The rise in CO2 emissions is causing major problems like glaciers melting and sea levels rising. To help tackle these issues, the DESOLINATION project introduces a cutting-edge power cycle for desalination systems, using innovative CO2-based mixtures as the next generation of working fluids. This paper highlights the project’s benefits and the technical hurdles overcome in designing the necessary machinery.
Key factors were considered when developing the thermal cycle and choosing the working fluid, including safety, environmental impact, material compatibility, and efficiency.
The system relies on turbomachinery—specifically a pump and an expander—to recover heat from a primary solar-powered cycle. This setup allows flexible heat production while simulating different solar conditions.
One major challenge was picking the right CO2 blend to balance efficiency and practicality. By adding a “dopant” to CO2, the fluid’s properties could be adjusted, allowing the system to use a pump instead of a compressor. This makes heat exchange more efficient by keeping the fluid at a temperature suitable for the solar heat source. Several dopants were tested to find the best one for efficiency and compatibility.
Material compatibility was another challenge, as the equipment needs to handle temperatures as high as 550°C, typical for solar-thermal power technology. The final dopant choice was a trade-off between reducing corrosion and maximizing performance.