US2855272A - Regenerating spent cooking liquors produced in making paper pulp - Google Patents
Regenerating spent cooking liquors produced in making paper pulp Download PDFInfo
- Publication number
- US2855272A US2855272A US548525A US54852555A US2855272A US 2855272 A US2855272 A US 2855272A US 548525 A US548525 A US 548525A US 54852555 A US54852555 A US 54852555A US 2855272 A US2855272 A US 2855272A
- Authority
- US
- United States
- Prior art keywords
- carbon
- liquor
- alkali metal
- paper pulp
- making paper
- 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
Links
- 238000010411 cooking Methods 0.000 title description 13
- 229920001131 Pulp (paper) Polymers 0.000 title description 4
- 230000001172 regenerating effect Effects 0.000 title description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 24
- 238000000034 method Methods 0.000 description 17
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 15
- 229910052799 carbon Inorganic materials 0.000 description 15
- 229910052783 alkali metal Inorganic materials 0.000 description 14
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical class [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 13
- 230000008569 process Effects 0.000 description 13
- 238000006243 chemical reaction Methods 0.000 description 12
- 229910052757 nitrogen Inorganic materials 0.000 description 11
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 10
- -1 alkali metal salts Chemical class 0.000 description 9
- LELOWRISYMNNSU-UHFFFAOYSA-N hydrogen cyanide Chemical compound N#C LELOWRISYMNNSU-UHFFFAOYSA-N 0.000 description 6
- 239000002655 kraft paper Substances 0.000 description 6
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 5
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 5
- XFXPMWWXUTWYJX-UHFFFAOYSA-N Cyanide Chemical compound N#[C-] XFXPMWWXUTWYJX-UHFFFAOYSA-N 0.000 description 5
- 239000001569 carbon dioxide Substances 0.000 description 5
- 229910002092 carbon dioxide Inorganic materials 0.000 description 5
- 229910002091 carbon monoxide Inorganic materials 0.000 description 5
- 238000010521 absorption reaction Methods 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 239000002023 wood Substances 0.000 description 4
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 150000001340 alkali metals Chemical class 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- LSNNMFCWUKXFEE-UHFFFAOYSA-L sulfite Chemical compound [O-]S([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-L 0.000 description 3
- BZWKPZBXAMTXNQ-UHFFFAOYSA-N sulfurocyanidic acid Chemical compound OS(=O)(=O)C#N BZWKPZBXAMTXNQ-UHFFFAOYSA-N 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 2
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 2
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 2
- 235000011941 Tilia x europaea Nutrition 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 229910000288 alkali metal carbonate Inorganic materials 0.000 description 2
- 150000008041 alkali metal carbonates Chemical class 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000001427 coherent effect Effects 0.000 description 2
- 229910001873 dinitrogen Inorganic materials 0.000 description 2
- 239000011872 intimate mixture Substances 0.000 description 2
- 238000002386 leaching Methods 0.000 description 2
- 239000004571 lime Substances 0.000 description 2
- 150000002825 nitriles Chemical class 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 238000004537 pulping Methods 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 229910000029 sodium carbonate Inorganic materials 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000005995 Aluminium silicate Substances 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
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- 239000005864 Sulphur Substances 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 235000012211 aluminium silicate Nutrition 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 238000003763 carbonization Methods 0.000 description 1
- 238000010000 carbonizing Methods 0.000 description 1
- 238000009993 causticizing Methods 0.000 description 1
- 239000003518 caustics Substances 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- KXZJHVJKXJLBKO-UHFFFAOYSA-N chembl1408157 Chemical compound N=1C2=CC=CC=C2C(C(=O)O)=CC=1C1=CC=C(O)C=C1 KXZJHVJKXJLBKO-UHFFFAOYSA-N 0.000 description 1
- 238000005352 clarification Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000012452 mother liquor Substances 0.000 description 1
- 229940072033 potash Drugs 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Substances [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 1
- 235000015320 potassium carbonate Nutrition 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 235000011121 sodium hydroxide Nutrition 0.000 description 1
- 229910052938 sodium sulfate Inorganic materials 0.000 description 1
- GRVFOGOEDUUMBP-UHFFFAOYSA-N sodium sulfide (anhydrous) Chemical compound [Na+].[Na+].[S-2] GRVFOGOEDUUMBP-UHFFFAOYSA-N 0.000 description 1
- 235000011152 sodium sulphate Nutrition 0.000 description 1
- 229910021653 sulphate ion Inorganic materials 0.000 description 1
- 239000004291 sulphur dioxide Substances 0.000 description 1
- 235000010269 sulphur dioxide Nutrition 0.000 description 1
Images
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
- D21C11/00—Regeneration of pulp liquors or effluent waste waters
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S423/00—Chemistry of inorganic compounds
- Y10S423/03—Papermaking liquor
Definitions
- the aim and object of my process is to recover for subsequent re-use the soda salts present in said liquor and simultaneously achieve a better utilization of the carbon resident in the contained organics, in part, in the form of hydrogen cyanide, same constituting a valuable byproduct.
