Di-ethyl ether-diesel blends fuelled off-road tractor engine: Part-I: Technical feasibility

Abstract

Modifications and improvements in fuel properties have become imperative to reduce engine-out emissions to comply with the existing and upcoming emission norms. Previous studies have demonstrated that using oxygenated fuels such as ethers and alcohols to augment diesel can reduce emissions significantly. An experimental investigation was performed to explore di-ethyl ether (DEE)-diesel blends on combustion, performance, and emissions characteristics of an off-road CI engine used in tractors. The test engine was fueled with three different DEE-diesel blends: DEE15 (15% v/v DEE and 85% v/v mineral diesel), DEE30 (30% v/v DEE and 70% v/v mineral diesel), DEE45 (45% v/v DEE and 55% v/v mineral diesel), and baseline mineral diesel. The engine was operated at a constant speed of 1500 rpm at varying engine loads, and results were compared. Peak in-cylinder pressure for DEE-diesel blends was lower than baseline diesel. At high loads, a relatively longer combustion duration was observed for DEE-diesel blends than baseline diesel. DEE-diesel blends exhibited slightly higher brake thermal efficiency (BTE), comparable exhaust gas temperature (EGT), and lower brake specific energy consumption (BSEC) compared to baseline diesel, owing to improved combustion of the oxygenated fuel blends. BSNOx emissions were relatively lower for all DEE-diesel blends compared to baseline diesel. The experimental investigations demonstrated that the test engine could work up to 45% (v/v) diesel substitution by DEE, without significant engine hardware modifications, but for low-to-medium engine loads only. At the highest substitution (DEE45), the test engine exhibited improved engine performance and lower NOx emissions than baseline mineral diesel operation. This experimental study demonstrated the potential for using DEE as a partial diesel substitute in the agricultural sector with significant performance and emission benefits.