Abstract: A composition comprising an enzyme exhibiting laccase activity and an enzyme enhancing agent, also referred to as a mediator, is disclosed. A process for oxidizing a substrate that comprises treating the substrate with a composition comprising an enzyme exhibiting laccase activity and an enzyme enhancing agent is disclosed. The process when used on lignin-containing material bleaches the lignin-containing material. A process for enhancing the activity of an enzyme exhibiting laccase activity that comprises adding an enzyme enhancing agent to the enzyme is also disclosed.

Abstract: A method to enhance brightness in Chemical and Mechanical pulps comprising adding an organic sulfide chelant is described and claimed.

Abstract: A method of bleaching cellulose pulp with ozone includes pumping cellulose pulp in form of a fiber suspension having a consistency range of 5 to 25% with a high-consistency pump to a fluidizing mixture in which oxygen and ozone containing gas is introduced and mixed into the pulp so as to generate a foam whereby the pulp fibers and the ozone used as the bleaching agent are brought to contact with each other, bleached, and the pulp is discharged from the mixer to a reaction vessel.

Abstract: A process of oxidizing a substrate is disclosed. The process comprising the step of treating the substrate with an oxidizing enzyme, a mediator that enhances the oxidative activity of the enzyme, and a chain transfer agent. In one example, the substrate is a lignin-containing material and the process results in bleaching of the lignin-containing material. Examples of some useful enzymes are laccase, catechol oxidase, monophenol monooxygenase, and bilirubin oxidase. A composition comprising an oxidative enzyme, a mediator that enhances the oxidative activity of the enzyme, and a chain transfer agent is also disclosed.

Abstract: Composite panels and pulp, and paper products of the pulp, are produced from Arundo donax. In the fabrication of the composite panels, Arundo donax is comminuted to a suitable size, combined with a binder, and consolidated into panels that meet standards for construction and/or furniture grade panels. The Arundo donax particulates may be combined with wood particulates to produce a mixed furnish that can be used in the preparation of composite panels. Comminuted Arundo donax is treated, in conventional pulping processes, to produce a high tensile strength pulp that can be used in the production of paper. The pulp has a lighter color than wood pulp, and thereby uses less bleaching chemicals to achieve a desired whiteness. The pulp can be combined with wood pulp to produce a variety of products.

Abstract: The subject process comprises providing chemical pulp and an Eop and/or Ep aqueous bleaching solution. The Eop aqueous bleaching solution comprises a peroxide compound, an oxygen-containing material, sodium hydroxide and magnesium hydroxide, in the absence of magnesium sulfate. Alternatively, the Eop aqueous chemical solution for bleaching chemical pulp comprises an Eop aqueous bleaching solution consisting essentially of a peroxide compound, an oxygen-containing material, sodium hydroxide and magnesium hydroxide. In any case, the chemical pulp is bleached with the Eop aqueous bleaching solution to form a bleached chemical pulp. The Ep aqueous bleaching solution comprises a peroxide compound, sodium hydroxide and magnesium hydroxide, in the absence of magnesium sulfate. Alternatively, the Ep aqueous bleaching solution consists essentially of a peroxide compound, sodium hydroxide and magnesium hydroxide.

Abstract: Chemical pulp is produced by cooking comminuted cellulosic fibrous material (e.g. wood chips) in a continuous digester or batch digesters or produce brown stock, and washing the brown stock in a brown stock washer to produce chemical pulp, oxygen delignifying the chemical pulp at medium consistency, and then screening the oxygen delignified pulp to produce an accept fraction and a shive-containing reject fraction. Drawbacks inherent in the prior art are overcome by directly transporting (i.e. without refining or accessory oxygen delignification) the shive-containing rejects fraction to the main fiber line before oxygen delignification (e.g. to just before a mixer for the oxygen delignification stage, to between the brown stock washer and mixer, to a coarse screen between the digester and the brown stock washer, and/or to a washer for the coarse rejects from the coarse screen).

