Research on Hydrogen Production Process by Photothermal-Driven Sludge-Coal Thermochemical Synergistic Conversion

In recent years, the amount of industrial sewage sludge awaiting treatment has continued to rise steadily, posing serious risks to human health and the ecological environment if mishandled. This study proposes a photothermal-driven supercritical water co-gasification of sludge-coal thermochemical synergistic conversion system for efficient hydrogen production. The main feature is that the medium-low temperature exothermic heating method uses concentrated solar energy to provide reaction heat for the co-gasification process. This approach synergistically converts solar energy into syngas chemical energy while meeting the heat demand of the co-gasification hydrogen production process. The results show that this co-gasification system for hydrogen production can achieve an energy efficiency of 56.82%. The sensitivity analysis shows that the molar flow rate of hydrogen increased from 44.02 kmol/h to 217.51 kmol/h as the gasification temperature increased from 500°C to 700°C. The concluded that the increase in temperature is favorable for the preparation of hydrogen. When the gasification pressure is increased from 230 bar to 310 bar, the molar flow rate of hydrogen decreases from 166.06 kmol/h to 138.09 kmol/h. The concluded that the gasification pressure does not have much effect on the preparation of hydrogen. The hydrogen yield increases continuously as the ratio of dry coal to dry sludge rises from 1.5 to 3. Under the same dry coal to dry sludge ratio, the hydrogen yield increases with the rise in total moisture content. Through the above research, the multi-energy complementary method of photothermal-driven sludge-coal thermochemical synergistic conversion is clarified. This establishes a novel approach that achieves both clean treatment and resource utilization of sludge simultaneously.