EP0250422A1 - Procede de preparation de pate a papier blanchie de matieres lignocellulosiques. - Google Patents

Procede de preparation de pate a papier blanchie de matieres lignocellulosiques.

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Publication number
EP0250422A1
EP0250422A1 EP86901881A EP86901881A EP0250422A1 EP 0250422 A1 EP0250422 A1 EP 0250422A1 EP 86901881 A EP86901881 A EP 86901881A EP 86901881 A EP86901881 A EP 86901881A EP 0250422 A1 EP0250422 A1 EP 0250422A1
Authority
EP
European Patent Office
Prior art keywords
stage
pulp
acid
raw material
peroxide
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP86901881A
Other languages
German (de)
English (en)
Other versions
EP0250422B1 (fr
Inventor
Lauri Aukusti Laamanen
Jorma Juhani Sundquist
Ilkka Yrjo Paavo Wartiovaara
Seppo Veli-Matti Kauliomaki
Kristiina Johanna Poppius
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
OY KESKUSLABORATORIO - CENTRALLABORATORIUM AB
Original Assignee
KESKUSLABORATORIO - CENTRALLABORATORIUM Oy AB
KESKUSLABORATORIO
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from FI851156A external-priority patent/FI851156A0/fi
Application filed by KESKUSLABORATORIO - CENTRALLABORATORIUM Oy AB, KESKUSLABORATORIO filed Critical KESKUSLABORATORIO - CENTRALLABORATORIUM Oy AB
Priority to AT86901881T priority Critical patent/ATE53613T1/de
Publication of EP0250422A1 publication Critical patent/EP0250422A1/fr
Application granted granted Critical
Publication of EP0250422B1 publication Critical patent/EP0250422B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/10—Bleaching ; Apparatus therefor
    • D21C9/16—Bleaching ; Apparatus therefor with per compounds
    • D21C9/163—Bleaching ; Apparatus therefor with per compounds with peroxides
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C3/00—Pulping cellulose-containing materials
    • D21C3/003—Pulping cellulose-containing materials with organic compounds

