Production and Characterization of Synthetic Diesel Fuel from Coal via Fischer–Tropsch Indirect Liquefaction

This study presents the development and experimental validation of a structural simulation model for hydrogen generation via water electrolysis that integrates alkaline and proton exchange membrane (PEM) electrolyser technologies. The model incorporates the effects of operating temperature, supply voltage, and dynamic power modes, including pulsed and intermittent feeding. Experimental investigations were conducted on a Nel A-150 alkaline electrolyser and a Proton OneSite PEM unit across temperature ranges from 35 to 80°C and voltage ranges from 1.7 to 2.3 V. Results demonstrated that increasing temperature significantly enhances current and hydrogen production rates, with the mass flow rising from 0.032 to 0.046 kg/h as temperature increased. A proportional-integral (PI) temperature control system was designed and tested, achieving stabilisation within 15 seconds and maintaining deviations of ±0.3°C following thermal disturbances. The validated simulation model achieved normalised root-mean-square errors below 0.98 under most conditions, confirming its predictive accuracy. The findings highlight the critical importance of precise thermal management and dynamic modelling for optimising industrial electrolyser performance and ensuring stable hydrogen output across varying operational conditions.