Abstract: Separation of dissolved and colloidal high molecular weight organic by-products from liquors or filtrates in a cellulosic pulping process to improve the overall efficiency of the process.

Abstract: Provided is a process for bleaching pulp with ozone. The process involves preparing a slurry of cellulosic pulp having a consistency in fibers of from 1-5 weight %. Such a low consistency slurry is then mixed with ozone under high shear conditions. The ozone is then maintained in contact with the cellulosic fibers to effect bleaching of the fibers. The present process offers the advantages of bleaching using a low consistency slurry, with the added advantages of employing ozone.

Abstract: The present invention is directed to a process for making a lyocell fiber by contacting an alkaline pulp having 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 of the pulp or increasing the copper number and then forming fibers from the pulp.

Abstract: Lignocellulose pulp is bleached by bleaching a pulp in aqueous alkali solution with oxygen and treating the pulp with a hemicellulase, while a liquid fraction delivered from the enzyme treatment step is separated from the hemicellulase treated reaction mixture, and subjected to a penetration treatment through a separation membrane, for example, reverse osmosis membrane, to separate a permeated fraction from a non-permeated fraction; the permeated fraction is fed to the alkali-oxygen bleaching (oxygen delignification) step and is used as a liquid medium of the bleaching system.

Abstract: Processes are disclosed for bleaching pulp with ozone in an environmentally friendly bleaching plant. The processes include removing a first filtrate from the pulp, bleaching the treated pulp with ozone, washing the bleached pulp with a washing liquid to provide a washed bleached pulp and a second filtrate including oxalic acid, recycling the second filtrate to the pulp prior to the bleaching step, and transferring the first filtrate to the bleached pulp.

Abstract: Methods for oxygen delignification of a pulp are disclosed, including initially delignifying the pulp at a delignification temperature of less than 90° C., adding oxygen to the pulp so that the oxygen is present during the initial delignification step, and further delignifying the pulp at a delignification temperature of greater than 90° C., the difference between the two delignification temperatures being less than about 20° C., and the pressure being greater in the initial delignification step. The method also includes adding alkali solely to the initial delignification step in order to obtain high alkalinity therein.

Abstract: A method of manufacturing high purity fiber cement grades of cellulose fibers is described. Additional washing steps, coupled with an elevated temperature, are used in the process to extensively wash the pulps and remove substantially all COD components remaining in the pulps. The pulps are counter-currently washed by diffusion and dewatering at elevated temperatures following the brown stock washer systems. During the additional washing steps, the pulps are soaked in counter-current heated water for a pre-determined time and some chemicals may be introduced to chemically break down the COD components in the pulps and to make them more soluble in the aqueous solution. The additional washing steps can be performed using existing equipment at conventional pulp mills. A formulation and a process of making fiber reinforced cement composite materials are also described using the low COD and high purity cellulose fibers.

Abstract: The invention relates to a system and a process for the oxygen delignification of pulp consisting of a lignocellulose-containing material that has a mean concentration of 8-18% pulp consistency. The oxygen delignification takes place in a first stage with a short dwell time of about 3-6 minutes, at a low temperature of about 85° C. and under a low pressure of approximately 0-4 bar. A concluding stage has a longer dwell time of about 50-90 minutes, at a higher temperature of approximately 100° C. and under a higher pressure of about 8-10 bar.

Abstract: Process for increasing the water retaining ability of fibrous paper stocks. The process includes knead dispersing a fibrous paper stock having a stock concentration of at least about 20% and a temperature greater than about 45° C. A treatment for the knead dispersing is at least about 10 seconds. The process further includes completing a post-treatment phase to a machine tub of a paper machine in a reaction time of no longer than about 30 minutes.

