Continuous Hydrogen Production via Hydrothermal Gasification of Biodiesel Industry Wastewater: Experimental Optimization and Energy Integration Simulation

This study reports the continuous production of H2 from the wastewater effluent of the biodiesel industry in a medium containing water under supercritical conditions. The effects of temperature and feed flow rate on the generation of hydrogen were evaluated and optimized. At a temperature of 700 degrees C and a 17.5 mL/min feed flow, a total gas flow of 5541 NmL/min was achieved. Among all identified gases, hydrogen represented the highest molar fraction of 73%. Under optimized conditions, a H2 yield of 357 NmL/geffluent feed was observed. The experimental results indicate a significant increase in the H2 production at the highest experimented temperatures. On the other hand, the feed flow only slightly influenced the process within the assessed range but showed a tendency to increase the H2 production at the highest values. Finally, information on energy efficiency optimization and scale-up are presented, and at the same time, different designs for industrial implementation of the hydrothermal gasification process are proposed.

Automated summary

This study reports the continuous production of H2 from the wastewater effluent of the biodiesel industry under supercritical conditions. The effects of temperature and feed flow rate on hydrogen generation were evaluated and optimized. The results indicate a significant increase in H2 production at higher temperatures, while the feed flow rate showed a tendency to increase H2 production at higher values.