Abstract: A process is provided for peroxygen bleaching of high yield pulp in which sodium carbonate replaces sodium hydroxide and sodium silicate. The process employs a chelating agent as a substitute for the silicate normally required so that the process can operate as a closed cycle system.

Abstract: Delignification and bleaching of lignocellulosic material is enhanced after the pulp has been treated with peroxomonosulfuric acid.

Abstract: A process is disclosed for bleaching wood pulp, cellulose or used paper by treatment the fibre material to be bleached before the bleaching steps with a natural or synthetic zeolite or a layer lattice silicate and an easily decomposable organic complex forming agent, e.g. citric acid.

Abstract: A method of brightening mechanical pulps by chelating and thickening to reduce the manganese content of the pulp to less than 30 parts per million and copper content less than 1 parts per million by adding ions preferably magnesium ions as magnesium sulphate MgSO.sub.4 in the amount of 400 to 3,000 ppm Mg ions retained by the pulp based on the oven dry weight of the pulp and thereafter applying a bleaching liquor composed of peroxide as hydrogen peroxide and an alkali as sodium hydroxide having a ratio of alkali to peroxide of between 1--1 and 2-1 in an amount to apply between 1 to 8 percent peroxide based on the oven dry weight of the pulp and containing no added sodium silicate. Preferably the bleaching liquor will contain magnesium sulphate in the amount of about 0.001 to 0.1% based on the oven dry weight of the pulp.

Abstract: The removal of manganese from pulp is enhanced by supplementing the treatment with a chelating agent by the addition of at least 500 ppm of magnesium ions prior to thickening of the pulp thereby to reduce the manganese content of the thickened pulp significantly more than the content would be reduced by the treatment with the chelating agent without the magnesium ions.

Abstract: A method for pretreating a cellulosic waste product with microwaves is disclosed as well as a method and apparatus for converting cellulosic wastes into soluble saccharides. The invention greatly enhances a reaction rate for enzymatic hydrolysis. A feed mixture of cellulose, water and acetic acid are irradiated with microwaves at a superatmospheric pressure in an autoclave reaction vessel and the treated cellulose is enzymatically hydrolyzed in a bioreactor. The acid and enzymes are optionally separated for reuse. As a feed stock for the culture of microbes, the sugars can be further processed into ethanol or food protein. High yield, low hazard potential, low energy usage and ready preparation in space of acetic acid and the enzyme makes the present invention well suited for use on long duration space missions.

Abstract: A process for delignifying and bleaching a lignocellulosic pulp without the use of elemental chlorine by partially delignifying the pulp to a K No. of about 10 or less and a viscosity of greater than about 13 cps; and further delignifying the partially delignified pulp with an effective amount of ozone for a sufficient time to obtain a substantially delignified pulp having a K No. of about 5 or less, a viscosity of greater than about 10, and a GE brightness of at least about 50%. The substantially delignified pulp may be brightened by the addition of a bleaching agent such as chlorine dioxide or a peroxide to obtain a final product having a GE brightness of at least about 65%, preferably above 70% to as high as 90%. Because of the absence of elemental chlorine in this sequence, filtrate from all stages but the chlorine dioxide stage (if used) can be recovered without sewering. Major environmental improvements are thus achieved.

Abstract: A composition for alkaline hydrogen peroxide bleaching of mechanical wood pulp which employs a quaternary amine compound, such as (3-chloro-2-hydroxy-propyl) trimethyl ammonium chloride, in the stabilized bleach solution. The brightness of the final paper product made from such bleached pulp shows marked improvement over that in which only chelating agents are employed to improve the brightness according to the known art. The process is useful in both silicate and silicate-free bleach solutions.

Abstract: A process for delignification and bleaching of chemically digested lignocellulose-containing pulp for reduced formation and discharge of halogenated organic compounds, while preserving the pulp quality, where the prebleaching with halogen-containing bleaching agent is replaced by a treatment, in a first step, with the addition of a complexing agent at elevated temperature and at a pH from 3.1 to 9.0, and in a second step, by using a peroxide-containing compound under alkaline conditions, whereupon spent liquor from the final bleaching with halogen-containing compounds is recycled to the first or second step of the halogen-free prebleaching.

Abstract: A process for the manufacture of high-yield pulps bleached with the aid of hydrogen peroxide in alkaline medium, which consists in subjecting the pulp to be bleached successively to:(a) a pretreatment with the aid of a sequestering agent for metal ions, followed by a washing operation,(b) a treatment with sulphite and a reducing agent which is more electronegative than the sulphite ion, which act together and in a medium of initial pH between 7 and 12.5, followed by a washing operation to remove the sulphite ions and the reducing agent, and(c) to a bleaching treatment with the aid of hydrogen peroxide in alkaline medium in the presence of a quantity of silicate of between 0% and 1%.

