US2947657A - Extraction of cellulose from vegetable matter - Google Patents
Extraction of cellulose from vegetable matter Download PDFInfo
- Publication number
- US2947657A US2947657A US640304A US64030457A US2947657A US 2947657 A US2947657 A US 2947657A US 640304 A US640304 A US 640304A US 64030457 A US64030457 A US 64030457A US 2947657 A US2947657 A US 2947657A
- Authority
- US
- United States
- Prior art keywords
- cellulose
- hydrosulfite
- vegetable matter
- alkali
- extraction
- 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.)
- Expired - Lifetime
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- 239000001913 cellulose Substances 0.000 title claims description 24
- 229920002678 cellulose Polymers 0.000 title claims description 24
- 235000013311 vegetables Nutrition 0.000 title claims description 22
- 238000000605 extraction Methods 0.000 title claims description 10
- GRWZHXKQBITJKP-UHFFFAOYSA-L dithionite(2-) Chemical compound [O-]S(=O)S([O-])=O GRWZHXKQBITJKP-UHFFFAOYSA-L 0.000 claims description 20
- 230000007935 neutral effect Effects 0.000 claims description 14
- 229910052500 inorganic mineral Inorganic materials 0.000 claims description 12
- 239000011707 mineral Substances 0.000 claims description 12
- 239000003381 stabilizer Substances 0.000 claims description 11
- 239000002253 acid Substances 0.000 claims description 10
- 230000006872 improvement Effects 0.000 claims description 10
- 229910052751 metal Inorganic materials 0.000 claims description 10
- 239000002184 metal Substances 0.000 claims description 10
- 229910052784 alkaline earth metal Inorganic materials 0.000 claims description 9
- LSNNMFCWUKXFEE-UHFFFAOYSA-L sulfite Chemical compound [O-]S([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-L 0.000 claims description 6
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 description 14
- 239000003513 alkali Substances 0.000 description 11
- 150000003839 salts Chemical class 0.000 description 11
- 229910052783 alkali metal Inorganic materials 0.000 description 10
- 238000010411 cooking Methods 0.000 description 8
- GRWZHXKQBITJKP-UHFFFAOYSA-N dithionous acid Chemical compound OS(=O)S(O)=O GRWZHXKQBITJKP-UHFFFAOYSA-N 0.000 description 8
- 238000000034 method Methods 0.000 description 7
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 6
- 229960001484 edetic acid Drugs 0.000 description 6
- JVBXVOWTABLYPX-UHFFFAOYSA-L sodium dithionite Chemical compound [Na+].[Na+].[O-]S(=O)S([O-])=O JVBXVOWTABLYPX-UHFFFAOYSA-L 0.000 description 6
- 230000008569 process Effects 0.000 description 5
- LSNNMFCWUKXFEE-UHFFFAOYSA-M Bisulfite Chemical compound OS([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-M 0.000 description 4
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 4
- 238000004061 bleaching Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 239000002023 wood Substances 0.000 description 4
- 229910052725 zinc Inorganic materials 0.000 description 4
- 239000011701 zinc Substances 0.000 description 4
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 3
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 3
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 description 3
- 238000011282 treatment Methods 0.000 description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- 235000008331 Pinus X rigitaeda Nutrition 0.000 description 2
- 235000011613 Pinus brutia Nutrition 0.000 description 2
- 241000018646 Pinus brutia Species 0.000 description 2
- 229920000388 Polyphosphate Polymers 0.000 description 2
- 241000219000 Populus Species 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 150000001340 alkali metals Chemical class 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 230000029087 digestion Effects 0.000 description 2
- 239000001205 polyphosphate Substances 0.000 description 2
- 235000011176 polyphosphates Nutrition 0.000 description 2
- 239000011734 sodium Substances 0.000 description 2
- 229910052708 sodium Inorganic materials 0.000 description 2
- 229910000029 sodium carbonate Inorganic materials 0.000 description 2
- GEHJYWRUCIMESM-UHFFFAOYSA-L sodium sulfite Chemical compound [Na+].[Na+].[O-]S([O-])=O GEHJYWRUCIMESM-UHFFFAOYSA-L 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- PENRVBJTRIYHOA-UHFFFAOYSA-L zinc dithionite Chemical compound [Zn+2].[O-]S(=O)S([O-])=O PENRVBJTRIYHOA-UHFFFAOYSA-L 0.000 description 2
- RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical compound S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 241000287127 Passeridae Species 0.000 description 1
