Performance simulation of solar-driven absorption heat pump-membrane distillation system for combined desalination brine concentration with feed recirculation and cooling applications

Desalination is the primary choice for securing freshwater provision in water-stressed regions and reduces the gap between rising demand and dwindling natural freshwater resources. However, global desalination plants are dominated by fossil fuel-driven desalination technologies with a 40-50 % recovery ratio. Hence, it is critical to decarbonize desalination and address brine effluent ecological concerns. In this paper, a solar-powered absorption heat pump (AHP)-membrane distillation (MD) system concept was proposed and analysed for smallscale RO plant brine reject management and space cooling applications. The MD subsystem is based on commercial MD modules with batch feed recirculation to reach saturation (from 70 to 260 g/kg salinity). The MD system's heating and cooling consumptions are supplied by the AHP (6.54 MWh and 13.47 MWh, respectively, for a complete batch cycle). The AHP is designed to supply hot water at 85 degrees C with 701.63 kW heating capacity and co-produced chilled water at 16 degrees C with a cooling capacity of 857.86 kW, about 67% is utilized to cool down the brine reject to feed temperature. The thermal and exergy COPs were 1.273 and 0.40 at a driving heat of 135 degrees C. The solar-powered AHP-MD system is useful for sustainable desalination deployment besides space cooling applications.