An example of a preferred mixture is a 65-70% aqueous solution of MMDMH, DMDMH, and 5,5-dimethylhydantoin (DMH) available under the tradename Dantogard® 2000 from Lonza, Inc of Fair Lawn, N.J. Bleaching With Hydrogen Peroxide Hydrogen peroxide is attractive as a bleaching agent for secondary fibers. The amount of the aldehyde donor added to the solution is typically sufficient to maintain a peroxide stabilizing effective concentration (i.e. A biocidal concentration of one or more biocides may also be added to or maintained in the solution. A two-stage process has an advantage in providing a cleaner pulp. is hereby incorporated by reference in its entirety. 150 and 300 ppm of an aqueous solution containing 55% by weight of glutaraldehyde were added to the remaining two beakers for a total concentration of 83 ppm and 166 ppm of glutaraldehyde, respectively. The Big Industries of Bleaching. According to a preferred embodiment, the concentration of aldehyde donor maintained in the slurry is less than a microbicidally effective amount. The organic matter is typically comprised of wood fiber (or pulp) and adjuvants, such as sizing and starch. Pulp Paper Mill All rights reserved. So, to get better benefit from hydrogen peroxide bleach, it is requires a careful control of alkali application to the pulp. U.S. Pat. where R is any functional group. Many mills use hydrogen peroxide as reinforcement in the extraction stage after chlorination, with or without additional oxygen reinforcement and in the second extraction stage. The effectiveness of a bleaching agent, although a … U.S. Pat. Now, most of the bleaching plant operates at 10 to 15% consistency whereas some are operate at 40 to 50% consistency. the concentration of hydrogen peroxide) using a thiosulfate titration kit (HACH Test Kit, Model HYP-1, available from Hach Company of Loveland, Colo.). A concentration of 500 ppm decreased the hydrogen peroxide decomposition rate to 48% of that of the untreated control. Don't forget to subscribe. BACKGROUND: The process of chemical pulp bleaching is based for the most part in chlorine dioxide within elemental chlorine free (ECF) technologies. A preferred blend includes benzisothiazolinone and at least one of MMDMH and DMDMH. Do you know for the fact that the industrial hydrogen peroxide is even utilized in the bleaching of paper as well? When it is used, it can be saved a great amount of ClO2 chemical in the subsequent stage. Direct inhibition of catalase by DMDMH solutions was demonstrated by monitoring catalase promoted hydrogen peroxide decomposition in a pH 9.2 borate buffer. It requires the retention time 45 minutes to 5 hours and 40 to 6o⁰C temperature. The mineral slurry may also contain an organic dispersing agent. The concentration of hydrogen peroxide added to or maintained in the solution is typically a bleaching effective concentration in the solution. The concentration of aldehyde donor in such an aqueous mixture typically ranges from about 5 to about 95% by weight and preferably from about 20 to about 75% by weight, based upon 100% weight of total mixture. Sorry if I had to re upload. A method of stabilizing hydrogen peroxide in an aqueous solution, such as a circulating water slurry, comprising a peroxide, such as hydrogen peroxide. 1.1. Generally, a mineral slurry comprises of from about 50 to about 80% by weight of mineral matter, such as, but not limited to, calcium carbonate or clay. It is also economical. The use of greener alternatives such as bleaching with hydrogen peroxide (P stage) is not widely used owing to selectivity concerns related to transition metal‐catalyzed decomposition reactions. 526 ppm of Dantogard® 2000 decreased the hydrogen peroxide decomposition rate to 32% of that of the untreated control. The biocidal efficacy of Dantogard® at 250 and 500 ppm (i.e. According to another embodiment, a blend of one or more aldehyde donors and a benzisothiazolinone is added to the solution (or slurry). Discusses the abstract of the research paper "Physicochemical Studies of Bleaching of Cellulosic Textile Materials With Hydrogen Peroxide. 5,728,263 describes the use of dialdehydes and acetals thereof, such as glutaraldehyde, to inhibit the decomposition of peroxide in the treatment of recycled and other fiber pulps. Moreover, in the presence of heavy metal ions the stability of peroxide is badly affected. It has both oxidizing and reducing properties which is pH depended. The method comprises adding hydrogen peroxide and an aldehyde donor to the slurry. Generally, the organic matter comprises from about 90 to about 99% by weight of wood fiber (or pulp), based upon 100% total weight of organic matter. 