AU738720B2 - A wood delignification chemical process using ammonium magnesium bisulphite as the active reagent - Google Patents
A wood delignification chemical process using ammonium magnesium bisulphite as the active reagent Download PDFInfo
- Publication number
- AU738720B2 AU738720B2 AU68586/98A AU6858698A AU738720B2 AU 738720 B2 AU738720 B2 AU 738720B2 AU 68586/98 A AU68586/98 A AU 68586/98A AU 6858698 A AU6858698 A AU 6858698A AU 738720 B2 AU738720 B2 AU 738720B2
- Authority
- AU
- Australia
- Prior art keywords
- acid
- bisulphite
- magnesium
- ammonium
- wood
- 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.)
- Ceased
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
- D21C3/00—Pulping cellulose-containing materials
- D21C3/04—Pulping cellulose-containing materials with acids, acid salts or acid anhydrides
- D21C3/06—Pulping cellulose-containing materials with acids, acid salts or acid anhydrides sulfur dioxide; sulfurous acid; bisulfites sulfites
- D21C3/14—Pulping cellulose-containing materials with acids, acid salts or acid anhydrides sulfur dioxide; sulfurous acid; bisulfites sulfites ammonium bisulfite
-
- 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
- D21C3/04—Pulping cellulose-containing materials with acids, acid salts or acid anhydrides
- D21C3/06—Pulping cellulose-containing materials with acids, acid salts or acid anhydrides sulfur dioxide; sulfurous acid; bisulfites sulfites
- D21C3/10—Pulping cellulose-containing materials with acids, acid salts or acid anhydrides sulfur dioxide; sulfurous acid; bisulfites sulfites magnesium bisulfite
Landscapes
- Paper (AREA)
- Chemical And Physical Treatments For Wood And The Like (AREA)
- Polysaccharides And Polysaccharide Derivatives (AREA)
Abstract
The present innovation consists of the use of a reagent solution (FINAL COOKING ACID) where ammonium magnesium bisulphite is the active chemical. This new process is particularly useful to those industrial plants where the cellulose pulp is obtained by the magnesium acid process. The present innovation consists of the introduction of ammonium ions in the cooking acid used in such plants (initial cooking acid). The final cooking acid is obtained by the reaction of the initial cooking acid with ammonium hydroxide. Experimental results show the superiority of the present innovation over the magnesium acid bisulphite pulping process which is expressed by production of cellulosic fibres with higher mechanico-physical index values, decrease in the percentage of uncooked material, increase in wood yield and less environmental impact.
Description
DESCRIPTION
A WOOD DELIGNIFICATION CHEMICAL PROCESS USING AMMONIUM MAGNESIUM BISULPHITE AS THE ACTIVE REAGENT Several sulphite wood delignification process with industrial application have been known for a number of years. The distinction between them is based on the active chemical present in the reagent solution (cooking acid).
The compounds used as active chemicals are all monocationic bisulphites, mainly of calcium, magnesium, sodium or ammonium. The pulping process with calcium bisulphite is an exception, when dolomite is used to prepare the acid.
In the last 30 years the bisulphite cellulosic pulps have been losing competivness to KRAFT pulps, which are obtained by a chemical process in an alkaline medium.
The major disadvantage of bisulphite pulps is the weaker mechanophysical characteristics of their cellulosic fibres when compared with those obtained by the KRAFT process.
SU-A-1359387 discloses a pulping process for wood from deciduous trees.
This process is a semi-chemical process, the liquor pH is alkaline the liquor composition is MgSO 3
+(NH
4 2
SO
3
+[NH
4 and the active chemical agente is ammonium magnesium sulphite. US-A-463499 discloses a special hardwood sulphite delignification process using exclusively the ammonium base.
GB-A-734216 discloses a process for the treatment of wood chips with sulphur ioxide prior with digestion with alkali, namely caustic soda. US-A-4141787 AMENDED SHEET AMENDED SHEET discloses a special acid bisulphite process using calcium or magnesium base, followed by the feed of liquid SO 2 DD-151581 discloses a special wood delignification process using a monocationic bisulphite.
The present innovation refers to a chemical process for wood delignification and consists of the use of a reagent solution where ammonium and magnesium bisulphites are together the active chemicals.
