Functional Investigation, Multiple Response Optimization, and Economic Analysis of a VCR CI Engine Fired with Diesel, Calophyllum Inophyllum Oil, and Waste Biomass-Derived Producer Gas in Multi-fuel Mode

In this study, a variable compression ratio CI engine is tested to predict its performance and emission characteristics by varying input criterions like engine load, CR, and fuel types. The brake thermal efficiency (BTE) is considered as the performance characteristic and the emissions of carbon monoxide, hydrocarbon, nitrogen oxide, and smoke opacity are considered as the emission characteristics for this study. The tests are conducted for variation in load from 4 to 12 kg and compression ratio from 14 to 18 in the multi-fuel mode of operation with 0%, 50%, and 100% of Calophyllum Inophyllum biodiesel blend and producer gas. The use of waste biomass like leaves, small tree branches, vegetable waste, and cow dung in producer gas generation is attempted in this work toward better energy production and management of environmental waste. It has been identified that load mostly influences the brake thermal efficiency, NOx emission, and opacity with a contribution of 58%, 67.5%, and 41.7%, respectively, whereas multi-fuel and compression ratio mostly affect CO emission and HC emission with a contribution of 41.8% and 58.9%, respectively. The maximum BTE and minimum emissions of CO, HC, NOx, and opacity are 15.49%, 0.525 ppm, 54.7 ppm, 125.032 ppm, and 37.99 HSU, respectively, are predicted as the optimum performance of the test engine for composite desirability D of 0.910037. An economic study is conducted to determine the % relative cost variation of the current sample fuel in comparison with diesel fuel. At optimum performance, the predicted fuel MF33.56 costing 10% more than MF0 has been observed.