After calculating the activation energy for biomass pyrolysis via kinetic analysis of TGA data, I went on to calculate the enthalpy of reaction and got ΔH = 180 kJ/mol. The TGA data was generated by an SDT machine, so it is accompanied by heat flow data. At low heating rates (10 degC/min), I have evaluated (from heat flow data) the heat required for pyrolysis to be positive, Q = 1.6 MJ/kg, which is in line with the calculated positive enthalpy of reaction. At high heating rates (>50 degC/min), I obtain ΔH = 170 kJ/mol which is comparable with the low heating rate value. However, my heat flow data seem to suggest that there is heat being generated by the pyrolytic process (negative, Q = -6.7 MJ/kg). Can I use this discrepancy as a strong reason to discard the heat flow data?