NO133034B - - Google Patents

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Publication number
NO133034B
NO133034B NO184469A NO184469A NO133034B NO 133034 B NO133034 B NO 133034B NO 184469 A NO184469 A NO 184469A NO 184469 A NO184469 A NO 184469A NO 133034 B NO133034 B NO 133034B
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pulp
impregnation
temperature
stated
sulphite
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NO184469A
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Norwegian (no)
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NO133034C (en
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B K Howe
F R F Hardy
D A Clark
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Laporte Chemical
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Publication of NO133034C publication Critical patent/NO133034C/no

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/835—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with germanium, tin or lead
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/84—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/843—Arsenic, antimony or bismuth
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/27—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation
    • C07C45/32—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation with molecular oxygen
    • C07C45/37—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation with molecular oxygen of >C—O—functional groups to >C=O groups
    • C07C45/38—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation with molecular oxygen of >C—O—functional groups to >C=O groups being a primary hydroxyl group
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/27—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation
    • C07C45/32—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation with molecular oxygen
    • C07C45/37—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation with molecular oxygen of >C—O—functional groups to >C=O groups
    • C07C45/39—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation with molecular oxygen of >C—O—functional groups to >C=O groups being a secondary hydroxyl group
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/56—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds from heterocyclic compounds
    • C07C45/57—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds from heterocyclic compounds with oxygen as the only heteroatom
    • C07C45/60—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds from heterocyclic compounds with oxygen as the only heteroatom in six-membered rings
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/78—Separation; Purification; Stabilisation; Use of additives
    • C07C45/783—Separation; Purification; Stabilisation; Use of additives by gas-liquid treatment, e.g. by gas-liquid absorption
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/78—Separation; Purification; Stabilisation; Use of additives
    • C07C45/79—Separation; Purification; Stabilisation; Use of additives by solid-liquid treatment; by chemisorption
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/78—Separation; Purification; Stabilisation; Use of additives
    • C07C45/81—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation
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    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/78—Separation; Purification; Stabilisation; Use of additives
    • C07C45/85—Separation; Purification; Stabilisation; Use of additives by treatment giving rise to a chemical modification
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    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C49/00—Ketones; Ketenes; Dimeric ketenes; Ketonic chelates
    • C07C49/04—Saturated compounds containing keto groups bound to acyclic carbon atoms
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    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D233/00—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings
    • C07D233/04—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having one double bond between ring members or between a ring member and a non-ring member
    • C07D233/28—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having one double bond between ring members or between a ring member and a non-ring member with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
    • C07D233/30—Oxygen or sulfur atoms
    • C07D233/40—Two or more oxygen atoms

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
  • Paper (AREA)

Description

Fremgangsmåte for fremstilling av nøytralsulfitmasse. Procedure for the production of neutral sulphite mass.

Nøytralsulfitmasse fremstilles vanligvis med utbytter på 65—90 % ved oppslut-ting av ved, hovedsakelig løvved, med dina-triumsulfitoppløsning, tilsatt soda, ved temperaturer, som i alminnelighet ligger mellom 160 og 180° C, og derpå følgende mekanisk defibrering av det oppsluttede material. Neutral sulphite pulp is usually produced with yields of 65-90% by digesting wood, mainly hardwood, with disodium sulphite solution, with added soda, at temperatures which are generally between 160 and 180° C, and then mechanical defibration of the digested material.

