Combustion potential of pinewood pyrolysis oil blend with heavy fuel oil: Insights into rheological compatibility and calorific performance

The demand for sustainable energy is encouraging industries to replace fossil fuels with alternative renewable fuel sources, partially. This work examines the fuel thermo-physical properties of furnace oil and pinewood pyrolysis oil, as well as the potential for blending pinewood pyrolysis oil with furnace oil. Gross calorific value, viscosity, and auto ignition temperature analysis of blends containing 2.5–25 wt% pyrolysis oil was evaluated. The blends containing up to 10 wt% pyrolysis oil demonstrated a calorific value of approximately 41 MJ/kg, while also exhibiting acceptable ignition and flow properties over typical operating temperatures. These properties align well with the operational requirements of industrial combustion systems, providing a viable way to minimise fossil fuel dependency without significant changes to existing industrial combustion infrastructure. However, blends exceeding 10 wt% resulted in a considerable decrease in calorific value and an increase in auto ignition temperature, highlighting a practical limitation. These findings suggest that low-level bio-oil blending (≤10 wt%) offers a technically feasible route to reduce fossil fuel use in existing furnace oil-fired systems with minimal retrofit. The work highlights the practical limitations of incorporating bio-oil and outlines a pathway for the industry to gradually introduce bio-based fuels while controlling performance risks and operational costs.