According to a first aspect of the present invention there is provided a chemical process for wood delignification characterised by the use of an aqueous unsaturated solution, containing an ionic mixture of ammonium and magnesium bisulphite salts (herein called ammonium magnesium o1 bisulphite reagent), fully dissociated: HSO 3 Mg 2
NH
4 a pH 2-4 kept through an excess of dissolved sulphur dioxide, where [SO 2 the percentage of total SO2, free plus combined forms, being kept within 4% to wherein the percentage of combined SO 2 is from 1.8% to According to a second aspect of the present invention there is provided delignified wood produced by the process of the first aspect of the invention.
15 According to a third aspect of the present invention there is provided a process for preparing the ammonium magnesium bisulphite reagent referred to in the first aspect of the invention, characterised by having as reaction reagents the initial cooking acid and ammonium hydroxide, according to the equation: INITIAL COOKING ACID: Mg(HSO 3 2 (aq) SO2(g) AMMONIUM HYDROXIDE ADDITION: NH4OH(aq)
II
REACTION PRODUCT: NH4(HSO3)(aq) FINAL COOKING ACID COMPOSITION: Mg(HSO 3 2
NH
4
(HSO
3 SO2(diss.), wherein the two salts are fully dissociated in aqueous unsaturated solution containing at pH 2-4 kept through an excess of dissolved sulphur dioxide, where [SO 2 the percentage of total
SO
2 free plus combined forms, being kept within 4% to wherein the percentage of combined
SO
2 is from 1.8% to In a fourth aspect of the present invention there is provided an ammonium bisulfite reagent prepared according to the third aspect of the invention.
The combination of both ammonium and magnesium cations as bisulphite is the novelty of this application.
This new pulping process is particularly useful to those industrial plants where cellulose pulp
W
T
s obtained by the magnesium acid bisulphite process.
[I:\DAYLIB\LIH]790.doc:mef The expression "ammonium magnesium bisulphite" means an aqueous unsaturated solution containing an ionic mixture of ammonium and magnesium bisulphite salts, fully dissociated: HS03-
NH
4 a pH 2-4 kept through an excess of dissolved sulphur dioxide.
The bisulphite cooking is an aqueous solution of bisulphite containing an excess of S02 called "True free".
The composition of bisulphite cooking acid is determined by the total amount of dioxide sulphur in liquor and by ratio of Combined SO 2 to Free S02. The amount of Free S0 2 is the total of the True Free plus one half of S0 2 in bisulphite form. It is the amount of S0 2 in excess of the amount theoretically required to form monosulphite. By the same token, the Combined SO 2 is equal to one-half of S0 2 in the bisulphite, or equal to the amount of S02 held as monosulphite.
*9
S.
9 e 5 *5 9* 5 e *S [I:\DAYLB\LIBH]790.doc:mef The specific cooking acid of magnesium acid bisulphite pulping process is, physically, a gas-liquid system. The liquid phase is a magnesium bisulphite and sulphur dioxide aqueous solution in equilibrium with the SO 2 gas phase. The system is kept at temperature and pressure values of about 500C and 2 Kgcm 2 respectively.
This particular cooking acid will be referred further on this document as the INICIAL COOKING ACID.
The basis of the present innovation is the inclusion of the ammonium ion in the initial cooking acid, as described by the following equation: INITIAL COOKING ACID: Mg(HSO 3 2 (aq) SO 2 (g) Ammonium hydroxide addition:
NH
4 0H(aq)
II
Reaction product:
NH
4 (HSO3)(aq) The cooking acid obtained by this reaction will be referred to in this document as the FINAL COOKING ACID.
FINAL COOKING ACID composition: Mg(HSO 3 2
NH
4
(HSO
3
[SO
2 =f(pH)] The amount of SO2 stoichiometrically in excess is a function of pH.
The addition of ammonium hydroxide must drive the initial pH value of inicial cooking acid to a final value between 2 and 4, depending on the needs of the process. This operation could be performed in a tank with the initial cooking acid under pressure (accumulator) or in the reactor (digester).
SIn the FINAL COOKING ACID the percentage of total SO2, free plus 3 T o0 AMENDED SHEET combined forms, must be kept within 4% to depending on the requirements of the process, the percentage of combined S0 2 being between 1.8% and Preferably, the total percentage of SO 2 total should be between 5% and the percentage of combined S0 2 being between 2.2% and 2.7%.
The pulping process operated at a higher pH value, such as that attained after ammonium hydroxide addition, decreases the wood degradation process, enables the production of cellulosic fibres with higher mechanico-physical index values, and decreases the specific consumption of wood.
