Efficiency and energetic analysis of the production of gaseous green fuels from the compressed steam and supercritical water gasification of waste lube oils

The gasification of a waste lube oil (WLO), using water under vapor and supercritical states leads to its valorization into green fuels with high energetic power like H2 and CH4. This work investigates how the most important variables of a flow continuous gasification process, temperature, pressure and reaction time, influence the efficiency of gasification and the amounts and characteristics of the gases produced. The study of the influence of these variables on the energetic efficiency of the process was also completed. The highest production yields, 2.4 10-2 molH2 goil -1 and 3.0 10-2 molCH4 goil-1, were registered at supercritical water conditions (750 degrees C, 250 bar and 1.87 min). The energetic study revealed that the energetic efficiency increased as the reaction time was lengthened. Gasification kinetics were slower as pressure increased but the reaction times inside the flow reactor were longer. A pressure range from 150 bar, steam region, to 250 bar, supercritical region, was identified as optimal since allowed the most suitable balance between kinetics and the reaction times achieved.

Automated summary

This study examines the impact of temperature, pressure, and reaction time on the gasification efficiency, gas production, and characteristics of waste lube oil. It was found that the highest yields of hydrogen and methane were achieved under supercritical water conditions. Additionally, increasing reaction time led to improved energy efficiency in the gasification process.