The ethylene glycol liquid-phase hydrogenation plant of Henan Energy Qianxi Coal Chemical Industry has been successfully put into operation

Thread Content

The liquid-phase hydrogenation process for producing ethylene glycol at Henan Energy Qianxi Coal Chemical Industry has been successfully put into operation. Author/Source: Yaha Coal Chemical Industry; Date: 2019-09-27; Clicks: 9. The ethylene glycol production project operated by Qianxi County Qianxi Coal Chemical Industry Investment Co., Ltd., which is controlled by Henan Energy and Chemical Industry Group Co., Ltd., has an annual production capacity of 300,000 tons. The main manufacturing process makes use of the CTEG (High Chemistry-Donghua Technology Consortium) technology for producing ethylene glycol from syngas. After the operation of this ethylene glycol plant began, the yield of ethylene glycol in polyester grade remained between 94% and 95%. To increase the yield of ethylene glycol of polyester grade, reduce the proportion of industrial-grade ethylene glycol products, and improve the economic efficiency of the enterprise, Qianxi Coal Chemical decided to carry out a technological upgrade using liquid-phase hydrogenation for ethylene glycol at the beginning of 2019. For this project, the patented technology for liquid-phase ethylene glycol hydrogenation, the process package, and the catalysts are provided by Hefei Jiangxin Chemical Technology Co., Ltd., while the engineering design is carried out by Guizhou Donghua Engineering Co., Ltd. Hefei Jiangxin was fully involved in tasks such as engineering design coordination, factory inspection of the reactor, the three-inspections and four-fixations procedures for the installation, guidance on catalyst loading, operation training, and commissioning support. With the strong push from the leaders at Qianxi Coal Chemical and the close cooperation of all parties involved in the project, this ethylene glycol liquid-phase hydrogenation unit was successfully put into operation at 12:18 p.m. on September 25, 2019. As a result, the ethylene glycol distillation unit ceased to purchase industrial-grade ethylene glycol and began to produce polyester-grade ethylene glycol 100% of the time. This project is the second set of ethylene glycol liquid-phase hydrogenation technology to be used in the CTEG ethylene glycol plant; the ethylene glycol liquid-phase hydrogenation technology employed in the first plant was also provided by Hefei Jiangxin. After several hours of operation, the effectiveness and technical advantages of the liquid-phase hydrogenation catalyst provided by Hefei Jiangxin became apparent. The analysis results at 16:40 on the afternoon of September 25 are as follows: the ultraviolet transmittance of ethylene glycol at 220nm, 250nm, and 275nm during liquid-phase hydrogenation was 7.9%, 18.1%, and 24.6% respectively ； The ultraviolet transmittances at 220 nm, 250 nm, and 275 nm for the ethylene glycol liquid-phase hydrogenation outlet are 37.4%, 85.3%, and 85.0%, respectively ； At 02:05 on the morning of September 26, the ultraviolet transmittances at 220 nm, 250 nm, and 275 nm for the ethylene glycol liquid-phase hydrogenation outlet were 49.4%, 92.6%, and 94.7%, respectively. After liquid-phase hydrogenation with ethylene glycol, its ultraviolet transmittance increases significantly: the ultraviolet transmittance at 220 nm increases by more than 40%, while that at 275 nm increases by more than 70%. As the liquid-phase hydrogenation process operates continuously and the material in the ethylene glycol product tower is continuously replaced, the quality of the reflux liquid from the ethylene glycol product tower as well as the ethylene glycol product obtained through side extraction will gradually improve. The operational results of industrial projects once again demonstrate that the ethylene glycol liquid-phase hydrogenation technology provided by Hefei Jiangxin can solve the following problems: 1) It can reduce aldehyde content and increase the yield of ethylene glycol of polyester grade, raising the yield of this grade to nearly 100% ； 2) The ethylene glycol product obtained through side extraction meets polyester-grade standards, which extends the service life of the dealdehyde resin or eliminates the need to use such a resin, thereby reducing operating costs.