A method and an apparatus for treating plant based raw material with an enzymatic hydrolysis

(canceled)

A method for treating plant based raw material with an enzymatic hydrolysis, in which the plant based raw material is treated to form lignocellulosic material, and the lignocellulosic material or a solid fraction thereof is subjected to the enzymatic hydrolysis, wherein the method comprises

• treating the plant based raw material in at least one treatment stage for forming the lignocellulosic material including over 80% fine solid particles which are fiber-like or indefinable particles smaller than 0.2 mm, defined by an optical measurement device, and the viscosity of the lignocellulosic material is below 18000 mPas at 12% dry matter content, measured by Brookfield viscosity device at about 53° C. and spindel type Vane,
• subjecting the lignocellulosic material or at least one solid fraction of the lignocellulosic material into the enzymatic hydrolysis for forming a lignin based material, and subjecting the lignin based material into at least one solid-liquid separation stage after the enzymatic hydrolysis and separating a lignin fraction and a soluble carbohydrate containing fraction.