Addition of ammonia and/or oxygen to an ionic liquid for delignification of miscanthus

► Miscanthus can be dissolved in the ionic liquid 1-ethyl-3-methylimidazolium acetate. ► This pretreatment induces per se a partial delignification of miscanthus. ► Gaseous NH3 and O2 are able to enhance such delignification. ► We obtain pretreated materials with a lignin content as low as ca. 10%. ► Neither NH3 nor O2 has a negative influence on global recovery of carbohydrates.