Detailed experimental investigation and optimization of oxygenated diglyme–diesel–n-pentanol ternary blends on compression ignition engine behaviors

Abstract

The aim of this study is to evaluate the performance of engines and the produced emissions by adding diethylene glycol dimethyl ether (DGM), an oxygen-rich additive with a high cetane number, into n-pentanol and diesel fuel blends. Using pure diesel (OXG0) as the benchmark, five fuel blends were tested in a single-cylinder compression ignition engine. While always keeping a diesel ratio of 70%, the blends displayed a range of DGM content ranging from 5 to 20%. Analysis showed that by 1.27% in contrast to pure diesel, the mix of 70% diesel, 10% n-pentanol and 20% DGM (OXG4) enhanced brake thermal efficiency (BTE). Moreover, OXG4 was shown to be efficient in lowering CO and NO_x emissions under all load conditions, therefore demonstrating its ability to control negative emissions. Still, when the DGM content rose, CO₂ emissions clearly started to rise—probably because of improved combustion efficiency. Furthermore, the study showed that compared to OXG0 other blends—OXG1, OXG2 and OXG3—often produced greater brake-specific fuel consumption and slightly worse BTE. The findings highlight the feasibility of DGM as a suitable additive to enhance diesel fuel blends to get better emission characteristics without appreciably compromising engine performance.