50 ml of an undiluted white water sample of Example 4 was treated with Dantogard® at concentrations of 250 and 500 ppm (100 and 200 ppm DMDMH). White water is generally separated liquid that is re-circulated to a preceding stage of a papermaking process, especially to the first disintegration stage, where paper, water and chemicals are mixed. The pulp slurry may also contain other adjuvants known in the art. Hydrogen peroxide stability is enhanced by the addition of glutaraldehyde. All such obvious variations are within the patented scope of the appended claims. The aldehyde donor significantly reduces the decomposition rate of hydrogen peroxide by catalase and other peroxide decomposing enzymes. The aldehyde donor may be added directly to the solution (e.g. The recycled feed stock had been subject to deinking and peroxide bleaching in the tissue and towel mill. The temperature was 23° C. The results are shown Table 7. 4,908,456 teaches the use of methylolated hydantoin, especially 1,3-dimethylol-5,5-dimethylhydantoin (DMDMH) as an antimicrobial agent. Application Focus: Bleaching In the paper manufacturing process, wood pulp leaving the digester wash unit often must be bleached to attain the desired level of paper whiteness. The peroxide decomposition rate was monitored during the decrease in peroxide concentration from 390 to 350 ppm by ultraviolet absorbance at 240 nm. 45 Issue 8, p42 . According to a preferred embodiment, the wood fiber is at least partially derived from recycled paper. 60/210,252, filed Jun. A. Hydrogen Peroxide Formula: H2O2 (HOOH/HOO-). Hydrogen peroxide is a very versatile liquid and can be used as a first-aid antiseptic, bleaching agent, hair dye, toothpaste, mouthwash, laundry stain remover, and bathroom cleaner. & Terms of Use. In tests on newsprint they have found that magnesium bicarbonate, used alone or in conjunction with hydrogen peroxide, greatly reduce darkening of paper when it is exposed to light. According to one embodiment, the aldehyde donor causes a log reduction in microorganism population of less than 0.5 or 1. As a result, peroxide stability is limited and bleaching effectiveness is reduced. The brightness of the paper that is made from hydrogen peroxide bleach is more stable. I accidentally delete this video. TEXTILE BLEACHING PROCESS WITH HYDROGEN PEROXIDE The bleaching bath is composed of hydrogen peroxide (50% by wt.) Laboratory bleaching studies were carried out on kraft pulp to investigate the influence of two bleaching oxidizers and of operating variables, namely temperature and charge of oxidizers, on pulp properties. High consistency is great for maximum brightness, retention time and lower chemical dosage, but it can create maintenance problems and the equipment costs are higher. It has many advantages for us to use hydrogen peroxide (H2O2) bleaching agent for the pulp: Strong adaptability for high yield pulp, chemical pulp, waste paper pulp and other pulps; Good whiteness stability of the pulp after hydrogen peroxide (H 2 O 2) bleaching, just light yellowing; DMDMH hydrogen peroxide stabilization was demonstrated in a sample of white water obtained from a paperboard mill using recycled paper (50% mix, 15% corrugated, 15% news, and 20% other) as follows. Some of the methods employed to stabilize hydrogen peroxide include biocide treatments (e.g. Most aerobic bacteria synthesize peroxide-degrading enzymes (e.g. Low free formaldehyde compositions reduce workplace exposure risk to formaldehyde. The method comprises adding hydrogen peroxide and an aldehyde donor to the slurry. The immense use of Hydrogen Peroxide inspires us to become the leading Hydrogen Peroxide Suppliers. Effect of temperature For example, a mixture of hydrogen peroxide and peracetic acid may be added to the solution (or slurry) or peroxide bleaching solution. This ion is originated by the ionization process. The term “log reduction in the microorganism population” refers to the difference between the logarithm (base 10) of the microorganism count of an untreated substrate after a given contact time, such as 3 hours or less, and the logarithm of the microorganism count of an identical substrate