Pyrolysis and carbon dioxide gasification kinetics of hydrochar produced from cow manure

This study focuses on determining the kinetic parameters of pyrolysis and gasification of manure-derived hydrochar. Hydrochar was first pyrolyzed in Thermogravimetric analyzer at heating rates of 5, 10, and 20 degrees C min(-1) with N-2 and gasified afterwards with CO2 at 800, 900, and 1000 degrees C for 30, 60, and 90 min. Morphology of the pyrolysis and gasified chars were analyzed with FT-IR and scanning electron microscope (SEM). Kissinger's method was used to evaluate kinetic parameters for pyrolysis, while Arrhenius method was implemented to evaluate gasification kinetic parameters. Activation energy for pyrolysis and gasification were 211.5 +/- 7.7 kJ mol(-1) and 270 +/- 20 kJ mol(-1), respectively. FT-IR analysis revealed that -OH and aliphatic C-H groups were significantly reduced compare to raw hydrochar during gasification. A decrease of particle size and an increase of amorphous region were observed in SEM analysis, while energy-dispersive x-ray spectroscopy analysis revealed an increase in oxygen and carbon contents in gasified char. (c) 2018 American Institute of Chemical Engineers Environ Prog, 38: 154-162, 2019