Abstract: Methods for catalytic generation of formic acid at an oxygen partial pressure of less than 1 bar and regeneration of the catalyst used in this process, wherein a polyoxometallate ion of the general formula [PMoxVyO40]n?, which serves as the catalyst, is brought in contact with an alpha-hydroxyaldehyde, an alpha-hydroxycarboxylic acid, a carbohydrate, a glycoside or a polymer containing a carbon chain with at least one OH group bound as a repeatedly occurring substituent to the carbon chain and/or an O, N or S atom occurring repeatedly in the carbon chain in a liquid solution in a vessel, at a temperature above 70 ° C. and below 120 ° C.

Abstract: The present invention relates to a method using sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL). More specifically, it relates to a sulfite-based chemical process for pretreating biomass in solutions to reduce access barriers of enzymes to the lignocellulose, resulting in efficient conversion through enzymatic saccharification.

Abstract: Methods to control organic contaminants in fibers are described. One method involves contacting the fibers with a) at least one zeolite and optionally b) detackifier, or an ester hydrolyzing enzyme, or both, for a sufficient time and in a sufficient amount to control the organic contaminants present in the fibers. This method is effective to reduce stickies in paper mill furnish formed with recycled fibers. A method for pitch control in paper mill furnish formed with virgin fibers is also provided. Resulting paper products formed from the processed fibers are also described as well as methods to make them.

Abstract: This invention relates to wood preservatives containing copper complexes and calcium ions, zinc ions or calcium and zinc ions for protection of wood, cellulose, hemicellulose, lignocellulose, cellulosic materials and articles derived from cellulosic materials from decay caused by fungi. The calcium ions, zinc ions, or calcium and zinc ions improve the penetration of copper preservative agent into the interior of a treated material or article.

Abstract: The delignification and bleaching of chemical pulp by a bleaching stage, in which the chemical pulp is reacted first with chlorine dioxide and, after reaction of the chlorine dioxide, is further reacted without intermediate washing with hydrogen peroxide in the presence of a molybdate or tungstate, permits the production of chemical pulp having a whiteness of at least 89.5%, having improved stability to yellowing and reduced oxidative damage.

Abstract: The present invention relates to a process for preparing a high-yield pulp comprising a) treating a lignocellulose containing material chemically by means of an oxidizing system comprising at least one non-enzymatic oxidant substantially free from ozone and chlorine dioxide and an activator at a pH from about 2 to about 6.5; and b) treating the lignocellulose containing material mechanically for a time sufficient to produce a high-yield pulp, wherein the lignocellulose containing material is chemically treated prior to and/or during any mechanical treatment stage, and wherein the lignocellulose containing material is not chemically treated at a pH from about 11.5 to about 14 between stages a) and b).

Abstract: A method for alteration of the morphology of cellulose fibers, particularly softwood fibers, by (a) subjecting the fibers to a metal ion-activated peroxide treatment carried out at a pH of between about 1 and about 9, preferably between 3 and 7, and (b) subjecting the treated fibers to a refining treatment thereby converts SW fibers to HW-like fibers in many respects. The metal ion-activated peroxide treatment has been noted to act on pulp cellulose and hemi-cellulose, causing oxidation and oxidative degradation of cellulose fibers. The chemical treatment of the pulp, taken alone, is not sufficient to attain the desired modification of the morphology of the fibers, however, subsequent refining or like mechanical treatment of the chemically-treated fibers to achieve a given degree of refinement of the fibers requires dramatically less refining energy to achieve a desired end point of refinement and to impart other desirable properties to the pulp.

Abstract: A method for producing pulp by extracting hemicellulosic materials from lignocellulosic materials using water in an extraction stage, wherein the extraction stage is either a single extraction or a double extraction process; treating the lignocellulosic materials with an oxidizing agent in a treatment stage, wherein the treatment stage is selected from the group consisting of a second extraction process, an agent impregnation process, and a first pretreatment process; treating the lignocellulosic materials with a reducing agent in the treatment stage, wherein the treatment stage is selected from the group consisting of the second extraction process, the agent impregnation process, and a second pretreatment process; and then subjecting the lignocellulosic materials to a modified Kraft pulping process to produce pulp.

