A process for producing refined cotton with a high polymerization degree includes: a. selection of material; b. impurity removal; c. impregnation; d. pretreatment: compounding triethanolamine, sodium carbonate, copper sulfate and magnesium oxide in equal proportion to form a cooking compound adjuvant with a mass concentration of 0.2-0.5%, putting the cookingcompound adjuvant into a spherical digester together with the cotton linter subjected to the impregnation treatment, heating to 70 C, stopping heating, and subjecting to idling pretreatment for 40-60 min; e. cooking; f. cooling of the spherical digester; g. formulating a chlorine dioxide bleaching stabilization solution; h. a first stage of bleaching; I. alkali treatment; J. a second stage of bleaching; K. dechlorination; and 1. rolling and drying by baking.

A method for co-producing molded food-container pulp and fulvic acid from cotton stalk, which belongs to the field of comprehensive utilization of crop straw resources. The method adopts digesting, defibering and bio-treating measures to remove pectin and hemicellulose and other anionic waste generating sources in cotton straw raw materials to obtain a pulp with low beating degree; and retains part of lignin to help form oil-proof and waterproof film of a molded food-container and improves the stiffness and water filtration of the molded food-container and increases a yield of fiber pulp; adopts ammonium sulfite method to pulping to meet fiber requirements while obtaining fulvic acid.

According to an example aspect of the present invention, there is provided a process for the conversion of cellulosic waste material into a recycled cellulose product comprising the steps of cooking the waste material in a cooking liquor to remove lignin from the waste material and provide a delignified pulp, dissolving the delignified pulp in an ionic liquid to provide a spinning dope suitable for dry jet-wet spinning in an ionic liquid solution, and subjecting the spinning dope to a further processing step to provide a recycled cellulose product, said further step selected from the group of spinning cellulose fibers for use in textiles from the solution, extruding a film product for use in packaging, regenerating the dope as a hydrogel and regenerating the dope as an aerogel.

A method of producing chemical pulp including at least the following steps: a) wood chips or other comminuted ligno-cellulosic fibrous material is treated with a polysulfide-containing cooking liquor in an impregnation stage at a temperature of 90-145° C., and b) slurry of fibrous material from step a) is heated into cooking temperature and cooked for producing pulp having a desired kappa number. After step a) mercaptide ions are added into the slurry of fibrous material and the fibrous material is treated at cooking temperature in step b).

A digestion accelerator which is safe and has a high digestion acceleration effect is provided. The digestion accelerator according to the present invention contains tannin or a polyphenol compound that is a hydrolysate of the tannin, a salt of the polyphenol compound, or ester of the polyphenol compound.

A process for increasing digestion efficiency of lignocellulosic material in a treatment vessel includes providing lignocellulosic material comprising lignocellulosic biomass, providing an alkyl polyglycoside, an alkoxylated alcohol, and a white liquor comprising sodium hydroxide and sodium sulfide, combining the lignocellulosic material, the alkyl polyglycoside, the alkoxylated alcohol, and the white liquor to form a mixture, and heating the mixture in the treatment vessel to a temperature of from about 125° C. to about 185° C. to digest at least a portion of the lignocellulosic material. The alkyl polyglycoside and the alkoxylated alcohol are present in the mixture in a weight ratio of actives from about 5:95 to about 95:5, respectively. The mixture is free of added surfactants that are not the alkyl polyglycoside and/or the alkoxylated alcohol. The process has increased digestion efficiency as compared to a process that does not utilize a combination of the alkyl polyglycoside and the alkoxylated alcohol.

A method of increasing the throughput and/or decreasing the energy usage of a pulping process includes the steps of providing a plurality of lignocellulosic chips, providing a refining composition, applying the refining composition to the plurality of lignocellulosic chips, and mechanically refining the plurality of lignocellulosic chips to form pulp. The refining composition includes water and a lubricating additive including the reaction product of a sugar and an alcohol. The step of applying the refining composition to the lignocellulosic chips is conducted less than 5 minutes prior to, or concurrently with, the step of mechanically refining the wood chips to form pulp.

The invention relates to a refiner plate segment in a refiner plate for mechanically refining of lignocellulosic material in a refiner, said refiner plate segment comprising at least a first, generally radially extending bar, a second, generally radially extending bar, a groove arranged and defined between said first, generally radially extending bar and said second, generally radially extending bar, and a main dam, which has a height H and is arranged in the groove, wherein a pre-dam is arranged in front of the main dam, said pre-dam has a height h which is less than the height H of the main dam.

A method of digesting lignocellulosic material includes the steps of providing the lignocellulosic material and a caustic composition having a pH of at least about 10. The caustic composition includes water, an alkaline- or alkaline earth-metal hydroxide, and up to about 1 percent by weight based on a total weight of the composition of a branched digestion additive. The branched digestion additive has the structure: wherein A is at least one alkyleneoxy group and each alkyleneoxy group has from 2 to 4 carbon atoms, n is 0 or 1, B is a branched aliphatic hydrocarbon group having from 8 to 15 carbon atoms, X is H or B-0-(A).sub.m, and each m is independently an average value from 3 to 30, and wherein the caustic composition has a Draves Wetting Time of less than 100 seconds as determined using ASTM D2281. ##STR00001##

Digestion of cellulosic biomass solids may be complicated by release of lignin therefrom. Methods and systems for processing a reaction product containing lignin-derived products, such as phenolics, can comprise hydrotreating the reaction product to convert the lignin-derived products to desired higher molecular weight compounds. The methods and systems can further include separating the higher molecular weight compounds from unconverted products, such as unconverted phenolics, and recycling the unconverted phenolics for use as at least a portion of the digestion solvent and for further conversion to desired higher molecular weight compounds with additional hydrotreatment. The methods and systems can further include a further hydrotreatment step configured for additional lignin conversion and/or a further hydrotreatment step configured for generating hydrogen.