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000005352 clarification Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 229910000037 hydrogen sulfide Inorganic materials 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- JESHZQPNPCJVNG-UHFFFAOYSA-L magnesium;sulfite Chemical compound [Mg+2].[O-]S([O-])=O JESHZQPNPCJVNG-UHFFFAOYSA-L 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- HYHCSLBZRBJJCH-UHFFFAOYSA-M sodium hydrosulfide Chemical compound [Na+].[SH-] HYHCSLBZRBJJCH-UHFFFAOYSA-M 0.000 description 1
- 229910052938 sodium sulfate Inorganic materials 0.000 description 1
- 235000011152 sodium sulphate Nutrition 0.000 description 1
- 235000010265 sodium sulphite Nutrition 0.000 description 1
- 238000010561 standard procedure Methods 0.000 description 1
- 239000010902 straw Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 235000000346 sugar Nutrition 0.000 description 1
- 150000008163 sugars Chemical class 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000005418 vegetable material Substances 0.000 description 1
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
- D21C3/22—Other features of pulping processes
- D21C3/222—Use of compounds accelerating the pulping processes
Definitions
- Another object is to improve the cooking liquors of this type. Another object is to stabilize the improved liquors with novel stabilizers. Yet another object is to improve the homogeneity of the pulps produced by these processes. Another object is to eliminate or minimize the occurrence of black spots in such pulps.
- the objects of the invention are accomplished by digesting the vegetable matter containing ligno cellulose in a neutral or acid liquor containing at least one of the sulphites ind bisulphites of alkali and alkali earth metals, which are used in the usual concentrations, and a metal hydrosulphite, preferably zinc or sodium hydrosulfite, the liquor preferably being stabilized, especially when the temperature of the cook is to be about 120-l70 C., by the addition of stabilizers of which formaldehyde, complex chelates, and polyphosphates are exemplary.
- ethylenediaminetetracetic acid is an exceptionally eflicient stabilizer.
- the cooks thatare carried out under pressure employ temperatures that are relatively high, circa 120 to 170 C., at which the hydrosulfites are relatively unstable, and under such circumstances it is desirable to add a stabilizer for the hydrosulfite to the liquor. Satisfactory stability is obtained with stabilizers of the type of formaldehyde, complex chelates, ethylene diamine tetraacetic acid, polyphosphates.
- hydrosulfite In carrying out the cook in the presence of hydrosulfite the formation of a part of the colored products is prevented.
- the hydrosulfites have marked reducing power and prevent the oxidation of the sugars and other organic products released in the disintegration of the vegetable materials, or destroy them after formation, thus producing a clearer and less colored pulp.
- the hydrosulfites because of their combined sulfur, which occurs in different forms, plays the double role of a delignifying agent and assists in the production of more homogeneous and softer pulps.
- the products NaI-IS and H 8 are delignifiers of strength and their action is added to that of the cooking liquors of alkali metal, or alkali, sulfite or bisulfite base and produce jointly a disintegration of the vegetable matter that is more thorough and more homogeneous. From this fact, the presence of sodium hydrosulfite in the cooking liquor makes the action of the mineral salt liquors more selective and protects the cellulose better.
- the invention is applicable to all the liquors employing mineral salts in acid or neutral medium and to all types of vegetable matter from pine wood to straw. This produces clearer pulps which may be used directly without bleaching, particularly if the medium is the neutral sulfite or bisulfite with hydrosulfite.
- hydrosulfites are the alkali and alkali earth metal hydrosulfites and zinc hydrosulfite.
- Sodium hydrosulfite is excellent and is generally employed, but it is not exclusively useful.
- the pulps produced by this method can be bleached by the standard methods. Particularly interesting results are obtained by submitting such pulps to a simple treatment with sodium hydrosulfite under conditions the same as those used for bleaching groundwood pulp. The improvement in whiteness is greater than that obtained with pulps not made in the presence of hydrosulfite.
- Example 1 The cooking of 2.5 kg. of poplar wood chips, 89% dry, by a mixture of calcium and magnesium sulfite in water at standard concentration, was carried out in a pressure digester (autoclave) of stainless steel.
