SE501836C2 - Bleaching of chemical pulp whereby the pulp is treated with complexing agents before and after an ozone step - Google Patents
Bleaching of chemical pulp whereby the pulp is treated with complexing agents before and after an ozone stepInfo
- Publication number
- SE501836C2 SE501836C2 SE9303066A SE9303066A SE501836C2 SE 501836 C2 SE501836 C2 SE 501836C2 SE 9303066 A SE9303066 A SE 9303066A SE 9303066 A SE9303066 A SE 9303066A SE 501836 C2 SE501836 C2 SE 501836C2
- Authority
- SE
- Sweden
- Prior art keywords
- pulp
- bleaching
- treated
- ozone
- complexing
- Prior art date
Links
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
- D21C9/1026—Other features in bleaching processes
- D21C9/1042—Use of chelating agents
-
- 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
- D21C9/147—Bleaching ; Apparatus therefor with oxygen or its allotropic modifications
- D21C9/153—Bleaching ; Apparatus therefor with oxygen or its allotropic modifications with ozone
-
- 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
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
- Paper (AREA)
Abstract
Description
501 836 2 Enligt föreliggande uppfinning elimineras dessa problem genom att förfarandet är förhållandevis enkelt samtidigt som det ger en hög ljushet hos massan. According to the present invention, these problems are eliminated in that the process is relatively simple while giving a high brightness of the pulp.
Uppfinningens kännetecken framgår av patentkraven.The features of the invention appear from the claims.
I det följande skall uppfinningen beskrivas närmare i anslutning till figuerna. Q Fig 1 är ett exempel på flödesschema för ett förfarande enligt uppfinningen. ' Fig 2 är ett diagram som visar ljusheten som funktion av väteperoxidsatsningen, dels för kända förfaranden och dels för ett förfarande enligt uppfinningen.In the following, the invention will be described in more detail in connection with the figures. Fig. 1 is an example of a flow chart for a method according to the invention. Fig. 2 is a diagram showing the brightness as a function of the hydrogen peroxide charge, partly for known processes and partly for a process according to the invention.
Enligt flödesschemat i fig l förs kemisk massa först till ett första komplexbildarsteg 10 för behandling med EDTA eller DTPA. Massakoncentrationen bör vara 1-10% och behand- lingen utföras under 1-60 minuter, lämpligen 5-30 minuter.According to the flow chart of Fig. 1, chemical pulp is first transferred to a first complexing step 10 for treatment with EDTA or DTPA. The pulp concentration should be 1-10% and the treatment is carried out for 1-60 minutes, preferably 5-30 minutes.
Temperaturen bör vara 20-70°C, lämpligen 20-40°C och pH-värdet 2-5.The temperature should be 20-70 ° C, preferably 20-40 ° C and the pH 2-5.
Efter det första komplexbildarsteget 10 tvättas och avvattnas massan, exempelvis i en tvättpress 11, för av- lägsnande av lösta metalljoner. Därifrån förs massan till ett ozonsteg 12 för ozonblekning. Omedelbart efter ozonsteget 12 späds massan till en koncentration av 1-10% och förs till ett andra komplexbildarsteg 13. Där utföres en behandling med komplexbildare, lämpligen DTPA eller EDTA, under 1-30 minuter, lämpligen 5-20 minuter, vid temperaturen 20-90°C, lämpligen 40-80°C och pH-värdet 1,5-5. Mängden satsad DTPA eller EDTA kan lämpligen vara upp till 0,5 kg/ton massa.After the first complexing step 10, the pulp is washed and dewatered, for example in a washing press 11, to remove dissolved metal ions. From there, the pulp is passed to an ozone stage 12 for ozone bleaching. Immediately after the ozone step 12, the pulp is diluted to a concentration of 1-10% and passed to a second complexing step 13. There, a treatment with complexing agents, preferably DTPA or EDTA, is carried out for 1-30 minutes, preferably 5-20 minutes, at the temperature 20- 90 ° C, preferably 40-80 ° C and the pH 1.5-5. The amount of DTPA or EDTA charged can suitably be up to 0.5 kg / ton pulp.
