Kinetic analysis and modeling of maize straw hydrochar combustion using a multi-Gaussian-distributed activation energy model

Combustion kinetics of the hydrochar was investigated using a multi-Gaussian-distributed activation energy model (DAEM) to expand the knowledge on the combustion mechanisms. The results demonstrated that the kinetic parameters calculated by the multi-Gaussian-DAEM accurately represented the experimental conversion rate curves. Overall, the feedstock combustion could be divided into four stages: the decomposition of hemicellulose, cellulose, lignin, and char combustion. The hydrochar combustion could in turn be divided into three stages: the combustion of cellulose, lignin, and char. The mean activation energy ranges obtained for the cellulose, lignin, and char were 273.7-292.8, 315.1-334.5, and 354.4-370 kJ/mol, respectively, with the standard deviations of 2.1-23.1, 9.5-27.4, and 12.1-22.9 kJ/mol, respectively. The cellulose and lignin contents first increased and then decreased with increasing hydrothermal carbonization (HTC) temperature, while the mass fraction of char gradually increased.

Automated summary

The combustion kinetics of hydrochar were studied using a multi-Gaussian-distributed activation energy model, revealing the process can be divided into different stages and changes with temperature variations.