On the other hand, the presence of ammonium ions accelerate the reaction process decreasing both wood chip impregnation time and percentage of uncooked material. This latter effect improves the wood yield of the process.
The experimental results obtained with hard wood, namely eucalyptus, show the superiority of the present innovation over the magnesium acid bisulphite pulping process, which is expressed by.
a Production of cellulosic fibres with a higher mechanico-physical index values.
b Decreased percentage of uncooked material.
c Increased wood yield.
d Less environmental impact.
Lij 4 AMENDED
SHEET
Claims (9)
1. A chemical process for wood delignification characterised by the use of an aqueous unsaturated solution, containing an ionic mixture of ammonium and magnesium bisulphite salts (herein called ammonium magnesium bisulphite reagent), fully dissociated: HSO 3 Mg 2 NH4 a pH 2-4 kept through an excess of dissolved sulphur dioxide, where [SO 2 the percentage of total SO 2 free plus combined forms, being kept within 4% to wherein the percentage of combined SO 2 is from 1.8% to
2. The chemical process for wood delignification, according to claim 1, characterised by a Final Cooking Acid containing: SO 2 Total 5-6, SO 2 Combined 2.2-2.7 and a pH value between 2 and 4 at which the process must be run by the controlled addition of NH 4 OH to the initial cooking acid, whose pH is nearly
3. The chemical process for wood delignification according to claim 2, which being applied to eucalyptus and taking a monocationic acid bisulphite process, namely magnesium, as reference, is characterised by a pulp production having cellulosic fibres with higher physical 15 properties, mainly tensile Index end Tear Index respectively 25% and 15%, at least higher.
4. The chemical process for wood delignification according to claim 2, which being applied to eucalyptus and taking a monocationic acid bisulphite process, namely magnesium, as reference, is characterised by a decrease in the percentage of uncooked material nearly 30% and an increase in the wood yield nearly
5. The chemical process for wood delignification according to claim 2, which taking a monocationic acid bisulphite process, namely magnesium, as reference, is characterised by the Ssignificant improvement of the environmental impact resulting from the lower amount of sulphur dioxide released to the air when the cook is discharged.
6. Delignified wood produced by the process of any one of claims 1 to 25
7. A process for preparing the ammonium magnesium bisulphite reagent referred to in claims 1 to 5, characterised by having as reaction reagents the initial cooking acid and ammonium hydroxide, according to the equation: INITIAL COOKING ACID: Mg(HSO3) 2 (aq) SO2(g) AMMONIUM HYDROXIDE ADDITION: NH4OH(aq) II REACTION PRODUCT: NH4(HSO 3 )(aq) FINAL COOKING ACID COMPOSITION: Mg(HSO 3 2 NH 4 (HSO3) SO2(diss.), wherein the two salts are fully dissociated in aqueous unsaturated solution containing at pH 2-4 kept through an excess of dissolved sulphur dioxide, where the percentage of total SO 2 free plus combined forms, being kept within 4% to wherein the percentage of combined SSO 2 is from 1.8% to [R:\LIBH]790.doc:mef 6
8. The process according to claim 7, characterised by a Final Cooking Acid containing: SO 2 Total 5-6, SO2 Combined 2.2-2.7 and a pH value between 2 and 4 at which the process must be run by the controlled addition of NH 4 OH to the initial cooking acid, whose pH is nearly
9. An ammonium bisulfite reagent prepared by the process of claims 7 or 8. Dated 3 August, 2001 Joao Manuel Almeida Oliveira Baptista Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON e *S S eS oo* *o* [R:\LIBH]790.doc:mef
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PT101999A PT101999B (en) | 1997-04-28 | 1997-04-28 | CHEMICAL PROCESS OF DESLENHIFICATION OF WOOD USING AS AN ACTIVE REAGENT THE COMPOUND - DOUBLE BISCULPTURE OF MAGNESIUM AND AMMONIUM |
PT101999 | 1997-04-28 | ||
