Creusot-loire

Maurice Gelus

Pierre Berger

Process and device for hydrolyzing cellulose material in an extruder with two parallel screws in which the material introduced in the moist condition and, transported by the screws is malaxated, heated to a temperature of above 200.degree. C. in the downstream part of the extruder where it is contacted with an acid solution and progressively compressed, to a pressure higher than the saturated vapor pressure of the liquid phase of the hydrolyzed material at the temperature reached in the downstream part and maintained by a control device for the evacuation of the material. According to the invention, there is provided in the control device for the evacuation of the material, a separation of the liquid phase and of the solid phase from hydrolyzed material with maintenance of the output pressure, through the use for this purpose of a second extruder comprising two screws with axes perpendicular to that of the hydrolysis extruder, rotated within a sleeve into the central part of which the hydrolyzed material coming from the first extruder is discharged and in which a pressure is maintained higher than the saturated vapor pressure of the liquid phase by regulating the extrusion characteristics to form, at the downstream end of the output extruder, a plug of compressed material fluid-tight at said pressure, the latter being regulated by means of a pressure reducing valve controlling the evacuation of the liquid phase concentrated in the upstream part of the extruder and in which glucose formed by hydrolysis is dissolved.

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Le Creusot, France

Maurice Gelus