Potential of amyl alcohol mixtures derived from Scenedesmus quadricauda microalgae biomass as third generation bioenergy for compression ignition engine applications using multivariate-desirability analysis

Abstract

ABSTRACT This study is aimed at synthesizing amyl alcohol from Scenedesmus quadricauda third-generation microalgae biomass which is cultivated sustainably using reactor combinations and Ehrlich biosynthetic pathway. Systematic experimentation was carried out on a compression ignition engine at maximum throttle pedal position condition to assess the potential of amyl alcohol-diesel mixture combinations and to assess its environmental impact at different loads. Optimum mixture proportion of amyl alcohol-diesel blends were identified statistically using multivariate principal component and desirability analysis based on the experimental data acquired from the engine testbed. From the study, it was inferred that a dry biomass yield rate of 4.2 g/L was achieved when the light intensity was maintained at ~51-56 μmol/m2/s in the in-situ raceway pond while cultivating Scenedesmus quadricauda. Experimentation showed that the fuel consumption reduced by 72.4% for AA20D80 at low-high load conditions. Improved combustion characteristics are achieved at higher concentrations of amyl alcohol operating at medium-high loads. The lowest smoke and NOX emission of 52.85 mg/m3 and 104 ppm was observed for AA40D60 at no-load condition. Statistical analysis revealed that the optimal amyl alcohol-diesel mixture combinations to be AA20D80 with combined desirability of 0.497.