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 multi-function process is described for the separation of cellulose fibers from the other constituents of lignocellulosic biomass such as found in trees, grasses, agricultural waste, and waste paper with application in the preparation of feedstocks for use in the manufacture of paper, plastics, ethanol, and other chemicals. This process minimizes waste disposal problems since it uses only steam, water, and oxygen at elevated temperature in the range of 180° C. to 240° C. for 1 to 10 minutes plus a small amount of chemical reagents to maintain pH in the range 8 to 13. An energy recuperation function is important to the economic viability of the process.

Abstract: The present invention relates to a process for the removal of lignin from lignocellulose containing material comprising treating the lignocellulose containing material prior to a high-yield pulping process with a delignifying gas comprising gaseous compounds comprising at least one oxygen atom such as chlorine dioxide containing gas.

Abstract: The present invention relates to a method of and apparatus for treating pulp. More precisely, the present invention relates to a method and apparatus for treating pulp with oxygen. Especially preferably the method and apparatus according to the invention relate to oxygen delignification of chemical pulp, i.e. so-called oxygen bleaching.

Abstract: Provided is a process for bleaching pulp with ozone. The process involves preparing a slurry of cellulosic pulp having a consistency in fibers of from 1 up to 5 weight %. Such a low consistency slurry is then mixed with high partial pressure ozone under high shear conditions. The ozone is then maintained in contact with the cellulosic fibers to effect bleaching of the fibers. The present process offers the advantages of bleaching using a low consistency slurry, with the added advantages of employing ozone.

Abstract: The present invention relates to a method of treating chemical pulp in order to optimize the consumption of bleaching chemicals and to improve the quality of the pulp. Especially the invention relates to a method according to which filtrate obtained from a suitable stage of the washing of brown stock preferably cooked by an alkaline cooking method is treated with an oxidizing chemical prior to the oxygen stage following the brown stock washing.

Abstract: The present invention is directed to a process for making a lyocell fiber by contacting an alkaline pulp having 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 of the pulp or increasing the copper number and then forming fibers from the pulp.

Abstract: A process for delignification and bleaching of chemically digested lignocellulose-containing pulp. In a first embodiment, the pulp is acid treated at a pH of between about 1 and about 6, whereupon a water-soluble compound containing an alkaline earth metal is added at a pH of between about 1 and about 7 before the pulp is treated with a chlorine-free bleaching agent. In a second embodiment, the acid and alkaline earth metal treatments are carried out in a single step. The chlorine-free bleaching agent includes peroxide compounds, ozone, oxygen and sodium dithionite in an optional sequence or mixture. After the treatment according to the invention, the pulp may be finally bleached to the desired brightness, suitably with a chlorine-free bleaching agent, such as ozone, to completely avoid formation and discharge of AOX.

Abstract: Improvements in the catalytic processing of organic compounds for fuels and for other uses, and ways in order to better utilize the heat from the above processing and also from other sources.

Abstract: A system and a process for the oxygen delignification of pulp consisting of lignocellulose-containing material whose mean concentration is 8-18% pulp consistency, in at least two stages. The invention is characterized in that the oxygen delignification takes place in a first stage with a short dwell time of approx. 3-6 minutes, at a low temperature of approx. 85° C. and under a low pressure of approx. 0-4 bar, followed by a concluding stage with a longer dwell time of approx. 50-90 minutes, at a higher temperature of approx. 100° C. and under a higher pressure of approx. 8-10 bar. This makes it possible, in an industrial process, to exploit the kinetics of the oxygen delignification in an optimal manner for the purpose of obtaining a selective oxygen delignification at low installation cost and at low operating cost.

Abstract: The present invention provides methods for reducing fluorescence in a paper-containing sample. Methods for destroying fluorescent whitening agents in a paper-containing sample are also provided.

