Industrialization of efficient and energy-saving sulfur recovery technology

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The newly built sulfur recovery unit of Shaanxi Weihua Group has recently started trial operation. The total investment in this facility exceeds 50 million yuan. It is designed to have a sulfur recovery capacity of 34 tons per day; once operational, it will be able to recover all the sulfur-containing waste gases generated by Weihua Group’s 300,000 tons per year coal-based synthetic ammonia production facility and 600,000 tons per year methanol production facility, resulting in an annual output of over 10,000 tons of sulfur. 　　The entire system consists of the Claus sulfur recovery unit from Shell Netherlands and the Ltscot low-temperature hydrogenation sulfur recovery unit from JACOBS Netherlands. Jia Baoxiang, head of the company’s Technical Development Department, explained that by effectively combining traditional processes with new sulfur recovery technologies, it is possible to increase the sulfur recovery rate and reduce the emission of harmful substances. This approach also significantly enhances the operational flexibility and safety of the facilities, resulting in energy savings, cost reduction, and improved efficiency. 　　The trial operation results of the Weihua unit show that by using the specialized catalyst from JACOBS Company, organic sulfur can be hydrogenated at lower temperatures and under milder pressures, and the unit can operate stably within a load range of 20% to 110%. The exhaust gas volume treated by the Ltscot device is only 70 ppm, which is less than 1/5 of the **latest emission standards, with a total sulfur recovery rate of over 99.9%. Compared to a conventional Claus sulfur recovery unit, it reduces sulfur dioxide emissions by over 930 tons per year. 　　According to Wang Zhenyue, the technical services manager at JACOBS Company, the commonly used sulfur recovery technologies at present mainly include the Claus sulfur recovery technology and the Scot hydrogenation technology. The former requires that the hydrogen sulfide content in the reaction medium be 25%–32%, and about 5% of the sulfur in the exhaust gases cannot be recovered. Although the latter can handle low-concentration sulfur-containing media, it has a short catalyst lifespan, requires high hydrogenation temperatures and pressures, and is energy-intensive. To address these challenges, in 2004 JACOBS Company began laboratory development of the Ltscot technology; industrial pilot testing was completed in 2009, followed by its rollout in Europe, the Americas, and the Asia-Pacific region. 　　The Ltscot technology can be seamlessly integrated with the Claus technology, effectively addressing the challenges related to the treatment of sulfur-containing fluids and energy conservation in petrochemical enterprises; it has been well received by users since its introduction. Currently, there are nearly 20 such installations in the country, but only Weihua Group has one that is operational.