The 250,000-ton/year cyclohexane dehydrogenation unit (Phase I) of Guangxi Hengyi’s 1.2 million tons/year caprolactam and polyamide integrated production project was completed and brought online successfully with a single batch of feed

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Recently, significant progress was made in Guangxi Hengyi’s 1.2 million tons per year caprolactam polyamide integrated production project: the 250,000 tons per year cyclohexane dehydrogenation unit (Phase I) successfully completed its commissioning process and started operating after a single trial run. Once the entire process was operational, qualified products were produced continuously, and the unit ran smoothly. This device utilizes a low-temperature process and catalysts developed independently by the Chinese Academy of Chemical Sciences, offering advantages such as high energy efficiency, few by-products, and environmental friendliness. Its reaction conversion rate, selectivity, and product quality are all superior to those of similar domestic devices. As a key link in the industrial chain, this unit converts cyclohexane, a by-product of the cyclohexanone production facility, into benzene and hydrogen. After purification, these substances are reused in the cyclohexanone production facility, creating a closed-loop system within the facility for raw materials and products, thereby improving resource utilization efficiency. Faced with numerous challenges such as the rainy season in the Qinzhou area, concurrent construction activities, the construction of large-scale irregular foundations for compressors, quality control during compressor installation, as well as heat treatment and welding quality control for 12Cr1MoVG pipes (used for ultra-high pressure steam at 12.5 MPa), the project team devised a scientific approach, coordinated all efforts, and developed a detailed construction plan. It maintained close communication with all involved parties, continuously improved the construction methods, and strengthened on-site management. As a result, the planned milestones were achieved on schedule, demonstrating the company’s efficient construction organization, professional safety management capabilities, and strong installation skills. This successful one-time operation marks that China Chemical Engineering now possesses the technical capabilities for cyclohexane dehydrogenation processes on a scale of over 100,000 tons, as well as the ability to develop industrial catalysts. This will facilitate the transformation of the Qinzhou petrochemical industry toward more sophisticated and high-end products, thereby contributing to the development of a green chemical industry cluster and promoting high-quality economic growth in the region.