【Ten Years of Rapid Development in Chemical Equipment】From 2014 to 2022, Tianhua Research Institute designed and manufactured China’s first polypropylene polymerization reactor using the Rums process, which was successfully put into operation
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Witnessing the decade-long rapid development of chemical processing equipment: Praise for China’s prosperous and strong era. Replies will be rewarded; discussions are welcome. ------------------------------------------- Recently, the first polypropylene polymerization reactor built using the Rumus process, designed and manufactured by Tianhua Institute, was successfully put into operation at CNOOC Ningbo Daxie Petrochemical Co., Ltd.’s 300,000-ton-per-year polypropylene production facility. As the core equipment of the project, this polymerization reactor adheres to domestic regulations in terms of materials and design standards. At present, the device is operating stably, and all key parameter indicators meet the design requirements. The successful operation of this project marks an important step forward for Tianhua Institute in promoting the localization and self-reliance of polypropylene reaction equipment. The polymerization reactor for the polypropylene project at CNOOC Ningbo Daxie Petrochemical is the first device in China to use the Ruums process. The Rums process is a gas-phase polypropylene production method that offers great flexibility in terms of reactor arrangement; the two reactors can be connected in series or in parallel as needed. This flexibility enables the production of various polypropylene products, including homopolymers, random copolymers, terpolymers, and impact-resistant copolymers. The polymerization reactor is a key device in the Rumus process; previously, patent holders believed that there were no equipment manufacturers in China capable of meeting the requirements for such reactors, and all existing plants used imported equipment. As an outstanding supplier of equipment for the polypropylene industry in China, Tianhua Yuan possesses extensive technical expertise in equipment design and manufacturing. Its strong design capabilities and manufacturing skills have enabled it to provide high-quality technical services to various polypropylene production enterprises across the country, earning recognition from chemical companies both at home and abroad. In March 2020, experts from CNOOC Daxie Petrochemical, after conducting various investigations, concluded that Tianhua Institute possessed the comprehensive capabilities necessary to meet all the requirements for the design and manufacture of polymerization reactors. As a result, it was decided that Tianhua Institute would be responsible for designing and manufacturing the polymerization reactors for CNOOC’s 300,000-ton polypropylene project.
Completing the domestic design and manufacturing of such equipment is no easy task. As required by the manufacturing process, the specifications of this polymerization reactor are Φ4850mm X 10000mm X 72mm, with the thickness of the head reaching 130mm. Due to the characteristics of polymerization reactions, the design pressure must reach 4.0 MPa; meanwhile, the gap between the bottom agitator and the container during operation is required to be around 2 mm. This poses significant design challenges and high requirements for processing, so many difficulties must be overcome during the process of local production. As the entity responsible for the task of localizing this key equipment, during the design and manufacturing process, the project team from Tianhua Institute drew on experience from existing operational projects as well as years of research in the field of polypropylene reactions. Taking into account the requirements of the process patent holders and the differences in standards between domestically produced equipment and imported equipment, they carefully studied relevant domestic and international materials, and pursued innovations in the processes and equipment design. They successfully overcame various challenges related to equipment design, material selection, the installation of multiple internal temperature sensors, and the manufacturing of tungsten alloy components. ——In terms of material selection, the domestically produced 09MnNiD material was used in place of the imported TStE420 material; it boasts better low-temperature resistance and has been widely employed in domestic polypropylene plants, ensuring adequate equipment safety. ——In the design of the head, die stamping was employed, along with 3D laser scanning technology to adjust the dimensions of the head; this not only greatly improved the accuracy of the head but also reduced the amount of secondary processing required. ——In terms of the integration of components, based on the characteristics of the chemical reaction process and the requirements for integrating internal tubes, 14 temperature measurement points were combined together using built-in multi-point temperature sensors (E1). Additionally, tungsten alloy components were utilized to integrate the installation tubes for the two nuclear level detectors as well as the propylene nozzle tubes on the circulation gas pipes of the polymerizer reactor, thereby preventing the project from being hindered by these components. ——In terms of the selection of analysis methods, finite element analysis was employed to conduct stress and displacement analyses on the agitator head at the bottom of the reactor, ensuring that the stress and deformation of the head remained within optimal limits and thus guaranteeing the safety of the reactor under various loads. ——In terms of the precision of the equipment, an innovative approach that combines laser scanning modeling with CNC lathes ensures the high precision in processing large-scale equipment. In July 2021, China’s first polypropylene polymerization reactor built using the Rums process – a result of nearly 3 years of effort by Tianhua Corporation – was successfully manufactured and delivered. This event took place in the presence of representatives from 15 companies, including the China Special Equipment Inspection and Research Institute, the Shanghai Institute of Organic Chemistry of the Chinese Academy of Sciences, the patent holder of Rums technology, CNOOC Ningbo Daxie Petrochemical Company, Sinopec Engineering Co., Ltd., China Global Engineering Co., Ltd. Beijing Branch, China Tianchen Engineering Co., Ltd., China Hualu Engineering Co., Ltd., Sinopec Ningbo Engineering Co., Ltd., and China Flexible Packaging Group Co., Ltd.
Wish a prosperous and strong China.