Ved oppvarming av tre til det tempe-raturområde som er angitt ovenfor dannes organiske syrer, som bevirker brunfarging av vedstoffene. For i noen grad å motvirke dette, blir det satt soda eller bikarbonat til natriumsulfitoppløsningen, slik at dens buffervirkning økes. Vanligvis utgjør soda-tilsetningen ca. y4 av den sulfit som be-nyttes. På grunn av den økete buffervirkning blir da organiske syrer som dannes bunnet i større utstrekning og misfarvin-gen av veden blir mindre sterk. Ren na-triumoppløsning har en pH-verdi på ca. 9,5 og er uten buffervirkning. Vanligvis fremstilles impregneringsoppløsningen ved oppløsning av natriumsulfit og soda eller bikarbonat, men i visse tilfeller fremstilles den også ved innføring av S02 i en soda-oppløsning, til det oppnås ønsket sammen-setning av natriumsulfit og soda. When wood is heated to the temperature range indicated above, organic acids are formed, which cause browning of the wood materials. To counteract this to some extent, soda or bicarbonate is added to the sodium sulphite solution, so that its buffering effect is increased. Usually the soda addition amounts to approx. y4 of the sulphite used. Due to the increased buffering effect, the organic acids that are formed are neutralized to a greater extent and the discolouration of the wood becomes less severe. Pure sodium solution has a pH value of approx. 9.5 and has no buffering effect. Usually, the impregnation solution is prepared by dissolving sodium sulphite and soda or bicarbonate, but in certain cases it is also prepared by introducing SO 2 into a soda solution, until the desired composition of sodium sulphite and soda is achieved.

Forsøk har imidlertid vist, at det ved Experiments have shown, however, that it knows

en nøyaktig gjennomført impregnering av flisen ikke er nødvendig å ha noen særlig bufferevne for sulfitoppløsningen i pH-området 9,5 — 7,5. Videre har det vist seg at sulfitoppløsningens innhold av kullsyre, fri eller bundet, er direkte skadelig for pro-sessen, da soda eller bikarbonat ved opp- a precisely completed impregnation of the tile is not necessary to have any particular buffering capacity for the sulphite solution in the pH range 9.5 - 7.5. Furthermore, it has been shown that the sulphite solution's content of carbonic acid, free or bound, is directly harmful to the process, as soda or bicarbonate when

sluttingen spaltes i flisen under dannelse av gassformet kullsyre, som trenger ut en del kokevæske og det blir vanskeligere å nøytralisere de syrer som er dannet, hvilket øker faren for brunfarging av flisen. Det har også kunnet konstateres, at selve impregneringen blir vanskeligere når det anvendes sulfitoppløsninger som er bufret med soda eller bikarbonat. Gassformet kullsyre minsker også vanndampens partial-trykk. En passende mengde damp må derfor stadig avblåses for at en ønsket reak-sjonstemperatur skal kunne opprettholdes. the slurry splits in the tile to form gaseous carbonic acid, which forces out some of the cooking liquid and it becomes more difficult to neutralize the acids that are formed, which increases the risk of browning of the tile. It has also been found that the impregnation itself becomes more difficult when sulphite solutions that are buffered with soda or bicarbonate are used. Gaseous carbonic acid also reduces the partial pressure of water vapour. A suitable amount of steam must therefore be constantly blown off so that a desired reaction temperature can be maintained.

Det er også konstatert, at ved en omhyggelig gjennomført impregnering av veden blir massens lyshet øket hvis impreg-neringsoppløsningens pH-verdi minskes i området 9,5 — 6, dog naturligvis under den forutsetning at oppsluttingen skjer under lignende betingelser med hensyn på temperatur o.s.v. som forutsatt i tabellene It has also been established that when the wood is carefully impregnated, the lightness of the pulp is increased if the pH value of the impregnation solution is reduced in the range of 9.5 - 6, although of course on the condition that the impregnation takes place under similar conditions with regard to temperature etc. as provided in the tables

I — IV. I — IV.