Abstract: A process comprising treating a lignocellulosic material preferably pulp in the presence of a transition metal catalyst with a oxidizing agent selected from a group consisting of hydrogen peroxide, hypochlorite, hypochlorous acid and any combination thereof to form a treated lignocellulosic material having a viscosity equal to or less than about 17 cp and having reducing functional groups selected from the group consisting of aldehyde and aldehyde type functional groups at the C6 and C1 positions but predominating at the C1 position.

Abstract: The present invention relates to processes for enhancing a refiner's production rate and/or reducing the specific energy consumption for a freeness target through the use of lubricant(s) or carrier(s)/frictionizer(s), respectively.

Abstract: Lignocellulosic biomass comprising lignin is treated by selective extraction and oxidation of lignin using a solvent solution comprising water in combination with at least one Mn(III) salt to produce readily saccharifiable carbohydrate enriched biomass.

Abstract: Mechanical or Chemical pulp is treated with about 0.01 weight % to about 5 weight % of a Mixture. The Mixture is water; diethylenetriaminepentakis(methyl)phosphonic acid or its known salts; polyacrylic acid or its known salts; and optionally one or more inert compounds. This Mixture acts to either maintain the brightness level of the pulp at the target level or to increase the brightness level of the pulp. In addition the Mixture allows for maintaining the pulp at the target level of brightness even when the amounts of other ingredients, such as hydrogen peroxide, hydrosulfite, sodium silicate and magnesium, that are typically added to the pulp, are reduced.

Abstract: A cellulose fiber having extended biostability and the method of its manufacture are described. While prior treatments of cellulose with biotoxic metal compounds have given improved resistance to decay, these treatments have not been entirely satisfactory where the fiber had to be refined before use. Refining energy was very high and fiber length loss was substantial. Treatment of cellulose fiber with dideyldimethylammonium chloride (DDAC) or bromide (DDAB), these materials in combination with low levels of copper, or low levels of copper alone, has given a product with very good biostability without a major increase in refining energy or loss of fiber length. The treated fiber is particularly advantageous as a reinforcing component for cement board products.

Abstract: A cellulose fiber having extended biostability and the method of its manufacture are described. While prior treatments of cellulose with biotoxic metal compounds have given improved resistance to decay, these treatments have not been entirely satisfactory where the fiber had to be refined before use. Refining energy was very high and fiber length loss was substantial. Treatment of cellulose fiber with dideyldimethylammonium chloride (DDAC) or bromide (DDAB), these materials in combination with low levels of copper, or low levels of copper alone, has given a product with very good biostability without a major increase in refining energy or loss of fiber length. The treated fiber is particularly advantageous as a reinforcing component for cement board products.

Abstract: A cellulose fiber having extended biostability and the method of its manufacture are described. While prior treatments of cellulose with biotoxic metal compounds have given improved resistance to decay, these treatments have not been entirely satisfactory where the fiber had to be refined before use. Refining energy was very high and fiber length loss was substantial. Treatment of cellulose fiber with didecyldimethylammonium chloride (DDAC) or bromide (DDAB), these materials in combination with low levels of copper, or low levels of copper alone, has given a product with very good biostability without a major increase in refining energy or loss of fiber length. The treated fiber is particularly advantageous as a reinforcing component for cement board products.

Abstract: The invention relates to a method for separating hemicelluloses from a biomass containing hemicelluloses. The method includes the steps of: a) extracting the hemicelluloses from the biomass containing hemicelluloses by treating them with a complex compound in an aqueous solution, and forming a soluble hemicellulose complex, and b) separating the complexed hemicelluloses from the biomass. The method is especially suitable for producing high-quality chemical conversion pulp from raw cellulose. The products produced with the method of the invention have a high degree of purity, and the method is extremely economical and causes few emissions. Hemicelluloses in a pure form can be obtained as by-products of the method.