Definitions

  • the present invention relates to a process for preparing bleached pulp out of lignocellulosic raw material in accordance with the preamble of claim 1.
  • the raw-material is first treated with a pulping liquor containg oxidizing components, whereupon the pulp is bleached.
  • Non-polluting pulping has been aimed at by using closed processes. Furthermore, there have been efforts to find chemicals, the use of which is accompanied with a diminishe adverse environmental influence, when compared with conven ⁇ tional pulping chemicals, and which would allow the process to be closed even better .
  • the closing of the process in the first stage of convention pulping, i.e. during cooking, has to rather a high degree already been achieved for the present pulping processes. This is true especially for the chemical circulation of the main process, i.e. the kraft process. In this context, the formation of malodorous sulphur-containing volatile compoun which exhibit an adverse environmental influence is, however still a problem.
  • the closing of the process of the second stage of pulping, i.e. bleaching is difficult.
  • the present bleaching processe are mainly based on the use of chlorine and compounds there ⁇ of, but 100 % recirculation of bleaching waste-liqours containing chlorine compounds in the process has proved to be very difficult mainly due to corrosion problems. The various detrimental chlorine compounds formed during bleaching are therefore to rather a large extent emitted to the environment.
  • Pulping which causes a minimun of environmental pollution is best reached when the chemicals used therein contain carbon, hydrogen, and oxygen only. Many of the new methods tested do not, however, fulfil this requirement; they may contain e.g..nitrogen which is an unpredictable element when it comes to the environmental influence thereof. It may even prove to be very troublesome.
  • the first stage of pulping i.e. cooking-, using chemicals containing carbon, hydrogen, and oxygen only, has mainly been investigated in the connection with so-called organo- solv pulping methods.
  • Said methods are based on the use of organic solvents. These usually contain some compound which is called catalyst, which enhances the degradation of lignin and the conversion thereof into a dissolving form.
  • the drawback of said organosolv-methods lies in their rela- tively low delignification capacity and the difficulty of pulping softwood.
  • the catalysts oftentimes con ⁇ tains undesired elements, such as chlorine or sulphur, which make the non-polluting character of the method questionable when larger amounts of catalysts are employed.
  • the dissolving of ligni in certain organosolv-solvents may be significantly increased when a lignin-oxidizing chemical, e.g. hydrogen peroxide, is used instead of said catalyst.
  • a lignin-oxidizing chemical e.g. hydrogen peroxide
  • hydrogen peroxide is added to a liquid carboxylic acid, such as acetic or formic acid
  • lignin is oxidized to dissolve in carboxylic acid.
  • Hydrogen peroxide forms together with carboxylic acids peroxyacids, which in an acid system have a strong influence on lignin but much less influence on the other components of wood.
  • a selective delignification is thus achieved by means of which the wood fibres may be separated from each other, i.e. pulp is obtained.
  • Chlorine-free bleaching methods are known per se. Thus, during the recent years, great expectations have been focused on ozon bleaching ' employing as its main bleaching' chemical an ozon containing gas dissolved in a suitable medium. Hydrogen peroxide has been used in the bleaching of cotton, linen and wool based textiles for long. It has also to some extent been used in the bleaching of mechanical pulp and for the bleaching of pulp from sulphite and sulphate proces ⁇ ses. In last mentioned applications, it has not been used to any larger extent, since it is not possible to obtain as high a brightness or viscosity as in multistage chlorine bleaching. Said methods are exemplified by the solution mentioned in the FI Patent Specification No. 68685.
  • Said publication discloses a bleaching process in two stages for bleaching of sulphite pulp, in the first stage of which hydrogen peroxide (0,2 - 3,0 % by weight) and peracid pre ⁇ pared out of an organic carboxylic acid (0,1 - 5,0 % by weight) is employed, and in the second stage of which an alkaline peroxide treatment is conducted by adding aqueous alkali to the liquor obtained from the first stage.
  • One object of the present invention is to offset the draw ⁇ backs related to the known pulping and bleaching processes and to provide an entirely novel process for preparing pulp directly out of lignocellulosic raw material essentially in two stages.
  • the invention is based upon using in a first stage a pulping liquor containing peroxyacids derived from carboxylic acids and subsequently treating the defibrated pulp thus obtained with an alkaline solution of peroxyacids in a second stage.
  • the liquor employed in the first stage containing peroxyacids is preferably provided by the addition of hydrogen peroxide to an organic carboxylic acid, e.g. formic, acetic, propionic, or butyric acid.
  • an organic carboxylic acid e.g. formic, acetic, propionic, or butyric acid.
  • the process according to the invention forms, in spite of the provision of two stages, an integrated delignification system; the stages of which function synergetically.
  • an integrated delignification system the stages of which function synergetically.
  • the brightness of the pulp in accordance with the invention is about twice as high as that of the unbleached kraft pulp after treatment with an alkaline peroxide solution.
  • the apparatus required by the process is simple.
  • the acid stage as well as the alkaline one may be conducted at normal pressure, since there is no need for raising the reaction temperatures above the boiling point of the mixture.
