Before impregnation with sulfuric acid the lignocellulosic feedstock was shred to a fine powder in a coffee grinder. For impregnation the required amount of 96 % sulfuric acid was weighed in a 500 mL round bottom flask and diluted with about 50 mL diethyl ether respectively ethanol, the latter for the impregnation at Fraunhofer IWKS, per 5 g biomass. Here, the acid content is given in % based on the total mass including acid load itself. After adding the biomass the resulting suspension was stirred for 1 h at room temperature. The solvent was then removed under reduced pressure and the product was dried on the Schlenk line.