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.

The invention relates to novel methods for processing lignocellulosic material. More specifically, the invention proves an integrated approach for processing cellulose to obtain paper and pulp and valorizing lignin to obtain value-added chemicals and products.

A process for the isolation of cellulose nanofibers, in particular carboxylic acid functionalized cellulose nanofibers (MxG-CNF-CO2H) from the sustainable grass hybrid Miscanthus x. giganteus (MxG). The process includes the steps of performing bleach treatment on a quantity of MxG followed by ammonium persulfate oxidation. The resulting MxG-CNF-CO2Hs have good dispersibility in aqueous and polar organic solvents. They are also able to form gels at relatively low concentrations. The MxG-CNF-CO2H show significantly higher reinforcement effect when compared to carboxylic acid functionalized cellulose nanocrystals at the same weight percent in a composite composition.

A super strong and tough densified wood structure is formed by subjecting a cellulose-based natural wood material to a chemical treatment that partially removes lignin therefrom. The treated wood retains lumina of the natural wood, with cellulose nanofibers of cell walls being aligned. The treated wood is then pressed in a direction crossing the direction in which the lumina extend, such that the lumina collapse and any residual fluid within the wood is removed. As a result, the cell walls become entangled and hydrogen bonds are formed between adjacent cellulose nanofibers, thereby improving the strength and toughness of the wood among other mechanical properties. By further modifying, manipulating, or machining the densified wood, it can be adapted to various applications.

The APPARATUSES, METHODS AND SYSTEMS FOR APPARATUSES, METHODS AND SYSTEMS FOR YIELD INCREASE IN A KRAFT COOKING PLANT present synergies for at least two parallel cooking plants, e.g., one producing dissolving pulp in a prehydrolysis kraft process, and the other producing kraft pulp by kraft pulping process, which may facilitate increased cooking yield in the kraft cooking plant producing kraft pulp by recovering the hemicelluloses solubilized in the acidic hydrolysate of the prehydrolysis kraft process. In some implementations, there may be no cold caustic extraction step on the dissolving pulp line as the target pulp purity can be achieved by performing just a prehydrolysis step, with reutilization of an acidic hydrolysate stream in a kraft pulp line.

A pulping method includes chemical cooking of softwood chips to retain a high lignin content of about 18% to about 28% by weight and fiberization of the cooked softwood chips to a low residual wood shive content of at most 15% by weight.

A super strong and tough densified wood structure is formed by subjecting a cellulose-based natural wood material to a chemical treatment that partially removes lignin therefrom. The treated wood retains lumina of the natural wood, with cellulose nanofibers of cell walls being aligned. The treated wood is then pressed in a direction crossing the direction in which the lumina extend, such that the lumina collapse and any residual fluid within the wood is removed. As a result, the cell walls become entangled and hydrogen bonds are formed between adjacent cellulose nanofibers, thereby improving the strength and toughness of the wood among other mechanical properties. By further modifying, manipulating, or machining the densified wood, it can be adapted to various 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 method for manufacturing dissolving pulp using wood material is disclosed. The method comprises subjecting the wood material to a hydrothermal treatment using steam and/or water, digesting the wood material obtained to a pulp in a kraft cooking process; subjecting the pulp to a cold caustic extraction CCE; and dewatering, washing and pressing the pulp to get a pulp product having a carbohydrate content. The wood material can be a coniferous wood material, and whereby the mild hydrothermal treatment is performed to reach a P-factor of from 100-300, and whereby the cold caustic extraction is executed to reach a combined concentration of anhydromannose and anhydroxylose of 5 weight %, or less, of the carbohydrate content of the pulp product.

A method for degumming bast fibers comprising soaking a source of bast fiber in a saline solution. The source of bast fiber may be soaked in a saline solution having a concentration ranging between less than 1 part per thousand to about 200 parts per thousand. The saline concentration may vary as the source of bast fiber is soaking, or by alternating bast fiber between aqueous solutions of differing ionic concentrations. In one embodiment, the source of bast fiber is soaked in seawater, wherein the saline concentration varies by alternating the salinity using a tide. The source of bast fiber may be hemp.