Efter detta andra komplexbildarsteg 13 utföres en tvättning och avvattning till en koncentration av 8-40% i ett andra tvättsteg 14 varefter massan förs till ett peroxidsteg 15 för peroxidblekning. 4 Enligt detta förfarande kan massan blekas till en ljushet överstigande 83% ISO.After this second complexing step 13, a washing and dewatering is carried out to a concentration of 8-40% in a second washing step 14, after which the pulp is passed to a peroxide step 15 for peroxide bleaching. According to this procedure, the pulp can be bleached to a brightness exceeding 83% ISO.
I diagrammet i fig 2 redovisas ljusheten som funktion av peroxidsatsningen vid olika typer av behandling mellan ozon och peroxidsteg.The diagram in Fig. 2 shows the brightness as a function of the peroxide investment in different types of treatment between ozone and peroxide steps.
Kurva 1 avser ett konventionellt förfarande med pe- roxidblekning efter enbart tvätt och avvattning av den ozon- 501 836 blekta massan.Curve 1 relates to a conventional process with peroxide bleaching after washing and dewatering of the ozone-bleached pulp only.
Kurva 2 avser peroxidblekning av ozonblekt massa som på känt sätt tvättats, avvattnats, komplexbildarbehandlats samt tvättats och avvattnats på nytt före peroxidblekningen.Curve 2 refers to peroxide bleaching of ozone-bleached pulp that has been washed, dewatered, complex image-treated in a known manner and washed and dewatered again before the peroxide bleaching.
Kurva 3 avser ett förfarande enligt uppfinningen.Curve 3 relates to a method according to the invention.
Av fig 2 framgår att blekningen enligt uppfinningen (kurva 3) ger ett väsentligt bättre resultat än konventionell blekning enligt kurva 1. Vidare framgår att blekningen enligt uppfinningen ger ett resultat som nära nog motsvarar resultatet av blekningen enligt kurva 3 trots att förfarandet enligt uppfinningen är betydligt enklare. Även erfarenheter från fabriksmiljö visar att skillnaden mellan de båda sistnämnda förfarandena (kurva 2 och 3) är mycket liten.Fig. 2 shows that the bleaching according to the invention (curve 3) gives a significantly better result than conventional bleaching according to curve 1. Furthermore, it appears that the bleaching according to the invention gives a result which closely corresponds to the result of the bleaching according to curve 3 despite the process according to the invention being significant. easier. Experience from the factory environment also shows that the difference between the two latter methods (curves 2 and 3) is very small.
Uppfinningen är givetvis inte begränsad till det visade utföringsexemplet utan kan varieras inom ramen för uppfin- ningstanken.The invention is of course not limited to the exemplary embodiment shown but can be varied within the scope of the inventive concept.
Claims (3)
Priority Applications (9)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE9303066A SE501836C2 (en) | 1993-09-21 | 1993-09-21 | Bleaching of chemical pulp whereby the pulp is treated with complexing agents before and after an ozone step |
JP7509711A JPH09503028A (en) | 1993-09-21 | 1994-08-22 | Chlorine-free bleaching of chemical pulp including two-step treatment with chelating agents |
PCT/SE1994/000758 WO1995008666A1 (en) | 1993-09-21 | 1994-08-22 | Chlorine-free bleaching of chemical pulp involving a two stage treatment with chelating agent |
EP94928521A EP0720675A1 (en) | 1993-09-21 | 1994-08-22 | Chlorine-free bleaching of chemical pulp involving a two stage treatment with chelating agent |
AU77923/94A AU7792394A (en) | 1993-09-21 | 1994-08-22 | Chlorine-free bleaching of chemical pulp involving a two stage treatment with chelating agent |
CA002168445A CA2168445A1 (en) | 1993-09-21 | 1994-08-22 | Chlorine-free bleaching of chemical pulp involving a two stage treatment with chelating agent |
