WO1989004395A1 - Procede de recuperation chimique de kraft - Google Patents

Procede de recuperation chimique de kraft Download PDF

Info

Publication number
WO1989004395A1
WO1989004395A1 PCT/US1988/003801 US8803801W WO8904395A1 WO 1989004395 A1 WO1989004395 A1 WO 1989004395A1 US 8803801 W US8803801 W US 8803801W WO 8904395 A1 WO8904395 A1 WO 8904395A1
Authority
WO
WIPO (PCT)
Prior art keywords
kraft
sodium
recovery furnace
sodium sulfate
aqueous phase
Prior art date
Application number
PCT/US1988/003801
Other languages
English (en)
Inventor
Kenneth R. Kurple
Original Assignee
Kurple Kenneth R
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Kurple Kenneth R filed Critical Kurple Kenneth R
Publication of WO1989004395A1 publication Critical patent/WO1989004395A1/fr

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
    • D21C11/00—Regeneration of pulp liquors or effluent waste waters
    • D21C11/04—Regeneration of pulp liquors or effluent waste waters of alkali lye

Definitions

  • the kraft pulping process contains a kraft recovery furnace which converts concentrated kraft black liquor into an inorganic ash which is then further chemically processed into caustic chemicals which are used to convert wood into pulp.
  • the kraft pulping process is a closed loop pulping process wherein the spent kraft liquor is used to produce the pulping chemicals that are used in the process.
  • the kraft recovery furnace is usually the single most expensive piece of equipment at a kraft pulp mill.
  • the cost of just one kraft recovery furnace is usually in excess of 100 million dollars.
  • the capacity of a kraft recovery furnace limits the total pulp production of the kraft pulp mill. Even though the rest of the kraft pulp mill could produce more pulp it is the capacity of the kraft recovery furnace that determines how much pulp is produced.
  • the present invention discloses a new process that allows a kraft pulp mill to dramatically increase its production of pulp without overloading the kraft recovery furnace. In fact no additional kraft recovery furnace is required and therefore no new investment for a kraft recovery furnace is needed.
  • This new process enables a kraft pulp mill to take advantage of peak demands for pulp and paper without the risk of overloading the recovery furnace.
  • this new process provides the kraft pulp mill with additional revenue from by-products that were previously burned for their fuel value.
  • This new process is able to accomplish this without interfering with the chemistry of the kraft pulping process. That is, no new chemicals or process chemistry is introduced into the kraft pulping process. This approach avoids any major investment that would be required to make such changes.
  • FIG. 1 illustrates the conventional process flow diagram for the kraft pulping process. This is still the standard process for operating kraft pulp mills. In this diagram, it should be noted that the entire process stream, the concentrated kraft black liquor, is processed in the kraft recovery furnace to produce an inorganic ash which is further chemically processed into pulping chemicals.
  • the new process of the present invention (Fig.
  • kraft lignin that is present in the kraft black liquor is removed from the process stream so that all that remains in the kraft black liquor are the wood sugars and other organics, organic acids and also the inorganic or organic anion from the acid that is used to acidify the kraft black liquor in order to remove the kraft lignin.
  • the residual liquor will contain sodium sulfate where sulfuric acid has been used to acidify the black liquor in order to remove the kraft lignin.
  • this sodium sulfate may be left in this residual liquor and concentrated and then burned in the kraft recovery furnace. This is because sodium sulfate is reduced in the recovery furnace to produce sodium sulfide which is one of the pulping chemicals.
  • sodium sulfate added to the kraft recovery furnace in order to maintain a sodium sulfide balance. Therefore the presence of a certain amount of sodium sulfate in this residual liquor may be tolerated with no problems.
  • This concept is shown in Figure 2, the Bypass Process.
  • the economic advantages of this Bypass Process as shown in Figure 2 will be appreciated by those skilled in the art.
  • This invention allows the kraft black liquor to be converted to pulping chemicals by bypassing the recovery furnace. This is accomplished by a series of well known and established chemical reactions. One such reaction is where the sodium sulfate is reacted with calcium oxide to produce sodium hydroxide and calcium sulfate which is insoluble.
  • the sodium hydroxide is a pulping chemical and calcium sulfate which is gypsum can be used as pigment or sold into commerce as a commodity chemical.
  • Figure 2 showing the invention illustrates the lignin separation from the weak black liquor which passes to an inorganic separation.
  • Organics from this step are channeled to the recovery furnace and inorganics go to a conversion station where conversion to caustic takes place. This material is then used in producing white liquor.
  • the choice of acid that is used to precipitate the kraft lignin may depend on the commercial value of the calcium anion. For instance if phosphoric acid is used, then calcium phosphate is produced which will separate and can be sold as a commercial fertilizer. If carbon dioxide is- used, then sodium carbonate is produced which may be reacted with calcium oxide to produce sodium hydroxide, a pulping chemical.
  • the kraft lignin is removed by using various techniques (such as disclosed in U.S. Patent No. 4,111,928) from 3,000 parts of weak kraft black liquor (approximately 15% solids) .
  • Sulfuric acid is used to acidify the kraft black liquor and the residual solution contains sodium sulfate.
