In the present research work, the performance, combustion and emission characteristics of compression ignition engine fuelled 22 different biodiesels categorised as (first, second, third generation, waste oil, and animal oil) biodiesel (B100) are evaluated numerically and compared with diesel fuel. Diesel-RK, a full-thermodynamic cycle engine analysis tool was used to carry out the numerical analysis. The engine power, fuel consumption, ignition delay, maximum cylinder pressure, oxides of nitrogen (NO_x), and carbon dioxide (CO₂) emission were investigated at four different engine operating loads. Power output was observed to be higher for Corn oil biodiesel, while Jatropha oil biodiesel produced lower fuel consumption among all other biodiesel. 9.1% increase in-cylinder peak pressure was found for waste transformer oil biodiesel than diesel, while ignition delay was found to be lowest for Rapeseed oil BD, Rice bran oil BD among all other biodiesel. The NO_x emissions were higher for biodiesel by 30–32%, while CO₂ emissions were reduced by 10–12% compared to diesel. The physicochemical properties of biodiesel were responsible for the diverse characteristics of the engine.

Increasing energy consumption and minimisation of fossil fuels have motivated the researchers to probe biodiesel as a transportation fuel. However, large scale of biodiesel production has run into food versus fuel problem and hence efforts are being made to produce biofuel from non-edible sources. The present article focuses on the potential and prospects of biodiesel made from tamarind seeds, which are known as waste product and can be thought to be an alternative energy source. Tamarind seed oil biodiesel possesses excellent combustion properties and can be sanctioned for its adoption in engine. Moreover, the tamarind seed oil biodiesel is environment-friendly and can contribute in the reduction of carbon emission when used as an engine fuel. A summary of tamarind seed oil biodiesel has shown that the total greenhouse gas emission can be reduced greatly. Overall future of tamarind seed oil biodiesel largely depends on plantation, pricing and establishing of low-cost biodiesel production technologies.

During wartime and disaster management military logistics such as combat vehicles, heavy-duty trucks must be capable of any transportation fuel available in forward area. In present work potential use of biodiesel derived from Karanja and Jatropha oil was investigated for a heavy-duty military vehicle. Performance and emissions of 12 cylinders, supercharged diesel engine was evaluated using JP-8, Karanja Oil Methyl Ester (KOME) and Jatropha Oil Methyl Ester (JOME) and compared with baseline standard diesel at variable speed range. Engine performance was slightly reduced with KOME and JOME. However from emission point of view, both the biodiesels contributed to reduction in CO and HC emissions as well as smoke opacity, with penalty in NOx emissions. Reduction in exhaust sound was seen for biodiesel fuels which is of upmost important during wartime. Thus, biodiesels can be used for military combat vehicles without any modifications in existing engine configurations.

Due to the different chemical composition of biodiesel and diesel fuel, the comparative effect of long-term usage of this fuel can have significant effect on engine service life. In present work, the durability and lubricating oil degradation of diesel engine fuelled with Tamarind seed oil methyl ester (TSOME) was studied in 512 hours endurance test and results were compared with baseline diesel fuel. Diesel operated engine showed higher carbon deposition on engine components than TSOME. Piston wear lowered by 18-20%, while piston rings also showed lower weight loss for TSOME fuel. Similarly, the wear of fuel injection components was reduced by 29-36% for TSOME operated engine. Long-term usage of biodiesel lowered the viscosity lubricating oil by 4-6%, however other properties such as density, flash point and total base number did not show much alteration. The overall results indicate that TSOME can deliver excellent endurance performance in diesel engines.