BR9407555A BR9407555A (en) | 1993-09-21 | 1994-08-22 | Process for bleaching fiber material containing lignocellulose in the form of chemical pulp without using chlorine bleaching agents |
NO961139A NO961139L (en) | 1993-09-21 | 1996-03-20 | Chlorine-free chemical pulp bleaching by two-stage bleaching with chelating agent |
FI961279A FI961279A0 (en) | 1993-09-21 | 1996-03-20 | Chlorine-free chemical pulp bleaching comprising a two-stage treatment with chelating agent |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE9303066A SE501836C2 (en) | 1993-09-21 | 1993-09-21 | Bleaching of chemical pulp whereby the pulp is treated with complexing agents before and after an ozone step |
Publications (3)
Publication Number | Publication Date |
---|---|
SE9303066D0 SE9303066D0 (en) | 1993-09-21 |
SE9303066L SE9303066L (en) | 1995-03-22 |
SE501836C2 true SE501836C2 (en) | 1995-05-22 |
Family
ID=20391160
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
SE9303066A SE501836C2 (en) | 1993-09-21 | 1993-09-21 | Bleaching of chemical pulp whereby the pulp is treated with complexing agents before and after an ozone step |
Country Status (9)
Country | Link |
---|---|
EP (1) | EP0720675A1 (en) |
JP (1) | JPH09503028A (en) |
AU (1) | AU7792394A (en) |
BR (1) | BR9407555A (en) |
CA (1) | CA2168445A1 (en) |
FI (1) | FI961279A0 (en) |
NO (1) | NO961139L (en) |
SE (1) | SE501836C2 (en) |
WO (1) | WO1995008666A1 (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SE504803C2 (en) * | 1995-08-24 | 1997-04-28 | Sunds Defibrator Ind Ab | Treatment of pulp with complexing agents in at least two mixing steps without intermediate washing |
SE508239C2 (en) * | 1997-01-03 | 1998-09-21 | Sunds Defibrator Ind Ab | Treatment of pulp with complexing agents in at least one mixing step, without the use of the bleaching tower |
CN102587186B (en) * | 2012-03-20 | 2015-03-11 | 昆明理工大学 | Method for bleaching dendrocalamus giganteus chemical pulp |
RU2634586C1 (en) * | 2016-08-01 | 2017-10-31 | федеральное государственное бюджетное образовательное учреждение высшего образования "Пермский национальный исследовательский политехнический университет" | Method of bleaching hardwood sulphate cellulose |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
BR9205490A (en) * | 1991-01-03 | 1994-04-05 | Union Camp Patent Holding | Processes for the manufacture of bleached pulp having a final GE britho of at least about 75 and for the delignification and bleaching of a lignocellulosic pulp |
SE468355B (en) * | 1991-04-30 | 1992-12-21 | Eka Nobel Ab | CHEMISTRY OF CHEMICAL MASS THROUGH TREATMENT WITH COMPLEX PICTURES AND OZONE |
-
1993
- 1993-09-21 SE SE9303066A patent/SE501836C2/en unknown
-
1994
- 1994-08-22 WO PCT/SE1994/000758 patent/WO1995008666A1/en not_active Application Discontinuation
- 1994-08-22 AU AU77923/94A patent/AU7792394A/en not_active Abandoned
- 1994-08-22 JP JP7509711A patent/JPH09503028A/en active Pending
- 1994-08-22 EP EP94928521A patent/EP0720675A1/en not_active Ceased
- 1994-08-22 CA CA002168445A patent/CA2168445A1/en not_active Abandoned
- 1994-08-22 BR BR9407555A patent/BR9407555A/en not_active Application Discontinuation
-
1996
- 1996-03-20 NO NO961139A patent/NO961139L/en unknown
- 1996-03-20 FI FI961279A patent/FI961279A0/en unknown
Also Published As
Publication number | Publication date |
---|---|
AU7792394A (en) | 1995-04-10 |
CA2168445A1 (en) | 1995-03-30 |
BR9407555A (en) | 1996-12-31 |
EP0720675A1 (en) | 1996-07-10 |
SE9303066L (en) | 1995-03-22 |
SE9303066D0 (en) | 1993-09-21 |
FI961279A (en) | 1996-03-20 |
NO961139D0 (en) | 1996-03-20 |
JPH09503028A (en) | 1997-03-25 |
FI961279A0 (en) | 1996-03-20 |
NO961139L (en) | 1996-03-20 |
WO1995008666A1 (en) | 1995-03-30 |
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