- Example 2 2.5 kilos of Austin pine chips, 7075% dry, were cooked in a liquor containing a mixture of bisulfites of calcium and magnesium in an autoclave of stainless steel. The liquor at the start of the operation, mixed with the chips contained:
- a temperature of 105 C. was reached at 3 hrs. and 45 min. When the pressure reached 5 kg. it was maintained for 5 hrs. When the temperature reached 128, which required 1 hr. min. from 105, a second steady cook of 6 hrs. was used, so that the total cook was 16 hrs.
- the digester was blown, the product was washed and sent to a disintegrator.
- the pulp was examined, standard test samples showed reflectance of 45% with a Wratten blue filter and revealed lumps and numerous black spots.
- Example 3 A pulp was prepared from 2.5 kg. of poplar wood chips, 89% dry, using neutral sodium sulfite liquor buffered with sodium carbonate of which the composition, by weight based on thedry wood, was:
- Example 2 The same conditions as Example 1 were used except that the steady cook took place at 160 for 7 hrs.
- the pulp had a reflectance, by like test, of 51%.
- This pulp could be used directly for making printing paper without bleaching.
- the improvement which comprises digesting the vegetable matter in a liquor containing at least one of the sulfites and bisulfites of alkali and alkali earth metals, a metal hydrosulfite, of a metal from the group Zn and Na, in an amount between about .3 to about 2% by weight of the dry ligno-cellulose matter, and a stabilizer for the hydrosulfite, consisting in its essential operative constituent of ethylene diamine tetraacetic acid, at a temperature of l20l70 C.
- the improvement which comprises digesting the vegetable matter in a liquor containing at least one of the suliites and bisulfites of alkali and alkali earth metais, a metal hydrosulfite, in an amount between about .3 to about 2% by weight of the dry lignocellulose matter, and as a stabilizer for the hydrosulfite, ethylene diamine tetraacetic acid, at a temperature of -170 C.
- a cooking liquor of non-alkaline pH composed in its essential delignitying ingredients of at least one of the sulfites and bisulfites of alkali and alkali earth metals, a metal hydrosulfite, and a hydrosulfite stabilizer.
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- Paper (AREA)
Description
EXTRACTION OF CELLULOSE FROM VEGETABLE MATTER Robert Peteri, Paris, France, assignor to Compagnie de Saint-Gobain, Paris, France No Drawing. Filed Feb. 15, 1957, Ser. No. 640,304 Claims priority, application France Feb. 18, 1956 7 Claims. (Cl. 162-76) This invention relates to the extraction of cellulose from vegetable matter containing ligno-cellulose by acid or neutral liquors of mineral salt type and constitutes an improvement over known processes.
It is known that during the deligniiication of vegetable matter containing ligno-cellulose by cooking with mineral salts such as neutral sulfite or by bisulphite liquors the fibres become colored of which the intensity and hue depend onthe raw materials employed and the process of digestion adopted. In most cases the fibres must undergo subsequent treatments for clarification or bleachmg.
It is an object of the invention to produce pulp by these processes that is of better color and which requires no after treatment.
Another object is to improve the cooking liquors of this type. Another object is to stabilize the improved liquors with novel stabilizers. Yet another object is to improve the homogeneity of the pulps produced by these processes. Another object is to eliminate or minimize the occurrence of black spots in such pulps.
The objects of the invention, generally speaking, are accomplished by digesting the vegetable matter containing ligno cellulose in a neutral or acid liquor containing at least one of the sulphites ind bisulphites of alkali and alkali earth metals, which are used in the usual concentrations, and a metal hydrosulphite, preferably zinc or sodium hydrosulfite, the liquor preferably being stabilized, especially when the temperature of the cook is to be about 120-l70 C., by the addition of stabilizers of which formaldehyde, complex chelates, and polyphosphates are exemplary. I have also discovered that ethylenediaminetetracetic acid is an exceptionally eflicient stabilizer.
By this invention one produces directly, by digesting cellulosic vegetable matter with mineral salts, pulps which are both less colored and more homogeneous than was previously feasible. The hydrosulfites of sodium and zinc are particularly useful. The amount to use depends on the kind of ligno-cellulosic matter being digested and the conditions, such as temperature, of the cook. In general good results are obtained if one uses a proportion of hydrosulfite on the order of .3% to 2% of the weight of the dry cellulose matter. At the same time one uses of the non-alkaline sulfite or bisulfite the same proportions that are presently recommended.