I motsetning til det som tidligere var ansett riktig, har det vist seg å være over-ordentlig viktig at flisen, før den varmes over intervallet 110—120° C, er vel impreg-nert med kokevæske, hvis misfarging og unødig nedbryting av vedsubstans skal unn-gås. Hvis flisen ikke er helt gjennomtruk-ket med kokevæske, skjer det nemlig ved flisens oppvarming i det nevnte tempera-turområde en begynnende misfarging av massen, hvilket gjør seg ennå mere gjel-dende ved de temperaturer 140—180° C som vanligvis anvendes i praksis. In contrast to what was previously considered correct, it has been shown to be extremely important that the chip, before it is heated above the interval 110-120° C, is well impregnated with cooking liquid, if discoloration and unnecessary breakdown of wood substance should un-goose. If the tile is not completely soaked with cooking liquid, when the tile is heated in the aforementioned temperature range, an initial discoloration of the mass occurs, which is even more true at the temperatures of 140-180° C that are usually used in practice .

En basing av flisen letter i høy grad impregneringen og alt etter vedslag, tørr-stoffinnhold, flisstørrelse m. m. bestem-mes lengden av basingstiden. Denne må derfor fastslås fra tilfelle til tilfelle og kan variere innenfor vide grenser. F. eks. for flis av forskjellig bjørkeved har basingstiden måttet varieres mellom 5 og 10 mi-nutter for at det skal oppnås fullgod impregnering. Basing the tile greatly facilitates the impregnation and the length of the basing time is determined depending on adhesion, dry matter content, tile size etc. This must therefore be determined from case to case and can vary within wide limits. For example for chips made of different birch wood, the basing time has had to be varied between 5 and 10 minutes in order to achieve full impregnation.

Ved en vel gjennomført basing må normal flis av bjørk, alt etter fuktighets-innholdet etter basingen, være i kontakt med kokevæsken y2—2 timer hvis impregneringen skal bli så god, at massen får høyeste lyshet. Med hensyn til det tidligere nevnte kritiske temperaturintervall, er det også meget viktig, at temperaturene under impregneringsperioden holdes under 110° C, hensiktsmessig omkring 100° C og lavere. In the case of a well-executed basing, normal birch chips, depending on the moisture content after basing, must be in contact with the cooking liquid for y2-2 hours if the impregnation is to be so good that the mass achieves the highest lightness. With regard to the previously mentioned critical temperature interval, it is also very important that the temperatures during the impregnation period are kept below 110° C, suitably around 100° C and lower.

E. L. Keller og J. N. McGovern har i en artikkel i TAPPI, vol 32, nr. 9, meget riktig konstatert, at fargen på massen ved anvendelse av ikke buffret natriumsulfit får en høyere lyshet enn med buffer, men den lyshet de oppnådde er dog meget lav, 52 % G. E. i forhold til det resultat som oppnås i henhold til - oppfinnelsen, og dette forhold må vesentlig tilskrives for høy temperatur O 120° C) ved impregneringen. E. L. Keller and J. N. McGovern, in an article in TAPPI, vol 32, no. 9, very correctly stated that the color of the pulp when using unbuffered sodium sulphite gets a higher lightness than with a buffer, but the lightness they achieved is however very low , 52% G.E. in relation to the result obtained according to the invention, and this ratio must be largely attributed to the high temperature (O 120° C) during the impregnation.

Forsøk har nemlig vist, at det ved en nøyaktig gjennomført impregnering kan oppnås en lyshet på f. eks. bjørkemasse av 62—65 % i utbytteområdet 80—90 %, hvis det tas tilbørlig hensyn til både den høyeste tillatte temperatur 110—120° C og den nødvendige tid av 20—120 min. ved impregneringen. Experiments have indeed shown that a lightness of e.g. birch mass of 62-65% in the yield range 80-90%, if due consideration is given to both the highest permitted temperature 110-120° C and the required time of 20-120 min. during the impregnation.

Impregneringstidens lengde er minst like viktig som temperaturen foråt det skal oppnås fullgod impregnering. Det har vist seg, at en vel baset flis må være i kontakt med impregneringsoppløsningen i minst 30 min. for at resultatet av impregneringen skal bli tilfredsstillende og ofte må tiden forlenges til 60—120 min. The length of the impregnation time is at least as important as the temperature before full impregnation is to be achieved. It has been shown that a well-based tile must be in contact with the impregnation solution for at least 30 minutes. for the result of the impregnation to be satisfactory and often the time must be extended to 60-120 min.

