Effects of alumina nanoparticles in waste chicken fat biodiesel on the operating characteristics of a compression ignition engine

An experimental investigation was carried out to study the performance, emissions and combustion characteristics of a compression ignition (CI) engine fuelled with waste chicken fat biodiesel with alumina nanoparticles as an additive. The disposal of waste chicken creates environmental pollution, hence it is decided to extract oil from the waste chicken fat and produce biodiesel through transesterification process. As the chicken fat contains 13.6 % free fatty acid (FFA), a pre-treatment process was carried out using Ferric sulphate as a catalyst in order to reduce the FFA content less than 1 % to prevent soap formation during the process. Potassium hydroxide was used as catalysts for the effective conversion of triglycerides of waste chicken fat into methyl ester. Various diesel–biodiesel–alumina blends were prepared by varying the biodiesel proportions of 20 and 40 % by volume and 25 and 50 ppm of alumina nanoparticles to study its operating characteristics on a computerized single cylinder, constant speed CI engine. Aluminium oxide (Al₂O₃) nanoparticles were used as fuel born catalyst in order to enhance the combustion characteristics and reduce the harmful emissions. The engine test results showed less improvement in brake thermal efficiency and significant reduction on the hydrocarbons and carbon monoxide emissions. However, higher nitrogen oxide emissions were recorded due to the increase in combustion temperature as the nanoparticles enhanced the surface area to volume ratio which improves the thermal conductivity of the fuel blend resulted in improved combustion. Smoke reduction of 52.8 % was observed in B40 fuel blend with 50 ppm alumina nanoparticles under full load conditions.