Abstract: An improved method for treating lignocellulosic material, including a prehydrolysis-mass transfer process, which produces a concentrated hydrolysate volume during the time required for the hydrolysis itself. The improved process comprises the heating of the digester and chip content by direct steam to the required hydrolysis temperature, starting a flow of hot, stored hydrolysate to the top of the chip bed in order to create a trickle-bed type down-flow of hydrolysate, collecting a first fraction of the trickled-down hydrolysate as a product fraction, adding extraction liquid and continuing the trickle flow to collect a second hydrolysate fraction, which will be discharged from the digester to a hot hydrolysate storage tank to be used as the first trickle flow liquid in the next batch.

Abstract: A method for the preparation of pulp by means of alkaline cooking, in which method spent liquor is transferred to pressurized tanks, and at least one liquor is expanded corresponding to a temperature difference of 1 to 5° C. The generated steam is led to turpentine recovery. Thus, the removal of turpentine and gases dissolved in said liquor is effective, the amount of recovered turpentine increases, and pulp of better washability and higher quality is obtained.

Abstract: Methods for producing chemical pulp from lignocellulose-containing material in processes for kraft pulp production are disclosed including charging the lignocellulose-containing material to a digester, initially treating the lignocellulose-containing material with an impregnation liquor, and then treating the impregnated lignocellulose-containing material with hot liquor and displacing calcium-containing spent liquor from the digester during that treatment, heating and cooking the heated lignocellulose-containing material to produce cooked lignocellulose-containing material and cooking liquor and displacing the cooking liquor from the digester using at least a portion of the displaced calcium-containing spent liquor.