Recently, the People's Government of Lanshan District, Rizhao City, released a public notice for the proposed review of environmental impact assessment documents for a construction project. The experimental project of thermally coupled seawater hydrogen production combined with strategic element extraction by Shandong Rizhao Dawang Clean Energy Co., Ltd. has entered the EIA public notice stage. The project has a total investment of 10 million yuan and will utilize existing factory buildings to build an experimental platform for conducting experimental research on seawater desalination, seawater electrolysis for hydrogen production, thermal energy coupling utilization, and extraction of strategic marine elements.
Annual production of 10,000 Nm³ of hydrogen, with an alkaline electrolyzer design capacity of 20 Nm³/h
The project is located north of Shugang Avenue and west of the south gate of Shangang in Lanshan District, Rizhao City, covering an area of approximately 300 m². It will utilize existing factory buildings to build the experimental platform. The main product of this project is hydrogen, produced through alkaline water electrolysis.The designed hydrogen production capacity is 20 Nm³/h, with an annual capacity of approximately 10,000 Nm³. Annual hydrogen production is 10,000 Nm³, with a volume fraction of ≥99.99%, premium grade, and no storage facilities; it is directly vented. Annual oxygen production is 5,000 Nm³, with no storage facilities; it is directly vented.
The project does not involve industrial production or commercial product output, nor is it a pilot-scale project. Through systematic experiments, it explores and tests the effects of experimental factors and operating conditions on seawater desalination, hydrogen production, and high-value water quality, identifies optimal process parameters and operating mechanisms, obtains equipment parameters for stable operation, and provides a solid theoretical basis and technical support for the subsequent construction of a pilot base for the development and utilization of strategic marine resources and engineering applications. The facility operates 504 hours per year, with the remaining time in shutdown and maintenance status. The project is designed to operate for 5 years.
Thermal coupling system + seawater screening to achieve recovery and utilization of low-grade waste heat
In terms of process, the project adopts a thermal coupling system to recover and utilize the "low-grade waste heat" (typically 80-90°C) generated when 30% of the electrolyzer's operating energy is converted to heat, providing the required steam for the seawater screening system. The seawater screening system uses the steam generated by thermal coupling to pretreat natural seawater. Freshwater produced by low-temperature distillation enters the electrolysis hydrogen production system through pipelines, and the total dissolved solids in the concentrated seawater are controlled within 110 g/L, with recycling and no external discharge.
The alkaline hydrogen production system is equipped with one unit, using 30% potassium hydroxide solution as the alkaline electrolyte. Freshwater produced by seawater screening is electrolyzed to generate hydrogen and oxygen. The alkaline solution passes through a gas-liquid separation system into the thermal coupling system, is concentrated in a flash evaporation tank, and is recycled, with appropriate replenishment based on annual specific gravity measurements.
In addition, the project is equipped with two PEM electrolysis hydrogen production systems (one 2 Nm³ and one 8 Nm³), which use high-value water produced by flash evaporation and solid proton exchange membranes (alkali-free) to generate hydrogen and oxygen through electrolysis. The proton exchange membrane replacement life is 1,000 hours. The project operates 504 hours per year, and no replacement is required during operation. The intelligent distillation unit, under vacuum and reduced pressure conditions, uses a four-stage distillation column system for vapor-liquid countercurrent heat exchange, producing approximately 1.2 kg of high-value water per month.
Self-developed experimental equipment, with a total investment of 10 million yuan
The main experimental equipment of the project includes a seawater treatment unit, thermal coupling unit, alkaline hydrogen production unit, PEM hydrogen production unit, and intelligent distillation unit, all of which are self-developed. The project has a staffing of 10 people, working 504 hours per year, approximately 21 days, with a 24-hour, 3-shift, 8-hour work schedule per day.
In terms of main raw and auxiliary materials and energy consumption, the annual consumption includes 2 m³ of seawater (recycled), 24 m³ of fresh water, 0.01 t of KOH, 50,000 kWh of electricity, 10 m³ of nitrogen, and 1 m³ of pure water (self-produced).
The advancement of this project explores a new path for the engineering application of coupled seawater desalination and electrolysis hydrogen production technology, and also provides experimental support for the comprehensive utilization of strategic marine resources.
