Major breakthrough achieved in the methanol production plant of Yankuang Guohong’s 500,000-ton low-temperature methanol washing process

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Since September 12, the gasification workshop of Guohong Company has been conducting technical training for its staff through systematic water-linked debugging. The water interlocking commissioning involves operating the low-pressure ash water pump, deoxidation water pump, slag pool pump, and ash water circulation pump, establishing the flow path from zone 703 to zone 704, while also checking the accuracy of the relevant instruments and automatic control valves. During the debugging process, each team participated actively; all members engaged in practical training and successfully completed the three steps of initiating water operation, adjusting system balance, and stopping water operation, thereby achieving the goal of skill development for their respective positions. (Zhang Yuanfei) On September 15, the B air separation system of Guohong Company was successfully commissioned, producing qualified oxygen. The air separation unit of Guohong Company is responsible for supplying oxygen as a raw material for gasification and synthesis, and it represents the key link in the methanol production system. To ensure oxygen production as planned, Guohong Company carried out thorough organization and meticulous planning, formulating detailed commissioning plans and adjustment procedures. It conducted systematic testing of the equipment, instruments, and electrical systems, going through processes such as turbine startup, pipeline purging, molecular sieve replacement, and cold box cooling, **and completed all commissioning tasks. The purity of the liquid oxygen produced reached 99.75%, meeting the specified requirements. Currently, the conditions for supplying oxygen and nitrogen are available, laying the foundation for subsequent feeding and trial production. (Wang Xiaotao) At 6:38 p.m. on October 18, the first feeding trial run of Gasifier No. B at Guohong Company was successful, marking a breakthrough in the joint commissioning efforts for Guohong Company’s 500,000-ton methanol project. To ensure the success of the commissioning with feedstock, the project commissioning command center of Guohong Company organized everything carefully and made detailed plans for the feedstock introduction process. It also carried out debugging of the DCS system in the control room, as well as the ESD safety logic systems of the on-site equipment, instruments, and electrical installations. After feeding the materials, the coal slurry transportation, oxygen supply, and safety interlock control systems operated properly under conditions of heat and pressure; the effective content of syngas reached 80%, meeting the requirements of the process specifications. (Wu Zehua, Wang Xiaotao) Purifying methanol feed gas using low-temperature methanol as a solvent (to remove acidic gases such as hydrogen sulfide and carbon dioxide) is one of the key processes in the coal-to-methanol production process. The low-temperature methanol circulation pump (P2204A methanol-poor pump) used by Guohong Company is an important piece of equipment for carrying out this process. This pump is distributed by Shanghai Gaode Company and manufactured by United Pump Company in the United States; it is currently the largest low-temperature methanol circulation pump in use in China within its industry. On September 13, both pumps P2204A and B exhibited abnormalities during testing: they started up and operated normally for extended periods, but after shutdown, attempting to rotate them found that the pumps were stuck and could not turn. After the accident, everyone at Guohong Company was extremely worried and repeatedly urged United Pumping Company in the United States to send people to the site to resolve the issue. The other party remained indifferent and arrogantly emphasized that the manufacturing technology of this pump was advanced and its internal structure was highly precise, prohibiting any disassembly; they also unreasonably stated that maintenance services could only be provided after ordering a set of pump rotors first. Is foreign technology truly so “mysterious” that it’s unfathomable and unattainable? Should we wait until the rice is ready to use and delay the project timeline by 2-3 months, or should we find rice to cook with and carry out technical upgrades to accelerate the testing process? Is it really okay to willingly submit to others? If you want to do something well, you can always find a way. Under the circumstances of tight testing schedules, heavy tasks, and high pressure, the determined staff at Guohong resolutely mobilized their resources to disassemble and inspect the pump. It was found that there were 4 impeller mouth ring frictional adhesions in total in this pump; the condition was most severe at the inlet mouth ring of the fourth stage on the low-pressure side. The gap between the wear-resistant ring of the pump casing and the wear-resistant ring of the impeller contained a large amount of metal debris resulting from wear, which had stuck together, preventing the pump from rotating properly. Where is the problem? The top leaders of Guohong Company were on site, working together with technical personnel from Yankuang Daliujī Factory who were brought in to analyze the situation, discuss it, and identify the causes. Visits were made to factories such as the Dezhou Fertilizer Plant to examine the operation of the low-temperature methanol washing process. After numerous in-depth discussions and scientific calculations with technical experts from Yankuang Daliu Machinery Company, the root cause was finally identified: in order to improve the wear resistance of the pump, its rotating and stationary parts were made of the same material – X30Cr13 stainless steel – and no heat treatment to create a difference in hardness was applied, resulting in equal hardness in both parts. When the pump stopped and passed through the resonance zone, adhesion occurred due to this condition, preventing the pump from rotating. As a result of thorough research, decisive actions were taken: the intermediate support bearing shells of the pump, the impeller throat rings of the pump body, the balance plugs, and the throttle rings were changed from the original X30Cr13 material to tin bronze. The two modified pumps, P2204A and B, started successfully on October 31 in a single attempt, and could be started and stopped freely, completely eliminating the biggest hazard that had been preventing the operation of the low-temperature methanol washing process. One difficulty after another is overcome, and one joy after another emerges. Oxygen was produced via air separation on September 15, qualified methanol was obtained through distillation in the synthesis tower on October 10, and the first feeding to the gasifier was successful on October 18. At present, the overall commissioning of Guohong Company’s 500,000-ton methanol project is progressing in an orderly manner as planned, and the production of high-quality methanol is just around the corner. (Wang Xiaotao, Li Ming) At 22:10 on November 29th, Guohong Company successfully connected the methanol synthesis system to the gas supply, completing the entire process for methanol production. Qualified crude methanol was produced sequentially, and the trial production run was a **success**, laying a solid foundation for full-scale operation in the future. Guohong Company focused closely on all the tasks related to testing and pilot production, made thorough plans and detailed arrangements, set backward schedules, and ensured safe debugging and testing; it completed the testing and pilot production tasks in a high-quality, efficient, and rapid manner. To ensure that all tasks were carried out effectively, the company held a mobilization meeting for the trial production phase, established a command center for the testing and commissioning process, developed a corresponding plan for these activities, implemented 24-hour supervision, and assigned skilled personnel to oversee the process. Testing was carried out first on a single unit before moving on to joint tests, thereby ensuring that the commissioning work progressed steadily in accordance with established procedures and plans. During the commissioning process, given the complex nature of the methanol production process, its advanced technology, and the numerous logical interconnection control points at various stages, they overcame various problems that arose during testing. By using their creativity to find solutions, they managed to overcome these difficulties and ensure the successful completion of the commissioning of large-scale equipment such as heat and power boilers, air separation turbines, compressors, and gasification furnaces, as well as other phase-specific tasks including pipeline purging and system airtightness testing. (Wang Xiaotao)