Hydrogen-rich syngas production via catalytic gasification of sewage sludge and wheat straw using corn stalk char-supported catalysts

Abstract

The co-gasification of wheat straw and wet sewage sludge for hydrogen-rich gas production was investigated in a fixed bed reactor with corn stalk char (CSC)-supported catalysts. The Ni/CSC, Ni-Fe/CSC, and Ni-Fe-La/CSC catalysts were characterized via ultimate analysis, X-ray fluorescence, thermogravimetric, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, Brunauer-Emmett-Teller, and Fourier transform infrared spectroscopy analyses. A series of experiments were performed to explore the effects of reactor temperature, catalyst type, moisture content of wet sludge, and catalyst recycling performance on the composition and yield of gasification gases. The experiments demonstrated that the nickel-iron alloy (Fe0.64Ni0.36) was detected in the Ni-Fe-La/CSC catalyst, and the Ni-Fe-La/CSC catalyst showed much higher hydrogen production compared with the Ni/CSC and Ni-Fe/CSC catalysts. Furthermore, La2O3 effectively maintained the catalytic performance of the catalyst by relieving carbon deposition. Compared with non-catalyst biomass gasification, H2 yield increased from 3.80 mol/kg to 11.96 mol/kg using Ni-Fe-La/CSC catalyst at 600 °C. The newly developed tri-metallic Ni-Fe-La/CSC catalyst exhibited high catalytic activity for biomass gasification at low temperature.