Construction contents of the caprolactam expansion project at Cangzhou Xuyang Chemical

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Contents of the caprolactam expansion project at Cangzhou Xuyang Chemical Co., Ltd. Cangzhou Xuyang Chemical Co., Ltd. currently has 1 set of **production facility with an annual capacity of 100,000 tons, 1 set of **oxime production facility with an annual capacity of 100,000 tons, and 1 set of caprolactam production facility with an annual capacity of 100,000 tons. Accepted in 2017. Cangzhou Xuyang Chemical’s caprolactam expansion project aims to produce liquid caprolactam using raw materials such as lignite, benzene, fuming sulfuric acid, and alkali solutions. The construction site is located within the Cangzhou Xuyang Chemical Industrial Park. The construction scope includes a 300,000-ton/year caprolactam plant, a 450,000-ton/year ammonium sulfate plant, a 270,000-ton/year ** plant, a 300,000-ton/year synthetic ammonia plant, an 80,000 m3/h lignite-based hydrogen production plant, and a 120,000-ton/year hydrogen peroxide plant (equivalent to 100%). In March 2018, the Management Committee of Cangzhou Bohai New Area published for public comment the environmental impact assessment documents related to the expansion project of caprolactam production at Cangzhou Xuyang Chemical Co., Ltd., with approval for such documents being sought. According to the environmental impact assessment document, the main construction contents of the project are as follows. Main construction contents: Gas production – The water-coal slurry prepared from lignite, together with oxygen from the air separation unit, is used to gasify raw coal in Jinhua furnaces to produce raw gas; this raw gas is then purified before being sent to the shift cooling unit. A sulfur-resistant, wide-temperature shift process is employed, with the shifted gas being sent to an acid gas removal unit; low-temperature methanol washing is used to remove acidic gases such as CO2 and H2S from the shifted gas. The cooling capacity for the acid gas removal unit comes from the ammonia compression refrigeration of the refrigeration unit. The purified gas from the acidic gas removal unit is sent to the PSA hydrogen production unit to produce hydrogen product, which is then sent to downstream processes. Ammonia synthesis: The synthetic fresh gas from the liquid nitrogen washing unit consists mainly of N2 (99.999%) and H2 (at 35°C and 5.4 MPa); with a hydrogen-to-nitrogen ratio of 3.0, this gas is compressed before being sent to the ammonia synthesis process. Ammonia is synthesized using axial radial synthesis technology. Hydrogen peroxide: The production of hydrogen peroxide is carried out using the anthraquinone process. ****Its production uses the benzene hydrogenation-cyclohexene hydration process. Different from the benzene hydrogenation-cyclohexane oxidation process used in existing projects. First, benzene undergoes partial hydrogenation in the presence of a catalyst to produce cyclohexene ； Cyclohexene is hydrated to produce cyclohexanol ； Cyclohexanol is dehydrogenated in the presence of a catalyst to form **. This process generates very few other by-products aside from cyclohexane. Compared with the traditional benzene method, it features significant energy savings and improved safety. Aminoximation and caprolactam: The production of aminoximation and caprolactam employs the \"H2O2 aminoximation–liquid-phase rearrangement process\" introduced from the Italian company Enichem. The entire process is illustrated in Figure 1. Figure 1 Process schematic