Methanol enables long-term operation

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Aiming to achieve both timely completion of tasks and meeting targets, Yankuang Group’s Lunan Chemical Company integrates the management of key work objectives with innovation initiatives, adopts a series of measures to optimize system operations, strengthens management, and taps into internal potential to ensure the achievement of efficiency goals. The methanol system has now been in operation for 1,071 days, meeting the target of a major overhaul every three years. The company actively carries out efforts to save water and energy. Since the beginning of summer, in light of factors such as hot and dry weather and tight groundwater supplies, the company has carried out extensive technical upgrades to optimize its systems and reduce water consumption. The 130 t/h condensate from the air separation unit is now routed to the desalinated water system without passing through the ion exchange system, and after ammonia is added it is supplied externally directly. After the modification, the desalinated water system can reduce the water production volume by 130 tons per hour, generating savings of 40,000 yuan per month. For the purification III desulfurization and decarbonization units, as well as desulfurization compressors A and B#, the cooling water has been changed from primary water to recycled water, resulting in savings of 21,600 yuan per month. Using the purified II steam condensate as make-up water for circulating water generates an economic benefit of 7,000 yuan per month. The 0.2MPa steam of low quality from Purification IV has been upgraded for recovery; 7 tons of such low-quality steam are recovered per hour, generating an economic benefit of 360,000 yuan per month. Taking advantage of the system maintenance period, two additional primary water connection pipelines were installed to enable the sharing of primary water resources between the eastern and western plant areas. With the operation of the surface water treatment unit and the modified pipelines starting in April, 400–550 m3 of groundwater is saved per hour. The company actively leverages the connectivity effect. The addition of a steam connection at 1.3 Mpa in the East Plant has effectively extended the operational time of the ester production units in the West Plant; compared to the same period last year, both the operational time and output of the ethyl ester and butyl ester production units have increased. In the first half of this year, by leveraging the connection between the east and west plant sites, production of the core products methanol increased by 12,100 tons, while acetic acid production increased by 43,500 tons. The gasification furnace was switched over in the western plant area; by utilizing the interconnected media such as water gas, CO, and CO2 between the eastern and western plants, the operation of the Methanol II and Acetic Acid systems, as well as the dual-system setup in the eastern plant, was ensured. This prevented unplanned shutdowns of the methanol system, the Purification IV system, and the acetic acid system, effectively reduced the time required to restore these systems to normal operation, and minimized material losses resulting from system shutdowns and startups.