- the cyanized mass from the nitrogen treatment step is next cooled and leached with water yielding a solution of alkali metal cyanide and a residue consisting largely of carbon.
- this residue is in part commingled with fresh evaporated liquor prior to carbonizat on.
- re-cycling can theoretically raise the carbon ratio to any extent desired.
- the aim and object of such increase of carbon is to present a dry mass entirely without stickiness in the nitrogen absorption phase.
- the solution of sodium cyanide obtained in the leaching step is next commingled with carbon dioxide. Hydrogen cyanide is evolved and is recovered by conventional means, such as compression to the liquid state in which form it is shipped.
- the solution now consists largely of carbonate of the alkali metal used in cooking the pulp, with shome sulphocyanide which may be ignored or, if it be desired to save it, recovered. If the solution be saturated with carbonate it is only necessary to cool same to obtain a copious crystallization of carbonate which is readily separated by thecentrifuge leaving a mother liquor correspondingly high in sulphocyanide.
- any liquor may require clarification.
- the method selected to make the carbon-alkali metal complex is in itself of no moment as I consider it as out-
- a convenient method is to feed a slurry of the mixed recycled carbonaceous residue and evaporated liquor to a, rotary kiln heated by direct fire to such a temperature that finished material, having the general appearance of cement clinker, issues from the firing end.
- Thermassbeingcyanided is contained in a chamber so placed between, twoheataccumulators that nitrogen traversing said mass alternately .in opposite direction is heated by; abstracting. heat fromone of said regenerators while conveying heat to the-other regenerator after having passed through the reacting mass.
- a oint intermediate between the reaction chamber and the heat accumulator absorbing heatsufficient air is admitted to burn virtuallyall the carbon monoxide made in said reaction.
- Thegases entering theheating or. absorbing accumulator are thus increased'in temperature by the heat developed by said burning carbon monoxide and this heat is likewise stored in said accumulator thus furnishing all the heat required.
- the source of the nitrogen is found in the process itself.
- the addition of air to burn the carbon monoxide produced inthe reaction will furnish more nitrogen than the process'consumes .so a part must be voided. All that is required is tostrip the cooled gas issuing from the absorbing-accumulator of its increment of carbon dioxide by any conventional means :such as absorption in water under pressure, in solutionsof alkaline carbonates,,in caustic washes, or in organic absorbing media. Further instructions would be superfluous.
- soda salts and alkali metal salts have been used indiscriminately. In practice, of course, all commercial use is with the cheaper soda, nevertheless as potash could be substituted advantageously, due to more ready nitrogen absorption. I have used the term alkali metal as a generic expression for either potassium or sodium or to a mixture of both.