Abstract: This invention relates to a process of treating a lignocellulosic material to produce bio-ethanol. The process includes the steps of: (a) exposing the lignocellulosic material to conditions including a pH not less than about 8, and steam at a first pressure, to produce a step (a) product; (b) explosively discharging the step (a) product to a second pressure less than the first pressure to produce a step (b) product; and (c) further processing the step (b) product to produce bio-ethanol and other co-products. In another embodiment, the invention relates to a conical auger fractionation column. The fractionation column includes a column body having an input and an output. A conical filter is positioned inside the column body, the filter having a larger diameter end directed toward the input and a smaller diameter end directed toward the output.

Abstract: A cellulose fiber having extended biostability and the method of its manufacture are described. While prior treatments of cellulose with biotoxic metal compounds have given improved resistance to decay, these treatments have not been entirely satisfactory where the fiber had to be refined before use. Refining energy was very high and fiber length loss was substantial. Treatment of cellulose fiber with didecyldimethylammonium chloride (DDAC) or bromide (DDAB), these materials in combination with low levels of copper, or low levels of copper alone, has given a product with very good biostability without a major increase in refining energy or loss of fiber length. The treated fiber is particularly advantageous as a reinforcing component for cement board products.

Abstract: This invention relates to an improved process for manufacturing bleached thermomechanical aspen pulp having reduced yellow after treatment with aluminum based chemicals such as alum which are used in paper making processes. In this improved process the pulp is washed prior to, after or between the bleaching stages or a combination of the foregoing.

Abstract: A process for making lyocell fibers including the steps of pulping raw material in a digester to provide an alkaline pulp, wherein the raw material includes sawdust in an amount greater than 0% up to 100%; contacting the alkaline pulp including cellulose and at least about 7% hemicellulose under alkaline conditions with an amount of an oxidant sufficient to reduce the average degree of polymerization of the cellulose to the range of from about 200 to about 1100 without substantially reducing the hemicellulose content or substantially increasing the copper number of the pulp; and forming fibers from the pulp.

Abstract: A fiber cement composite material providing improved rot resistance and durability, the composite material incorporating biocide treated fibrous pulps to resist microorganism attacks. The biocide treated fibers have biocides attached to inner and outer surfaces of individualized fibers to protect the fibers from fungi, bacteria, mold and algae attacks. The biocides selected have strong affinity to cellulose and do not interfere with cement hydration reactions. This invention also discloses the formulation, the method of manufacturing and the final fiber cement products using the biocide treated fibers.

Abstract: A substantially sulfur free process for the manufacturing of a chemical pulp with an integrated recovery system for recovery of pulping chemicals is carried out on in several stages involving physical and chemical treatment of lignocellulosic material in order to increase accessibility of the lignocellulosic material to reactions with an oxygen-based delignification agent. Spent cellulose liquor comprising lignin components and spent chemical reagents is fully or partially oxidized in a gas generator wherein a stream of hot raw gas and a stream of alkaline chemicals and chemical reagents is formed for subsequent recycle and reuse in the pulp manufacturing process.

Abstract: The invention relates to a method for separating hemicelluloses from a biomass containing hemicelluloses. Said method comprises the following steps: a) the hemicelluloses are extracted from the biomass containing hemicelluloses by means of treatment with a complex compound in an aqueous solution, forming a soluble hemicellulose complex, and b) the complexed hemicelluloses are separated from the biomass. The inventive method is especially suitable for producing high-quality chemical conversion pulp from raw cellulose. Not only does the inventive method enable the obtained products to have a high degree of purity, but it is also extremely economical and causes few emissions. The inventive method is also characterised in that polymer hemicelluloses in a pure form can be obtained as by-products.

