In vertical concentrating washing machines, processed raw material is transported upward but ends up containing shower water. That is, the moisture content ends up increasing during the transport process even though the material has been dewatered. A transport blade (8) has a plate-like shape in plan view and includes a fan-shaped portion (10) that extends rearward in the rotational direction, developing into a fan shape, and the transport blade is attached such that a plate surface thereof has a slanted orientation with respect to the axis direction of a rotary shaft (6), with a forward side, in the rotational direction, of the plate surface being disposed lower than a rearward side thereof. A plurality of the transport blades (8) is attached so as to delineate a helix along the circumferential direction of the rotary shaft (6) while leaving a communicating portion that is straight in the vertical direction. Shower water falls from gaps (S) between the transport blade (8). The transport blades (8) have a fan shape that widens toward the inner wall side of the rotary drum (5). A surface area on which the material rests stably and a sufficient gap (S) are secured in a well-balanced fashion.

This disclosure relates to methods of making novel dissolving wood pulps by processes comprising acid prehydrolysis, pulping, and a multi-stage bleaching process comprising oxidation with a catalyst and peroxide under acidic conditions, as well as to products made therefrom having a combination of medium-purity, low viscosity, and improved reactivity, filterability, and/or clogging that can be used as a substitute for traditional high-purity dissolving pulps in a wide variety of applications.

This disclosure relates to methods of making novel dissolving wood pulps by processes comprising acid prehydrolysis, pulping, and a multi-stage bleaching process comprising oxidation with a catalyst and peroxide under acidic conditions, as well as to products made therefrom having a combination of medium-purity, low viscosity, and improved reactivity, filterability, and/or clogging that can be used as a substitute for traditional high-purity dissolving pulps in a wide variety of applications.

A low energy production process for producing paper pulp from lignocellulosic biomass, the process comprising the following successive steps: a) extracting lignins and hemicellulose from lignocellulosic biomass by putting at least one solid lignocellulosic raw material in the presence of a mixture, composed only of water and of formic acid, at atmospheric pressure and under controlled conditions of reaction temperature between ambient temperature and the reflux temperature of the mixture at atmospheric pressure, preferably between 80° C. and 100° C., with a weight ratio of the at least one solid lignocellulosic raw material/liquid mixture comprised between 1/1 and 1/15, and for a determined period of time of reaction; and b) separating, at atmospheric pressure and at the reaction temperature, a solid fraction, constituting raw paper pulp, from an organic phase containing in solution at least the starting formic acid and water mixture, solubilized monomeric and polymeric sugars, lignins.

A low energy production process for producing paper pulp from lignocellulosic biomass, the process comprising the following successive steps: a) extracting lignins and hemicellulose from lignocellulosic biomass by putting at least one solid lignocellulosic raw material in the presence of a mixture, composed only of water and of formic acid, at atmospheric pressure and under controlled conditions of reaction temperature between ambient temperature and the reflux temperature of the mixture at atmospheric pressure, preferably between 80° C. and 100° C., with a weight ratio of the at least one solid lignocellulosic raw material/liquid mixture comprised between 1/1 and 1/15, and for a determined period of time of reaction; and b) separating, at atmospheric pressure and at the reaction temperature, a solid fraction, constituting raw paper pulp, from an organic phase containing in solution at least the starting formic acid and water mixture, solubilized monomeric and polymeric sugars, lignins.

A method for manufacturing bleached pulp from a feedstock that includes recycled paper. The method includes steps of: (1) impregnating the feedstock with cooking liquor to yield an impregnated material having a liquor-to-fiber mass ratio of at most about 4:1; (2) cooking the impregnated material to remove at least a portion of the lignin within the impregnated material, thereby yielding a cooked pulp; and (3) bleaching the cooked pulp.

A method for manufacturing bleached pulp from a feedstock that includes recycled paper. The method includes steps of: (1) impregnating the feedstock with cooking liquor to yield an impregnated material having a liquor-to-fiber mass ratio of at most about 4:1; (2) cooking the impregnated material to remove at least a portion of the lignin within the impregnated material, thereby yielding a cooked pulp; and (3) bleaching the cooked pulp.

There is provided a process for chemically pretreating reclaimed cellulose fibres to be used in the production of moulded bodies from regenerated cellulose, wherein the pretreatment includes one stage, in which stage acid metal removal and acid oxidative bleaching are carried out together. Advantages include that the propensity of the regenerated cellulose to clog when flowing in a tube and through a nozzle is reduced. This is believed to be an effect of an efficient metal removal. The need for additional bleaching steps and/or metal removing steps is reduced or even eliminated. A one-stage method is more efficient, faster and less costly compared to a multi-stage method according to the prior art. From an environmental perspective, acidic metal removal is preferred over removal by chelating agents such as EDTA.

The invention relates to the chemical industry, namely to the production method of cellulose from all types of plant cellulose-containing raw material. The method includes raw material impregnation and hydrolysis in a hydrolysis solution, cellulose filtration, washing with water, filtration and drying, accompanied with the use of cycles that include heating of the material to a temperature of 115° C. or less, high-speed impulse action of vacuum with a pressure change in the range up to 5 mm Hg for a time of less than 10 seconds, followed by exposure under vacuum and vacuum relief.

Both solution of nitric or sulphuric acids, their mixture and alkaline solution can be used as hydrolysis solution.

Technical result of the claimed method consists in. reducing the duration of the cellulose hydrolysis process, reducing the temperature of the processes while obtaining the required chemical and structural homogeneity of the cellulose.

The invention relates to the chemical industry, namely to the production method of cellulose from all types of plant cellulose-containing raw material. The method includes raw material impregnation and hydrolysis in a hydrolysis solution, cellulose filtration, washing with water, filtration and drying, accompanied with the use of cycles that include heating of the material to a temperature of 115° C. or less, high-speed impulse action of vacuum with a pressure change in the range up to 5 mm Hg for a time of less than 10 seconds, followed by exposure under vacuum and vacuum relief.

Both solution of nitric or sulphuric acids, their mixture and alkaline solution can be used as hydrolysis solution.

Technical result of the claimed method consists in. reducing the duration of the cellulose hydrolysis process, reducing the temperature of the processes while obtaining the required chemical and structural homogeneity of the cellulose.