Abstract: Process for the production of cellulose paper pulps from vegetable masses, comprising the steps of mixing and conditioning a vegetative mass suitable to form a culture medium with an inoculum constituted of edible ligninolythic mushrooms, such as Lentinus edodes, Pleurotis Peryngii, Psajor-caju, and the like; extracting the so-obtained enzyme and adding it to the vegetative material for the production of paper pulp, mainly constituted of cultivated annual plants such as kenaf, hemp, flax, cotton and various stems and/or agricultural-industrial residues, such as cereal straws, maize stalks, and the like; conditioning and causing the mass to react; and lastly washing the mass after the biological attack, obtaining in this way a cellulose pulp to be submitted to possible mild final cooking and bleaching treatment. Apparatus for the realiztion of the process, and cellulose pulps obtained by biodelignification of cultivated annual plants and/or agricultural-industrial residues.

Abstract: In a method and apparatus for treating pulp, a peroxide treatment of chemical pulp, i.e., both sulphite pulp and kraft pulp, is used to quickly reduce the Kappa number of the pulp. The method involves treating a chemical pulp with at least hydrogen peroxide or its equivalent, the kappa number of which chemical pulp has been brought to a level below 20 by either at least cooking or cooking and delignifying. The pulp is treated in a fast alkaline or neutral peroxide stage (Pk) (e.g. a small reactor having a volume of, or proportional to, less than about 90 cubic meters for 1500 tons per day pulp treatment) to reduce the kappa number by 1-10 units, and preferably by 3-7 kappa units, in which treatment the reaction time is less than 10 minutes, and is preferably less than 5 minutes. The pulp is then transferred substantially without intermediate washing of any type to a bleaching tower, and then bleached further in an acidic bleaching step (e.g. a D or Z step) in the bleaching tower.

Abstract: A method and apparatus for bleaching medium consistency pulp with ozone using at least 2 fluidizing mixers to mix ozone and carrier gas into the pulp. The method is particularly applicable when the volume of the bleaching gas is larger than the volume used in conventional ozone bleaching, e.g. 2 m3/adt.

Abstract: An aqueous alkaline slurry of cellulose pulp is bleached with oxygen or peroxide by using a compound represented by general formula (1), (2) or (3) as a bleaching assistant: R1—O—[(C2H4O)m/(AO)n]—H  (1) R2—O—[(C2H4O)m/(AO)p]—(AO)q—H  (2) (R3)t—X—[(C2H4O)m/(AO)p]—(AO)r—H  (3) where R1 stands for a branched alkyl group having 6 to 12 carbon atoms, m stands for an average added mol number of 4 to 15, A stands for a propylene, butylene or phenylethylene group, n stands for an average added mol number of 0 to 4, the addition shown in [ ] is in a random or block form, R2 stands for a linear or branched alkyl group having 6 to 12 carbon atoms, p stands for an average added mol number of 0 to 3.9, q stands for an average added mol number of 0.

Abstract: A pulp bleaching line has an initial stage using gaseous bleaching reagent followed by its subsequent stages without intervening washing or pumping steps. The pulp is transported from the initial stage through a mixer in which the pulp is heated and/or dosed with bleaching chemicals and through the subsequent stage by retained gas pressure developed in the initial stage. A portion of the retained gas may be separated and purged from the mixer through a pressure regulating device to optimize pressure for processes which follow the mixer/heater. This permits elimination of a washer and pump normally provided between the initial reactor and subsequent bleaching stage.

Abstract: The present invention relates to a process for producing pulp which is cooked under alkaline conditions and which is bleached without using chlorine-containing bleaching chemicals, in which process used cooking chemicals are recovered in a first recovery installation and used bleaching chemicals are recovered in a second recovery installation. The used cooking and bleaching chemicals can be regenerated and reused.

Abstract: Methods for oxygen delignification of a pulp are disclosed, including initially delignifying the pulp at a delignification temperature of less than 90° C., adding oxygen to the pulp so that the oxygen is present during the initial delignification step, and further delignifying the pulp at a delignification temperature of greater than 90° C., the difference between the two delignification temperatures being less than about 20° C., and the pressure being greater in the initial delignification step. The method also includes adding alkali solely to the initial delignification step in order to obtain high alkalinity therein.