Husband skriver i en artikkel i TAPPI, vol. 36, nr. 12, at massens lyshet i høy grad avhenger av impregneringen, hvilket stem-mer godt med de resultater som oppnås i henhold til oppfinnelsen, men til tross for at Husband anvendte evakuering av flisen, har hans impregneringstid 15 min. ved 100° C vært for kort til å gi tilfredsstillende lyshet. Husband writes in an article in TAPPI, vol. 36, no. 12, that the lightness of the mass depends to a large extent on the impregnation, which agrees well with the results obtained according to the invention, but despite the fact that Husband used evacuation of the tile, his impregnation time is 15 min. at 100° C was too short to give satisfactory brightness.

, Hvis impregneringen er utført på den måte, at flisen etter basingen er kompri-mert og har fått ekspandere direkte i kokevæsken, f. eks. i henhold til den såkaldte Asplund-metode, kan impregneringstiden forkortes vesentlig, men forsøkene har dog vist, at impregneringstiden ikke kan gjøres , If the impregnation is carried out in such a way that the tile is compressed after basing and has been allowed to expand directly in the cooking liquid, e.g. according to the so-called Asplund method, the impregnation time can be significantly shortened, but experiments have shown, however, that the impregnation time cannot be

kortere enn 3—10 min., hvis f. eks. bjør-kemasse skal få en hvithet på ca. 60—65 shorter than 3-10 min., if e.g. Birch pulp should have a whiteness of approx. 60-65

G. E. G.E.

Det er konstatert, at en impregnerings-væske, som er fremstillet ved innføring av S02 i natronlut til en pH-verdi, som ligger i intervallet 9,5 — 6, spesielt mellom ca. 7,5 — 6,5, er mere hensiktsmessig enn noen annen sulfitoppløsning for fremstilling av nøytralsulfitmasse med høy lyshet ved et utbytte mellom 80 og 90 %. Kokingen må da drives slik at pH-verdien etter kokingen ligger mellom 4,5 og 6,5 og koketempera-turen mellom 175 og 165° C, hvilket for den høyere temperatur tilsvarer en koketid av 15—20 min., og for den lavere 60—70 min. Observeres bør det dog at de lavere pH-verdiene ved samme satsinger av Na .O kre-ver mere SO„ hvilket medfører en noe større kjemikalieomsetning. Ned til en pH-verdi på ca. 6,5 er imidlertid denne mer-omkostning meget ubetydelig. It has been established that an impregnation liquid, which is produced by introducing SO 2 in caustic soda to a pH value that lies in the interval 9.5 - 6, especially between approx. 7.5 — 6.5, is more suitable than any other sulphite solution for the production of neutral sulphite mass with high brightness at a yield of between 80 and 90%. The boiling must then be carried out so that the pH value after boiling is between 4.5 and 6.5 and the cooking temperature between 175 and 165° C, which for the higher temperature corresponds to a cooking time of 15-20 min., and for the lower 60-70 min. It should be noted, however, that the lower pH values at the same amounts of Na .O require more SO„, which entails a somewhat greater chemical turnover. Down to a pH value of approx. 6.5, however, this additional cost is very insignificant.

Det kan således ved en nøyaktig impregnering etter en vel gjennomført basing, avveining av koketemperatur og koketid samt anvendelse av en egnet ikke buffret sulfitoppløsning, som inneholder sulfit og bisulfit, oppnås en hittil ikke oppnådd kvalitet på nøytralsulfitmasse av bjørkeved med god styrke ved høyt utbytte, 80—90 % og med en lyshet som er fullt til-strekkelig for fremstilling av avis- og tids-skriftpapir. Thus, by precise impregnation after a well-executed basing, weighing of cooking temperature and cooking time as well as the use of a suitable non-buffered sulphite solution, which contains sulphite and bisulphite, a hitherto unachieved quality of neutral sulphite mass of birch wood with good strength and high yield can be achieved, 80-90% and with a lightness that is fully sufficient for the production of newspaper and magazine paper.

