Comparative analysis of PODE3 and PODE4 fuel additives for emission reduction and soot characteristics in compression ignition engines

Polyoxymethylene dimethyl ethers (PODEn) have been regarded as promising fuel additives in reducing engine emissions due to their extra oxygen content and absence of C-C bonds. This research compares the effectiveness of PODE3 and PODE4 as fuel additives (10 % oxygen content) in a compression ignition (CI) engine. The results show that PODE can retard the ignition delay and shorten the combustion duration. They can both reduce HC emissions, with PODE4 having the greatest reduction. Both additives comparably reduce NOx emissions while consuming similar oxygen amounts. PODE alters particle size distribution, favoring higher nucleation mode particles and reducing accumulation mode particles, especially for the case with Diesel/PODE3. Further, this study investigates the soot characteristics when with different fuel blends. Thermogravimetric analysis (TGA) reveals enhanced oxidative reactivity in soot when with Diesel/PODE3 and Diesel/PODE4 fuel blends. Raman spectroscopy shows reduced crystalline structure and increased crystalline width in soot when with PODE additives. Fourier transform infrared (FT-IR) spectroscopy indicates improved relative intensity of aliphatic C-H groups and intensified aromatic C-H groups with PODE addition. In summary, PODE3 and PODE4 are promising CI engine fuel additives, substantially reducing particulate matter (PM) emissions and enhancing soot reactivity. These findings hold significance for cleaner combustion technologies.

Automated summary

Polyoxymethylene dimethyl ethers (PODEn) are promising fuel additives that can reduce engine emissions. This study compares the effectiveness of PODE3 and PODE4 as fuel additives, finding that they can reduce HC and NOx emissions while improving soot characteristics.