The effect of adding green synthesized and commercial silver nanoparticles to biodiesel on diesel engine performance and emissions

Abstract

This study evaluates the impact of silver nanoparticles synthesized via a green method using Humulus lupulus L. and commercial silver nanoparticles (CAS: 7440-22-4) on biodiesel performance and emissions in diesel engines. Biodiesel from waste cooking oil was tested under partial load (1-4 kW) with the following blends: 100 % diesel (D), 50 % diesel-50 % biodiesel (BD50), biodiesel with green-synthesized nanoparticles (200, 400, 600 ppm: B_G200, B_G400, B_G600), and biodiesel with commercial nanoparticles (200, 400, 600 ppm: B_C200, B_C400, B_C600). The results showed that green-synthesized nanoparticles significantly reduced CO emissions (up to 71.42 % at 4 kW for B_G600), HC emissions (48.88 %), and particulates. Combustion efficiency improved, increasing CO2 emissions (peak 2.59 % for B_G600 at 4 kW). However, exhaust temperatures rose (583 degrees C for B_G600), and NOx emissions increased, peaking at 237 ppm for B_G400 at 4 kW. Green nanoparticles were more effective than commercial ones in reducing CO, HC, and particulate emissions while enhancing combustion. However, increased CO2 and NOx emissions suggest the need for further optimization. This study highlights green nanotechnology's potential to improve biodiesel performance sustainably while addressing environmental challenges.