Experimental Investigation on Performance and Exhaust Emission Characteristics of Variable Compression Ratio Diesel Engine Fueled with Microalgae Biodiesel Blends

In the current competitive situation, microalgae are the finest prominent alternative of biodiesel among all the other available sources. Microalgae are non-eatable and doesn't require crop land for its cultivation which makes the microalgae most attractive source to study. This paper is aimed to investigate experimentally the competency of novel, less considered biodiesel from microalgae species, which will be developed as an alternative fuel in place of traditional diesel. In this study, the most common chemical process, transesterification was used to extract biodiesel from microalgae. As per the requisite of experimentation five microalgae blends (MAB) were prepared on volumetric basis. The experimentation was performed on single cylinder variable compression ratio diesel engine to investigate the impact of microalgae biodiesel and its blends on performance as well as exhaust emission characteristics. All the experiments were carried out as per standard operating procedure and with due precautions. Brake power, brake specific fuel consumption and brake thermal efficiency were the performance characteristics focused during the experimentation. Microalgae blends indicated reduction in torque and hence brake power which resulted in average reduction of 7.14 % in the brake thermal efficiency. Brake specific fuel consumption increased by 11.54 % for microalgae as equated to traditional diesel. As a need of time emission characteristics must be evaluated along with performance. So, the main emission characteristics were also investigated in this work. As blending ratio increased, considerable reduction in exhaust emission characteristics of carbon monoxide (CO) plus hydrocarbon (HC) were recorded. Conversely, for all microalgae biodiesel blends, nitrogen oxides (NOx) and carbon dioxide (CO2) increased little which was compatible and in acceptable range. The performance as well as emission characteristics using microalgae biodiesel were found satisfactory.