A surfactant treated bleached softwood kraft pulp fiber, useful as a starting material in the production of cellulose derivatives including cellulose ether, cellulose esters and viscose, is disclosed. Methods for making the kraft pulp fiber and products made from it are also described.

The present invention is in the field of delignifying and/or bleaching of pulp, more in particular wood pulp. Such a process is useful in paper production. More in particular, the method relates to the use of an enzyme for delignification and/or bleaching, more in particular a bacterial laccase. Even more in particular, it provides a method for delignifying and/or bleaching of a pulp, comprising an enzymatic treatment step wherein lignin-containing pulp and a laccase are reacted at alkaline pH, wherein the laccase has an amino acid sequence according to SEQ ID NO: 1 or an amino acid sequence at least 90% identical to SEQ ID NO: 1.

The present invention is in the field of delignifying and/or bleaching of pulp, more in particular wood pulp. Such a process is useful in paper production. More in particular, the method relates to the use of an enzyme for delignification and/or bleaching, more in particular a bacterial laccase. Even more in particular, it provides a method for delignifying and/or bleaching of a pulp, comprising an enzymatic treatment step wherein lignin-containing pulp and a laccase are reacted at alkaline pH, wherein the laccase has an amino acid sequence according to SEQ ID NO: 1 or an amino acid sequence at least 90% identical to SEQ ID NO: 1.

The purpose of the present invention is to provide a method which is for producing pulp fibers for cellulose nanofiberization from pulp fibers of used sanitary products, and which can produce pulp fibers for cellulose nanofiberization that have low lignin content and a low distribution thereof and that have excellent cellulose nanofiberization properties. This method is described below. The method is characterized by involving: a step for supplying, from a mixed solution supply port (32) to a treatment tank (31), a mixed solution (51) which contains superabsorbent polymers and pulp fibers derived from used sanitary products; a step for supplying an ozone-containing gas (53) from an ozone-containing gas supply port (43) to a treatment solution (52) inside of the treatment tank (31); a step in which, by raising the ozone-containing gas (53) while lowering the superabsorbent polymers and pulp fibers in the treatment tank (31), the ozone-containing gas (53) is brought into contact with the superabsorbent polymers and the pulp fibers, and pulp fibers for cellulose nanofiberization are formed from the pulp fibers; and a step for discharging the treatment solution (52) from a treatment solution discharge port (33), wherein the pulp fibers for cellulose nanofiberization have a lignin content of less than or equal to 0.1 mass %.

A process for obtaining cellulose, hemicellulose and lignin from lignocellulose can be carried out in an environmentally friendly manner when it comprises the following steps: step a) wherein a lignocellulose from plant biomass is provided, step b) wherein the lignocellulose is brought into contact with a first mixture M1 containing water and an alkaline component, and a first suspension S1 forms, the first suspension S1 comprises a first solid F1 and a first liquid phase P1, wherein the first solid F1 contains a crude cellulose, and the first liquid phase P1 contains hemicellulose and lignin, and step c) wherein the crude-cellulose-containing solid F1 is brought into contact with a second mixture M2 containing formic acid and water and optionally acetic acid, and a second suspension S2 forms, the second suspension S2 comprises a second solid F2 and a second liquid phase P2, wherein the second solid F2 contains a pure cellulose, and the second liquid phase P2 contains hemicellulose and lignin.

A process for obtaining cellulose, hemicellulose and lignin from lignocellulose can be carried out in an environmentally friendly manner when it comprises the following steps: step a) wherein a lignocellulose from plant biomass is provided, step b) wherein the lignocellulose is brought into contact with a first mixture M1 containing water and an alkaline component, and a first suspension S1 forms, the first suspension S1 comprises a first solid F1 and a first liquid phase P1, wherein the first solid F1 contains a crude cellulose, and the first liquid phase P1 contains hemicellulose and lignin, and step c) wherein the crude-cellulose-containing solid F1 is brought into contact with a second mixture M2 containing formic acid and water and optionally acetic acid, and a second suspension S2 forms, the second suspension S2 comprises a second solid F2 and a second liquid phase P2, wherein the second solid F2 contains a pure cellulose, and the second liquid phase P2 contains hemicellulose and lignin.

A process for pretreating reclaimed cotton fibers to be used in the production of molded bodies from regenerated cellulose, characterized by effective metal reduction and adjustment of the degree of polymerization and brightness, including a metal removing stage and an oxidative bleaching stage of the reclaimed cotton fibers or pulp produced thereof. Reclaimed cotton fibers treated according to the described process may be used alone or in blends with conventional dissolving pulp as raw material for the production of molded bodies from regenerated cellulose. The process enables technically smooth, safe, and economically feasible spinning via the Viscose or Lyocell process, therefore, the current invention provides an efficient recycling pathway for cotton waste materials.

A process for pretreating reclaimed cotton fibers to be used in the production of molded bodies from regenerated cellulose, characterized by effective metal reduction and adjustment of the degree of polymerization and brightness, including a metal removing stage and an oxidative bleaching stage of the reclaimed cotton fibers or pulp produced thereof. Reclaimed cotton fibers treated according to the described process may be used alone or in blends with conventional dissolving pulp as raw material for the production of molded bodies from regenerated cellulose. The process enables technically smooth, safe, and economically feasible spinning via the Viscose or Lyocell process, therefore, the current invention provides an efficient recycling pathway for cotton waste materials.

An ozone generator includes a high-voltage electrode and at least one counter electrode, which define an interstice in which at least one dielectric is arranged and through which a gas flows in the flow direction. The high-voltage electrode and the at least one counter electrode are provided with a connection for an electrical voltage supply to generate corona discharges which are discharged from surface discharge locations. The mean sparking distance and the mean spacing between the high-voltage electrode and the at least one counter-electrode are constant. The number of surface discharge locations decreases in the flow direction.

An ozone generator includes a high-voltage electrode and at least one counter electrode, which define an interstice in which at least one dielectric is arranged and through which a gas flows in the flow direction. The high-voltage electrode and the at least one counter electrode are provided with a connection for an electrical voltage supply to generate corona discharges which are discharged from surface discharge locations. The mean sparking distance and the mean spacing between the high-voltage electrode and the at least one counter-electrode are constant. The number of surface discharge locations decreases in the flow direction.