Abstract: Methods for oxygen delignification of chemical pulps are disclosed including contacting the chemical pulp with oxygen first in an upstream reactor vessel and then in a downstream reactor vessel. The upstream reactor vessel is maintained at pressures of greater than about 3 bar, and the downstream reactor vessel is maintained at temperatures of between about 90 and 120° C. and corresponding predetermined pressures. Heating of the partially delignified chemical pulp between the upstream and downstream reactors is accomplished by contacting the partially delignified chemical pulp with low pressure steam.

Abstract: A single stage method delignification process for pulps, preferably sulphite pulps. The improvement to conventional oxygen delignification process comprises in situ addition of a reducing agent substantially non-reactive with oxygen. The end result is a pulp having enhanced strength properties and higher viscosity. Sodium borohydride is the preferred reducing agent, and MgO is the preferred alkali source. Similar results can be obtained with a two-stage oxygen delignification wherein the pulp is treated with the reducing agent in the first stage, and then washed and pressed conventionnally before proceeding with the oxygen delignification in a second stage.

Abstract: Provided is a method of treating chemical paper pulp having the steps of: adjusting the pH of the pulp to be between 1 and 6; treating the pulp with ozone to reduce the kappa number of the pulp; treating the pulp with a chelating agent after the ozone treating step without any intervening washing step between the ozone treating step and the chelating agent treating step; adjusting the pH of the pulp by adding alkali together with or after the addition of chelating agent to a pH exceeding 3; washing the pulp; and bleaching the pulp with peroxide.

Abstract: Methods for oxygen delignification of a pulp are disclosed, including initially delignifying the pulp at a delignification temperature of less than 90° C., adding oxygen to the pulp so that the oxygen is present during the initial delignification step, and further delignifying the pulp at a delignification temperature of greater than 90° C., the difference between the two delignification temperatures being less than about 20° C., and the pressure being greater in the initial delignification step. The method also includes adding alkali solely to the initial delignification step in order to obtain high alkalinity therein.

Abstract: A method for conditioning an ozone gas recycle stream in an ozone pulp bleaching process. The method includes the steps of providing an oxygen containing feed gas to an ozone generator; generating ozone from said feed gas to produce an ozone rich oxygen gas; bleaching pulp with said ozone rich gas, thereby producing an exhaust gas containing contaminants including carbon dioxide and entrained pulp fibers; removing at least some of said contaminants by at least removing entrained pulp fibers from the exhaust gas to produce a recycle gas; directing said recycle gas into the ozone generator to provide at least a portion of said oxygen containing feed gas; and removing carbon dioxide during said contaminant removal step in an amount sufficient to a level of about 6 wt. wt. % to thus allow operation of the ozone generator at or approaching full capacity.

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: Methods for oxygen delignification of a pulp are disclosed, including initially delignifying the pulp at a delignification temperature of less than 90° C., adding oxygen to the pulp so that the oxygen is present during the initial delignification step, and further delignifying the pulp at a delignification temperature of greater than 90° C., the difference between the two delignification temperatures being less than about 20° C., and the pressure being greater in the initial delignification step. The method also includes adding alkali solely to the initial delignification step in order to obtain high alkalinity therein.

Abstract: In the treatment of cellulose pulp in connection with bleaching, the pulp is first cooked and, if necessary, oxygen delignified in order to reduce the Kappa number below 24, preferably below 14, and after that the pulp is treated in an acid stage at a pH of 2-5 and at a temperature range of 75-130° C. in order to reduce the Kappa number by 2-9 units. To prevent essential weakening of the strength properties of the pulp in the acid stage treatment tower, the retention time, t min, is 30 to 300 minutes and the treatment temperature, T° C. is Tmin<T<Tmax, in which T min = 10517 24 + ln ⁡ ( 2 ⁢ t ) - 273 and Tmax=Tmin+23° C.

