Performance analysis of a low temperature waste heat-driven adsorption desalination prototype plant

This paper discusses the performance analysis of adsorption desalination cycles with different configurations. The salient features of the AD cycle are the ability to the utilization of low temperature waste heat (typically less than 85°C), the deployment of environmentally friendly adsorbent/adsorbate pair (silica gel/water pair) and no major moving parts. The advanced AD cycle that incorporates the internal heat recovery between the condenser and evaporator by a heat recovery circuit is compared with conventional two-bed and four-bed AD cycles. Mathematical models to investigate the performance of the cycles are also presented. Extensive experiments have been conducted to explore the performance of such systems and are analysed in terms of key performance indicators namely the specific daily water production (SDWP) and the performance ratio (PR). Based on the experimental data, it is found that the SDWP of the advanced AD cycle with the condenser-evaporator heat recovery circuit is about 15 m³ of potable water per tonne of silica gel which is nearly two times that of the conventional AD cycles. Moreover, it is also found that the advanced AD cycle can be operational at 50°C hot water temperature with SDWP 4.3.