treated with an aldehyde donor after the same contact time. Other suitable biocides include, but are not limited to, thiocarbamates, such as sodium dimethyl dithiocarbamate; glutaraldehyde; dibromo nitrile propionamide (DBNPA); bromnitropropanediol; tetrakis (hydroxymethyl) phosphonium sulfate; bromonitrostyrene (BNS); benzisothiazolones; methylene bis(thiocyanate); 2-mercaptobenzothiazole (MBT); isothiazolines, including 5-chloro-2-methl-4-isothiazolin-3-one (CMI), 2-methyl-4-isothiazolin-3-one (MI), octyl-4-isothiazolin-3-one, and mixtures thereof; bistrichloromethylsulfone (BTCMS); quaterary ammonium compounds, such as alkyldimethylbenzyl ammonium chlorides and dialkydimethyl ammonium chlorides; 2-bromo-4-hydroxyacetophenone (BHAP); and 5-oxo-3,4-dichloro-1,2-dithiol; and any combination of any of the foregoing. Maximum brightness is obtained at pH 10.5 or higher. 50 ml of the undiluted white water sample of Example 2 was treated with 250 and 500 ppm Dantogard®. Determination of original color, surface, or character of paper; it may be impossible to return an object uniformly to selected “original color”, resulting in the balance of color being thrown of… It should be stored in a cool, dry, well-ventilated area and away from any flammable substances. According to one embodiment, a blend of one or more aldehyde donors, CMI, and MI is added to the solution (or slurry). The test water temperature was 37° C. and the pH was ˜7.0. As a result, less hydrogen peroxide needs to be added to a solution to effectively bleach organic matter in the solution. Notify me of follow-up comments by email. The consumption rate of peroxide is also maximum at this pH because of OH– ion. Ours bleaching plant is two stages and medium consistency system. Pulp Paper Mill provides information on pulp mill and paper mill chemical and paper machine. The test temperature was 32° C. and the pH was 7.6. God Bless! The present invention provides a method of stabilizing a peroxide, such as hydrogen peroxide, in an aqueous solution comprising the peroxide. The chemical formula of this bleach is H2O2. It controls the metal levels. Microorganism count reductions of only 0.06 and 0.23 log were observed for Dantogard® concentrations of 250 and 500 ppm, respectively. Direct inhibition of catalase by DMDMH solutions was demonstrated by monitoring catalase promoted hydrogen peroxide decomposition in sterile media. This application claims the benefit of U.S. patent Hydrogen peroxide bleaching is a single-stage or two-stage process. 1.1. The following examples are intended to describe the present invention without limitation. Peroxide bleaching introduces in the year 1907, but commercial development took place at 1941. The microorganism count values were then converted to their corresponding log value. slurry or slurry dilution water) or bleaching solution as a solid or liquid. 263 ppm of Dantogard® 2000 decreased the hydrogen peroxide decomposition rate to 62% of that of the untreated control. At moderate temperatures hydrogen peroxide bleach improving the brightness of pulps without significant yield loss. a compound which can identify aldehyde groups. As the front reaction produce H+, so high pH will increase the HOO– ion. Additionally, take a glance at the industries where Hydrogen Peroxide is utilized. Other bleaching chemicals have specific uses and requirements, but peroxide can be used for delignification or brightening and it doesn't require any special equipment. 2,269,191 describes the use of an organic peracid that has a disinfectant effect on catalase producing microorganisms at neutral or acidic pH. The aqueous solution can be (i) a circulating water slurry comprising organic matter or (ii) a slurry dilution water. generation, Inhibition of hydrogen peroxide decomposing enzymes during bleaching of cellulose fibers, Method for inhibiting enzymatic decomposition of peroxide in the treating of fiber pulp using dialdehydes and acetals, Hydantoin-enhanced halogen efficacy in pulp and paper applications, Low free formaldehyde methylolhydantoin compositions, Process for preparing methylolated hydantoins, Enzyme inhibitors, uses and compositions containing same, <- Previous Patent (Plasma etching syste...). Some bleaching plant design the system as the first tower is at medium consistency whereas the second tower at high consistency. The results, shown in Table 1, correlate to the amount of