Method for processing cellulose-containing biomass

Method for processing a cellulose-containing biomass,

• comprising
• subjecting a treatment mixture comprising said cellulose-containing biomass, water, and methanesulfonic acid
• to a temperature in the range of from 100° C. to 200° C. at a pressure in the range of from 1 to 20 bars (100 to 2000 kPa) wherein the pressure is selected so that at least a part of the water is in the liquid state
• to generate a treated cellulose-containing biomass,
• (i) wherein said treatment mixture further comprises one or more compounds selected from the group consisting of
• at least one compound of formula (I)
• and a surfactant which is not a compound of formula (I),
• wherein in formula (I)
• R1 and R2 are independently selected from the group consisting of hydrogen, unsubstituted and substituted alkyl with 1 to 22 carbon atoms (C1- to C22-alkyl) and unsubstituted and substituted aryl, wherein in said substituted C1- to C22-alkyl and said substituted aryl each substituent is independently selected from the group consisting of —OSO3H, —SO3H, —COOH and −OPO3H2 and salts thereof
• each Rx in said x groups
• is independently of each further R′ selected from the group consisting of hydrogen and alkyl with 1 to 20 carbon atoms (C1- to C20-alkyl)
• x is an integer from 1 to 2400
• or
• (ii) wherein said treatment mixture does not comprise any compound selected from the group consisting of compounds of formula (I) as defined above and does not comprise any surfactant which is not a compound of formula (I) as defined above.