Abstract: The present invention describes a process involving liquefaction of a biomass slurry by treatment in hot compressed water (HCW), said process comprising: —a first decomposition step being performed at an average pH level of at most 4.5, wherein a hemicellulose fraction in the biomass slurry is decomposed to water soluble mono- and/or oligomers, and wherein a cellulose fraction undergoes a pre-treatment for decrystallization of the cellulose polymer; —a separation step; and —a second decomposition step, wherein the cellulose fraction in the biomass slurry is decomposed to water soluble mono- and/or oligomers; wherein both of the first and second decomposition steps are performed at sub-critical temperatures implying relatively moderate conditions.

Abstract: The present invention relates to regulation of the p H of a liquefaction process. Presented is a method for treatment of a biomass feedstock wherein the biomass feedstock is subjected to liquefaction, at a p H of at most 4, by treatment with hot compressed liquid water (HCW) at subcritical and/or supercritical conditions to improve the conversion efficiency. The present invention is also directed to quenching of a liquefaction process according to above, preventing, minimizing or eliminating clogging and/or fouling of sticky biomass components in process equipment during processing as according to above, and to the use of additives in a biomass liquefaction process.

Abstract: The present invention relates to a method of production of a fuel containing at least one hydrocarbon from a biomass, comprising the steps of: -A) chemical decomposition of the biomass in a solvent to at least one chemical intermediate compound chosen from the group consisting of a hexose, a pentose and a derivative of lignin, or a combination thereof, optionally produced together with at least one other target chemical, to form a first solution; - B) complete reduction of the first solution with a reducing agent to at least one hydrocarbon to form a fuel; wherein the steps A) and B) are performed below 300° C.