peroxide present at the specific time interval, expressed as ppm of hydrogen peroxide. Examples of aldehyde identifying reagents include, but are not limited to, Benedicts solution, Tollens reagent, and acetyl acetone. Examples of methylolhydantoins include, but are not limited to, 1-hydroxymethyl-5,5-dimethylhydantoin (a MMDMH), 3-hydroxymethyl-5,5-dimethylhydantoin (a MMDMH), and 1,3-bis(hydroxymethyl)-5,5-dimethylhydantoin (DMDMH) mixtures (which are available as aqueous solutions under the tradenames Dantogard® and Glydant® from Lonza Inc. of Fair Lawn, N.J.). In the pulp and paper industry, hydrogen peroxide is used in three areas: for delignification and bleaching of cellulose, pulp bleaching (pulp of high yield), and for re-cycling waste paper (de-inking). Typical pulp slurries in paper applications contain from about 0.2 to about 18% by weight of organic matter, based upon 100% total weight of slurry. Hope you enjoy. Generally, the pH of the solution ranges from about 7 to about 13 and preferably from about 8 to about 11. The temperature was 23° C. The results are shown Table 6. Preparation: Reagent grade hydrogen peroxide is preferred; commercial hydrogen peroxide is acidic and usually too strong for use as a conservation bleach; it must be diluted and alkali added to increase the pH and obtain the concentration of HOO- which is This ion little effect on cellulose, but selectively reacts with the organic coloring matter. The peroxide decomposition rate was monitored during the decrease in peroxide concentration from 390 to 350 ppm by ultraviolet absorbance at 240 nm. The aldehyde donor may be added before, simultaneously with, or after the hydrogen peroxide is added to the aqueous solution, or alternatively to the peroxide bleaching solution itself. Glutaraldehyde, however, has a poor safety profile and high concentrations of it are required to inhibit peroxide decomposition. Alibaba.com offers optimal quality, commercial use hydrogen peroxide bleaching paper in powdered and granulated forms. Examples of such adjuvants include, but are not limited to, slimicides; sodium hydroxide (or other caustic); peroxide stabilizers, such as sodium silicate, magnesium sulfate, and polyphosphates; chelating agents, such as EDTA; fatty acids; and combinations thereof. The solutions were tested at 37° C. and a pH of 7.8. The concentration of hydrogen peroxide maintained in the solution preferably ranges from about 1 to about 50,000 ppm, more preferably ranges from about 10 to about 10,000 ppm, and most preferably ranges from about 100 to about 1,000 ppm. they generally provide less than a 2 log reduction in the microorganism population in short contact time applications (e.g. The excellent mixing, high temperature 2,269,191 ,which is hereby incorporated by reference. Great Britian Patent Publication No. Both of them were bleached by a totally chlorine-free sequence performed in three stages, using 5% hydrogen peroxide in the two initial, and a 0.25N NaOH solution in the last one. One was retained as a control. It is usually added with magnesium sulfate. Effect of pH 150 and 300 ppm of an aqueous solution containing 40% by weight of 1,3-bis(hydroxymethyl)-5,5-dimethylhydantoin (DMDMH) (Dantogard®) were added to two beakers for a total concentration of 60 ppm and 120 ppm of DMDMH, respectively. Paper - Almost 60% of Hydrogen Peroxide is used in paper-bleaching or pulp-bleaching. Dantogard® 2000 is a 65% aqueous mixture of DMDMH, MMDMH and DMH having a minimal free formaldehyde concentration. The aqueous solution may include organic matter. Into three separate beakers were placed 100 ml of a white water sample obtained from a tissue and towel mill using recycled newsprint as a pulp feed stock. The term “aldehyde donor” as used herein is defined as any material which is not an aldehyde but upon aqueous dilution liberates a compound which gives positive reactions with aldehyde identifying reagents, i.e. The test water temperature was 32° C., and the pH was 7.6. Into three separate Pyrex® beakers, 100 ml of the diluted white water was added. Another embodiment is a method of bleaching recycled papers in a circulating water slurry comprising organic matter. Many variations of the present matter will suggest themselves to those skilled in the art in light of the above detailed description. It is appropriate for chemical, mechanical and recycled pulp to achieve a wide range of