Impact of alumina and cerium oxide nanoparticles on tailpipe emissions of waste cooking oil biodiesel fuelled CI engine

Abstract

Biofuels are one of the most sought-after renewable energy sources to overcome the current energy crisis in the world. Diesel blended with esters derived from oils has shown appreciable results for its use in compression ignition engines. In this work, B20 (20% biodiesel + 80% diesel by volume) fuel blend comprising 80% diesel and 20% biofuel extracted from waste cooking oil is used as a fuel. Two different metallic oxide nanoparticles (NPs), namely, cerium oxide (CeO 2 ) and aluminium oxide (Al 2 O 3 ) each having size of 30 nm, are dispersed in B20 biodiesel blend and used to investigate their combined influence on engine combustion. Experiments are conducted to study the engine exhaust emissions of a single cylinder four-stroke diesel engine running at constant speed of 1,500 rpm with varying engine loads. Experiments are carried out with B20 fuel and adding mixtures of CeO 2 and Al 2 O 3 nanoparticles in 50-30, 40-40 and 30-50 ppm, respectively, to B20 biodiesel blend. Responses recorded are the emissions of CO, HC, CO 2 , NOx and smoke. The results reveal that, on adding the nanoparticles, the engine observed a smooth combustion with reduction in the exhaust emissions compared to neat B20 biodiesel operation. B20 blend with 50 ppm of CeO 2 and 30 ppm of Al 2 O 3 nanoparticles showed lower exhaust emissions compared to other fuel blends. For the best fuel blend, CO, HC, NOx and smoke are reduced by 57.3%, 22.3%, 24.3% and 7.36%, respectively, compared to neat B20 operation.

Size Effect of Nanoceria Blended with CIME Biodiesel on Engine Characteristics

“…It is observed from other studies that ceria NPs between 30 nm and 40 nm size are most desirable for the purpose of improving the BTE [ 38 ]. The NPs have high surface-to-volume ratio and assist in better atomization due to micro-explosion and micromixing [ 78 ]. However, smaller NPs tend to agglomerate, and this leads to higher fuel viscosity [ 79 ] and poor atomization.…”

“…However, comparatively high NOx values are reported with NPs other than cerium oxide in the literature. The explanation for this is attributed to the NOx reducing property of cerium oxide NPs [ 78 ]. The lowest NOx values are observed for BD40.…”

Emulsification of waste cooking oil biodiesel blend with hydrogen peroxide to assess tailpipe emissions and performance of a compression ignition engine

“…The use of biodiesel derived from waste cooking oil (WCO) has been widely reported in the literature. 4,5 The transesterification process is the most commonly followed method for the production 6 followed by the water wash method for the purification of WCO biodiesel. Due to environmental concerns, waterless purification has gained interest.…”

“…Due to the additional fuel‐bound oxygen in the biodiesel, more complete combustion is promoted leading to a reduction in carbon and HC emissions. The use of biodiesel derived from waste cooking oil (WCO) has been widely reported in the literature 4,5 . The transesterification process is the most commonly followed method for the production 6 followed by the water wash method for the purification of WCO biodiesel.…”

“…Reduction of NO x is more evident with the emulsification of biodiesel/diesel blends with water that reduces the cylinder temperature 17 . Another important fuel modification is the application of nanoparticle additives 5 which has further enhanced the quality of combustion in a CI engine and drastically reduced engine‐out emissions. However, issues of stability, cost of production, and its environmental impact limit its use 18 .…”