Abstract: A paper pulp refining and bleaching process wherein the pulp is treated in one or more refiners with a sodium hydrosulfite bleach liquor in the presence of a strong alkali such as NaOH, whereby the bleaching solution has an alkaline pH, preferably 10 to 12, and the pulp is discharged from the refiner at a pH of from about 5 to 6. The bleaching produces a brightness gain of at least 8 to 13 ISO points in the refiners. The process is preferably carried out by passing the pulp successively through a primary refiner at elevated pressure, a secondary refiner at atmospheric pressure and a bleaching tower, an alkaline hydrosulfite solution being fed to each.

Abstract: A process for making cellulose acetate from wood pulp takes wet wood pulp and instead of converting it into dry pulp sheet which is the usual feedstock for acetate, dries and mechanically separates the pulp into a cellulose flock using a pin mill through which a hot drying gas is passed. Deactivation of the cellulose is avoided by control of the drying gas exit temperature to 80.degree. C. to 95.degree. C. and of the moisture content of the cellulose flock to 4 to 15% by weight. The flock produced may be acetylated directly without any need for reactivation treatments additional to the normal activation with acetic acid.

Abstract: Delignification and bleaching of lignocellulosic material is enhanced after the pulp has been treated with peroxomonosulfuric acid. The starting pH of the reaction with peroxomonosulfuric acid is between 7 and 11, and the reaction is continued until a final pH of 3 to 5 obtained. Subsequently the pulp is delignified and bleached with peroxide and/or oxygen.

Abstract: A method and article of manufacture thereof is provided for reducing brightness reversion in bleached lignin-containing pulps or newsprint by the treatment of the bleached lignin-containing pulp or newsprint with a compound which donates a hydrogen atom to a photo-excited group or free radical more easily than does the lignin contained in the treated pulp. The hydrogen donating compounds include compounds with certain formyl functionality, including formate salts such as sodium, magnesium and calcium formate, formamides, formic acid esters, and formylurea. In one embodiment, calcium carbonate is added to enhance the activity of the formyl compound. The further addition of a trace amount of superoxide anion quencher such as copper sulfate or ascorbic acid is also provided to still further enhance the activity of the formyl compound, especially formate salts.

Abstract: Lignin contained in a cellulosic or lignocellulosic pulp product is removed by contacting the product with a gaseous medium containing ozone in the presence of a liquid agent which is a lower fatty acid, such a formic, acetic or propionic acid, having only a low solvent capacity for lignin; as a consequence of this treatment, lignin which is present in the product will be converted into a lignin derivative that has an increased solubility in the fatty acid and can be removed quantitatively by extraction from the lignocellulosic material. Purified pulp can thus be obtained with increased processing efficiency and without most pollution problems of prior art processing methods because the fatty acid used as the main constituent of the processing liquid in all stages of pulp production can be circulated counter-currently through the stages of the process with purification of the acid for recirculation only after its use in the digestion step where the normal starting materials of pulp production, i.e.

Abstract: A process is described in which, by the addition of formamidinesulfinic acid in association with an ozone or ozone/oxygen treatment, the viscosity and strength of wood pulps are stabilized at the level that is obtained with use of conventional, chlorine-containing bleaching processes.

Abstract: The present invention provides a process for bleaching and delignifying cellulose-containing products with peroxides and/or oxygen and/or ozone, wherein there is additionally used 0.01 to 2.5% by weight of cyanamide and/or cyanamide salts, referred to the dry weight of the cellulose.

Abstract: Alkaline pulping (such as Kraft) processes for various lignocellulosic materials, such as coniferous or disiduous wood chips, into pulp is improved by adding relatively small amounts of a digestive additive selected from the group consisting essentially of anionic surfactants, nonionic surfactants, and anionic/nonionic surfactant blends, such as sodium alpha-sulfo methyl laurate, cocodiethanolamide, butyl ethylenoxide-propylenoxide block copolymers, etc. to the alkaline cooking media to obtain pulps having a select Kappa number range with a reduction in pulp material reject percentage, a reduction of H-factor, a reduction of white liquor requirements and a reduction of cooking time period, relative to H-factor, reject percentages, white liquor requirements and digestion periods experienced in similar alkaline digestion processes without the inventive digestive additive.

