The tri-pyrolysis of polyethylene (P-E), cornstalk (C-S) and anthracite coal (A(G)) was performed using a thermogravimetric analyser (TGA) coupled to a Fourier transform infrared spectrometer (FTIR). The pyrolysis and kinetic characteristics of the raw feed materials (P-E, C-S and A(G)) along with selected mass blend ratios was investigated and compared. The tri-pyrolysis process for the selected mass blend ratios is characterised by three distinct stages, which is sequentially dominated by cornstalk C-S, polyethylene P-E, and anthracite A(C). It was found that the activation energies representing the tri-pyrolysis process are different with respect to the activation energies associated with the individual raw feed materials. It is observed that for any given fixed mass blend ratio of P-E as the contribution of C-S is increased the initial decomposition temperature at which tri-pyrolysis takes place is significantly lowered to < 190 degrees C. Therefore, the increased addition of C-S is considered to enhance the tri-pyrolysis process. An increase in the mass blend ratio of A(C) resulted in higher yields of pyrolysed residue. The yield of tri-pyrolysed residue accounted for up to 40 wt% when the mass blend contribution of A(C) was >= 0.5. Activation energies of < 130 kJ mol(-1) for the suite of mass blended materials was determined with little variation in the actual EA's between the respective mass blend ratios. The tri-pyrolysis reaction is thought to be more stable than the pyrolysis of the individual raw feed materials and it is further suggested that a synergy between the respective feed materials exists during the tri-pyrolysis process.