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At Huayu Coal Chemical, all four gasifiers are now capable of burning high-sulfur coal. Author/Source: Huayu Coal Chemical; Date: May 14, 2021; Page views: 30. At 10:08 a.m. on May 12, all four gasifiers in Huayu Coal Chemical’s methanol production system operated stably for 24 hours while burning high-sulfur coal. All process parameters related to gas purification remained within normal limits, and the sulfur recovery unit achieved its designed output capacity. Thus, the trial run involving the use of high-sulfur anthracite in the methanol production system was a complete success. The design concept of the company’s methanol system was to achieve low-cost operation by utilizing the inexpensive, high-sulfur anthracite available locally in Jincheng. However, since the system was put into operation, the total sulfur content in the purified gas has remained high, whether the four furnaces were operating at full capacity under a \"two-highs-two-lows\" or \"three-highs-one-low\" operating regime. This persistent problem has become a challenge in the operation and management of the entire production system, and it is also a major factor contributing to the high costs associated with methanol production ； How to reduce the total sulfur content in the purified gas has been a topic of long-term research for the production system and the purification workshop. Efforts to achieve this include learning from well-performing plants by sending personnel there, inviting experts to give lectures, continuously reflecting on and summarizing experiences during operations, and taking measures such as sealing leaks in gas coolers. The bottleneck in systems that burn high-sulfur coal entirely lies in the Rectisol process; thus, improving the desulfurization efficiency is a crucial factor. In the initial stage of operation, the methanol circulation rate is relatively high, resulting in a high thermal load on the system, excessive steam consumption, high pump currents, and overheating of pump motors ； Through the continuous accumulation resulting from long-term operational experience, the bold decision to make process adjustments by reducing the circulation volume and thermal load yielded excellent results; this allowed for an adjustment in the methanol circulation volume used in low-temperature methanol washing, thereby laying the foundation for burning high-sulfur coal entirely. Through experiments on partially burning high-sulfur coal in the fourth furnace via gasification, progress is made in small steps with an emphasis on stability ； Through a major overhaul, the tubes of the sulfur recovery acid condenser were replaced to ensure that all the acidic gases from the four furnaces can be completely processed ； Replacing all the precision desulfurization agents during the major overhaul provides the final safeguard for the system ； Through a major overhaul, leakages in the gas cooler are sealed once again to ensure absolute reliability ； Through further optimization of various systems, all problems associated with burning high-sulfur coal were resolved. Based on calculations of operating the system at full capacity with high-sulfur coal, the coal cost can be saved by 187,500 yuan per day thanks to the difference in coal prices; moreover, sulfur recovery allows for an increase in sulfuric acid production of 3 tons per hour, as well as an increase in supplementary steam production of 11 tons per hour ； It has yielded favorable economic benefits; the methanol system now operates at full capacity and at low costs. This has laid a solid foundation for the company to achieve “consistent profitability each quarter,” “profitability throughout the year,” and a successful start to the 14th Five-Year Plan period.