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The Technology Department of Zhongyan Hongsi Fang Advances Technological Innovations to Solve Technical Challenges in the Ethylene Glycol Distillation Unit / Author/Source: Zhongyan Anhui Hongsi Fang Co., Ltd. Date: 2020-06-22 Clicks: 73 Recently, through collective brainstorming, repeated experiments, and thorough evaluations by the technical staff at Zhongyan Hongsi Fang, technical improvements were made to the ethylene glycol distillation unit, resulting in an increased rate of high-quality products. The successful operation of this project has fully utilized the capacity of the facility, making a positive contribution to focusing on the company’s annual goals and ensuring high-quality development. The 300,000 tons per year synthetic gas-based ethylene glycol production project of Sino Salt Hongsi Fang Phase II came online in October 2018. In accordance with the requirements of the process design, the guaranteed rate of first-class polyester-grade ethylene glycol is above 90%, and the actual rate of first-class product in operation is nearly 91%; the remaining 9% is industrial-grade ethylene glycol, resulting in 27,000 tons of industrial-grade ethylene glycol produced each year. Due to the small market size for industrial-grade ethylene glycol, it is somewhat difficult to sell it. To address this challenge, technicians from the Development and Technology Department went straight to the production sites to understand the actual operating conditions of the equipment, identify shortcomings and problems, and then devised targeted solutions and technical improvement measures. Due to the technical barriers associated with the production of ethylene glycol from coal in China, technicians conducted repeated experiments and various analyses on different approaches. By utilizing advanced domestic processing technologies and new catalysts, they carried out technical upgrades to the ethylene glycol distillation unit; they also added a unit for liquid-phase hydrogenation to improve the quality of the ethylene glycol. Using these new hydrogenation catalysts, organic impurities in industrial-grade ethylene glycol were removed in a hydrogen-rich environment, thereby increasing the product’s ultraviolet transmittance. All of the resulting industrial-grade ethylene glycol was converted into polyester-grade ethylene glycol, further increasing the proportion of high-quality products. At the end of 2019, the ethylene glycol liquid-phase hydrogenation unit project was completed, and operations began with trial runs. After being processed by a liquid-phase hydrogenation unit, industrial-grade ethylene glycol sees a significant increase in its ultraviolet transmittance; following distillation in an alcohol removal tower and a product tower, it is entirely converted into polyester-grade ethylene glycol. After several months of stable operation, the device is functioning well and has initially met the design requirements. After a performance evaluation plan was developed jointly by the Technology Center, the Production Center, and the Ethylene Glycol Workshop, the unit underwent a 72-hour performance test from May 20 to 23. Based on the performance evaluation metrics, both the production capacity of the device and its ultraviolet transmittance have reached the design values, while the proportion of high-quality polyester-grade ethylene glycol has increased significantly. The operating cost of this device is around 200 yuan. Considering that industrial-grade ethylene glycol costs 600 yuan less per ton than polyester-grade ethylene glycol, 27,000 tons of ethylene glycol can generate an annual profit of nearly 10 million yuan for the enterprise.