Comparison and analysis of pyrolysis characteristics and kinetics of alfalfa and timothy based on TG ‐ DTG ‐ DSC

Abstract This paper aims to study the pyrolysis characteristics and kinetics of alfalfa and timothy and conduct a comparative analysis. Multiple analytical methods were used to comprehensively characterize the physical and chemical properties of alfalfa and timothy. A thermal analyzer was used to analyze the kinetics of the material pyrolysis process at various heating rates. The results showed that alfalfa and timothy are suitable as energy fuels due to their high volatile matter, three main components (cellulose, lignin, hemicellulose), and low moisture. At different heat rates, the devolatilization index and heat flow area of timothy are both greater than alfalfa. In addition, the average activation energies of alfalfa and timothy calculated by the Flynn–Wall–Ozawa (FWO) method were 243.58 and 221.9 kJ mol −1 , respectively; calculated by the Kissinger–Akahira–Sunose (KAS) method are 246.5 and 223.62 kJ mol −1 , respectively. The average activation energy of these two methods indicates that timothy's (222.76 kJ mol −1 ) pyrolysis activity is slightly higher than that of alfalfa (245.039 kJ mol −1 ). The pyrolysis mechanism for the two materials can be modelled with the equation .