Exploring the potential of schizochytrium algal biodiesel blends on diesel engine combustion, performance, and emission characteristics

The present study investigates the combustion, performance, and emission characteristics of biodiesel blends (B20 and B50) derived from Schizochytrium, a relatively underexplored marine microalgae. The algae is cultivated under controlled in-house conditions, processed for lipid extraction, and transesterified to produce biodiesel. Engine tests are conducted on a single-cylinder diesel engine operating at 1800 rpm across 10–30 Nm load conditions. At full load, peak in-cylinder pressure decreases by 4.57% for B50 and 1.3% for B20 compared with pure diesel. Both blends exhibit shorter ignition delay and longer combustion duration, accompanied by reductions in peak heat release rates of 5.77% (B50) and 1.68% (B20). Brake thermal efficiency decreases by 4.19% for B50 and 1.01% for B20, while brake-specific fuel consumption increases by 7.9% and 2.5%, respectively. Exhaust gas temperature rises by 6.42% for B50 and 2.51% for B20. Emission analysis shows notable reductions in unburned hydrocarbons (30.76% for B50, 15.38% for B20), carbon monoxide (18.73% and 9.11%), and particulate matter (8.9% and 3.5%), along with higher CO2 and NOx emissions. These findings demonstrate the viability of Schizochytrium-based biodiesel as a renewable fuel, emphasizing efficiency–emission trade-offs by identifying B20 as most favourable among tested blends for diesel engine applications.