Abstract: A method in bleaching of pulp is described, in which the pulp is subjected to a peroxide bleaching step, whereupon the pulp is washed and the washing liquid from the washing is separated from the pulp in the form of a filtrate. The method is characterised in that the filtrate is treated with an aluminium compound, such as aluminium sulphate or polyaluminium sulphate, for precipitation of interfering substances, such as oxygen-demanding organic material and metals, that the precipitated material is removed from the filtrate, that the aluminium content of the filtrate after precipitation of interfering substances is adjusted to at most 20 ppm, and that the filtrate is then recirculated to the peroxide bleaching step. By the method, a reduced consumption of hydrogen peroxide in the peroxide bleaching step is achieved.

Abstract: This invention relates to an improved process for manufacturing bleached thermomechanical aspen pulp having reduced yellow after treatment with aluminum based chemicals such as alum which are used in paper making processes. In this improved process the pulp is washed prior to, after or between the bleaching stages or a combination of the foregoing.

Abstract: A method for selectively delignifying lignocellulosic materials and bleaching of pulp and dyes using a combination of an oxidative enzyme and a metal complex. More specifically, the process involves the oxidation of a transition metal redox complex by a phenol oxidizing enzyme such as laccase or peroxidase to mediate the catalytic delignification of chemical pulp and bleaching of textile dye. This process is unique in that only a catalytic amount of metal complex mediator is required on softwood or hardwood kraft pulp, and that recycling or regeneration of the mediator for further pulp delignification is possible. The redox mediator is characterized in that it contains a transition metal ion coordinated with molecules or ions in such a way that the complexes have a formal redox potential between 0.5 and 1.2 volt measured against a normal hydrogen electrode.

Abstract: A cellulose fiber having extended biostability and the method of its manufacture are described. While prior treatments of cellulose with biotoxic metal compounds have given improved resistance to decay, these treatments have not been entirely satisfactory where the fiber had to be refined before use. Refining energy was very high and fiber length loss was substantial. Treatment of cellulose fiber with didecyldimethylammonium chloride (DDAC) or bromide (DDAB), these materials in combination with low levels of copper, or low levels of copper alone, has given a product with very good biostability without a major increase in refining energy or loss of fiber length. The treated fiber is particularly advantageous as a reinforcing component for cement board products.

Abstract: A process for bleaching chemical pulp for paper manufacturing comprising delignifying and bleaching chemical pulp which has been treated by cooking by simultaneous use of chlorine dioxide, a peroxide, and at least one reaction catalyst selected from the group consisting of oxoacids of elements of Groups IV, V and VI and salts of these acids. Formation of organic chlorine compounds as by-products is suppressed by decreasing the amount of chlorine dioxide used in the ECF bleaching process in the first stage, and thus environmental toxicity in the waste water discharged from the bleaching process is decreased. Chemical pulp having a high degree of brightness is economically produced because increase in the production capacity is not required at all or suppressed to the minimum, and the investment cost is reduced to the minimum when the bleaching with chlorine in the first stage is converted into the bleaching with chlorine dioxide which is an ECF bleaching process.

Abstract: Transition metal complex compounds of polydentate ligands with improved delignifying and bleaching performance. These polydentate ligands are organic ligands which, in aqueous solution and in the presence of atmospheric oxygen, or hydrogen peroxide, form a complex with a transition metal, in particular cobalt. The complexes are mono- or polynuclear and they have, when peroxo compounds are used, better delignifying and bleaching performances than conventional transition metal complex compounds. A delignifying and bleaching method, in which these transition metal complex compounds with polydentate ligands having improved delignifying and bleaching performance are used as catalysts, is also described.

Abstract: A method for the preparation of cellulosic pulp capable of being defibrated (fluffed) for the manufacture of an absorbent material intended to be incorporated as a component in absorbent products. A stock of cellulosic fibres in aqueous suspension is pH-adjusted to 4<pH<8, that at least any water-soluble, non-polymeric aluminium salt is added to the stock, said salt in aqueous solutions at said pH forming at least any hydrocomplex with aluminium of the type Al(OH)nx, where n is a number between 1 and 3, and x is o, + or 2+, that said salt in aqueous solution is caused to act on the cellulosic fibres in said suspension at said pH during a period of time of at least 2 min, and that the fibre pulp thereafter is formed to a web, which is dewatered and dried. The invention also relates to the prepared cellulose pulp as such and to its use in absorbent products.