Foreliggende oppfinnelse angår en fremgangsmåte for fremstilling av halvkjemisk nøytralsulfitmasse, og det sær-egne består i at vedflis etter basing impregneres omhyggelig med en oppløsning av natriumsulfit og -bisulfit med en pH-verdi mellom 9,5 og 6 og fri fra løs eller bundet kullsyre, befris for overskudd av impregneringsoppløsning, oppsluttes uten nærvær av fri væske ved en temperatur av 165—175° C og deretter defibreres. The present invention relates to a method for the production of semi-chemical neutral sulphite mass, and the peculiarity consists in that after basing, wood chips are carefully impregnated with a solution of sodium sulphite and sodium bisulphite with a pH value between 9.5 and 6 and free from loose or bound carbonic acid , freed of excess impregnation solution, digested without the presence of free liquid at a temperature of 165-175° C and then defibrated.

Det har nå vist seg, at en ytterligere høyning av hvitheten kan oppnås, hvis massesuspensjonen etter avsluttet koking og grovdefibrering befris for avlut ved pressing til stadig økende tørrstoffinnhold, uten at noe fortynnings vann tilsettes. Da oppslutningen ved denne fremgangsmåte skjer uten at fri væske er tilstede, kan det vise seg nødvendig etter grovdefibreringen å tilføye en mindre væskemengde for å let-te massens transport. Derved bør det helst anvendes ikke fortynnet avlut fra pressen. Pressingen gjennomføres hensiktsmessig i kontinuerlige presser, f. eks. skruepresser eller skivepresser av vanlige typer i cellu-loseindustrien. It has now been shown that a further increase in whiteness can be achieved, if the pulp suspension after the end of boiling and coarse defibration is freed from leachate by pressing to an ever-increasing solids content, without any dilution water being added. As the digestion in this method takes place without free liquid being present, it may prove necessary to add a smaller amount of liquid after the coarse defibration to facilitate the transport of the mass. Thereby, undiluted liquor from the press should preferably be used. The pressing is suitably carried out in continuous presses, e.g. screw presses or disk presses of common types in the cellulose industry.

Allerede en pressing til et tørrstoffinn-hold på 30 % før fortynning med vann har medført en lyshetsøking på ca. 2 G. E.-en-heter sammenlignet med en utvasking i diffusør. Ved pressing til et tørrstoffinn-hold på 40 % har lyshetsøkingen gått opp i ca. 3 G. E.-enheter. Ved tørrstoffinnhol-det 50 % er lysheten ytterligere øket med ca. 1 G. E.-enhet. Already a pressing to a dry matter content of 30% before dilution with water has resulted in an increase in brightness of approx. 2 G. E. units compared to a washout in a diffuser. When pressed to a dry matter content of 40%, the increase in brightness has increased to approx. 3 G. E. units. At a dry matter content of 50%, the lightness is further increased by approx. 1 G. E. unit.

Etter pressingen er massen blitt fortynnet med vann til 3—4% konsentrasjon, raffinert, fortynnet, avvannet og formet til ark. Lyshetsmåling er utført på det pa-pir som er oppnådd. After pressing, the pulp has been diluted with water to a 3-4% concentration, refined, diluted, dewatered and formed into sheets. Lightness measurement is carried out on the paper that has been obtained.

