New and effective combination of an absorption desalination systems with adsorption and humidification-dehumidification desalination systems utilizing internal heat recovery methods

Abstract

The fast growth in population and the need for human comfort leads to a significant rise in freshwater shortage and energy usage. This article provides new and effective combinations between absorption (ABDC), adsorption (ADDC), and humidification-dehumidification (HDH) desalination plants. Four new configurations employing different external and internal heat recovery methods between the plants and their components are proposed to enhance the overall system performance, water production, and utilization of the used energy. In all configurations, the solar water heating system is used to power the ABDC. While the ADDC and HDH were powered by the heat recovery from condensation, absorption, or generation processes. Internal heat recovery methods are also applied between the evaporator and condenser in ABDC and ADDC plants to increase energy utilization. The results are evaluated and compared with standalone ABDC results and with previous related studies at different conditions. The production share percentage (%) from each plant for the suggested configurations with regeneration temperatures is also investigated. The maximum water production is achieved by the fourth configuration (3 m3.day−1 with a gain output ratio (GOR) of 1.316 at 120 °C) when the ADDC is worked by the outlet hot water from the ABDC, and internal heat recovery utilized between the condensation and evaporation components of both ABDC and ADDC. The highest GOR is obtained from the second configuration (1.714 at 90 °C). The finding expressed that the proposed configurations have a better performance than traditional ABDC systems. Also, the proposed configurations express another advantage over traditional ABDC, that the configurations have the potential at low-temperature heat sources (55–65 °C) to improve the water productivity to about 455 % and GOR to about 120 %.