Abstract: A process for alkaline hydrogen peroxide bleaching of mechanical wood pulp which employs a quaternary amine compound, such as (3-chloro-2-hydroxypropyl)trimethyl ammonium chloride, in the stabilized bleach solution. The brightness of the final paper product made from such bleached pulp shows marked improvement over that in which only chelating agents are employed to improve the brightness according to the known art. The process is useful in both silicate and silicate-free bleach solutions.

Abstract: A method for the delignification of lignocellulosic materials with acidic aqueous solutions of monoperoxysulfuric acid for the production of cellulosic pulps for use in papermaking and regenerated cellulose products and for use as animal feeds and other products where removal of lignin is required.

Abstract: A method for producing a novel pulp, primarily wood pulp, from chips using pre-treatment with stabilizers and alkaline peroxide prior to mechanical fiberization (refining) to increase the brightness of the resulting fibers and the papermaking strength achievable with the fibers. The novel aspect of the pretreatment prior to refining is that it reuslts in the "in situ" formation within the chips of a stabilizing flock or sol.

Abstract: A method for the preparation of a mixture of fused ring quinone type compounds from lignin and lignin derived substances. The mixture of fused ring quinone compounds has been found useful in the wood pulping process as an accelerator in the degradation and separation of wood lignin from the other principal wood constituents, cellulose and hemicellulose.

Abstract: The viscosity of paper pulp is maximized, while chlorine bleaching is minimized or eliminated, by subjecting the pulp suspension to multiple consecutive oxygen bleaching stages, with a countercurrent wash between O.sub.2 stages. A chelating agent--such as EDTA--may be added to the countercurrent wash liquid, and/or another chelating agent--such as DTPA--may be used to pretreat the pulp.

Abstract: A method for the continuous countercurrent production of lignins and sugars from wood and other ligno cellulosic materials by organosolv delignification or saccharification at elevated temperatures and pressures is disclosed. The novel method comprises: (a) continuously introducing comminuted lignocellulose materials with a natural mositure content into a reaction vessel from one end; (b) continuously introducing a cooking liquor comprising a major proportion of organic solvent, a minor proportion of water, and a slight amount of inorganic acid countercurrently into the reaction vessel from the opposite end; (c) causing the comminuted lignocellulosic material to be contacted by the cooking liquor; and (d) continuously withdrawing cooking liquor from the reaction vessel after it has commingled with and has dissolved sugars and lignin and other substances from the comminuted lignocellulosic material.

Abstract: A process for the separation of the fibres from each other in lignocellulosic (straw, bagasse, wood) composites, and at the same time to dissociate the Lignin and the Xylan in the middle lamella and the primary wall of the lignocellulosic material, to enable a simple non reactive solvent extraction of the middle lamella and primary wall components while substantially retaining the structural integrity of the fibre bundle, sometimes referred to as the S2 layer, which is the strength member of the lignocellulosic fibre. The purpose of this process is to produce a fibre suitable to replace conventional Chemical Thermal Mechanical Pulp, for paper or as a carrier for high absorbency Cellulose in diaper and similar absorbent material applications, and at the same time to recover the chemical components of the middle lamella and the primary wall of the fibre, as co-products in a marketable, chemically reactive form.

Abstract: A process for the pulping of lignocellulose-containing material, wherein the material is contacted with a pulping medium containing at least 75% by weight of a solvent system, which solvent system comprises from 20 to 95% by weight formic acid; from 5 to 80% by weight of at least one member selected from primary alcohols having from 1 to 3 carbon atoms and esters of formic acid with primary alcohols having from 1 to 3 carbon atoms; and up to 70% by weight of at least one component selected from acetic acid and esters of acetic acid with primary alcohols having from 1 to 3 carbon atoms; and allowing the material to digest at a temperature in ther range of from 140.degree. to 200.degree. C.

Abstract: Compositions and a method are disclosed for minimizing brightness reversion of chromophore-containing wood pulps, especially low-cellulose wood pulps, such as groundwood and thermomechanical pulps, which have been reductively bleached or bleached with hydrogen peroxide. Ascorbic acid and palmitoyl ascorbate are particularly effective for preventing such reversion at low levels.

Abstract: A process for the production of a pulp from bast fibers, which includes reacting a mixture of the bast fibers and an aqueous digestion liquid at a temperature of 60.degree.-130.degree. C. The digestion liquid includes (a) hydrogen peroxide or a compound capable of generating hydrogen peroxide in the presence of water, (b) an alkali metal carbonate, and (c) an oxalate.

Abstract: A method for producing novel pulp, primarily wood pulp, from chips using pre-treatment with stabilizers and alkaline peroxide prior to mechanical fiberization (refining) to increase the brightness of the resulting fibers and the papermaking strength achievable with the fibers. The novel aspect of the pre-treatment prior to refining is that it results in the "in situ" formation within the chips of a stabilizing flock or sol.

