A comprehensive review on humidifiers and dehumidifiers in solar and low-grade waste heat powered humidification-dehumidification desalination systems

Theoretical review based on the technologies developed in solar desalination.

“…Today, the shortage of drinking water and the increasing demand for energy is the greatest challenge facing [1], [2], due to the continuous increase in population, industrial activities and the fact that a quarter of mankind suffers from inadequate freshwater use [3], [4]. The water emergency situation is very alarming, mainly in arid and remote areas, despite the fact that the planet is covered by 97% of water, however, fresh water comprises only 2.5% of the total amount, the rest being seas, glaciers, ice caps and groundwater [5] Brackish water has salinity in the range of 10,000 ppm, where the possible limit for drinking water is (500 to 1,000 ppm), so, to obtain these acceptable ranges is achieved through water desalination [6], [7], However, desalination is an energy-intensive process that requires 10,000 tons of fossil fuels per year to produce 1,000 cubic meters of water per day [8]- [10].…”

Accelerated Water Desorption of Oligomeric Poly(ethylene glycol) by Addition of Poly(propylene glycol) for Energy-Efficient Water Recovery Systems

“…The effective utilization of low-grade heat promises to contribute to achieving energy sustainability . A wide range of technologies are currently being developed to utilize low-grade heat in air conditioning, power generation, agricultural processes, and water systems . There has been particular interest in the development of adsorbents for desiccant air conditioning (DAC) and atmospheric water harvesting (AWH) systems, which enable the recovery of water vapor from the air under low humidity conditions in an energy-efficient manner.…”

“…5 A wide range of technologies are currently being developed to utilize low-grade heat in air conditioning, power generation, 6 agricultural processes, 7 and water systems. 8 There has been particular interest in the development of adsorbents for desiccant air conditioning (DAC) 9 and atmospheric water harvesting (AWH) 10 systems, which enable the recovery of water vapor from the air under low humidity conditions in an energy-efficient manner. In these systems, it is important to develop adsorbents that can be regenerated using low-grade heat to achieve autonomous DAC and AWH.…”

Multiobjective Modeling and Optimization of a Heat and Mass Transfer-Integrated Network in a Desalination System

“…8−11 Increasing the contact time between air and seawater by adopting a multistage HDH system can improve system performance and reduce external energy consumption. 12 Xu and Dai 13 presented a twostage desalination system based on the HDH process, and a mathematic model is developed and validated by the experimental results. Xu et al 14 designed a two-stage humidification desalination system to reuse the condensation heat produced by the precooler.…”

“…In a basic HDH system, the air stream only completes humidification once by performing heat and mass transfer with the seawater stream in the humidifier. − Increasing the contact time between air and seawater by adopting a multistage HDH system can improve system performance and reduce external energy consumption . Xu and Dai presented a two-stage desalination system based on the HDH process, and a mathematic model is developed and validated by the experimental results.…”