Catalytic Gasification of Sewage Sludge in Supercritical Water: Influence of K2CO3 and H2O2 on Hydrogen Production and Phosphorus Yield

In this work, the catalytic gasification of sewage sludge in supercritical water was investigated in a batch reactor (460 °C, 27 MPa, 6 min), and the separate and combined effects of the catalyst on the H2 production and phosphorus yield were investigated. The experimental results indicated that K2CO3 alone improved the H2 yield, gasification efficiency (GE), and carbon gasification efficiency (CE). The largest H2 yield of 54.28 mol/kg was achieved, which was approximately three times that without a catalyst. Furthermore, the inorganic phosphorus (IP) yield increased with the addition of K2CO3. However, when H2O2 was added, the H2 yield quickly decreased with increasing H2O2 coefficient, and more than 97.8% of organic phosphorus (OP) was converted into IP. The H2 yield increased with the addition of various K2CO3/H2O2 ratios, whereas the IP yield decreased.