  • the low temperatures result in huge savings in energy consumption.
  • the present delignification process in two stages may be used for delignification of all kinds of lignocellulosic materials. It is particulary well suited for chips of hardwood and softwood commonly employed in pulping. De ⁇ lignification of hardwood proceeds somewhat better than that of spruce and pine chips. Annual plants, grass, straw and bagasse may also be used as raw materials.
  • the first stage of the process i.e. the peroxyacid stage, is preferably conducted by using a mixture of some " liquid carboxylic acid and hydrogen peroxide.
  • the carboxylic acids are oxidized to peroxyacids which form the active agents of the cooking liquor.
  • the peroxyacid reacts with lignin, and the oxidization products formed from this reaction dissolve in the solution of carboxylic acids.
  • the various carboxylic acid have a different capability of forming peroxyacids, i.e. their oxidative capacity di fers. In principle, no carboxylic acid may be excluded from the process .
  • Alifatic as well as aromatic acids are suitable. In practice, formic and acetic acids are particulary preferred, of which the first mentio ⁇ ned acid more easily forms peroxyacid, and it is therefore in this sense preferred.
  • the pulp obtained when using formic acid in the first stage is darker than that obtained by using acetic acid, on the other hand, the viscosity of the pulp is lower when the last-mentioned acid has been employed.
  • propionic and butyric acids may also be used.
  • the formation of peroxyacids may be enhanced by using some known catalysts, e.g. sulphuric, phosphoric or boric acids, but this is neither necessary nor always even preferable. It has been discovered that, e.g., sulphuric acid may degrad the carbohydrates during the cooking, which leads to a decreased viscosity of the pulp.
  • the concentration of the carboxylic acid employed is in the range of 40...100 %, preferably in the range of 70...100 %, the liquid-to-wood ratio being from 2:1 up to 10:1.
  • the ratio 8:1 normally used in pulping may be used, it is, however, preferable to use a smaller liquid- ratio, e.g. 4:1, because said ratio makes it possible to decrease the required amount of hydrogen peroxide and enhance the progress of the delignification reaction. Pulp yield and brightness of the pulp are also improved by a smaller liquid-to-wood ratio.
  • an azeotropic formic acid-water solution containing 80 % of formic acid, but on the.other hand, when it comes to de- lignification, it is preferable to use an acid containing as small an amount of water as possible.
  • the peroxyacids may be formed in the solution in some other known manner, e.g. by reacting the corresponding aldehydes with molecular oxygen or an oxygen- ozone mixture.
  • the carboxylic acids needed for the dissolution of the reaction products are formed as decomposition products of the peroxyacids.
  • the peroxyacids may also be formed in the cooking liquor prior to the addition of the cellulosic raw material.
  • the peroxide used may comprise, e.g., an industrially prepared hydrogen peroxide solution, the concentration of which is 50 %.
  • concentration of the peroxide may, how ⁇ ever, be higher or lower, i.e. from about 30 % up to 90 % by weight.
  • the amount used varies within a large range dependin on the extent to which the delignification is to be conducte during the acid stage. It is preferable to achieve a de- fibration of the chips before the second stage.
  • the amount of peroxide used in the examples has been varied from 5 % up to 60 % based on the oven dry (o.d.) weight of the chips, but said values are no absolute limits.
  • Water present in the carboxylic acid, in the peroxide as well as in the chips is introduced into the cooking liquor.
  • the water content of the acid influences especially the dissolution of the oxidized lignin. Thus, it should be kept as low as possible.
  • the acid peroxy-treatment may be conducted at any tempera ⁇ ture between ambient temperature and the boiling point of the system used.
  • high temperatures are not suitable due to the fact that the peroxyacids are decomposed when the temperature is raised, whereby the delignification capacity of the cooking liquor is lost.
  • the oxidizing capacity of a pure formic acid/peroxide mixture disappears altogether within an hour when the temperature is 80°C.
  • the oxidizing capacity of the mixture of acetic acid and peroxide is conserved rather a long time even at 95 °C , but this is due to the fact that the rate of peroxyacid formation is slower for acetic acid than for formic acid.
  • the cooking temperature to be selected depends on the acid used. For formic acid the temperature is preferably in the range of about 70°- 90°C, and for acetic acid somewhat higher. For propionic and butyric acids still higher temperatures may be used.
  • the cooking liquor is heated for some time at a higher tempera- ture, e.g. at about 90°C, whereupon the actual cooking is conducted at a lower temperature of, e.g., from 70°C up to 75°C.
  • Cooking time may also vary within a large range depending on the temperature. At ambient temperature the treatment lasts for several days, whereas it may be- as short as half an hour near to the boiling point of water. Too long a treatment time at high temperature lowers the viscosity of the pulp.
  • the acid used and the temperature of the cooking the cooking time is from 2 hours up to 10 hours, preferably from 4 hours up to 6 hours.
  • the impregnation may be conducted at ambient temperature. It has been discovered that a delignifying pretreatment of the chips decreases considerably the amount of hydrogen peroxide needed in the peroxyacid treatment stage, thus reducing the actual cooking time. This is true especially for birch raw material.
