Pranjal Kumar, Abhijit Date, Ratan Kumar Das, Bahman Shabani
Freshwater supply is one of the major challenges in large-scale renewable hydrogen production. This paper presents the details of a study assessing the feasibility of recovering electrolyser and fuel cell waste heat to desalinate seawater to be fed into the electrolyser in a standalone renewable hydrogen system. A lab-scale experimental setup was developed to investigate the waste-heat-powered direct contact membrane distillation system for hydrogen water circularity and validate a model of this arrangement created in MATLAB. The developed lab-scale experimental setup mainly consists of custom designed stack developed for mimicking electrolyser/fuel cell stack (producing a total of 300 W effectively available waste heat), a heat recovery arrangement and a direct contact membrane distillation module. The performance of this desalination system was evaluated under varying operating conditions, including stack temperature, feed water salinity, and feed water inlet temperature to a shell and tube heat exchanger, i.e., used for heat recovery. The results of the experimental study showed that the selected desalination system can produce 1.16 kg/m 2 ·h using 300 W of waste heat at the flow rate of 0.35 L/min of feed saline flow with 35 g/L of salinity and permeate flow. The produced water exhibited low total dissolved solids (5.415 mg/L) and conductivity (13.81 μS/cm), significantly outperforming tap water quality in Melbourne and meeting the requirements for commercial electrolyser systems equipped with water de-ionising units. • EL/FC waste heat utilisation for seawater desalination for electrolysis. • Experimental analysis of proposed EL/FC waste heat powered DCMD system. • DCMD unit achieved 1.16 kg/m 2 .h flux production using 300 W low grade waste heat. • Produced water (TDS 5.4 mg/L and 13.8 μS/cm) is of better quality than tap water. • Produced water is suitable for tap water dependent electrolyser.