Nanoparticle Additives in Biodiesel-Fueled Compression Ignition Engines

Nanoparticle additives have emerged as a transformative approach to enhance the performance and emissions profile of biodiesel in compression ignition engines. By exploiting the high surface-to-volume ratio and catalytic activity of nanoscale metal and metal-oxide particles, researchers have tailored fuel properties—such as viscosity, density and cetane number—to promote more complete and efficient combustion. These particles act as oxygen buffers and catalytic centres within the combustion chamber, facilitating rapid oxidation of fuel molecules and reducing soot formation. Typical additives include cerium oxide, aluminium oxide, titanium dioxide and iron-doped variants, each selected for its redox behaviour and stability in biodiesel blends. Optimised dispersion techniques, such as ultrasonic agitation and green synthesis routes, ensure uniform suspension and prevent agglomeration. The global drive to decarbonise transport, coupled with stringent emissions standards, has propelled research into nano-enhanced biodiesel towards practical applications in automotive, marine and power-generation sectors, where improvements in brake thermal efficiency, reductions in brake specific fuel consumption and lower emissions of nitrogen oxides, carbon monoxide and unburnt hydrocarbons can deliver both environmental and economic benefits.

Research from Nature Portfolio

Studies have explored aluminium oxide and titanium dioxide nanoparticles added to biodiesel derived from Guizotia abyssinica oil, evaluating energy, exergy and sustainability metrics. One investigation demonstrated that a blend containing aluminium oxide at 1800 rpm achieved an energy efficiency of 29.5 % and the lowest fuel consumption (203 g kWh⁻¹) at 1600 rpm, with simultaneous reductions in NOx and CO emissions. Artificial neural network validation confirmed consistent performance and exergy improvements, highlighting the potential of such blends for industrial application.

Another study examined the impact of cerium oxide nanoparticles (75 ppm) in castor oil biodiesel–diesel blends across B5 to B25 formulations. The inclusion of CeO2 increased thermal efficiency by up to 22.2 % in the B10 blend, reduced brake specific fuel consumption and soot opacity by more than 11 %. Emission trends showed lower hydrocarbon and CO2 outputs at higher speeds, while NOx peaks shifted with and without nanoparticles, underlining the additive’s dual role in combustion enhancement and emission control.

Nanoparticle Additives in Biodiesel-Fueled Compression Ignition Engines publication trend

The graph below shows the total number of articles in nanoparticle additives in biodiesel-fueled compression ignition engines across all publications each year (not limited to Nature Index journals).

Technical terms

Nanoparticle additive: A material with dimensions below 100 nm introduced into fuel to modify combustion chemistry and heat release.

Biodiesel: A renewable diesel substitute produced by transesterifying vegetable oils or waste oils with alcohol, usable in compression ignition engines.

Cetane number: An index of ignition quality for diesel fuels; higher values indicate shorter ignition delay and smoother combustion.

Brake thermal efficiency (BTE): The ratio of useful mechanical work output to the chemical energy input of the fuel.

Brake specific fuel consumption (BSFC): The mass of fuel consumed per unit of power produced, typically expressed in g kWh⁻¹.

Exergy: A measure of the maximum useful work obtainable from a system as it reaches equilibrium with its environment.

References

1. Exergy-energy, sustainability, and emissions assessment of Guizotiaabyssinica (L.) fuel blends with metallic nano additives. Scientific Reports (2024).
2. Emission and performance analysis of diesel engine running with CeO2 nanoparticle additive blended into castor oil biodiesel as a substitute fuel. Scientific Reports (2024).
3. Strategies in the application of nanoadditives to achieve high-performance diesel, biodiesels, and their blends. Fuel Communications (2024).
4. An optimization study on a biosynthesized nano-particle and its effect on the performance-emission characteristics of a diesel engine fueled with parsley biodiesel blend. Energy Reports (2023).
5. Experimental Investigation on Performance of a Compression Ignition Engine Fueled with Waste Cooking Oil Biodiesel–Diesel Blend Enhanced with Iron-Doped Cerium Oxide Nanoparticles. Energies (2019).