Combustion, Performance, and Emission analysis of a CH₃OH- Micro-Algae B20 Dual-Fuel CI Engine with CeO₂ Nano-particle Additives

¹ Department of Mechanical Engineering, Aarupadai Veedu Institute of Technology, Vinayaka Mission’s Research Foundation, Deemed to be University, Tamil Nadu, India
² Department of Mechanical Engineering, Aditya University, Surampalem, India
³ Department of Mechanical engineering, New Prince Shri Bhavani College Of Engineering & Technology, Chennai.

Published online: 16 April 2026

Abstract

This paper investigates the effect of adding cerium oxide (CeO?) nanoparticles to the pilot fuel during the operation of dual-fuelCI engine with a B20 microalgae biodiesel with diesel mixture and CH3OH at a fixed 10% energy share with respect to the performance, emission and combustion characteristics, through experimental testing over a array of operational conditions. The nanoparticles were dispersed in the B20 blend added to the engine at strengths of 5, 10, in addition to 15 ppm and the engine was tested under constant speed and varied load conditions. Results showed that the BTE(BTE) consistently improved with the dosage of nanoparticles. BTE showed an increase from 31.2% for the base B20 + M10 blend to 31.95%, 32.7%, and 33% at full load when 5, 10, and 15 ppm CeO? were used, representing improvements of 2.4%, 4.8%, and 5.8%, respectively. At the same time, it was reduced the BSEC from 9677 kJ/kWh (base fuel) to 9527, 9377, and 9227 kJ/kWh, presenting reductions of 1.6%, 3.1%, and 4.7%, respectively. The pollutants results showed that the incomplete combustion products were significantly reduced, HCemissions were reduced by 2.1%, 4.3%, and 6.4% at full load, while carbon monoxide emissions were significantly reduced by 31%, 62.5%, and 93.7% at 5, 10, and 15 ppm, respectively. As the concentration of nanoparticle content increases, smoke opacity was also reduced by 2.9%, 5.9%, and 8.8%. Alternatively, caused by the increased temperature of combustion, the NO_X emissions were elevated by 5.2%, 10.5%, and 15.7% for the respective dosages. From combustion analysis, it was shown that nanoparticles promoted higher rates of pressure development and higher rates of heat-release. The peak pressure in the cylinder raised approximately 1-3%, and the premixed heatrelease peak increased from 20.68 for the baseline blend to 21.31 for the 15-ppm case. Average results show that low-quantity CeO₂ nanoparticles function well to improve combustion efficiency and to lower incomplete combustion emissions in a B20-CH₃OH(methanol) dual-fuel operation with 10-15 ppm providing the best performance-emission compromise.