  • the pretreatment may be conducted at ambient temperature or preferably at increased temperature by means of some chemi ⁇ cal, e.g. an alkali solution or preferably formic acid as taught by the SU Patent Specification No. 821614.
  • the acid treatment is carried out, e.g., at the boiling point of the acid, whereat prolonging of the pretreatment time lowers the kappa number.
  • pretreatment acid spent liquor of the peroxyacid cooking may be used.
  • the alkali solution used may be the same as in the second phase of the process.
  • a preferred embodiment of the first stage of the invention when using softwood chips comprises pulping the chips first in peroxyformic acid, thereafter in formic acid and sub ⁇ sequently again in peroxyformic acid. Delignified pulp (kappa number on the order of 10) is easily obtained by said procedure.
  • Peroxyacetic acid pulping may also be conducted in a similar manner.
  • the defibrated pulp is preferably washed with water such that the pulp obtained is at least approximately neutral.
  • the acid of the spent liquor obtained from this phase may be re-used after recovery.
  • the acid is separated from the solid substance, e.g., by means of distillation.
  • Formic acid and water form an azeotropic mixture which boils already at 107°C. This azeo- tropic mixture contains about 80 % of formic acid and may be re-used as such.
  • the second phase of the present pulping process may. be conducted by using a water-soluble alkali and hydrogen peroxide.
  • the amount of the alkali depends on the amount consumed during the treat ⁇ ment.
  • the pH value of the treatment liquor shall initially exceed 10, the required amount being dependent upon the amount required for reaching said pH level. It has been ascertained that acceptable results are reached already at pH values slightly in excess of 10. Higher pH values may of course also be employed, but when it comes to the bleach ⁇ ing result or the economy of the chemicals, it is not sen ⁇ sible to increase the alkalinity to a high level. It has further been ascertained that the amounts of alkali and hydrogen peroxide are somewhat interdependent. The more hydrogen peroxide is used, the more alkali is needed. During the treatment the pH of the liquor decreases to some extent, usually about one pH unit.
  • the alkaline peroxide phase may also be accomplished such that the calculated amount of peroxide is used in several portions, e.g. in 3 to 6 portions.
  • the bleaching liquor is removed from the pulp after each phase.
  • the pulp is preferably washed between the phases of treatment, but if the bleaching is conducted as a so-called displacement bleaching this is not necessary.
  • a multiphase bleaching has been discovered to have a preferable influence on the brightness of the pulp. The viscosity of the pulp remains high at the same time.
  • the alkali used may be selected from the group consisting of alkali metal and earth alkali metal hydroxides, carbonates and bicarbonates. Alkali metal hydroxides and carbonates are preferred, particulary preferred are sodium hydroxide and sodium carbonate.
  • The- alkali may also comprise mixtures of said compounds. It is preferable to use sodium hydroxide because by means of it minor amounts already result in the required pH value.
  • Sodium carbonate on the other hand is suitable in the sense that it may be obtained by calcination of the spent liquor from the alkali phase. Because the pulp treated in the second phase is almost neutral, no carbondi- oxide is evolved from the carbonate, which might make the treatment more difficult.
  • the temperature of the treatment may vary, but e.g. the common temperature, 80°C, used in peroxide bleaching of conventional pulps may also be used in this context.
  • the duration of the treatment varies according to the temperature, but at 80°C the suitable time is about 1 hour.
  • a peroxide residue after this stage in the order of 0.2 % of the pulp should be aimed at.
  • the required amount of peroxide depends on the kappa number, i.e. the lignin content, of the pulp coming to said stage. Generally, the amount is from 1 % up to 20 %. It has been discovered empirically that the added amount of hydrogen calculated as per cent of the dry weigh of the matter coming to the treatment amounts to about 0.20 to 0.80, preferably 0.25 to 0.70, most preferably 0.45 to 0.65 times the kappa number of the pulp from the first phase.
  • the second phase may be accomplished in a different manner also.
  • the alkali and the hydrogen peroxide required may be substituted by a peroxide derivative.
  • a peroxide derivative e.g. a metal peroxide, preferably sodium peroxide, which dissolved in water forms hydroxide and hydrogen peroxide.
  • one or a few peroxide stabilizers may be added.
  • citric acid may be used, whereas e.g. diethy- lene triaminepenta acetic acid (DTPA) or/and one magnesium salt, e.g. Mg sulfate, may be used during the alkaline peroxide stage.
  • DTPA diethy- lene triaminepenta acetic acid
  • Mg sulfate e.g. Mg sulfate
  • the amount of the stabilizer is preferably on the order- of a few promilles .
  • the invention will now be examined in more detail by means of the following non-limitative practical examples .
  • the brightness values indicated in the examples have been deter- mined according to the SCAN C-ll method and the viscosity values correspondingly according to the SCAN C-15 method.
  • the kappa numbers have been measured by the SCAN C-l:77 method. All of the indicated per cent amounts have been calculated per weight.
  • the initial pH value was 10.3, and it decreased to a value of 9.4 during the treat ⁇ ment.
  • the stabilizing agent comprised 0.2 % of DTPA. After the treatment, the pulp was washed and acid was added, whereupon the pulp was dried.
  • the final brightness of the pulp was 89.0 %, the viscosity 830 cm ⁇ /g, and the pulp yield in per cent of the raw material 44.4 %'.