The cooks thatare carried out under pressure employ temperatures that are relatively high, circa 120 to 170 C., at which the hydrosulfites are relatively unstable, and under such circumstances it is desirable to add a stabilizer for the hydrosulfite to the liquor. Satisfactory stability is obtained with stabilizers of the type of formaldehyde, complex chelates, ethylene diamine tetraacetic acid, polyphosphates.
In carrying out the cook in the presence of hydrosulfite the formation of a part of the colored products is prevented. The hydrosulfites have marked reducing power and prevent the oxidation of the sugars and other organic products released in the disintegration of the vegetable materials, or destroy them after formation, thus producing a clearer and less colored pulp.. In addition, at the relatively high temperatureof such cooks the hydrosulfites, because of their combined sulfur, which occurs in different forms, plays the double role of a delignifying agent and assists in the production of more homogeneous and softer pulps. By decomposition during digestion the hydrosulfite gives, according to the pH of the cooking liquor, the following reactions:
With a neutral liquor, sodium hydrosulfide:
With a sulfurous acid medium, hydrogen sulfide:
The products NaI-IS and H 8 are delignifiers of strength and their action is added to that of the cooking liquors of alkali metal, or alkali, sulfite or bisulfite base and produce jointly a disintegration of the vegetable matter that is more thorough and more homogeneous. From this fact, the presence of sodium hydrosulfite in the cooking liquor makes the action of the mineral salt liquors more selective and protects the cellulose better.
The invention is applicable to all the liquors employing mineral salts in acid or neutral medium and to all types of vegetable matter from pine wood to straw. This produces clearer pulps which may be used directly without bleaching, particularly if the medium is the neutral sulfite or bisulfite with hydrosulfite.
Among the useful hydrosulfites are the alkali and alkali earth metal hydrosulfites and zinc hydrosulfite. Sodium hydrosulfite is excellent and is generally employed, but it is not exclusively useful.
The pulps produced by this method can be bleached by the standard methods. Particularly interesting results are obtained by submitting such pulps to a simple treatment with sodium hydrosulfite under conditions the same as those used for bleaching groundwood pulp. The improvement in whiteness is greater than that obtained with pulps not made in the presence of hydrosulfite.
In all cases the process produces pulp that is better cooked and more homogeneous than by prior art methods, making bleaching easier. An advantage of technological and commercial nature arises from the fact that the chemicals and steam used in the digesters may be reduced while producing a pulp at least equal to that previously obtainable. No modification of present standard apparatus is necessary.
The following examples are exemplary, not limiting.
Example 1 The cooking of 2.5 kg. of poplar wood chips, 89% dry, by a mixture of calcium and magnesium sulfite in water at standard concentration, was carried out in a pressure digester (autoclave) of stainless steel. The cooking liquor, at the time of admission to the digester, containing its necessary water, had the following composition:
. G./l. S0 total 60 CaO 7.7 MgO 3.3
Example 2 2.5 kilos of Landes pine chips, 7075% dry, were cooked in a liquor containing a mixture of bisulfites of calcium and magnesium in an autoclave of stainless steel. The liquor at the start of the operation, mixed with the chips contained:
S02, total CaO 7.7 h1g0 3.3
A temperature of 105 C. was reached at 3 hrs. and 45 min. When the pressure reached 5 kg. it was maintained for 5 hrs. When the temperature reached 128, which required 1 hr. min. from 105, a second steady cook of 6 hrs. was used, so that the total cook was 16 hrs.
The digester was blown, the product was washed and sent to a disintegrator. The pulp was examined, standard test samples showed reflectance of 45% with a Wratten blue filter and revealed lumps and numerous black spots.
Operating under the same conditions, but with the addition of 2% of sodium hydrosulfite stabilized by .6% formaldehyde there was obtained a pulp free from lumps and with very few black spots. The same test showed a reflectance of.5 1%, an improvement of 6 points.
Example 3 A pulp was prepared from 2.5 kg. of poplar wood chips, 89% dry, using neutral sodium sulfite liquor buffered with sodium carbonate of which the composition, by weight based on thedry wood, was:
Percent Sodium sulfate 14 Sodium carbonate 4.5
The same conditions as Example 1 were used except that the steady cook took place at 160 for 7 hrs. The pulp had a reflectance, by like test, of 51%.
I When the operation was repeated but with the addition of 1% sodium hydrosulfite, stabilized by .3% formaldehyde, the reflectance of a standard sample was 56%, a gain of 5 points.
