Thermal degradation behavior of Ball-milled miscanthus plants and its relationship to enzymatic hydrolysis

Abstract

Correlations were determined between the thermal degradation behaviors of ball-milled Miscanthus plants and their enzymatic digestibilities. Overall, thermal degradation temperatures of Miscanthus giganteus were higher than those of M. sinensis. The differential thermogravimetric (DTG) curve of M. giganteus had a characteristic shoulder peak near 292 °C as opposed to that of M. sinensis. The thermal degradation temperatures of both ball-milled samples decreased with increased ball-milling time, although the composition was not changed by ball milling. Remarkable changes in the DTG curves of M. sinensis and M. giganteus occurred with ball milling for more than 60 min and 120 min, respectively. These thermal degradation results were similar to the results for physicochemical pretreatments and enzymatic digestibilities. The thermal decomposition temperatures of both ball-milled samples at 20% weight loss were most negatively correlated with the enzymatic digestibilities with a value of approximately -1.0.