13- Measures to prevent the generation of large amounts of SO2 and sulfur in hydrogen fluoride production facilities

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This post was last edited by luoli519 on 2023-10-3 at 17:42. A few days ago, I and Mr. Xu, an expert in the industry, were invited to attend a meeting regarding the technical upgrade project for the hydrofluoric acid production facility at a well-known fluorine chemical company in the industry. During the meeting, the company requested discussions on measures to address the high levels of SO2 generated by its hydrofluoric acid production facility. We went to the site and inspected equipment such as its rotary reactor and sulfur capturers to assess the situation; we found that the rotary reactor was severely corroded, and both sulfur capturers were filled with sulfur. This is also a problem that many hydrogen fluoride production companies are facing or have faced in the past. Fluoride hydrogen/hydrofluoric acid production plants generate large amounts of SO2 and sulfur, whose main hazards are as follows: 1. It causes severe equipment corrosion, resulting in high maintenance costs. Especially the core reaction equipment, the rotary furnace. 2. It results in a high consumption of H2SO4, leading to high production costs. 3. This prevents the sulfur capture unit from operating continuously under long-term overload conditions, resulting in high maintenance costs. Additionally, the SO2 content in the exhaust gases is high, and the acid recovery index does not meet the standards. The production of hydrogen fluoride/hydrofluoric acid facilities face significant issues with SO2 and sulfur, which indeed requires companies to pay close attention to prevention measures. Regarding the excessive generation of SO2 and sulfur in hydrogen fluoride/hydrofluoric acid production plants, the main reasons are generally as follows: 1. Severe corrosion of carbon steel equipment leads to the formation of SO2 and elemental sulfur; this phenomenon is particularly severe when the reaction temperature is too high, the acid mixture is not properly prepared, or the residence time in the reaction furnace is too long. 2. The raw fluorite powder contains excessive amounts of oleic acid and sulfides; during the incoming material inspection, only substances such as CaF, CaCO3, SiO2, and H2O are tested, while there is no monitoring of the levels of oleic acid and sulfides. During the reaction, oleic acid and sulfides produce not only SO2 but also H2S and elemental sulfur. I recommend taking the following measures and actions to prevent excessive generation of SO2, H2S, and elemental sulfur in hydrogen fluoride/hydrofluoric acid production facilities: 1. The raw material inspection process should include tests for oleic acid and sulfides in the fluorite powder used as raw material, in order to strictly control the quality of these raw materials. 2. In the production process, reaction conditions must be strictly controlled, especially the reaction temperature, the ratio of acids used, and the residence time, in order to avoid extensive production methods. 3. In addition, the exhaust gas treatment process should enhance the spray purification of SO2-containing exhaust gases, and vane-type separation elements should be used for the vent gases to capture acidic droplets carried in the gas phase, thereby preventing these acidic droplets from escaping the system through the exhaust fans and causing complex downstream treatment issues as well as severe environmental pollution. I would also like colleagues to share, based on their own corporate experience and lessons learned, the measures taken to prevent the generation of large amounts of SO2, H2S, and sulfur in hydrogen fluoride/hydrofluoric acid production facilities.