free to contact me if you have any questions

In the wet-process iron complexation method, a certain amount of thiosulfate is added to the starting agents in the system solution before operation; this is done to help the reaction reach equilibrium as quickly as possible within the system solution, while also preventing the formation of by-products.

The generation of by-products in the wet flue gas desulfurization process is inevitable; the quality of process operation control has a significant impact, as does the suitability of the equipment.

The removal efficiency is satisfactory. The advantages include lower operating costs compared to ferric chelate, as well as less formation of by-products; there is no wastewater discharge. We have implemented several systems of this type in the past, and they have all operated stably

No thiocyanate is formed in the wet-method complexed iron

What are the requirements for complexed iron when dealing with coker gas that contains impurities?