Global warming due to exhaust pollution and rapid depletion of petroleum reserves, has given us opportunity to find bio fuels. Bio diesel is an alternative diesel fuel that can be produced from renewable feedstock such as edible and non-edible vegetable oils, wasted frying oils and animal fats. Bio diesel is an oxygenated, sulphur free, non-toxic, biogradable and renewable fuel. Use of karanja oil methyl ester (KOME) biodiesel in a compression ignition engine was found highly compatible with engine performance along with low emission characteristics. A Military 780 hp, CIDI engine was operated using biodiesel (KOME) and diesel fuel respectively. These were subjected to 100 hours long term endurance tests. Lubricating oil samples drawn from engine after a fixed interval (20 hours), were subjected to elemental analysis. Metal debris concentration analysis was done by atomic absorption spectroscopy. Wear of metals were found to be about 30% lower for biodiesel operated engine. The additional lubricating property of biodiesel fuel due to higher viscosity as compared to diesel fuel resulted in lower wear of moving parts and thus improved the engine durability with a biodiesel fuel.

Investigating the impact of JP-8 fuel on diesel engine performance and emission is very important for military combat vehicles, due to its great potential as alternative fuel under single fuel strategy program for military operation. There is a known torque, horsepower and fuel economy penalty associated with the operation of a diesel engine with JP-8 fuel. On the other hand, a few experimental studies have suggested that JP-8 fuels have the potential for lowering exhaust emissions, especially NOx, CO, HC and smoke opacity compared to diesel fuel. This research evaluates the effect of using JP-8 fuel in a heavy duty diesel engine on performance, emission, and pump wear, and subsequently proposes change to the fuel injection pump calibration to match the designed required operational engine performance with diesel fuel. Experiments were carried out on a 558 kW, B-46-6, supercharged, 12-cylinders, CIDI engine with a hydraulic dynamometer. The results indicate that torque and horsepower of diesel fuel can be matched with fuel economy penalty lower than 4.5%, by increasing the volumetric fuel quantity to compensate the lower density of JP-8 fuel. The lower cetane number of JP-8 fuel caused a slight increase in ignition delay but improved the combustion at load condition, thus lowering the combustion noise. Emissions such as CO, HC, NOx, and smoke opacity were measured on engine maximum operating speed of 2000 rpm at 100% load condition, whereas volumetric fuel consumption was measured between 1200-2000 engine rpm under load conditions. The fuel pump wear was tested after 100 hours run.

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.