Utilizing supercritical water gasification for hydrogen production combined with a waste heat recovery system for domestic households

• Food waste gasification yields hydrogen, a clean and efficient fuel. • SCWG process tested at 400 °C, 450 °C, and 500 °C with 30 to 90 min reactions. • Hydrogen efficiency peaked at 9.2 % at 500 °C for a 90 min reaction time. • PEM cells convert hydrogen into electricity and heat at varying flow rates. • The system recovers 23.1 % waste heat, heating small homes with hydrogen. Hydrogen from food waste can provide sustainable energy. Food waste can be gasified into clean, efficient hydrogen gas using cutting-edge techniques. This study is about the gasification of food waste under different settings to determine gas production and efficiency. The supercritical water gasification (SCWG) method was used in experiments at 400 °C, 450 °C, and 500 °C with reaction durations of 30, 60 and 90 min. The results showed peak values of CO 2 , CO, CH 4 , H 2 at 90 min, equivalent to 6.2 % and 7.9 % hydrogen efficiency (HE) and cold gas efficiency (CGE). Peak CGE and HE were 6.7 % and 9.2 % at 500 °C, whereas peak CE and total gas output were 6.8 % and 8.6 %. To generate heat and power, a PEM cell was added. Gasification-generated hydrogen was warmed and fed in the PEM circuit at 0.7, 1 and 1.5 m/s. The peak velocity indicates a 23.1 % waste heat recovery rate and a higher hydrogen temperature difference of roughly 8.1 °C. At the temperature of peak gasification (500 °C), the values of CO 2 , CO, CH 4 , and H 2 are approximately 3.6 mol/kg, 0.3 mol/kg, 2.6 mol/kg, and 4.7 mol/kg, respectively. At the peak gasification temperature (500 °C), As a result, the suggested system is ideal for combining hydrogen production to generate both power and heat energy for use in heating small homes or buildings (the proposed system can deliver that much energy or at least partially fulfill it).