Research Projects

The Union Cabinet has approved the National Policy on Biofuels 2018, which includes exploring the 1st, 2nd, and 3rd generation raw materials for biofuel production. The scope of the policy expands the raw material utilization such as sugarcane juice, sugar-containing materials like sugar beet, starch-containing materials like corn, and damaged food grains like wheat or rotten potatoes for ethanol production. Under this policy, there is a thrust on advanced biofuels also, like dimethyl ether, 2nd generation ethanol, etc. However, given the production limitation of ethanol to fulfill the fuel requirement alone, its blending with other fuels also needs to be explored and developed. Ethanol is already gaining popularity in India as a substitute fuel for gasoline in the form of ethanol-gasoline blends–the government of India has set a target of 20% ethanol blending in petrol by 2025. Though the focus is kept on ethanol blending with petrol, the challenges of making diesel engines greener by reducing particulate and NOx emissions simultaneously can also be met by blending ethanol in diesel. Since the prime mode of transportation is largely based on petroleum fuel-based IC engines, ethanol utilization as an alternative fuel in combustion engines (particularly diesel engines) can benefit in achieving partial fuel independency, global CO2 emission reduction, lower particulate emission, etc. However, higher autoignition temperature, lower calorific value, extended ignition delay of ethanol (thus low cetane number) compared to diesel, and its low miscibility in diesel put forward the major challenges. At the same time, the higher heat release rate due to a higher vaporization rate before combustion seems beneficial from an optimized in-cylinder combustion point of view. In this direction, the current scope of work mainly includes the characterization and evaluation of ethanol utilization in diesel engines as a potential alternative fuel option. The first step is to investigate the mechanism of flash boiling atomization of diesel-ethanol blends by suitably adjusting the fuel and air temperatures and pressures. Following the first step, a dedicated fuel injection system and a Constant Volume Spray Chamber (CVSC) will be designed and fabricated with visualization windows for investigating the mechanism of flash atomization at high temperatures and pressure. The CVSC will be equipped with the newly developed ethanol-diesel fuel injection system and a high-speed imaging system which will be used to visualize the micro/macroscopic spray parameters. The micro/macroscopic spray parameters will be analyzed for varying fuel injection pressure, temperature, and blending ratios. Next, using a DICI engine, these micro/macroscopic parameters will be compared with the performance of the base fuel (mineral diesel) and conventional fuel injection systems.