Den virkning som er oppnådd har vist seg å bero på at, når massesuspensjonen etter utført koking fortynnes med vann eller vaskes, utfelles små mengder finkornet organisk stoff og adsorberes på fibrene, hvorved det oppnås en senking av massens lyshet. Dette forhold har kunnet konstateres ved fremstilling av høyutbyttemasse av løvtre, f. eks. bjørk og poppel. Høyutbytte-sulfitmasse av gran viser samme tendens, men økingen i lyshet er vesentlig mindre. The effect achieved has been shown to be due to the fact that, when the pulp suspension is diluted with water after boiling or washed, small amounts of fine-grained organic matter are precipitated and adsorbed on the fibers, whereby a lowering of the brightness of the pulp is achieved. This situation has been ascertained when producing high-yield pulp from hardwood, e.g. birch and poplar. High-yield sulphite pulp of spruce shows the same tendency, but the increase in lightness is significantly smaller.

Oppfinnelsen kjennetegnes videre ved at det oppnås en tidligere ikke oppnådd lyshet ved en relativt lav kjemikalietilset-ning, som høyst går opp til 42 kg Na=,0 og 45 kg S02 per tonn tørr ved. The invention is further characterized by the fact that previously unachieved lightness is achieved with a relatively low chemical addition, which at most goes up to 42 kg Na=.0 and 45 kg SO 2 per ton of dry wood.

Ved at impregneringen utføres i henhold til oppfinnelsen, oppnås det nemlig at alle deler av en flisbit har fått seg til-delt den kjemikaliemengde den trenger, uten at det på noe sted i flisbiten finnes noe unødvendig overskudd, hvorved det ved oppsluttingen oppnås et maksimum av lyshet og styrke under anvendelse av et minimum kjemikalier. Because the impregnation is carried out in accordance with the invention, it is achieved that all parts of a piece of tile have been allocated the amount of chemical it needs, without any unnecessary excess being found anywhere in the piece of tile, whereby a maximum of brightness and strength using a minimum of chemicals.

Claims (5)

1. Fremgangsmåte for fremstilling av halvkjemisk nøytralsulfitmasse med høy lyshet, av løvved, karakterisert ved at treflis etter damping ved en temperatur på maksimalt 110° C impregneres omhyggelig ved en temperatur på maksimalt 110" C med en oppløsning av natriumsulfit og -bisulfit med en pH-verdi mellom 9,5 og 6 og uten fri eller bundet kullsyre, befries for overskudd av impregneringsoppløsning, oppsluttes uten nærvær av fri væske ved en temperatur på 165—175° C og deretter defibreres.1. Process for the production of semi-chemical neutral sulphite mass with high lightness, from hardwood, characterized in that after steaming at a temperature of a maximum of 110° C, wood chips are carefully impregnated at a temperature of a maximum of 110° C with a solution of sodium sulphite and -bisulphite with a pH -value between 9.5 and 6 and without free or bound carbonic acid, freed from excess impregnation solution, digested without the presence of free liquid at a temperature of 165-175° C and then defibrated. 2. Fremgangsmåte som angitt i på-stand 1, karakterisert ved at flisen bases og bringes i kontakt med iin-pregneringsva;sken i minst 30 min. hensiktsmessig 60—120 min.2. Method as stated in claim 1, characterized in that the tile is grounded and brought into contact with the impregnation solution for at least 30 min. appropriate 60-120 min. 3. Fremgangsmåte som angitt i på- stand 1, karakterisert ved at fli sen bases, komprimeres og deretter eks-panderes i impregneringsvæsken, hvor den får oppholde seg i minst 3 min., hensiktsmessig mere enn 10 min.3. Procedure as stated in the stand 1, characterized in that fli sen bases, is compressed and then expanded in the impregnation liquid, where it is allowed to remain for at least 3 min., preferably more than 10 min. 4. Fremgangsmåte for øking av massens lyshet ved fremstilling av halvkjemisk nøytralsulfitmasse som angitt i på-stand 1, karakterisert ved at massen etter defibreringen uten nevneverdig fortynning med vann presses til et tørr-stoffinnhold på minst 40% før fraskilling av den vesentlige mengde avlut.4. Method for increasing the lightness of the pulp in the production of semi-chemical neutral sulphite pulp as stated in claim 1, characterized in that the pulp after defibration is pressed without significant dilution with water to a dry matter content of at least 40% before separation of the significant amount of waste liquor. 5. Fremgangsmåte som angitt i på-stand 4, karakterisert ved at massen etter defibreringen og før pressingen fortynnes med avlut fra pressen.5. Method as stated in claim 4, characterized in that the pulp after defibration and before pressing is diluted with effluent from the press.
NO184469A 1968-05-06 1969-05-05 NO133034C (en)

