【Ten Years of Great Progress in Chemical Technology】The world’s first cyclohexane dehydrogenation unit was put into operation between 2016 and 2019
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At 9:00 on September 19, 2019, the cyclohexane dehydrogenation project associated with the facility of Fujian Yongrong Technology Co., Ltd. produced qualified products; both the yield and purity of these products met the design specifications, enabling a successful first operation of the facility. The process technology used in this project was jointly developed by Beijing Engineering Company, Fujian Yongrong Technology Co., Ltd., and Beijing Saino Shifei Petrochemical Technology Co., Ltd. This device is the world’s first industrial-scale application unit; the hydrogen purity produced by it reaches 99.8%, while the yield of benzene product is over 95%. This project fills the gap in this technology both domestically and internationally; it increases the utilization rate of raw material benzene from the traditional 75% to over 99%, thereby establishing for the first time in the world a new technical approach that achieves \"zero waste of raw materials in production facilities\". Globally, the traditional technical approach involves the production of cyclohexane as a by-product during the manufacturing process. However, cyclohexane is not further processed or utilized; it is instead sold at low prices, which results in an effective utilization rate of around 75% for the raw material benzene. The new process developed for this project solves this global challenge: under certain temperatures, pressures, and with the action of a catalyst, cyclohexane, which is a by-product of the **plant, is converted into benzene and hydrogen. These benzene and hydrogen are then fed back into the **plant as raw materials, thus creating a closed-loop system. This approach also yields significant economic benefits, increasing the utilization rate of benzene as a raw material in the **plant to over 99%. This process is green, environmentally friendly, efficient, and energy-saving, achieving zero emissions. It has brought about a significant advancement in the caprolactam industry, while also opening up new business areas for Beijing Engineering Company and enhancing its core competitiveness.
This device is one of the three main production units in Phase I of CPL’s project, developed by Fujian Yongrong Technology Co., Ltd. Yongrong Technology’s **equipment utilizes a hydration-based coupling process**, and the cyclohexane produced as a by-product cannot be utilized on-site, which has long been a production challenge for the company. The accompanying cyclohexane dehydrogenation unit converts cyclohexane into benzene and hydrogen; both benzene and inexpensive hydrogen are recycled back to the **unit, thereby making full use of all by-products. This approach avoids the safety risks associated with transporting cyclohexane outside, and increases the utilization rate of benzene from 75% to over 99%, resulting in significant economic benefits. This innovative process can also improve the utilization rate of carbon atoms during the operation of the **equipment, thereby further increasing the conversion efficiency of the hydrolysis process**. It represents a breakthrough in terms of existing technologies as well as safety and environmental considerations, solving the global technical challenges faced by this industry and ensuring the green, efficient, and stable operation of Yongrong Technology’s CPL project.
In May 2021, led by the China Petroleum and Chemical Federation, with the participation of Fujian Yongrong, Beijing Petrochemical Engineering Co., Ltd. (abbreviated as Beiyou Engineering), and Beijing Saino Shifei, three industry experts were specially invited to conduct an on-site assessment of the process performance of Fujian Yongrong’s 180,000 tons per year cyclohexane dehydrogenation unit over a period of 72 hours. The assessment period runs from 00:00 on May 25, 2021, to 24:00 on May 27, 2021. The main assessment criteria include product quality indicators, catalyst performance, energy consumption metrics, and the operational stability of the facility. After 72 hours of data collection and analysis, as well as on-site verification by experts, the participating experts unanimously agreed that the assessment scheme was reasonable and feasible, and the data was valid. It is reported that this project is the world’s first production facility utilizing a \"green and efficient hydration-process coupled technology\" (the 180,000 tons per year cyclohexane dehydrogenation plant in Fujian Yongrong), and its design was carried out by Beiyou Engineering Company. The project’s process technology was jointly developed by Beiyou Engineering Company, Fujian Yongrong Technology Co., Ltd., and Beijing Saino Shifei Petrochemical Technology Co., Ltd. Since its commissioning, the unit has operated stably with good performance. The successful completion of this calibration provides sufficient baseline data for the evaluation of this device. At the same time, the benzene fraction and hydrogen produced by the cyclohexane dehydrogenation unit are entirely fed into **the device, enabling a closed-loop operation of the process; this clearly demonstrates that the utilization rate of benzene as a raw material in **the device has increased from 75% to over 99%. It marks the world’s first \"green and efficient water-based synthesis **coupled process\" that aligns with the development strategies of sustainability, efficiency, and low carbon emissions; it offers a new approach to enhancing economic efficiency in market economies, and its industrial application has reached international advanced levels.