Catalytic gasification of glycine and glycerol in supercritical water

Glycine and glycerol were used as the model compounds of protein and fattiness, respectively. A continuous tubular-flow reactor was used for the gasification experiments operated at 380-500 °C and 25 MPa with or without Na₂CO₃ catalyst. Compared with a negative effect on glycerol gasification, Na₂CO₃ could increase hydrogen yield and Chemical Oxygen Demand (COD) destruction efficiency, and the catalytic performance of 0.1 wt% Na₂CO₃ was better than that of 0.2 wt% for glycine gasification. When 1 wt% glycine solution with 0.1 wt% Na₂CO₃, or 1 wt% glycerol solution without Na₂CO₃ was gasified at 500 °C with the residence time of 0.98 min, their corresponding gasification efficiencies were up to 95.8% and 98%, and hydrogen yields could reach 4.14 and 5.08 mol/mol, respectively. Hydrogen molar fraction in gaseous product was about 60% and liquid effluents could be reutilized. Correspondingly, the ideal overall reaction equations for glycine and glycerol gasification were proposed.