- the method of recovering the alkali metal salts contained in a spent cooking liquor derived from the making of paper pulp, in a form suitable .for re-cycling into said cooking operation which comprises; evaporating said liquor and commingling same with a carbon residual derived from a later step; carbonizing saidmixture to yield an intimate mixture of alkali metal salts and carbon in the form of a coherent, porous body; traversingsaid carbonized substance with nitrogen gas at-a temperature between 1700 F. and 2600 F.
Landscapes
- Paper (AREA)
Description
Oct. 7, 1958 A. M. THOMSEN 2,855,272.
. REGENERATING SPENT cooxmc LIQUORS PRODUCED IN I MAKING: PAPER PULP Filed Nov. 22, 1955 FHA-6Z0; l/dzatdes caalerr I Mmpau- #1440121 I n Kaolin; m, {'ystem v MENTOR.
United States Patent REGENERATIN G SPENT COOKING LIQUORS PRODUCED IN MAKING PAPER PULP 7 Alfred M. Thomson, San Francisco, Calif.
Application November 22,1955, Serial No. 548,525
1 Claim. (Cl. 23-63) This application is a continuation, in part, of a disclosure previously made and bearing Ser. No. 165,885, filed June 3, 1950, now abandoned, being itself a continuation-in-part of U. S. No. 2,510,668. The instant application is concerned solely with that phase of said disclosure relating to the regeneration of the resident alkali metal salts in such a manner that they pass through the temporary phaseof alkali metal cyanides before becoming once more employed as a cooking liquor.
I will commence my description by taking a special type of such a liquor, that produced in Kraft cooking, though my process has a much wider application. Subsequently I shall describe sundry modifications that makes it available for practically any and all types of pulp making. Inasmuch as wood cooked ,by this well known method is generally pulped with 25% of its weight in a mixture of caustic soda and sodium sulphide and rather more than half of said wood, by weight, is put into solution, it follows that said liquor will consist roughly of one-third soda salts as originally added and two-thirds of organics derived from the wood. Variations in wood species and individual preferences prevent a more accurate specification as to actual composition of said liquor after its use in the cooking operation.
The aim and object of my process is to recover for subsequent re-use the soda salts present in said liquor and simultaneously achieve a better utilization of the carbon resident in the contained organics, in part, in the form of hydrogen cyanide, same constituting a valuable byproduct.
I wish to emphasize at this point that the chemistry involved in such recovery of soda salts and such production of hydrogen cyanide is very old, but though the chemical reactions are old I believe the application of same in the manner herein combined and executed is definitely new and will constitute a valuable addition to the pulp industry.
In my specific illustration which is illustrated in the drawing I take, as previously stated, spent liquor from the kraft process, evaporate it in conventional manner and then dessicate it completely raising the temperature employed to over 500 F. at the close soas to carbonize the organics. In this manner I obtain a very porous and yet coherent product consisting of alkali metal salts and carbon, the latter constituting about 40% of the total weight. In order to increase this percentage of carbon 1 commingle with the evaporated liquor before carbonization a carbonaceous residue obtained at a later step in my process and I can thus raise the content of carbon to virtually any extent desired. The advantage of this step will be commented upon at a later point in my description.
I then subject the carbonaceous or carbonized product to the action of highly heated nitrogen gas which is absorbed by the soda salts with the formation of cyanides,
2 regenerating a spent cooking liquor from the pulping operation.
The cyanized mass from the nitrogen treatment step is next cooled and leached with water yielding a solution of alkali metal cyanide and a residue consisting largely of carbon. As before mentioned this residue is in part commingled with fresh evaporated liquor prior to carbonizat on. Inasmuch as the ratio of carbon to soda in the liquor residue, without such admixture of re-cycled carbon, is greater than is actually consumed in the process, such re-cycling can theoretically raise the carbon ratio to any extent desired. The aim and object of such increase of carbon is to present a dry mass entirely without stickiness in the nitrogen absorption phase. I believe that much if not all of the difiiculty experienced in the past by other operators is inherent in any operation which does not use a carbon-alkali metal complex so constituted that the fused salts during nitrogen absorption remain securely held in a carbon matrix while still permitting the free passage of nitrogen between individual lumps, and through diffusion, access to the interior of said lumps. This object is attained in the manner herein described to better advantage than I have been able to find anywhere in the appropriate literature which is very extensive.
