Effect on performance, combustion and emission characteristics of Chlorella vulgaris methyl ester algae in a single cylinder CI engine

Microalgae biofuel has gained notoriety as a third-generation renewable fuel due to its high yield, rapid growth rate, and capability to absorb CO 2 . The current study provides insights into the combustion, performance and emission characteristics of neat algae oil and biodiesel from the Chlorella vulgaris microalgae as an alternative fuel source for compression ignition (CI) engine in comparison with diesel. In addition, elemental analysis and fuel characterisation studies of Chlorella vulgaris methyl ester (CVME) algae with GC–MS, FTIR, and UV–Vis are accorded. The spectral studies of CVME algae confess the existence of (C–H) along with (C–O), (C=O), (O–CH 3 ), etc. Further, the spectral study of CVME algae with GCMS imposes the presence of methyl oleate as a significant constituent and the chemical structure of algae biofuel is C 19 H 36 O 2 . Conversely, the elemental compositions of CVME algae with a CHN analyser illustrate the existence of carbon, hydrogen and oxygen in the proportions of 66.80%, 11.80%, and 21.40%, respectively. The BTE of the engine fuelled with CVME shows a closer resemblance with diesel, whereas the NCVO deteriorates owing to its higher viscosity. Regardless, the combustion phenomenon such as ignition delay period, in-cylinder pressure, combustion duration and heat release rate (HRR) of NCVO and CVME are significantly lower at maximum load conditions in comparison with diesel. However, the emissions of carbon monoxide (CO), unburned hydrocarbons (UBHC) and smoke are lesser with diesel than NCVO and CVME. In contrast, the emissions of nitrous oxide (NO x ) are higher for CVME compared to diesel and NCVO.