Polyoxymethylene dimethyl ethers

Polyoxymethylene dimethyl ethers (PODE or DMMn) are a class of chemical compounds with the molecular formula H₃CO(CH₂O)_nCH₃ where n is typically about 3 to 8.

PODE can be produced from methylal and formaldehyde or a formaldehyde equivalent such as paraformaldehyde or trioxane.

PODE is used as a diesel fuel additive and as a solvent.

The average cetane number is 76 and the quality of blended diesel with PODE (blending ratio between diesel and PODE is 85 to 15) is better than ultra-low-sulfur diesel. By comparison, the combustion efficiency can be improved for the blended diesel, the emissions of PM2.5 and CO can be reduced largely, and off-gas pollution can be cut by more than 50%.