Abstract: A method of rapidly and efficiently treating ligno-cellulosic material for removal of lignin and other non-carbohydrates as well as non-cellulosic carbohydrates from cellulosic matter. Such material is first impregnated with a liquor which is a reaction product obtained by mixing triethyleneglycol with an arylsulfonic or other organic acid. The impregnated material is then rapidly heated by microwaving or application of rf energy to a temperature between about 119 degrees Centigrade to 130 degrees Centigrade and maintained at that temperature for only two to five minutes to reduce the effects of hydrolysis. Thereafter, conventional filtration and washing techniques are applied to achieve a residue material suitable for further use as a wood pulp or for further hydrolysis for the production of organic chemicals.

Abstract: Process for the delignification of cellulosic substances comprising:a first stage of treatment of cellulosic substances with an acida second stage of treatment with hydrogen peroxide in an alkaline mediuma third stage of digestion in the presence of at least one chemical reactant chosen from hydroxides of alkaline or alkaline-earth metals.The process applies to the treatment of wood fragments.

Abstract: Process for the delignification of cellulosic substances comprising:a first stage of treatment of cellulosic substances with an acida second stage of treatment with hydrogen peroxide in an alkaline mediuma third stage of digestion in the presence of at least one chemical reactant chosen from sulphur-containing compounds and oxygen.The process applies to the treatment of wood fragments.

Abstract: An improved method of brown stock washing is disclosed. A nonionic surfactant in combination with a polyelectrolyte dispersant, and preferably a solvent, are utilized in the washing step in the pulping of virgin cellulosic fiber. The methods of the invention provide for the enhanced removal and recovery of cooking chemicals and organics from the pulp.

Abstract: The present invention describes a novel method of bleaching wood pulp by using an aqueous solution containing a salt of lactic acid or citric acid and chlorous acid wherein the aqueous solution is obtained by reacting lactic acid or citric acid and sodium chlorite at a temperature ranging from about 60.degree. F. and about 80.degree. F.

Abstract: Inhibition of calcium scale under the extreme temperature conditions found in pulp digesters has been accomplished by employing certain mixtures of polaminopoly(alkylenephosphonic acids) together with nonionic surfactants. Diethylenetriaminepenta(methylenephosphonic acid) together with a polyethoxynonylphenol has been found especially effective for the purpose.

Abstract: A lignocellulosic raw material is pulped with a cooking liquor containing organic peroxyacids, such as peroxyformic acid or peroxyacetic acid, and the defibered pulp is bleached with an alkaline solution containing hydrogen peroxide, the pH of which is at least 10 in the beginning of the treatment, and which is provided by adding to a sodium hydroxide solution, hydrogen peroxide in an amount which if calculated as a percent of the dry weight of the material coming to the treatment corresponds to from 0.20 to 0.80, preferably from 0.25 to 0.70 and most preferably from 0.45 to 0.65 times the kappa number of the pulp obtained from the previous stage of the process.

Abstract: A method for removing dissolved and colloidal material from the circulation water of a paper mill with chemical pulp fibers wherein fiber sludge which has been recovered from the paper manufacturing process and acidified to a pH of 1.5-2.5, is mixed with the circulation water of a paper mill whereby the dissolved and colloidal substances are precipitated.

Abstract: A process for the oxidative or reductive bleaching of wood pulp, especially in the presence of heavy metal salts, in which a complex former combination containing at least one phosphonic acid, at least one polyhydroxycarboxylic acid and at least one phosphate or salts thereof is added to a wood pulp slurry in an amount of from 0.5 to 50%, based on the dry mass of the wood pulp, and subsequent bleaching is carried out in the presence of a reducing agent. Also provided is a complex former combination for use in the oxidative or reductive bleaching of wood pulp, comprising at least one phosphonic acid, at least one polyhydroxycarboxylic acid and at least one phosphate or salts thereof.

Abstract: A process for the production of sugars, and optionally cellulose and lignin, from lignocellulosic vegetable materials which comprises subjecting the vegetable materials to a chemical pretreatment with a mixture of water and lower aliphatic alcohols and/or ketones at a temperature from 100.degree. to 190.degree. C. for a period of from 4 hours to 2 minutes with control of the breakdown of the hemicellulose components followed by separation of residue and a subsequent main chemical treatment with a similar solvent mixture at elevated temperatures for a further period of from 6 hours to 2 minutes.