This pulp could be used directly for making printing paper without bleaching.
Comparable results are obtainable using other hydrosulfites, particularly zinc hydrosulfites.
As many apparently widely different embodiments of the present invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited .to the specific embodiments.
What is claimed is:
' 1. In the extraction of cellulose from vegetable matter 3 containing ligno-cellulose by mineral salts in neutral and acid media, the improvement which comprises digesting the vegetable matter in a liquor containing at least one of the sulfites and bisulfites of alkali and alkali earth metals, a metal hydrosulfite, of a metal from the group Zn and Na, in an amount between about .3 to about 2% by weight of the dry ligno-cellulose matter, and a stabilizer for the hydrosulfite, consisting in its essential operative constituent of ethylene diamine tetraacetic acid, at a temperature of l20l70 C.
2. In the extraction of cellulose from vegetable matter containing ligno cellulose by mineral salts in neutral and acid media, the improvement which comprises digesting the vegetable matter in a liquor containing at least one of the suliites and bisulfites of alkali and alkali earth metais, a metal hydrosulfite, in an amount between about .3 to about 2% by weight of the dry lignocellulose matter, and as a stabilizer for the hydrosulfite, ethylene diamine tetraacetic acid, at a temperature of -170 C.
3. In the extraction of cellulose from vegetable matter containing ligno cellulose by mineral salts in neutral and acid media, the improvement which comprises digesting the vegetable matter in a liquor containing at least one of the sulfites and bisulfites of alkali and alkali earth metals, a metal hydrosulfite, in an amount between about .3 to about 2% by weight of the dry ligno cellulose matter, and a stabilizer for the hydrosulfite, at a temperature of 120170 C.
4. In the extraction of cellulose from vegetable matter containing ligno-cellulose by mineral salts in neutral and acid media, the improvement which comprises digesting the vegetable matter in a liquor containing at least one of the sulfites and bisulfites of alkali and alkali earth metals, a metal hydrosulfite, in an amount between about .3 to 2% by weight of the dry ligno-cellulose matter, and ethylene diamine tetraacetic acid.
5. In the extraction of cellulose from vegetable matter containing ligno-cellulose by mineral salts in neutral and acid media, the improvement which comprises digesting the vegetable matter in a liquor containing at least one of the sulfites and bisulfites of 'alkali and alkali earth metals, a metal hydrosulfite, and a stabilizer for the hydrosulfite.
6. In the extraction of cellulosefrom vegetable matter containing ligno-cellulose by mineral salts in neutral and acid media, the improvement which comprises digesting the vegetable matter in a liquor containing at least one of the whites and bisulfites of alkali and alkali earth metals, a metal hydrosulfite from the group consisting of alkali metals and zinc, and ethylene diamine tetraacetic acid.
7. A cooking liquor of non-alkaline pH composed in its essential delignitying ingredients of at least one of the sulfites and bisulfites of alkali and alkali earth metals, a metal hydrosulfite, and a hydrosulfite stabilizer.
References Cited in the file of this patent UNITED STATES PATENTS 1,451,125 Summers Apr. 10, 1923 1,910,613 Kylander May 23,1933 2,070,585 Dreyfus Feb. 16, 1937 2,656,244 Gray et al. Oct. 20, '1953 2,707,145 Sparrow et a1 ,Apr. 26, 1955
Claims (1)
- 5. IN THE EXTRACTION OF CELLULOSE FROM VEGETABLE MATTER CONTAINING LIGNO-CELLULOSE BY MINERAL SALTS IN NEUTRAL AND ACID MEDIA, THE IMPROVEMENT WHICH COMPRISES DIGESTING THE VEGETABLE MATTER IN A LIQUOR CONTAINING AT LEAST ONE OF THE SULFITES AND BISULFITES OF ALKALI AND ALKALI EARTH METALS, A METAL HYDROSULFITE, AND A STABILIZER FOR THE HYDROSULFITE.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR1063893X | 1956-02-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2947657A true US2947657A (en) | 1960-08-02 |
Family
ID=9601401
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US640304A Expired - Lifetime US2947657A (en) | 1956-02-18 | 1957-02-15 | Extraction of cellulose from vegetable matter |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US2947657A (en) |
