Why don’t the major petrochemical industries use H2S directly to produce sulfuric acid?

There are many plants that produce sulfuric acid directly, such as the sulfuric acid plant at Shanghai Coking and the sulfuric acid plant of Henan Jinkai Group. However, the concentration of H2S gas in the acidic exhaust gases from the petrochemical industry is generally not high. Moreover, a few years ago, the domestic technology for producing sulfuric acid from acidic gases was not yet fully developed; most plants used Topsoe’s wet-process sulfuric acid production method, which results in low sulfuric acid output and very high investment costs for plant construction. In recent years, similar processes for producing sulfuric acid from acidic exhaust gases have also been developed in China. Companies such as Shandong Ruixing Chemical and Anhui Haoyuan Chemical use the domestic acid production technology developed by Shanghai Keyang to convert the acidic exhaust gases generated during the low-temperature methanol washing process in coal-based ammonia synthesis projects into 98% sulfuric acid. These systems have been in operation for about two to three years now. The investment required for such domestic technologies is much lower; I estimate that it can be reduced by at least half compared to the Topsoe process.

The original poster is absolutely right; at present, most of the acidic gases in China are used to produce sulfur, and most of that sulfur is then used to make sulfuric acid. The main reasons for this are the numerous limitations associated with the storage and transportation of sulfuric acid, as well as the fact that its danger level is **higher than that of sulfur. These factors are what ultimately lead most companies to use acidic gases to produce sulfur instead of manufacturing sulfuric acid directly.

Thank you, thank you! For our new project here, the top leaders simply don’t consider the sulfuric acid process at all. . . . It is estimated that when choosing between safety and economic benefits, the economic benefits are relatively low. . .

Currently, the price of sulfur is low, so sulfuric acid is quite cost-effective. It’s mainly for the reasons mentioned by the moderators. Another possibility is a conceptual reason – the belief that sulfuric acid is dangerous.

Companies that do not use sulfuric acid generally do not produce it; at least, a smaller amount of sulfur makes it easier to store

Sulfuric acid is considered a hazardous substance; its production, storage, transportation, sales, and purchase by customers are all subject to regulation by relevant authorities. The procedures and approvals required make it much more complicated than it would be from an economic perspective. Many manufacturers also take this aspect into consideration.

I agree with the opinion above; from a design perspective, producing sulfuric acid is more environmentally friendly. From the owners’ point of view, if there is no market for sulfuric acid, it can cause significant problems for the company, whereas sulfur is much more flexible in terms of usage.

It depends on the owner’s requirements whether to use sulfur or sulfuric acid. Additionally, exhaust regulations have become stricter these days; what plans do you have regarding the Claus process for exhaust treatment?

Power wave/ammonia method/alkaline washing. . Under consideration!

Power wave tail scrubbing for desulfurization is a well-established technology that is safe, reliable, and has a proven track record; feel free to discuss it if you have any needs.