Synergistic effect on co-pyrolysis mechanism and kinetics of waste coal blended with high-rank coal and biomass

In this work, a comprehensive and systematic study on synergistic effect and kinetics of three coal ranks (anthracite coal, bituminous coal, and waste coal), and three biomass materials (wheat straw, sawdust, groundnut) were performed under different blending ratios. The kinetic parameters of coal and biomass devolatilization were estimated by means of thermogravimetric analysis (TGA) at 10, 20, 30 and 40 Kmin(-1). These kinetic parameters were subsequently validated using Artificial Neural Network (ANN) Model. Further, for fitting the experimental data, a numerical approach to distributed activation energy model (DAEM) has been evaluated and the experimental findings were compared with simulated data. Subsequently, the kinetic and thermodynamic parameters were estimated and compared with three model-free methods viz., KAS, OFW, and Friedman. The results from TG study indicate that the interactions between the waste coal with higher rank coal and biomass samples present an inhibitive effect during the devolatilization process. Furthermore, the values of activation energy were found in the range of 270, 250, 149 kJmol(-1) by using OFW, KAS and Friedman model, respectively. Additionally, the thermodynamic parameters viz., enthalpy (Delta H), Gibbs free energy (Delta G) and entropy (Delta S) were estimated as 275.2 kJ mol(-1), 184.5 kJmol(-1), and 59.7 Jmol(-1), respectively.

Automated summary

This work conducted a comprehensive and systematic study on the synergistic effect and kinetics of different coal ranks and biomass materials. Kinetic parameters were estimated using thermogravimetric analysis and validated using an Artificial Neural Network model. Various model-free methods were used to estimate kinetic and thermodynamic parameters. Results showed inhibitive interactions between waste coal, higher rank coal, and biomass samples during devolatilization, with activation energy values ranging from 149 to 270 kJ/mol for different models. Thermodynamic parameters were also estimated and compared across different methods.