Supercritical Water Gasification Staged at Intervals for Hydrogen Fermentation Residue of Food Waste

Abstract

To circumvent the problem of reactor plugging in supercritical water gasification (SCWG), we proposed an SCWG process operated at intervals with a continuous-flow system (10 kg/d) configured to feed water and feedstock in alternate steps. Hydrogen fermentation residues of soybean fiber and restaurant food waste (SFHFR and RWHFR, respectively) were employed as feedstock, and fine activated carbon was used as catalyst. Feedstocks of 2.0-10.0% SFHFR were gasified in a tubular reactor at 600 °C, 25 MPa with a residence time of 60-105 s. An 8% concentration SFHSR was gasified with a carbon gasification efficiency of 0.75 without plugging. A 4% RWHFR, a feedstock composed of more diverse substances, was gasified with a carbon gasification efficiency of 0.57.