  • Unbleached spruce kraft pulp the kappa number of which was 31,9, was bleached at 10 per cent stock at 80°C for 30 minu ⁇ tes.
  • the brightness of the pulp thus obtained was 46.5 % and the viscosity 750 cm ⁇ /g.
  • birch chips dry matter 90 %) were used instead of pine.
  • the cooking was carried out departing from the foregoing such that the temperature was raised to 70°C during 5 hours, whereinafter the temperature was raised to 80°C within one hour and the cooking was finished.
  • the shives amounted to 3.1 %, and the kappa number of the pulp was 5.3.
  • the alkaline hydrogen peroxide treatment was con- ducted at 80 C, the duration being one hour.
  • the pH of the solution was 10.4. Analysis of the pulp: brightness 89.0 %, viscosity 1050 cm g.
  • spruce chips dry matter 93 %) was used instead of pine.
  • the temperature of the cooking was raised to 80°C within 2.5 hours, and left at said temperature for 2.5 hours.
  • Shives 11.4 % and the kappa number of the pulp 14.0.
  • the pH of the solution was 10.8 %.
  • Analysis of the pulp brightness 84.3 %, viscosity 920 cm ⁇ /g and pulp yield 43.1 % (calculated on the wood)..
  • the pine chips was pretreated before the peroxide cooking for one hour at 90°C with 80 % formic acid.
  • the cooking was carried out by raising the temperature with ⁇ in 3 hours to 75°C, whereupon the cooking was finished. There were no shives.
  • the kappa number was 7.3.
  • the alkaline hydrogen peroxide treatment was conducted at 80°C, the dura- tion being two hours at 10 % stock.
  • the pH of the solution was 10.1.
  • Analysis of the pulp brightness 86.0 %, viscosity 900 cm3/g and the pulp yield (calculated on wood) 43.9 %.
  • the birch chips were pretreated prior to the peroxide cooking for one hour at 100°C with an alkali solution containing 6 % o.d. wood NaOH.
  • the cooking was car ⁇ ried out using the peroxide application rate 20 % per o.d. wood.
  • the temperature was raised within 4 hours 20 minutes to 75°C, the cooking being maintained at 75°C to 80°C for 2 hours.
  • the amount of shives was 12.6 %, and the kappa number was 14.5.
  • the alkaline peroxide treatment was con- ducted at 10 per cent stock during 1 hour.
  • the pH of the solution was 10.8. Analysis of the pulp gave: brightness 86-.5 %, viscosi ⁇ ty 1000 cm 3 /g and ' the pulp yield 43.2 % (calculated on the wood) .
  • the pulp obtained was bleached " with an alkaline solution of hydrogen peroxide such that the calculated amount of hydroge peroxide, 30.8 % of the pulp (16.3 % o.d. wood, i.e. 0.60 x the kappa number), was added in three portions .
  • the tempera- ture during all stages was 80°C, the reaction time 1 hour, and the initial pH value 10.5.
  • the stabilizer added compri ⁇ sed 0..2 % DTPA.
  • the brightness of the pulp was 90.3.
  • the total consumption of hydrogen peroxide was in this example 10 + 16.3 %, i.e. 26.3 % of the o.d. chips.
  • the amount of peroxide used was only 5 % of the chips, i.e. 5 ml of 50 % hydrogen peroxide was added.
  • the kappa number of the pulp was 62.2 %, the viscosity 1070 cm-Vg, the screened yield was 45.8 % and the amount of shive 19.7.
  • the pulp obtained was bleached as described in example 8, the calculated amount of hydrogen peroxide, 28 % of the pulp (12.8 % o.d. wood, i.e. 0.45 x the kappa number), was also ' this time added in three portions .
  • the brightness of the pulp was 87.0 %.
  • the total consumption of hydrogen peroxide in this example was 5 + 12.8 %, i.e. 17.8 % of the o.d. chips.
  • the birch chips were pretreated before the peroxyacid cooking by boiling them for 3 hours in 80 % for ⁇ mic acid under reflux conditions.
  • the cooking liquor was re ⁇ moved, the peroxyformic acid cooking being subsequently ⁇ ar- ried out employing 85 % formic acid to which 5 % hydrogen peroxide, of o.d. wood only had been added.
  • the temperature was raised in 50 minutes to 80°C and maintained at said temperature for 1 hour. After the cooking the pulp was was ⁇ hed to neutrality with the required amount of hot water.
  • the kappa number of the pulp was at this stage 14.7 and the viscosity 1180 cm 3 /g and the yield 42.3 % .
  • the pulp obtained was bleached with an alkaline solution of hydrogen peroxide such that the calculated amount of hydro ⁇ gen peroxide, 8 % of the pulp (3.4 % o.d. wood, i.e. 0.55 x the kappa number), was added in four portions: the duration of the first two stages was 1 hour, the duration of the two last ones was 2 hours. The temperature during all stages was 80°C, and the initial pH value 10.7.
  • the stabilizer added comprised 0.2 % DTPA and 0.5 % (calculated on o.d. wood) Mg sulfate.
  • the brightness of the pulp obtained was 90.1 %, an the viscosity 1140 cm 3 /g.
  • the spent liquor was filtered off and the somewhat softened chips were refluxed for 3 hours in 250 ml of 100 % formic acid.
  • the cooking liquor was removed and the chips were defibred in formic acid.
  • an other peroxyacid cooking was conducted, comprising as- cooking liquor 200 ml of 100 % formic acid, to which 5 % of hydrogen peroxide had been added.
  • the mixture was heated for 3 hours 30 minutes, the maximum temperature being 75°C.
  • the pulp was first washed with formic acid and thereafter with water.
  • the kappa number of the pulp was 9.0, the viscosity 980, the brightness 35.1 and the screened yield 41.4 %.
  • the amount-of shieves was only 0.2 %. •
  • the pulp obtained was bleached with an alkaline hydrogen peroxide solution such that the calculated amount of hydro- gen peroxide, 6 % of the pulp (2.5 % o.d. wood), was added in three portions .
  • the duration of the first stage was 1 hour, of the second one 2 hours, and of the third one 3 hours.
  • the temperature was 80°C.
  • the stabilizers were analogous to those employed in example 11.
  • the brightness of the pulp obtained was 90.5, and the viscosity 940.
  • the total consumption of hydrogen peroxide was in this example 10 + 2.5 %, i.e. 12.5 % of the o.d. chips.

