H2-rich gas production from gasification of oily sludge via supercritical water technology: Synergy effect of KOH, K2CO3, and reaction parameters

Yielding H-2 as a sustainable gaseous fuel from oily sludge is of critical importance in mitigating the environmental effects linked with the usage of conventional fossil fuels. The deficiency in the drying of biomass has ensued to the exploration of supercritical water gasification (SCWG) as an effective method for harvesting H-2-rich gas. This study utilized a combination of two alkali catalysts (KOH and K2CO3) in supercritical water to generate a H-2-rich gas from a conventional oily sludge. The Box-Behnken design was utilized to assess the impact of different operational variables, including temperature (400-600 degrees C), feed concentration (FC) (between 5 and 25 wt.%), residence time (RT) (15-45 min), and catalyst to feed mass ratios (FMR) (0-0.50). The maximum production of H-2 at 3.22 mmolg-feed(-1) was achieved under optimal conditions of 600 degrees C, 32.76 min, and a KOH to FMR of 0.45 and K2CO3 to FMR of 0.28.