Abstract: A process and composition especially suited for bleaching wood pulp characterized by the use of hypochlorous acid in combination with chlorine dioxide and/or a nitrogen compound having the characteristic of minimizing fiber degradation and enhancing fiber brightness. The preferred composition is in an aqueous solution adjusted to an optimum pH and is used as a direct replacement for conventional compositions so as to effect substantial savings in the costs of chemicals and energy per ton of bleached pulp.

Abstract: Bleaching of wood pulp is improved by the combination of a pretreatment of the pulp with a polyaminocarboxylic acid, e.g. ethylenediaminetetraacetic acid, prior to bleaching with an alkaline aqueous peroxide solution containing a stabilizing amount of an aminophosphonic acid derivative together with a polymer of an unsaturated carboxylic acid or amide or an alkylsulfonic acid substituted amide.

Abstract: The process of making a wet or dry dispersion containing anthraquinone suitable for use in the alkaline digestion of wood comprising cyclizing ortho-benzoylbenzoic acid at a temperature of about 150.degree. to 180.degree. C. and at an absolute pressure between about 5 and 40 millibars in the presence of between about 0.05 to 2 parts by weight of sulfuric acid, having a concentration of at least about 95%, per part by weight of ortho-benzoylbenzoic acid to form a reaction mixture containing anthraquinone, bringing the reaction mixture to a pH of at least about 7 by addition thereto at a temperature between about ambient temperature and 100.degree. C. of an aqueous solution of sodium hydroxide or potassium hydroxide containing between about 10% to 40% hydroxide by weight, and then forming a dispersion thereof and using such dispersion in the alkaline digestion of wood.

Abstract: An improved method for deresination of wood chips or pulp is provided. The method comprises contacting the chips or pulp with an ethoxylated alkyl phenol deresinating composition during processing to reduce the level of natural resins present therein. The improvement comprises substituting a sufonated fatty acid for part of the ethoxylated alkyl phenol while maintaining substantially the same level of deresination.

Abstract: The method of substantially removing and dispersing resinous or waxy contaminants from contaminant-containing secondary fiber during repulping, is disclosed. The method includes combining the contaminant-containing secondary fiber in an aqueous repulping medium with a substituted oxyethylene glycol nonionic surfactant, and a water soluble, low molecular weight polyelectrolyte dispersant, at an elevated temperature.

Abstract: A process for the delignification and bleaching of cellulose with oxygen and hydrogen peroxide, in which in a given case the delignification is carried out with oxygen in the presence of MgO, and the cellulose subsequently is bleached simultaneously with hydrogen peroxide and oxygen at a pH<5.

Abstract: A process for producing peracids from lactic acid-containing solutions derived from biomass processing systems comprising: adjusting the pH of the solution to about 8-9 and removing alkaline residue fractions therefrom to form a solution comprised substantially of lower aliphatic hydroxy acids; oxidizing the solution to produce volatile lower aliphatic aldehydes; removing said aldehydes as they are generated; and converting said aldehydes to peracids.

Abstract: This invention concerns a treatment for preserving or protecting moist wood against attacks from microorganisms (fungi) with the use of evaporable or sublimable ammonium salts. The protection is obtained by distributing the salts close to the wood so that the salts form an atmosphere around the wood in which the microorganisms cannot develop. The treatment is of special interest for moist wood during a storage period until it has been dried and is not further attached by fungi.

Abstract: A pressure-sensitive recording sheet is described. The sheet is comprised of a paper substrate which is treated with succinic acid derivatives having an alkenyl group or alkyl group containing from 4 to 18 carbon atoms, or salts thereof. This pressure-sensitive recording sheet is greatly reduced in the formation of fog which occurs in printing the sheet. Thus, it is very useful as no carbon paper.

Abstract: A two-stage process is provided for the conversion of lignocellulosic material, for instance, wood, to cellulose pulp, first oxidizing the lignocellulosic material to form aldonic acid end groups, preferably bound with 1,4-glycosidic bonds, in the polysaccharides, in an alkaline medium in the presence of the oxidized form of a redox additive which is converted into a reduced form in reaction with the wood and/or products formed from the wood, withdrawing the alkaline medium and then reoxidizing the reduced form of the redox additive in the absence of the lignocellulosic material at a rate to maintain the oxidized form of the redox additive in a major proportion in the alkaline medium during oxidation of the lignocellulosic material by contacting the withdrawn alkaline medium with oxygen-containing gas, and then continuing the digestion in an alkaline medium at a temperature within the range from about 160.degree. to about 200.degree. C.

Abstract: An improved process for the production of pulp from lignocellulosic material characterized by the employment of a cooking aid is disclosed. The cooking of the lignocellulosic material is carried out in the presence of a small amount of a compound selected from the group consisting of hydroxyanthracenes and derivatives thereof.