Oy Advanced Forest Automation Ab

Oy Lannen Tutkimus—western Research Inc.

Metso Paper Inc.

Valmet Technologies Oy

Valmet Technologies, Inc.

Afora Oy

Arbozon Oy Ltd.

Panu Tikka

Nils-Erik Virkola

Eric Enqvist

Aki Vilpponen

Tobias Wittmann

Henrik Wallmo

Päivi Uusitalo

Nils E Virkola

Anders Littorin

Ville Tarvo

Leopold Heinrich

Matti Luhtanen

Rolf De Vos

Paivi Uusitalo

Lignin-rich starting material is suspended in a first medium, which is acidic and aqueous, to form a aqueous acidic suspension, which is heated and allowed to form two continuous phases, a thermoplastic lignin phase and an aqueous phase. The thermoplastic lignin phase is separated from the aqueous phase and passed through a shape giving process into a second medium which is at a temperature lower than that of the thermoplastic lignin phase and in which the thermoplastic lignin phase is essentially insoluble. Solid lignin formed in the second medium is recovered.

Method for producing solid lignin

The invention relates to an improved process to break down lignin macromolecules and liberating cellulose fibers in lignocellulosic material using delignifying reactants with a gaseous organic agent as a heating and reaction-accelerating media. Lignocellulosic material is first impregnated with reactant chemicals, e.g. commonly used agents such as sodium hydroxide and sodium sulfide. Subsequently, the energy required for the delignification reactions is provided through heating with a gaseous organic agent such as methanol or ethanol, condensing and releasing energy to the solid lignocellulosic material. The temperature during the heating step with a gaseous organic agent is higher than the temperature during the impregnation step.

Production of pulp using a gaseous organic agent as heating and reaction-accelerating media

A process for the bleaching of chemical pulp, wherein the initial bleaching of the pulp includes a first chlorine dioxide treatment (D0) and a following alkaline treatment with oxygen and hydrogen peroxide (EOP), which stages are separated from each other with a washing stage, and a treatment of the pulp to reduce the content of transition metals of the pulp prior to the peroxide treatment. The process is characterized in that alkali is added to the pulp after addition of chlorine dioxide in the D0 stage to adjust the pH of the pulp to neutral or basic (N stage) prior to the washing stage following the chlorine dioxide stage, whereby the initial bleaching includes the sequence D0N EOP.

Bleaching process of chemical pulp

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.

Method for recovering hydrolysis products

A process for the bleaching of chemical pulp, comprising a first chlorine dioxide treatment (D) of the initial bleaching and chelation (Q) to be carried out in connection therewith, forming together a DQ treatment. The process is characterized in that the chelation is carried out at the pH of from 2 to 7, and it is followed by an alkalizing stage (N) of the pulp, without intermediate washing for raising the pH of the pulp to above 7 and at most to 12 prior to a following stage which is a washing step.

A method of controlling an alkaline pulping process, sulphate pulping in particular. The concentration of the dissolved components as well as the concentration of the recidual cooking chemical are measured. The measurements are carried out by means of an analyzer positioned outside of the cooking process in a separate liquid flow. The measuring devices are per se known detectors. The cooking process is observed and the necessary corrections are made on the basis of the measuring results.

Method of controlling alkaline pulping process

A method of rapid determination of the concentrations of the total sulphur dioxide and the lignosulphonate present in sulphite pulping process liquors. The lignosulphonates are separated from compounds which form the total sulphur dioxide by means of an ion exclusion column, whereby the filling material of the column consists of a cation exchange resin. The concentration measurements of the sulphur dioxide and the lignosulphonate are carried out from the liquor flow coming out from the separation column by means of UV-method at the wave length of 280 nm. The invention also relates to a method of controlling the sulphite pulping process by determining the total sulphite dioxide concentration in the pulping liquor.

Method of determining rapidly the concentration of the total sulphur

A method for rapid determination of the contents of lignin, monosaccharides and organic acids in the process solutions of sulfite pulping. Accordingly, any non-ionized compounds that disturbs the measurement of these concentrations are separated from the lignin material by an ion-exclusion technique. The measurements of concentrations are carried out by means of the UV-method, refractive-index method, and/or by means of the polarimetric method. The method of the present invention is usable for the controlling of sulfite cooking or other pulping or by-product production processes as well as for the characterization of the spent liquor.

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Espoo, Finland

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