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  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Paper (AREA)

Abstract

Des matières premières lignocellulosiques sont réduites en pulpe avec une solution de cuisson contenant des peroxyacides organiques tels que l'acide peroxyformique ou l'acide peroxyacétique. La pulpe défibrée est blanchie avec une solution alcaline contenant du peroxyde d'hydrogène dont le pH est égal à au moins 10 au début du traitement et qui est obtenue en ajoutant à une solution d'hydroxyde de sodium une quantité de peroxyde d'hydrogène comprise entre 0,20 et 0,80 pour cent du poids à sec de la matière à traiter, de préférence entre 0,25 et 0,70 pour cent, ou, ce qui est encore préféreable, entre 0,45 et 0,65 fois le numéro kappa de la pulpe obtenue à l'issue de l'étape précédente du procédé.
EP86901881A 1985-03-22 1986-03-24 Procede de preparation de pate a papier blanchie de matieres lignocellulosiques Expired - Lifetime EP0250422B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT86901881T ATE53613T1 (de) 1985-03-22 1986-03-24 Verfahren zur herstellung gebleichter pulpe aus lignocelluloserohstoff.

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
FI851156 1985-03-22
FI851156A FI851156A0 (fi) 1985-03-22 1985-03-22 Foerfarande foer framstaellning av blekt cellulosamassa av ligninhaltigt raomaterial.
FI860609 1986-02-11
FI860609A FI74750C (fi) 1985-03-22 1986-02-11 Foerfarande foer framstaellning av blekt cellulosamassa utav ligninhaltigt raomaterial.