Abstract: The present invention provides a process for producing aromatic compounds or polymers thereof from a plant material in a short period of time and by a simple procedure. Concretely, the process treats the plant material with supercritical water or subcritical water to liberate aromatic compounds, which are contained in the plant material, and/or aromatic compounds, which have been generated upon decomposition of components of the plant material, to the outside of the plant material, and isolates the liberated aromatic compounds to produce aromatic compounds or polymers thereof.

Abstract: A process for bleaching pulp, in which, after fiber liberation, a first filtrate containing metals, principally in ionic form, is separated off from the pulp, and supplied downstream to the pulp flow after a bleaching stage.

Abstract: The invention concerns solutions of alkoxides containing titanium and/or zirconium and/or hafnium and magnesium and/or calcium and/or strontium and/or barium of general formula (I): [MII(OR)2-y(OR1)y]n.[MIV(OR1)4-z(OR)2], in which: MII means magnesium and/or calcium and/or strontium and/or barium; MIV titanium and/or zirconium and/or hafnium; R is an alkyl group with 1 to 18 carbon atoms; R1 is an alkyl group with 1 to 18 carbon atoms, y has a value of between 0 to 2; z has a value of 0 and 4; and n is a number between 0.001 and 3, with the exception that n cannot be 1 when y is 2 and z is 0, or when y is 0 and z is 4. The invention further concerns the production of these alkoxides and their use.

Abstract: High-yield chemimechanical lignocellulosic pulp is produced from non-woody species by cutting and screening the non-woody species, soaking them in an acidic aqueous solution preferably containing a chelating agent, treating the washed non-woody species with an alkaline peroxide solution containing a second chelating agent, and mechanical refining. To further increase the bleaching efficiency the non-woody species are impregnated with ozone or peracetic acid. The resulting pulp has a relatively high brightness while the consumption of peroxide is reduced compared to prior art processes.

Abstract: A process for the delignification of a chemical pulp, such as a sulfate or sulfite pulp, in which process the pulp is treated with a peroxide and/or a peracid in the presence of an activating Ti-, V- or Cr-group transition metal, such as molybdenum, vanadium or tungsten. A compound containing at least one heteroatom, such as Si, P or B, which is capable of forming a heteropolyacid with the activating transition metal, is added to the pulp. The feeding of the activating transition metal and the heteroatom into the pulp may take place in one and the same alkaline solution, for example introduced into the solution or in the form of a compound of the silicomolybdenic acid type, formed in the solution. The peroxide and/or peracid treatment may constitute part of the bleaching sequence, which contains as potential other treatment steps, for example, a treatment with oxygen and a chelation for the removal of heavy metals such as iron, manganese and/or copper.

Abstract: A process for peroxide bleaching of pulp using magnesium oxide as sole alkaline source wherein said pulp is bleached in the presence of hydrogen peroxide for a maximum period of 180 minutes and achievement of a maximum target ISO brightness of 65 in regard to freshly prepared pulp characterized in that said magnesium oxide is utilized as MgO particles having a particle size of 5-500 microns and a particle surface area (PSA) of between 20-60 m.sup.2 /g. By using such parameters, a peroxide bleaching process may be carried out most efficiently on a commercial scale.

Abstract: A process for bleaching chemical pulp for paper manufacturing comprising delignifying and bleaching chemical pulp which has been treated by cooking by simultaneous use of chlorine dioxide, a peroxide, and at least one reaction catalyst selected from the group consisting of oxoacids of elements of Groups IV, V and VI and salts of these acids. Formation of organic chlorine compounds as by-products is suppressed by decreasing the amount of chlorine dioxide used in the ECF bleaching process in the first stage, and thus environmental toxicity in the waste water discharged from the bleaching process is decreased. Chemical pulp having a high degree of brightness is economically produced because increase in the production capacity is not required at all or suppressed to the minimum, and the investment cost is reduced to the minimum when the bleaching with chlorine in the first stage is converted into the bleaching with chlorine dioxide which is an ECF bleaching process.

