601075 Disclosed is a method of continuous hydrothermal pretreatment of cellulosic material, preliminary to enzymatic liquefaction and saccharification, comprising the steps of: a) conveying a cellulosic feedstock through at least one continuous, pressurised reactor, having at least two consecutive sections, in such manner that the pressurised part of the hydrothermal pretreatment is conducted at more than one set of temperature/pressure conditions with each set corresponding to a respective reactor section； b) pressing the feedstock under pressurised conditions between each stage having a set of temperature/pressure conditions, thereby creating a fibre fraction and a liquid fraction； and c) unloading the liquid fraction from the pressurised reactor between each stage having a set of temperature/pressure conditions, and preferably wherein liquid is removed from the feedstock by pressing during unloading of the at least one pressurised reactor using a sluice device, wherein unloading of feedstock from the at least one pressurised reactor is accomplished using steam explosion, and wherein solids unloaded from the at least one reactor are subsequently subject to enzymatic liquefaction and saccharification and further fermented to produce ethanol.
