Simulation study demonstrates exhaust heat recovery lowers electricity costs by 18.6% in hydrogen generator systems, highlighting waste energy integration as key to clean power.
Key Points
To evaluate and compare the thermodynamic and techno-economic performance of gasoline, open-cycle hydrogen, and waste-heat-recovery-integrated hydrogen generator systems.
Conducted unified thermodynamic and techno-economic modeling using an ASPEN-based process simulation framework comparing gasoline, open-cycle hydrogen, and waste-heat-recovery setups.
Integrated an exhaust-mounted electric turbogenerator coupled with a proton exchange membrane electrolyser to harvest exhaust energy for in-situ hydrogen regeneration.
Assessed system performance and levelised cost of electricity under operating parameters of 5 hours per day and 365 days per year across grey and green hydrogen scenarios.
At maximum stable equivalence ratios examined (φ = 1.045 for gasoline, φ = 0.857 for hydrogen), open-cycle hydrogen engines showed a 17.5% lower brake thermal efficiency than gasoline (33.4% vs. 40.5%).
Coupling an electric turbogenerator waste heat recovery system raised apparent extended system-level energy utilisation factors to 54.4% in ASPEN simulations and 52.3% theoretically.
Waste heat recovery reduced the levelised cost of electricity for grey hydrogen to 0.727 MYR kWh⁻¹, representing reductions of 39.4% relative to open-cycle hydrogen and 18.6% relative to gasoline.