Novel study on enhancing the ignition pattern of waste and inedible feedstock in a modified diesel engine-enhancing its effectiveness as renewable alternative

The objective of the present investigation is to enhance the performance of diesel engine using Capparis spinoza fatty acid distillate biodiesel (CFAB100) at various compression ratios. The experiments were carried out at compression ratios of 16.5:1, 17.5:1, 18.5:1, and 19.5:1. It was noted that an increase in compression ratio from 16.5 to 18.5 resulted in better engine characteristics for CFAB100 and reduced at compression ratio 19.5. Brake-specific fuel consumption of CFAB100 decreased from 0.42 to 0.33 kg/kWh with an increase in compression ratio. The brake thermal efficiency of CFAB100 at a compression ratio of 16.5 is 29.64% lower than diesel, whereas it is 11.32% low at a compression ratio of 18.5. The brake thermal efficiency of CFAB100 is 26.03% higher at a compression ratio of 18.5 compared to 16.5. Due to shorter ignition delay and reduced premixed combustion, the net heat release rate of CFAB100 is lower than diesel at all compression ratios. The peak cylinder pressure for diesel is 56.21 bar, and CFAB100 at compression ratios 16.5, 17.5, 18.5, and 19.5 were 52.36, 55.12, 61.02 and 58.25 bar at full load condition. CFAB100, at a compression ratio of 18.5, had the highest nitrogen oxide emissions (2400 ppm). Carbon monoxide, unburnt hydrocarbon, and smoke showed an average reduction of 46.58%, 40.68%, and 54.89%, respectively, when the compression ratio varied between 16.5 and 19.5. At an optimum compression ratio of 18.5, the CFAB100 resulted in improved performance and emission characteristics that can replace diesel to a possible extent.