Abstract: A process for producing a pulp suitable for papermaking from a nonwood fiber source material. Representative nonwood fiber source materials include corn stover and wheat straw. The process includes the steps of providing a nonwood fiber source material; digesting the nonwood fiber source material with an alkaline pulping solution at at least about atmospheric pressure; reducing the pH of the nonwood fiber source material to an acidic pH with an acid solution; treating the nonwood fiber source material having an acidic pH with ozone; and treating the nonwood fiber source material with a bleaching solution to form a papermaking pulp.

Abstract: The present invention provides methods for reducing fluorescence in a paper-containing sample. Methods for destroying fluorescent whitening agents in a paper-containing sample are also provided.

Abstract: In the treatment of cellulose pulp in connection with bleaching, the pulp is first cooked and, if necessary, oxygen delignified in order to reduce the Kappa number below 24, preferably below 14, and after that the pulp is treated in an acid stage at a pH of 2-5 and at a temperature range of 75-130° C. in order to reduce the Kappa number by 2-9 units. To prevent essential weakening of the strength properties of the pulp in the acid stage treatment tower, the retention time, t min, is 30 to 300 minutes and the treatment temperature, T° C.

Abstract: Multi-component system for modifying, degrading or bleaching lignin, lignin-containing materials or similar substances, includes

Abstract: An aqueous alkaline slurry of cellulose pulp is bleached with oxygen or peroxide by using a compound represented by general formula (1), (2) or (3) as a bleaching assistant:

Abstract: A process for the bleaching of chemical pulp, in which process the pulp is delignified with a peracid and additionally the pulp is chelated in order to bind heavy metals, such as Fe, Mn and/or Cu, into a chelate complex. According to the invention, the chelating is carried out using a chemical which has been selected from a group consisting of N-bis-((1,2-dicarboxy-ethoxy)-ethyl)-amine, N-bis-((1,2-dicarboxy-ethoxy)-ethyl)-aspartic acid and N-tris-((1,2-dicarboxy-ethoxy)-ethyl)-amine, as well as the alkali metal and earth-alkali metal salts thereof, and the peracid and chelating treatments are carried out simultaneously by combining the peracid and the said chelating chemical in the same solution phase. In the bleaching sequence the treatment according to the invention may follow, for example, an ozone delignification and precede an alkaline peroxide step, and in the latter case a magnesium compound, such as MgSO4, may be added to the pulp before the alkali step.

Abstract: The present invention concerns a method for producing a base paper for fine papers, the base paper being produced from a mixture of a mechanical pulp and a chemical pulp. The chemical pulp used comprises a chemical softwood pulp having a elastic modulus close to that of the mechanical pulp and a great bonding strength. It is preferred to use a chemical softwood pulp which produces a sheet having a elastic modulus of less than 6000 N/mm2 when the bonding strength is 400 J/m2. A pulp of this kind has a good ScottBond strength at the same light scattering. The base paper produced by the method can therefore be used in double-coated fine papers which require a large bonding strength of the base paper.

Abstract: A method for the manufacture of bleached cellulose pulp, in conjunction with which lignocellulose material is digested to form cellulose pulp by means of an alkaline digestion liquor, and the cellulose pulp in the form of a suspension is screened, if necessary, and subjected in series to at least oxygen gas delignification/bleaching (O), if required, chlorine dioxide bleaching (D) and bleaching with non chlorine-containing, oxidative bleaching agent (O, P, Z), with the various bleaching stages interspersed with washing and/or reconcentration of the cellulose pulp in at least one stage, characterized in that complexing agents are added to the cellulose pulp in conjunction with the chlorine dioxide bleaching. It is also important for the mol quotient of the cellulose pulp for magnesium/manganese, during bleaching with a non chlorine-containing, oxidative bleaching agent, to be maintained at or brought to a value exceeding 20, and preferably exceeding 40.