Experimental and statistical analysis of CRDI diesel engine powered with carbon black infused nano dairy scum biodiesel blends

This work explains the experimental and statistical analysis of common rail direct injection (CRDI) engine fuelled with dairy scum oil biodiesel blend (DSOBD B20) which can effectively substitute 20 % of petroleum diesel fuel and avoid massive external foreign exchange enabling fuel saving besides providing energy security to India. This work addresses the SDG 7 by ensuring affordable, reliable and sustainable energy supply for automotive traction besides addressing SDG 13 towards ill effects of climate change and its impacts on environmental pollution as the biodiesel fuels selected are renewable in nature. Accordingly dairy scum oil is transformed into its biodiesel and is mixed with diesel to make its DSOBD B20 blend. DSOBD B20 blend characteristics are modified with infusion of nanoparticles of carbon black (CB). Percentage of CB is varied from 40 % to 120 % by volume insteps of 20 % using sodium dodecyl sulfate (SDS) surfactant to produce respective nano-biodiesel blends. Homogeneity of nano-biodiesel blends are evaluated using zeta potential study. CB Nanoparticles in excess of 100 % resulted into agglomeration lowering homogeneity confirmed by inferior zeta potential values. Distribution of higher quantity of nanoparticles (NPs) in liquid media is still posing challenges and need further research. Physio-chemical properties of DSOBD B20 and their nano-biodiesel combinations are compared with diesel. Among the nano-biodiesel blends tested, DSOBD B20 CB100 nano-biodiesel blend fuelled CRDI engine exhibited lower smoke, hydrocarbon (HC), carbon monoxide (CO) emissions and higher nitric oxide NOx and improved brake thermal efficiency (BTE) compared to DSOBD B20 at full load. Combustion characteristics of CRDI engine powered with DSOBD B20 CB100 showed lower ignition delay (ID), combustion duration (CD) and higher peak pressure (PP) and heat release rate HRR as the blend enhanced combustion process compared to DSOBD B20. Response surface methodology (RSM) based nonlinear predictions established reasonable relation between input parameters and proposed attributes with engine output attributes at 95 % confidence interval. RSM analysis predicted optimized CRDI engine performance when powered with DSOBD B20 CB100 blend and for engine parameters of injection timing (IT) 15oBTDC, injection pressure (IP) 1000 bar, toroidal re-entrant combustion chamber (TRCC) and 8 hole injector with 0.2 mm hole diameter. RSM predicted results were in good agreement with experimental results.