Linggu Chemical Group Co., Ltd., established in 1966 (formerly the Yixing Fertilizer Plant of Jiangsu Province), is a manufacturer of synthetic ammonia and urea located in the Yixing Economic and Technological Development Zone of Jiangsu Province. Guided by the development philosophy of “Innovation, Green Development, Resource Conservation, Sustainability, and Shared Prosperity,” Linggu Group currently has an annual production capacity of 1 million metric tons of synthetic ammonia, 1.8 million metric tons of urea (including aqueous solutions), and 200,000 metric tons of industrial-grade carbon dioxide. The company also engages in related industries such as the production of various industrial gases and industrial sulfur, as well as the design and manufacture of Class I and II pressure vessels.

In 2024, Linggu Group commenced construction of a new project with an annual production capacity of 300,000 tons of high-purity (Coca-Cola grade) food-grade liquid carbon dioxide, along with an annual production capacity of 30,000 tons of dry ice. Our company is supplying the process package, detailed engineering design, patents, proprietary core equipment, and specialized hydrocarbon removal catalysts for this project.

This project utilizes low-to-medium concentration CO₂ tail gas emitted from the low-temperature methanol stripping process in the synthetic ammonia project as feedstock. The feed gas contains ethane and non-methane hydrocarbons of C2 and higher, whose concentrations far exceed the specified limits. After liquefaction and concentration, these concentrations will exceed product specifications. Neither adsorption nor multi-stage distillation can effectively remove these substances. To produce high-purity liquid CO2 that meets Coca-Cola standards and food safety requirements, a more thorough purification method is necessary. Currently, the most effective method for removing C2 and higher hydrocarbons (including oxygenated hydrocarbons) both domestically and internationally is catalytic oxidation dehydrocarbonization purification (our company’s patented technology, patents, and proprietary equipment). Therefore, this plan adopts the catalytic dehydrocarbonization purification process, combined with a series of processes including advanced desulfurization, adsorption drying, liquefaction, and distillation, to ensure that the quality of the carbon dioxide product meets the requirements of GB1886.228-2016 “National Food Safety Standard for Food Additive Carbon Dioxide” and the procurement standards of The Coca-Cola Company.

Through the joint efforts of the leadership of all departments at Linggu Chemical Group and our company’s technical staff, the project was successfully commissioned on October 25, 2025. After 72 hours of operation, all equipment functioned normally, the process and equipment met the expected objectives, and the product quality was found to be compliant.