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

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 CO 2 emissions (peak 2.59 % for B_G600 at 4 kW). However, exhaust temperatures rose (583 °C for B_G600), and NO x 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 CO 2 and NO x emissions suggest the need for further optimization. This study highlights green nanotechnology's potential to improve biodiesel performance sustainably while addressing environmental challenges.