| DE (1) | DE1063893B (en) |
| FR (1) | FR1145782A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3088861A (en) * | 1960-08-03 | 1963-05-07 | Weyerhaeuser Co | Method of manufacturing chemical pulp from lignocellulose material |
| US3363970A (en) * | 1963-11-29 | 1968-01-16 | Geigy Ag J R | Alkali metal salts of oxygen acids tetravalent sulfur and metal complexing agents inan acidic dyebath and polyamide dyeing therewith |
| US3448003A (en) * | 1966-01-03 | 1969-06-03 | Dow Chemical Co | On-stream cleaning of wood chip digesters using chelating agents |
| US4135967A (en) * | 1969-09-26 | 1979-01-23 | Societe Generale De Brevets Industriels Et Ohimiques | Process for producing cellulose pulp by solid phase digestion |
| US4767500A (en) * | 1985-05-18 | 1988-08-30 | Kraftanlagen Aktiengesellschaft | Sulfite cooking method for the production of cellulose from materials containing lignocellulose with recovery of the cooking chemicals |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1451125A (en) * | 1922-04-21 | 1923-04-10 | Bertrand S Summers | Process for the production of paper pulp and the like |
| US1910613A (en) * | 1927-03-17 | 1933-05-23 | Kylander Karl Yrjo | Preliminary boiling or cooking process for cellulose |
| US2070585A (en) * | 1933-03-07 | 1937-02-16 | Dreyfus Henry | Manufacture of cellulose from ligno-cellulosic products |
| US2656244A (en) * | 1950-07-15 | 1953-10-20 | Rayonier Inc | Process of recovering chemicals from smelts obtained in pulping operation |
| US2707145A (en) * | 1952-09-11 | 1955-04-26 | Scott Paper Co | Method of bleaching mechanically disintegrated wood pulp |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE742617C (en) * | 1941-03-28 | 1943-12-14 | Chem Fab Joh A Benckiser G M B | Process for preventing resin precipitations in paper manufacture |
| AT175782B (en) * | 1951-02-28 | 1953-08-10 | Waldhof Zellstoff Fab | Process for the production of semi-pulp |
| DE912169C (en) * | 1952-02-22 | 1954-05-24 | Georg Jayme Dr Ing | Process for the alkaline digestion of plant substances |
| DE942553C (en) * | 1954-03-11 | 1956-05-03 | Basf Ag | Process for the production of cellulose from plant material |
-
1956
- 1956-02-18 FR FR1145782D patent/FR1145782A/en not_active Expired
-
1957
- 1957-02-15 US US640304A patent/US2947657A/en not_active Expired - Lifetime
- 1957-02-16 DE DES52378A patent/DE1063893B/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1451125A (en) * | 1922-04-21 | 1923-04-10 | Bertrand S Summers | Process for the production of paper pulp and the like |
| US1910613A (en) * | 1927-03-17 | 1933-05-23 | Kylander Karl Yrjo | Preliminary boiling or cooking process for cellulose |
| US2070585A (en) * | 1933-03-07 | 1937-02-16 | Dreyfus Henry | Manufacture of cellulose from ligno-cellulosic products |
| US2656244A (en) * | 1950-07-15 | 1953-10-20 | Rayonier Inc | Process of recovering chemicals from smelts obtained in pulping operation |
| US2707145A (en) * | 1952-09-11 | 1955-04-26 | Scott Paper Co | Method of bleaching mechanically disintegrated wood pulp |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3088861A (en) * | 1960-08-03 | 1963-05-07 | Weyerhaeuser Co | Method of manufacturing chemical pulp from lignocellulose material |
| US3363970A (en) * | 1963-11-29 | 1968-01-16 | Geigy Ag J R | Alkali metal salts of oxygen acids tetravalent sulfur and metal complexing agents inan acidic dyebath and polyamide dyeing therewith |
| US3448003A (en) * | 1966-01-03 | 1969-06-03 | Dow Chemical Co | On-stream cleaning of wood chip digesters using chelating agents |
| US4135967A (en) * | 1969-09-26 | 1979-01-23 | Societe Generale De Brevets Industriels Et Ohimiques | Process for producing cellulose pulp by solid phase digestion |
| US4767500A (en) * | 1985-05-18 | 1988-08-30 | Kraftanlagen Aktiengesellschaft | Sulfite cooking method for the production of cellulose from materials containing lignocellulose with recovery of the cooking chemicals |
Also Published As
| Publication number | Publication date |
|---|---|
| FR1145782A (en) | 1957-10-29 |
| DE1063893B (en) | 1959-08-20 |
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