brightness. A method of bleaching recycled papers in a circulating water slurry comprising organic matter, wherein the organic matter is at least partially derived from the recycled papers, the method comprising: (a) adding hydrogen peroxide to the slurry and (b) adding a methylolhydantoin to the slurry in an amount effective to stabilize the hydrogen peroxide during the bleaching of the recycled papers. The consistency of the pulp has noticeable effects on the reaction rate during hydrogen peroxide bleaching. application Ser. The microorganism count values were then converted to their corresponding log value. In order improvement the efficiency of hydrogen peroxide bleaching sodium silicate and magnesium sulfate are added during preparation of the peroxide bleach. When the conservator at the National Gallery (Washington, DC) determine that a work on paper requires bleaching agent, they use hydrogen peroxide diluted with magnesium bicarbonate as the bleaching agent. Pure hydrogen peroxide is very light blue color but colorless in solution. No. water from processing recycled paper). One beaker was retained as a control. On an equivalent aldehyde basis, this corresponds to 0.65 mEq/l and 1.30 mEq/l, respectively. • At medium consistency (9-12%) depending upon other process parameters molar ratio of caustic soda to hydrogen peroxide is 1:1. H2O2 + OH– → HOO– + H2O. In another embodiment, the pH of the solution ranges from about 4 to about 13, preferably from about 7 to about 12, and more preferably from about 8 to about 11. The solution may be, for example, a pulp slurry, a papermaking slurry, a mineral slurry or white water. Peroxide is catalytically decomposed in the presence of metal ions such as iron, copper, lead and manganese. It reduces the consumption of the bleach and steam requirement. In a mill white water environment, temperatures and the availability of nutrients encourage bacterial growth. This bleaching agent can be used in extraction stage of the bleaching sequence. THE USE OF DIALDEHYDES AND ACETALS THEREOF FOR INHIBITING DECOMPOSITION OF PEROXIDE IN THE PRODUCTION AND THE TREATMENT OF RECYCLED FIBER PULP AND OTHER FIBER PULP. On a ppm product basis, the DMDMH surpassed the performance of the glutaraldehyde. Preferred organic dispersing agents include, but are not limited to, polyacrylates. When considered on a molar aldehyde basis, it is demonstrated that DMDMH surpasses the performance of glutaraldehyde when added at a concentration 73% lower in aldehyde equivalents. Other preferred aldehyde donors include, but are not limited to, low free formaldehyde compositions of dimethyloldimethylhydantoin, such as those described in U.S. Pat. 250 and 500 ppm of an aqueous solution containing 40% by weight of DMDMH, available as Dantogard® from Lonza Inc., (i.e. The production and consumption of Hydrogen Peroxide are highest in Asia due to the increased usage of hydrogen peroxide as a bleaching agent in the pulp & paper industry. 30 ppm of hydrogen peroxide was added to the samples. Yet another embodiment is a method of inhibiting catalase and/or other peroxide decomposing enzymes in an aqueous solution, such as a circulating water slurry, comprising adding an aldehyde donor to the aqueous solution. • In high consistency (20-30%) bleaching, best results are obtained at sodium hydroxide to hydrogen peroxide molar ratio of 0.25. One of the problems that occur when H 2 O 2 is used is that it is decomposed to H 2 O by certain enzymes that exist in the paper pulp. Lower consistency is mostly carried out as a batch wise in a beater, pulper or circulating tank. The present invention is a method of stabilizing hydrogen peroxide in an aqueous solution, such as a circulating water slurry, comprising a peroxide, such as hydrogen peroxide. 250 and 500 ppm of Dantogard® were added to the other two beakers, respectively. U.S. Pat. After that the development comes in rapidly. & Terms of Use. The primary product of wood pulp is paper, for which whiteness (similar to, but distinct from brightness) is an important characteristic. NORPAC has taken this bleaching process one step further through their patented refiner bleaching technology, which provides an enhanced and more efficient peroxide bleaching process. Another embodiment is a method of bleaching recycled papers in a circulating water slurry comprising organic matter.
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