# Performance, combustion, emission and optimization characteristics of biodiesel–n-butanol blends enriched with Ni2O3 nanoparticles in a diesel engine

## TL;DR

Adding nickel oxide nanoparticles to biodiesel blends improves diesel engine performance and reduces emissions without engine changes.

## Contribution

Demonstrates performance and emission benefits of Ni₂O₃ nanoparticles in biodiesel–n-butanol blends using a predictive optimization model.

## Key findings

- Peak in-cylinder pressure increased to 55.86 bar for B20 and 55.45 bar for B20But10 at 100 ppm Ni₂O₃.
- Brake thermal efficiency reached 24.89% for B20 and 24.94% for B20But10 with reduced fuel consumption.
- Emissions of HC, smoke opacity, and NOx decreased by 12–43% with nanoparticle additions.

## Abstract

In the pursuit of sustainable and clean energy, biofuels and nanofuels are increasingly investigated as practical solutions to improve diesel engine efficiency and emission characteristics. This study evaluates the effects of Nickel (III) oxide nanoparticles added to biodiesel (B20) and biodiesel–n-butanol (B20But10) blends on combustion, engine performance, emissions, and optimization using a single-cylinder, four-stroke, water-cooled, direct injection diesel engine. Experiments were conducted at multiple engine loads and nanoparticle concentrations ranging from 0 to 100 ppm. At full load and 100 ppm Ni₂O₃, peak in-cylinder pressure increased to 55.86 bar for B20 and 55.45 bar for B20But10, while maximum heat release rates reached 29.45 and 30.02 J/°CA, indicating enhanced premixed combustion behavior. Brake thermal efficiency increased to 24.89% for B20 and 24.94% for B20But10, accompanied by reductions in brake specific fuel consumption to 0.309 and 0.333 kg/kWh, respectively. Emission results showed reductions of 13–28% in HC, 8–43% in smoke opacity, and 12–21% in NOx. Response surface methodology was employed to develop both performance- and emission-oriented predictive models, yielding high reliability (R2 = 90.9–99.9%) and identifying optimal nanoparticle levels between 50 and 75 ppm. Overall, Ni₂O₃-enhanced blends provide measurable performance and emission benefits without requiring engine modifications.