The solution of sodium cyanide obtained in the leaching step is next commingled with carbon dioxide. Hydrogen cyanide is evolved and is recovered by conventional means, such as compression to the liquid state in which form it is shipped. The solution now consists largely of carbonate of the alkali metal used in cooking the pulp, with shome sulphocyanide which may be ignored or, if it be desired to save it, recovered. If the solution be saturated with carbonate it is only necessary to cool same to obtain a copious crystallization of carbonate which is readily separated by thecentrifuge leaving a mother liquor correspondingly high in sulphocyanide.
It will be obvious that having thus obtained the major part of the resident alkali metal of the spent cooking liquor in the form of carbonate the recovery is finished as it may be re-cycled to any conventional cooking step; thus: for kraft, sulphate, or soda cooking it will be recycled just prior to the causticizing step; for sulphite work it will be treated with sulphur dioxide. It is thus seen that my process delivers a reclaimed soda that can be used by any process, and conversely, any liquor can be used in place of kraft, the only difierence residing in the amount of sulphocyanide yielded as this chemical cannot be regarded as having any place in conventional pulping. However, inasmuch as cyanide in any form is far more valuable than any alkali metal carbonate such conversion is not a fault from an economic view point.
The expression any liquor may require clarification.
1 The conventional lime based acid sulphite cook liquor side of this disclosure.
cannot be used, per se. But if treated with sodium sulphate and/or carbonate and the lime salts precipitated removed, then it will function as indicated. Likewise, the liquor resulting from the magnesium based acid sulphite can be treated with sodium carbonate, as yielded by my process, and is then acceptable. If it be thought that the sulphur removal from the kraft liquor is objectionable it is, of course, corrected by increasing the sulphide content from another furnace to compensate.
The method selected to make the carbon-alkali metal complex is in itself of no moment as I consider it as out- A convenient method, however, is to feed a slurry of the mixed recycled carbonaceous residue and evaporated liquor to a, rotary kiln heated by direct fire to such a temperature that finished material, having the general appearance of cement clinker, issues from the firing end.
I have already called attention to the importance of having the mass to be cyanized in the correct mechanical condition of a most intimate mixture of soda salts and carbon while retaining it in the form of actual lumps that still are extremely porous. Another very important feature of my process is the way this mass and thenltrogen ,by which itlis ;trav,ersed.is heated to. reaction tempera ture herewithqspecified -as anythnig between .-.a low of 1700: 1'1. ,a1;d.ahigh of 2600 F. Below the lower temperature the reaction isso slow'as to-become impractical andabove the;higher lirnit,'volatilization of the cyanide and formation .oflcyanamidebothzcontribute to neutralize the ,good result, ;i. e., .speed of reaction, which naturally iSqfllCtIBSj-llli of the elevated temperature. Heatingzis accomplished inrthefollowing manner.
Thermassbeingcyanided is contained in a chamber so placed between, twoheataccumulators that nitrogen traversing said mass alternately .in opposite direction is heated by; abstracting. heat fromone of said regenerators while conveying heat to the-other regenerator after having passed through the reacting mass. At a oint intermediate between the reaction chamber and the heat accumulator absorbing heatsufficient air is admitted to burn virtuallyall the carbon monoxide made in said reaction. Thegases entering theheating or. absorbing accumulator are thus increased'in temperature by the heat developed by said burning carbon monoxide and this heat is likewise stored in said accumulator thus furnishing all the heat required. The reaction chamber and its contained mass is not heated save by heat transferred from the traversing nitrogen which becomes the heat carrier of the reaction, this being strongly endothermic. The correction of previous attempts of making cyanide by the joint elfect of the two improvements herein disclosed virtually removes=all formerly encountered difficulties.
