A method for converting lignocellulosic biomass materials into ethyl esters, said method comprising the following steps: (a) thermo-chemical pre-treatment of the biomass materials with an oxidizing agent solubilized in an acidic solution comprising an acid, ethanol, and water, thereby forming a pre-treatment slurry; (b) diluting the slurry with additional ethanol and additional acid species, and obtaining catalytic conversion of the biomass materials in the slurry into ethyl esters; and (c) recovery of the resulting products, wherein the resulting products include the ethyl esters; - characterized in that the oxidizing agent is selected from the group consisting of hydrogen peroxide, and a Fenton or a Fenton-type reagent; - in that the ethanol-to-water wt. ratio in the thermo-chemical pre-treatment step (a) is between 0.5 and 4.0; - in that the concentration of oxidizing agent in the acidic solution used in the thermo-chemical pre-treatment step (a)is higher than 6.0 wt.%; - in that the solution-to-biomass wt. ratio in the thermo-chemical pre-treatment step (a) is between 1.5 and 4.0; - in that the slurry prepared during the thermo-chemical pre-treatment step (a) is heated at a temperature T1 between 65°C and 145°C; - and in that step (b) is carried out at a temperature T2 around 180°C, namely at a temperature T2 of 180°C plus or minus 10%. (a) thermo-chemical pre-treatment of the biomass materials with an oxidizing agent solubilized in an acidic solution comprising an acid, ethanol, and water, thereby forming a pre-treatment slurry; (b) diluting the slurry with additional ethanol and additional acid species, and obtaining catalytic conversion of the biomass materials in the slurry into ethyl esters; and (c) recovery of the resulting products, wherein the resulting products include the ethyl esters; - characterized in that the oxidizing agent is selected from the group consisting of hydrogen peroxide, and a Fenton or a Fenton-type reagent; - in that the ethanol-to-water wt. ratio in the thermo-chemical pre-treatment step (a) is between 0.5 and 4.0; - in that the concentration of oxidizing agent in the acidic solution used in the thermo-chemical pre-treatment step (a)is higher than 6.0 wt.%; - in that the solution-to-biomass wt. ratio in the thermo-chemical pre-treatment step (a) is between 1.5 and 4.0; - in that the slurry prepared during the thermo-chemical pre-treatment step (a) is heated at a temperature T1 between 65°C and 145°C; - and in that step (b) is carried out at a temperature T2 around 180°C, namely at a temperature T2 of 180°C plus or minus 10%. - in that the ethanol-to-water wt. ratio in the thermo-chemical pre-treatment step (a) is between 0.5 and 4.0; - in that the concentration of oxidizing agent in the acidic solution used in the thermo-chemical pre-treatment step (a)is higher than 6.0 wt.%; - in that the solution-to-biomass wt. ratio in the thermo-chemical pre-treatment step (a) is between 1.5 and 4.0; - in that the slurry prepared during the thermo-chemical pre-treatment step (a) is heated at a temperature T1 between 65°C and 145°C; - and in that step (b) is carried out at a temperature T2 around 180°C, namely at a temperature T2 of 180°C plus or minus 10%.