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DE2922599A1 (en) * 1979-06-02 1980-12-04 Basf Ag METHOD FOR THE CONTINUOUS PRODUCTION OF GLYOXAL
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JPS5838227A (en) * 1981-09-01 1983-03-05 Mitsui Toatsu Chem Inc Preparation of aldehyde
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US4555583A (en) * 1982-08-30 1985-11-26 Mitsui Toatsu Chemicals, Incorporated Preparation process for glyoxal
US4439625A (en) * 1982-09-29 1984-03-27 E. I. Du Pont De Nemours And Company Production of formaldehyde
US4599459A (en) * 1984-08-31 1986-07-08 Masanao Hirose Method for the ultrasonic treatment of a dilute alcoholic solution
DE3643469A1 (en) * 1986-12-19 1988-06-30 Basf Ag METHOD FOR PRODUCING CARBONYL COMPOUNDS
DE3712856A1 (en) * 1987-04-15 1988-11-03 Basf Ag METHOD FOR PRODUCING CARBONYL COMPOUNDS
WO2007132011A1 (en) * 2006-05-17 2007-11-22 Basf Aktiengesellschaft Method for producing vicinal dioxo compounds by oxidation of vicinal dihydroxy compounds on a structured catalyst packing
US20090192335A1 (en) * 2006-05-17 2009-07-30 Basf Se Temperature-control in the performance of oxidation reactions of hydrocarbons
DE102008018480B4 (en) 2007-04-13 2020-10-15 Basf Se Process for the preparation of vicinal dioxo compounds by oxidation of vicinal dihydroxy compounds
DE102008002535A1 (en) 2007-06-25 2009-01-02 Basf Se Producing vicinal dioxo compounds, preferably glyoxal, useful as cross linker functionalized polymers, comprises gas phase oxidation of vicinal dihydroxy compounds in presence of gases containing oxygen on a catalyst comprising e.g. gold
JP2012514022A (en) 2008-12-29 2012-06-21 ビーエーエスエフ ソシエタス・ヨーロピア Methods for cleaning aqueous glyoxal solutions
WO2012041875A1 (en) 2010-10-01 2012-04-05 Basf Se Process for purifying aqueous glyoxal solutions
US8461396B2 (en) 2010-10-01 2013-06-11 Basf Se Process for purifying aqueous glyoxal solutions
CN115697955A (en) 2020-09-17 2023-02-03 巴斯夫欧洲公司 Process for preparing glyoxal

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US2462107A (en) * 1943-05-03 1949-02-22 Ninol Dev Co Process for preparation of diacetyl
FR1060331A (en) * 1951-08-02 1954-04-01 Basf Ag Process for obtaining ureins from ethanedial
US3049446A (en) * 1960-02-05 1962-08-14 Sun Chemical Corp Process for the manufacture of urea, glyoxal and formaldehye reaction product useful for improving cellulosic textile materials

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NL6906866A (en) 1969-11-10
CH535193A (en) 1973-03-31
DE1967147C2 (en) 1980-02-14
ES366867A1 (en) 1971-06-16
FR2007925A1 (en) 1970-01-16
DE1923048B2 (en) 1979-07-19
SE363816B (en) 1974-02-04
NO133034C (en) 1976-02-25
NL168487C (en) 1982-04-16
BE732584A (en) 1969-11-06
DE1967147B1 (en) 1979-06-13
GB1272592A (en) 1972-05-03

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