Abstract: A method that solves the problem of suppressing disturbing effects of transition and alkaline earth metal compounds during bleaching of chemically digested lignocellulosic pulp in a sequence with oxygen bleaching prior to oxidative stages with introduction of for instance ozone, superoxides, hydrogen peroxide and peroxy acids. The conditions during the oxygen bleaching are chosen so that the properties of these metal compounds are changed and the compounds removed from the pulp during the oxygen bleaching under such conditions that the attack on the cellulose is small and the fluctuations of the pulp quality due to fluctuating amounts of these metal compounds decrease markedly.

Abstract: Methods for separating metal ions from pulp material are disclosed including treating the pulp with a chelating agent to produce a pulp flow with dissolved metal ions, washing that pulp flow prior to bleaching with hydrogen peroxide or ozone and mixing the washed liquid containing metal ions with another flow of lignocellulose-containing material in order to bind the metal ions to that flow, washing that flow, and subsequently washing that flow at a reduced pH to produce a wash flow containing metal ions.

Abstract: The invention provides a novel composition for bleaching cellulose based materials, such as wood pulp and paper comprising:(a) an oxidatively stable bleach activator having the structure ##STR1## wherein Y.sub.1, Y.sub.3 and Y.sub.4 each represents a bridging group, i.e., zero, one, two or three carbon containing nodes for substitution, while Y.sub.2 is a bridging group of at least one carbon containing node for substitution, each said node containing a C(R), C(R.sub.1) (R.sub.2), or a C(R).sub.2 unit and each R substituent is the same or different from the remaining R substituents and is selected from the group consisting of H, alkyl, cycloalkyl, cycloalkenyl, alkenyl, aryl, alkynyl, alkylaryl, halogen, alkoxy, phenoxy, CH.sub.2 CF.sub.3, CF.sub.

Abstract: Repulping and/or decolorizing formulations and mixtures which include a catalytic amount of a salt of a metal such as copper, iron, silver, or nickel; a persulfate; and from 0-10% saccharide. Formulations containing a carbonate, sesquicarbonate or bicarbonate for adjusting pH are preferred. A method of repulping and/or decolorizing broke, whether containing wet strength resin or not, using the formulations or mixtures of the ingredients in the formulations.

Abstract: A method for delignifying wood pulp and fiber is disclosed. The method comprises the steps of obtaining a wood pulp and exposing the wood pulp to a polyoxometalate of the formula ?V.sub.1 Mo.sub.m W.sub.n Nb.sub.o Ta.sub.p (TM ).sub.q X.sub.r O.sub.s !.sup.x- where l is 0-18, m is 0-40, n is 0-40, o is 0-10, p is 0-10, q is 0-9, r is 0-6, TM is a d-electron-containing transition metal ion, and X is a heteroatom, which is a p or d block element, where l+m+n+o+p.gtoreq.4, l+m+q>0 and s is sufficiently large that x>0. The exposure is under conditions wherein the polyoxometalate is reduced. In a preferable form of the invention, the method additionally comprises the step of reoxidizing the polyoxometalate.

Abstract: Improved environmentally acceptable process for retaining chelant-containing effluent within pulp bleach plants, particularly total chloride-free bleaching sequence plants using a chelating agent closed re-cycle process. The process involves treating a pulp liquor in an acidic or near neutral stage with an effective chelating amount of a chelating agent to form a soluble, chelated metal species; removing the pulp to provide a chelated metal species-containing solution; treating this solution in an alkaline stage in the presence of sufficient Ca ions with an effective amount of an alkaline liquor to effect displacement of metals from the chelated metal species and precipitation of the metals as solids in alkaline solution; removing the solids from the alkaline solution to provide a metal-free, chelating agent-containing solution; and recycling the metal-free solution to the pulp liquor.

