Thermodynamic and Environmental Assessment of Integrating a Heat-Pump Tumble Dryer with a PEM Electrolyzer

Abstract

Hydrogen is increasingly regarded as an energy carrier for electrification and long-duration storage. This study presents a combined modeling and experimentally validated thermodynamic analysis of a household-scale hydrogen production concept integrating a heat-pump tumble dryer with a proton exchange membrane electrolyzer (PEME). The work combines steady-state thermodynamic and exergy modeling, experimental validation using air-side measurements, and a scenario-based life cycle assessment (LCA). A thermodynamic model of the integrated system was developed in engineering equation solver (EES), and a parametric analysis examined ambient temperature, relative humidity, tumble-air temperature, and alternative working fluids. Key metrics include coefficient of performance (COP), exergy destruction, condensate production, and hydrogen yield. Under baseline conditions, the system achieves COP = 4.90, produces 5.546 kg condensate/cycle, and yields 0.5453 kg H-2/cycle. Increasing ambient temperature (15-40 degrees C) raises COP by up to 14% and lowers exergy destruction (0.1999 -> 0.1775 kW). Raising tumble-air temperature (65-75 degrees C) increases COP (3.033 -> 5.406), reduces exergy destruction by 29%, and increases hydrogen output threefold. Exergy losses are dominated by the expansion valve (45%) and the condenser (39%). Among refrigerants, R600a and R1270 provide the highest gains in condensate and hydrogen production. A use-phase Life-cycle assessment (LCA) shows per-cycle Global Warming Potential (GWP) is reduced for condensate reuse (0.4087 -> 0.4070 kg CO2-eq/cycle). Overall, results suggest that dryer-condensate-fed electrolysis is technically feasible and offers thermodynamic and climate-impact benefits at the household scale.