An experimental investigation of performance-emission trade off of a CI engine fueled by diesel-compressed natural gas (CNG) combination and diesel-ethanol blends with CNG enrichment

In order to comply with the ever-stringent emission norms throughout the world and crunch in petroleum reserves, the modern day automobile industry is compelled to hunt for new and alternative means of fuel sources to keep the wheels spinning globally. Paradoxical objectives of attaining simultaneous reduction in emission along with high performance has provided with a few alternatives. The present study deals with one such approach in which the potential of diesel ethanol blending and subsequent CNG (compressed natural gas) enrichment have been investigated. The study starts with a miscibility test of ethanol in diesel, which paves the way for an experimental comparison between performance and emission characteristics of Diesel-Ethanol blends, Diesel-CNG combinations and Diesel-Ethanol blends with CNG enrichment. The results indicates that diesel ethanol blend D95E5 (95% diesel 5% ethanol) with low CNG enrichment produces a better performance-emission characteristics as compared to base diesel operation as well as diesel-ethanol blend operation. Results also portrayed ethanol's potential in reducing NOx emission, BSEC and smoke opacity.