PCT/PT1998/000002 WO1998049390A1 (en) | 1997-04-28 | 1998-04-20 | A wood delignification chemical process using ammonium magnesium bisulphite as the active reagent |
Publications (2)
Publication Number | Publication Date |
---|---|
AU6858698A AU6858698A (en) | 1998-11-24 |
AU738720B2 true AU738720B2 (en) | 2001-09-27 |
Family
ID=20085674
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
AU68586/98A Ceased AU738720B2 (en) | 1997-04-28 | 1998-04-20 | A wood delignification chemical process using ammonium magnesium bisulphite as the active reagent |
Country Status (8)
Country | Link |
---|---|
US (1) | US20020153108A1 (en) |
EP (1) | EP0977918B1 (en) |
AT (1) | ATE362010T1 (en) |
AU (1) | AU738720B2 (en) |
BR (1) | BR9809423A (en) |
DE (1) | DE69837755T2 (en) |
PT (1) | PT101999B (en) |
WO (1) | WO1998049390A1 (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2652193B1 (en) | 2010-12-15 | 2020-09-16 | IP2IPO Innovations Limited | Treatment |
US11118308B2 (en) | 2013-03-15 | 2021-09-14 | Ip2Ipo Innovations Limited | Treatment of lignocellulosic biomass with ionic liquid |
GB201520453D0 (en) | 2015-11-20 | 2016-01-06 | Imp Innovations Ltd | Process |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4141787A (en) * | 1974-09-24 | 1979-02-27 | Pwa Papierwerke Waldhof-Aschaffenburg Aktiengesellschaft | Process for preparing chemical cellulose according to the sulfite process by increasing the total SO2 content of cooking acid with liquid SO2 and digesting wood chips |
DD151581A3 (en) * | 1976-11-11 | 1981-10-28 | Kurt Doeink | PROCESS FOR CLOSING LIGNOCELLULESIC MATERIALS AFTER THE BISULFIT PROCESS |
SU1359387A1 (en) * | 1985-09-25 | 1987-12-15 | Центральный научно-исследовательский институт бумаги | Pulp for making corrugated paper |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NL87584C (en) * | 1952-02-15 | |||
JPS5653295A (en) * | 1979-10-04 | 1981-05-12 | Kogyo Gijutsuin | Pulping method of waste rubber material |
US4634499A (en) * | 1983-05-02 | 1987-01-06 | The Procter & Gamble Company | Sulfite process for making pulp having a tactile softness from hardwood chips |
SU1696631A1 (en) * | 1989-06-26 | 1991-12-07 | Сибирский научно-исследовательский институт целлюлозы и картона | Solution for treating wood pulp |
-
1997
- 1997-04-28 PT PT101999A patent/PT101999B/en not_active IP Right Cessation
-
1998
- 1998-04-20 US US09/403,864 patent/US20020153108A1/en not_active Abandoned
- 1998-04-20 WO PCT/PT1998/000002 patent/WO1998049390A1/en active IP Right Grant
- 1998-04-20 DE DE69837755T patent/DE69837755T2/en not_active Expired - Fee Related
- 1998-04-20 EP EP98914170A patent/EP0977918B1/en not_active Expired - Lifetime
- 1998-04-20 BR BR9809423-8A patent/BR9809423A/en not_active IP Right Cessation
- 1998-04-20 AT AT98914170T patent/ATE362010T1/en not_active IP Right Cessation
- 1998-04-20 AU AU68586/98A patent/AU738720B2/en not_active Ceased
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4141787A (en) * | 1974-09-24 | 1979-02-27 | Pwa Papierwerke Waldhof-Aschaffenburg Aktiengesellschaft | Process for preparing chemical cellulose according to the sulfite process by increasing the total SO2 content of cooking acid with liquid SO2 and digesting wood chips |
DD151581A3 (en) * | 1976-11-11 | 1981-10-28 | Kurt Doeink | PROCESS FOR CLOSING LIGNOCELLULESIC MATERIALS AFTER THE BISULFIT PROCESS |
SU1359387A1 (en) * | 1985-09-25 | 1987-12-15 | Центральный научно-исследовательский институт бумаги | Pulp for making corrugated paper |
Also Published As
Publication number | Publication date |
---|---|
US20020153108A1 (en) | 2002-10-24 |
WO1998049390A1 (en) | 1998-11-05 |
BR9809423A (en) | 2000-06-13 |
EP0977918A1 (en) | 2000-02-09 |
EP0977918B1 (en) | 2007-05-09 |
PT101999A (en) | 1998-11-30 |
AU6858698A (en) | 1998-11-24 |
DE69837755D1 (en) | 2007-06-21 |
ATE362010T1 (en) | 2007-06-15 |
DE69837755T2 (en) | 2008-01-31 |
PT101999B (en) | 2003-09-30 |
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Legal Events
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---|---|---|---|
FGA | Letters patent sealed or granted (standard patent) |