Abstract
The conversion of fast-growing non-food woody biomass into storable fuels and carbon-rich products may contribute to the diversification of regional renewable-resource systems. This exploratory pilot-scale study evaluated Paulownia wood chips in a continuously fed five-zone pyrolysis reactor at setpoint temperatures of 300, 400, and 500 °C. One 20 kg wet-feed run was evaluated at each setpoint at a nominal throughput of 20 kg h⁻¹ and a nominal residence time of 10 min. Reactor temperature, non-condensable gas volumetric flow, and electrical input power were recorded at 5 s intervals. Recovered biochar masses were 7.3, 7.4, and 5.8 kg, and recovered condensed-liquid masses were 9.1, 8.3, and 6.6 kg at 300, 400, and 500 °C, respectively. The combined solid-plus-liquid recovery decreased from 82.0 to 62.0% of wet feed. Because gas mass and composition were not measured, the remaining fraction cannot be interpreted as a gas yield, and a closed mass balance was not established. Mean non-condensable gas flow rates calculated from the time-series data were 1.65, 3.53, and 8.36 m³ h⁻¹, while mean measured reactor temperatures were 303.1, 398.5, and 498.0 °C. The highest observed carbon content and higher heating value of biochar occurred at 400 °C, at 76.99 wt.% and 30.47 MJ kg⁻¹. The calculated atomic H/C ratio decreased from 0.68 at 300 °C to 0.37 at 500 °C. The results describe temperature-dependent behaviour in one pilot-scale run per condition and do not provide inferential evidence of an optimum. Replicated reactor runs, gas chromatography, liquid-phase analysis, and expanded biochar characterisation are required before process efficiency or application suitability can be established.