Publications (2)

Publication Number Publication Date
EP0250422A1 true EP0250422A1 (fr) 1988-01-07
EP0250422B1 EP0250422B1 (fr) 1990-06-13

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP86901881A Expired - Lifetime EP0250422B1 (fr) 1985-03-22 1986-03-24 Procede de preparation de pate a papier blanchie de matieres lignocellulosiques

Country Status (6)

Country Link
EP (1) EP0250422B1 (fr)
JP (1) JPH0737720B2 (fr)
AU (1) AU5589286A (fr)
DE (1) DE3671924D1 (fr)
FI (1) FI74750C (fr)
WO (1) WO1986005529A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996035013A1 (fr) * 1995-05-03 1996-11-07 Sven Siegle Procede de production de pulpe d'un materiau cellulosique, pulpe obtenue et son utilisation
US6156156A (en) * 1996-11-06 2000-12-05 Chempolis Oy Method of producing pulp using single-stage cooking with formic acid and washing with performic acid

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FI80191C (fi) * 1988-03-30 1990-05-10 Valio Meijerien Foerfarande och konserveringsmedel foer ensilering av foder.
GB2304126A (en) * 1995-08-10 1997-03-12 Warwick Int Group Pulp treatment process
FI103588B1 (fi) * 1996-01-19 1999-07-30 Esa Rousu Consulting Oy Menetelmä tekokuitujen ja muiden kuitujen raaka-aineen valmistamiseksi ruohovartisista kasveista
FI116390B (fi) 1998-05-05 2005-11-15 Chempolis Oy Menetelmä massan valmistamiseksi
CN100430552C (zh) * 2003-05-29 2008-11-05 中国科学院成都有机化学研究所 一种造纸制浆用蒸煮催化剂
JP5938979B2 (ja) * 2012-03-23 2016-06-22 日本製紙株式会社 植物系原料の処理方法
RU2590882C1 (ru) * 2015-04-27 2016-07-10 Федеральное Государственное Бюджетное Учреждение Науки Институт Химии И Химической Технологии Сибирского Отделения Российской Академии Наук (Иххт Со Ран) Способ получения целлюлозы
DE102016219719B3 (de) * 2016-10-11 2018-01-25 Clariant International Ltd. Verfahren zur Gewinnung von Cellulose, Hemicellulose und Lignin aus Lignocellulose aus pflanzlicher Biomasse
CN112778539A (zh) * 2021-01-04 2021-05-11 中国林业科学研究院林产化学工业研究所 一种从纤维原料中制备高羧基含量的氧化木质素的方法

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE969093C (de) * 1948-11-11 1958-04-30 Aschaffenburger Zellstoffwerke Verfahren zur Herstellung von gebleichtem Zellstoff aus Holz oder anderem pflanzlichem Material
US2939813A (en) * 1956-04-25 1960-06-07 Columbia Cellulose Company Ltd Pulping of lignocellulosic material
US3458394A (en) * 1965-10-08 1969-07-29 Scott Paper Co Pulping wood chips with peracetic acid and chlorine dioxide
JPS5417041A (en) * 1977-07-07 1979-02-08 Mitsubishi Electric Corp Refractive index distribution type lens and production thereof
DE3005947B1 (de) * 1980-02-16 1981-01-29 Degussa Verfahren zur Bleiche von Zellstoffen mittels organischer Persaeure

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO8605529A1 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996035013A1 (fr) * 1995-05-03 1996-11-07 Sven Siegle Procede de production de pulpe d'un materiau cellulosique, pulpe obtenue et son utilisation
US6156156A (en) * 1996-11-06 2000-12-05 Chempolis Oy Method of producing pulp using single-stage cooking with formic acid and washing with performic acid

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AU5589286A (en) 1986-10-13
FI74750C (fi) 1988-03-10
DE3671924D1 (de) 1990-07-19
EP0250422B1 (fr) 1990-06-13
FI74750B (fi) 1987-11-30
FI860609A (fi) 1986-09-23
WO1986005529A1 (fr) 1986-09-25
FI860609A0 (fi) 1986-02-11
JPH0737720B2 (ja) 1995-04-26
JPS62502553A (ja) 1987-10-01

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