A Multi-generation system in Sabkha-Tah operating with nanofluids and a novel RO unit.

The extremely high temperatures in the Western Sahara region has to lead to difficulties in the supply of water and food. Sabkha-Tah in Morocco is one of the regions in the Western Sahara, which possesses conditions that prevent the farming of certain crops. Nevertheless, the region has the advantage of being in a zone 60 m below sea level. This geographical advantage has the potential to reduce energy consumption in the reverse osmosis unit (RO). An energy, water, and food nexus study that takes advantage of the region's geographical characteristics are performed. A multi-generation system that produces cooling, power, and freshwater for a greenhouse situated in the Sabkha-Tah is proposed and thermodynamically analyzed. The freshwater is supplied through a RO unit that uses the hydrostatic pressure of falling water from the Atlantic Ocean. Cooling is supplied through an absorption cooling cycle that uses the waste heat of the Rankine cycle condenser, while a solar-powered Rankine cycle is used to feed the system with the required power. The system uses a parabolic trough collector (PTC), which utilises the high solar irradiance in Sabkha-Tah to generate the energy needed by the Rankine cycle. The PTC uses Cu/Therminol VP1 nanofluid as the working fluid to enhance the efficiency of the system. The study results show a reduction in the RO's power consumption from 5.561 to 2.51 kWh/m³ by using an energy recovery turbine (ERT) and the hydrostatic pressure of the falling water. The system shows that 46.18 kW of pump work can be saved when using the hydrostatic water pressure. The overall energy and exergy efficiencies for the multi-generation system are calculated to be 60.81% and 29.76%, respectively, using TherminolVP1 in PTC, while the energy efficiency increased by 0.014% using nanofluid (Cu/TherminolVP1) with a volume fraction of 0.02.