To accomplish its work as a heat carrier the nitrogen must bepassed through the apparatus at a rapid rate, and this in turn is favorable to the reaction which is impeded by .the presence of more thansmall-amounts of carbon monoxide. It is obvious that the speed of flow will govern the amount of such carbon monoxide which should not be allowed to exceed 7% of-the introgen as it issues from the reaction chamber. Control is established by continuous gas readings on the carbon dioxide in the cool .gas issuing from the absorbing heat accumulator. If the current of nitrogen be so regulated as to keep the carbon dioxide below 10% excellent results will be certain to follow.
The source of the nitrogen is found in the process itself. The addition of air to burn the carbon monoxide produced inthe reaction will furnish more nitrogen than the process'consumes .so a part must be voided. All that is required is tostrip the cooled gas issuing from the absorbing-accumulator of its increment of carbon dioxide by any conventional means :such as absorption in water under pressure, in solutionsof alkaline carbonates,,in caustic washes, or in organic absorbing media. Further instructions would be superfluous.
It is likewise obvious that the time elapsing between each reversal of flow through the entire system is a matter concerned not with the process but with its apparatus. If the heat accumulators be relatively large then considerable time, say 10 minutes may elapse between each reversal, if they be made smaller as a matter of decreasing the capital cost then a more rapid reversal is mandatory. In any event the temperature of a definite spot should not vary more than F. from the start to the finish of a uni-directional flow. If the variation be greaterthan that then the reversal time must be shortened to avoid damage to the basic accumulators.
Throughout this disclosure the terms soda salts and alkali metal salts have been used indiscriminately. In practice, of course, all commercial use is with the cheaper soda, nevertheless as potash could be substituted advantageously, due to more ready nitrogen absorption. I have used the term alkali metal as a generic expression for either potassium or sodium or to a mixture of both.
Having thus fully described my process with a preferred version as applied to a kraft cooking liquor, I claim:
The method of recovering the alkali metal salts contained in a spent cooking liquor derived from the making of paper pulp, in a form suitable .for re-cycling into said cooking operation, which comprises; evaporating said liquor and commingling same with a carbon residual derived from a later step; carbonizing saidmixture to yield an intimate mixture of alkali metal salts and carbon in the form of a coherent, porous body; traversingsaid carbonized substance with nitrogen gas at-a temperature between 1700 F. and 2600 F. until the constituent alkali metal salts are substantially converted into the corresponding cyanides; leaching the cyanized mass'with water to produce a solution of alkali metal cyanides .anda residue of carbon; re-cycling said carbon residual to'where previously specified; commingling said cyanide solution with carbon dioxide thus obtaining a solution of alkali metal carbonate suitable for re-cycling into thepulping operation, with attendant evolution of hygroden cyanide gas.