Abstract: A method for delignifying wood pulp and fiber is disclosed. The method comprises the steps of obtaining a wood pulp and exposing the wood pulp to a polyoxometalate of the formula ?V.sub.l Mo.sub.m W.sub.n Nb.sub.o Ta.sub.p (TM).sub.q X.sub.r O.sub.s !.sup.x- where l is 0-18, m is 0-40, n is 0-40, o is 0-10, p is 0-10, q is 0-9, r is 0-6, TM is a d-electron-containing transition metal ion, and X is a heteroatom, which is a p or d block element, where l+m+n+o+p.gtoreq.4, l+m+q>0 and s is sufficiently large that x>0. The exposure is under conditions wherein the polyoxometalate is reduced. In a preferable form of the invention, the method additionally comprises the step of reoxidizing the polyoxometalate.

Abstract: A method for delignifying wood pulp and fiber is disclosed. The method comprises the steps of obtaining a wood pulp and exposing the wood pulp to a polyoxometalate of the formula ?V.sub.l Mo.sub.m W.sub.n Nb.sub.o Ta.sub.p (TM).sub.q X.sub.r O.sub.s !.sup.x- where l is 0-18, m is 0-40, n is 0-40, o is 0-10, p is 0-10, q is 0-9, r is 0-6, TM is a d-electron-containing transition metal ion, and X is a heteroatom, which is a p or d block element, where l+m+n+o+p.gtoreq.4, l+m+q>0 and s is sufficiently large that x>0. The exposure is under conditions wherein the polyoxometalate is reduced. In a preferable form of the invention, the method additionally comprises the step of reoxidizing the polyoxometalate.

Abstract: A process for hydrolysis of water-insoluble esters in the presence of a lipase, at a pH in the range of 3-7 particularly to such a process for hydrolysis of resin in pulp.

Abstract: A method for delignifying wood pulp and fiber is disclosed. The method comprises the steps of obtaining a wood pulp and exposing the wood pulp to a polyoxometalate of the formula [V.sub.l Mo.sub.m W.sub.n Nb.sub.o Ta.sub.p (TM).sub.q X.sub.r O.sub.s ].sup.x- where l is 0-18, m is . 0-40, n is 0-40, o is 0-10, p is 0-10, q is 0-9, r is 0-6, TM is a d-electron-containing transition metal ion, and X is a heteroatom, which is a p or d block element, where l+m+n+o+p.gtoreq.4, l+m+q>0 and s is sufficiently large that x>0. The exposure is under conditions wherein the polyoxometalate is reduced. In a preferable form of the invention, the method additionally comprises the step of reoxidizing the polyoxometalate.

Abstract: A method for oxidative degradation of lignin and polysaccharide fragments dissolved during polyoxometalate delignification or bleaching of wood pulp, wood fiber or pulp obtained from a non-woody plant. The method comprises the steps of obtaining a spent polyoxometalate bleaching solution containing a polyoxometalate of the formula [V.sub.l Mo.sub.m W.sub.n Nb.sub.o Ta.sub.p (TM).sub.q X.sub.r O.sub.s ].sup.x- where 1 is 0-18, m is 0-40, n is 0-40, o is 0-10, p is 0-10, q is 0-9, r is 0-6, TM is a d-electron-containing transition metal ion, and X is a heteroatom which is p or d block element, provided that l+m+n+o+p.gtoreq.4, l+m+q>0 and s is sufficiently large that x>0, and heating the solution in the presence of an oxidant under conditions wherein the dissolved organic compounds are oxidatively degraded to volatile organic compounds and water.

Abstract: The present invention relates to the addition of photosensitising compounds to woodpulps and mixtures thereof for enhancing their whiteness, brightness and chromaticity, as well as to the paper making fibres so obtained and the use thereof.

Abstract: A process for bleaching pulp, in which, after fiber liberation, a first filtrate containing metals, principally in ionic form, is separated off from the pulp, and supplied downstream to the pulp flow after a bleaching stage.