(Hong Kong – 12 June, 2024) China Risun Group Limited ("China Risun" or “the Group”, stock code: 1907.HK) announced the stable operation of the wastewater recycling project for the hydration unit of its 270,000 tons per year Phase II cyclohexanone hydration process in Cangzhou Park, contributing to the Group's energy conservation and efficiency enhancement efforts.
The main product at Risun Group's Cangzhou Park is caprolactam, with cyclohexanone being one of its primary raw materials. In China, the mainstream production processes for cyclohexanone include cyclohexane oxidation, hydration, and phenol methods. Cangzhou Park constructs two cyclohexanone production units: a traditional oxidation unit with an annual output of 135,000 tons (Phase I) and a hydration unit with an annual output of 270,000 tons (Phase II). The Phase II hydration unit is a core component of the expansion project aimed at increasing the park's caprolactam production capacity to 300,000 tons per year. This unit ensures a stable and high-quality supply of cyclohexanone for caprolactam production, while the Phase I oxidation unit can utilize cyclohexane, a byproduct of the hydration process, as a raw material. This synergy reduces the need for external purchases of cyclohexane and benzene-derived cyclohexane, creating a cost advantage and achieving efficiency gains across both phases.
The Phase II hydration unit at Cangzhou Park uses benzene and hydrogen as raw materials, with partial hydrogenation of benzene to produce cyclohexene, which is then hydrated to produce cyclohexanol. Cyclohexanol is subsequently dehydrogenated to produce cyclohexanone, which is purified and sent to the caprolactam unit, with hydrogen as a byproduct that is purified for use in the hydrogen peroxide unit. The hydration process offers several advantages over the traditional oxidation process:
Reduced Raw Material Consumption: The hydration process byproducts, such as cyclohexane, serve as raw materials for the Phase I oxidation process, achieving a carbon conversion rate of over 96% and reducing hydrogen consumption by approximately one-third.
Waste Reduction: Gas and liquid waste are reduced by over 90% before separation, with some waste repurposed as clean fuel, significantly enhancing green production levels and reducing waste treatment costs.
Enhanced Safety: Partial hydrogenation and hydration reactions occur in the aqueous phase under mild conditions, increasing safety and avoiding corrosion or byproduct clogging, thus offering higher operational stability.
High Product Purity and Quality: The absence of acid and ester byproducts associated with traditional processes significantly reduces the burden on downstream wastewater treatment facilities.
The Phase II hydration unit has been operating stably for two years, continuously optimizing energy efficiency and resource utilization. A recent technological upgrade focused on wastewater recycling within the hydration unit, successfully redirecting excess wastewater back into the hydration reactor. This reduced water consumption to below 2 tons per hour per line, maintaining normal conversion rates and selectivity, and decreased steam consumption and wastewater treatment load. The two lines now recycle approximately 5 tons of wastewater per hour, saving 40,000 tons of water annually, reducing desalinated water consumption, and lowering wastewater discharge. Additionally, this upgrade addresses the issue of unreacted water entering the purification system, reducing steam wastage and improving overall efficiency.
As a key installation at Cangzhou Park, the 270,000 tons per year hydration unit adheres to rigorous standards from design to construction, commissioning, and stable operation. The project features the largest single-line hydrogenation and hydration reactors in the country and incorporates an energy-saving dehydrogenation product recovery solution. Lessons from Phase I have been applied to Phase II, including heat recovery from the light column and the integration of a dry vacuum pump. Continuous optimization ensures operational safety, energy savings, and cost reductions.
Moving forward, China Risun's Cangzhou Park will continue its commitment to uncovering potential and systematically enhancing all processes, ensuring the facility maintains industry-leading standards. This will create a robust competitive advantage, enhance profitability, expand the scale of operations, and position Risun's chemical industry system for growth. The park will also explore other fine chemical and new material investment opportunities, laying a solid foundation for achieving the development goal of becoming the world's most competitive caprolactam and nylon new material leader, driven by technological innovation.