References Cited in the file of this patent UNITED STATES PATENTS 576,264 Gilmour Feb. ,2, 1897 1,308,184 McAfee Iulyl, 1919 1,408,754 McElroy Mar; 7, 1922 2,275,792 Moseby Mar. 10, 1942 2,495,248 Gagliarde Jan. 24, 1950 2,552,183 Knight May 8, 1951 2,586,030 Groombridge -Feb. 19, 1952
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US548525A US2855272A (en) | 1955-11-22 | 1955-11-22 | Regenerating spent cooking liquors produced in making paper pulp |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US548525A US2855272A (en) | 1955-11-22 | 1955-11-22 | Regenerating spent cooking liquors produced in making paper pulp |
Publications (1)
Publication Number | Publication Date |
---|---|
US2855272A true US2855272A (en) | 1958-10-07 |
Family
ID=24189210
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US548525A Expired - Lifetime US2855272A (en) | 1955-11-22 | 1955-11-22 | Regenerating spent cooking liquors produced in making paper pulp |
Country Status (1)
Country | Link |
---|---|
US (1) | US2855272A (en) |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US576264A (en) * | 1897-02-02 | James dick gilmour | ||
US1308184A (en) * | 1919-07-01 | Process of recovering the alkali used in pulp digestion | ||
US1408754A (en) * | 1918-02-27 | 1922-03-07 | Ferro Chemicals Inc | Fixation of nitrogen |
US2275792A (en) * | 1940-08-01 | 1942-03-10 | Mathieson Alkali Works Inc | Causticization of soda |
US2495248A (en) * | 1946-08-08 | 1950-01-24 | Comb Eng Superheater Inc | Smelting process of recovering chemicals from the black liquor derived in pulp mills |
US2552183A (en) * | 1945-04-07 | 1951-05-08 | Dorr Co | Two-stage causticizing |
US2586030A (en) * | 1947-05-08 | 1952-02-19 | Celanese Corp | Manufacture of cyanides |
-
1955
- 1955-11-22 US US548525A patent/US2855272A/en not_active Expired - Lifetime
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US576264A (en) * | 1897-02-02 | James dick gilmour | ||
US1308184A (en) * | 1919-07-01 | Process of recovering the alkali used in pulp digestion | ||
US1408754A (en) * | 1918-02-27 | 1922-03-07 | Ferro Chemicals Inc | Fixation of nitrogen |
US2275792A (en) * | 1940-08-01 | 1942-03-10 | Mathieson Alkali Works Inc | Causticization of soda |
US2552183A (en) * | 1945-04-07 | 1951-05-08 | Dorr Co | Two-stage causticizing |
US2495248A (en) * | 1946-08-08 | 1950-01-24 | Comb Eng Superheater Inc | Smelting process of recovering chemicals from the black liquor derived in pulp mills |
US2586030A (en) * | 1947-05-08 | 1952-02-19 | Celanese Corp | Manufacture of cyanides |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US1743080A (en) | Manufacture of pulp and treatment of residual liquors, etc. | |
US4098886A (en) | Gas purification liquors | |
US1502592A (en) | Process for preparing decolorizing carbon | |
US3711593A (en) | Fluidized process for regeneration of chemicals from sulfite pulping process | |
US2855272A (en) | Regenerating spent cooking liquors produced in making paper pulp | |
US1560900A (en) | Process of treating wate sodium monosulphite liquors | |
US2696424A (en) | Preparation of calcium bisulfite cooking acid from waste sulfite liquor | |
US2993753A (en) | Sodium sulphite liquor recovery | |
US2752243A (en) | Ammonia-sulfur dioxide cooking acid regeneration | |
US4208245A (en) | Pyrolysis of spent pulping liquors | |
CN108821244A (en) | The recovery process of alkali and catalyst in a kind of desulfurization waste liquor | |
US1852264A (en) | Method of dry distilling waste liquors from the soda pulp manufacture | |
US1934655A (en) | Treatment of residual liquors | |
JPH06506733A (en) | Chemical substances and energy recovery method from black liquor | |
US3654071A (en) | Process for replacing sodium and sulfur losses and for controlling the sulfide content in sodium- and sulfur-containing cellulosic digesting liquors | |
US2774666A (en) | Recovery of cooking liquor from spent soda pulping liquors | |
US3944462A (en) | Coking of waste kraft pulping liquors at lowered pH | |
US2750290A (en) | Recovery of cooking liquor from spent semi-chemical pulping liquors | |
US2947656A (en) | Processing of spent cooking liquors | |
US1606501A (en) | Treatment of residual liquor | |
US1345220A (en) | Process of treating waste gases or vapors from soda-cellulose factories | |
US1575703A (en) | Process for the manufacture of a highly-active decolorizing charcoal | |
US3038834A (en) | Method of carbonizing spent cooking liquor from pulp making | |
US1801945A (en) | Process for regenerating liquors containing alkali salts and organic matter | |
NO117606B (en) |