  • the residual solution in concentrated to 50-60% solids arid then this solution is allowed to cool to room temperature and the sodium sulfate readily crystallizes out and is easily separated from the solution by filtration or other appropriate method.
  • the residual solution may be burned in the recovery furnace to recover the heat value of the organics that are present.
  • the first crystallization may not remove all of the sodium sulfate.
  • the amount of sodium sulfate that remains in solution may be tolerated by the system since most kraft pulp mills do add a certain amount of sodium sulfate directly to kraft recovery furnaces in order to maintain the sulfur balance in the system.
  • the separated sodium sulfate may be sold to outside customers.
  • the kraft lignin is removed by using various techniques (as above noted) from 3,000 parts of weak kraft black liquor (approximately 15% solids) .
  • Sulfuric acid is used to acidify the kraft black liquor and the residual solution contains sodium sulfate.
  • the residual solution is concentrated to 50-60% solids and then allowed to cool to room temperature and the sodium sulfate readily crystallizes out and is easily separated from the solution by filtration or some other appropriate method.
  • the residual solution may be burned in the recovery furnace to recover the heat value of the organics that are present.
  • the first crystallization may not remove all of the sodium sulfate.
  • the amount of sodium sulfate that remains in solution may be tolerated by the system since most kraft pulp mills do add a certain amount of sodium sulfate directly to kraft recovery furnaces in order to maintain the sulfur balance in the system.
  • the sodium sulfate may be converted to a caustic pulping chemical.
  • EXAMPLE III In this example, phosphoric acid is to acidify the kraft black liquor.
  • the kraft lignin is removed by various techniques (as above noted) from 3,000 parts of weak black liquor (approximately 15% solids) . Since phosphoric acid is used to acidify the kraft black liquor, then the residual solution will contain sodium phosphate. At this point, it becomes necessary to remove the sodium phosphate because it is necessary to keep the phosphate ion out of the system.
  • the residual solution is concentrated to 50 to 60% solids and at room temperat ⁇ re the sodium phosphate will readily crystallize out and is easily separated from the solution by filtration or some other appropriate method.
  • the residual solution may be burned in the recovery furnace to recover the heat value of the organics that are present.
  • the separated sodium phosphate may be sold to outside customers.
  • phosphoric acid is to acidify the kraft black liquor.
  • the kraft lignin is removed by various techniques (as noted above) from 3,000 parts of weak black liquor (approximately 15% solids) . Since phosphoric acid has been used to acidify the kraft black liquor the residual solution will contain sodium phosphate. At this point, it becomes necessary to remove the sodium phosphate because it is necessary to keep the phosphate ion out of the system.
  • the residual solution is concentrated to 50 to 60% solids and at room temperature the sodium phosphate will readily crystallize out and can be easily separated from the solution by filtration or some other appropriate method. Once the sodium phosphate is removed, then the residual solution may be burned in the recovery furnace to recover the heat value of the organics that are present.
  • the separate sodium phosphate may be converted to calcium phosphate which is a valuable fertilizer. This is accomplished by concentrating the residual solution and allowing the sodium phosphate to crystallize out. This crystallized sodium phosphate (approximately 200 parts anhydrous), can be separated and then dissolved in 1,000 parts of water. Then 252 parts of calcium oxide is added under agitation and the temperature of this mixture is heated to 180 F for two hours or until the sodium phosphate is converted into sodium hydroxide and the calcium oxide is precipitated as calcium phosphate. The calcium phosphate may be filtered or separated by other means and the solution that is left is a caustic solution that may be used for pulping. The separate calcium phosphate can be sold as a fertilizer or to other markets.
  • EXAMPLE V the kraft lignin is insolublized by using carbon dioxide gas.
  • Kraft lignin is removed by various techniques (as noted above) from 3,000 parts of weak black liquor (approximately 15% solids) after the carbon dioxide gas has been allowed to insolublize the kraft lignin by various techniques.
  • the residual solution may be concentrated and burned in the kraft recovery furnace, or the residual solution could be concentrated to at least 50% solids so that the sodium carbonate or sodium bicarbonate will crystallize out and therefore be easily filtered or separated from the solution by various techniques.
  • sodium carbonate anhydrous weight
  • calcium oxide is added under agitation and the temperature of this mixture is heated to 180 F. for two hours or until the sodium carbonate is converted into sodium hydroxide and the calcium oxide is precipitated out as calcium carbonate.
  • the sodium carbonate may be sent to a slacker and causticizer where this sodium carbonate will be converted into sodium hydroxide.
  • This new invention allows different materials to be used to derive the maximum value for its products and by-products.
  • This new invention allows a kraft pulp mill to increase its production of pulp by as much as 20% or even higher without the huge capital investment for a recovery furnace.

Landscapes

  • Paper (AREA)

Abstract

Le procédé permettant d'augmenter la capacité de production de pâte d'un broyeur de kraft comprend les étapes d'élimination d'au moins une partie de la lignine de la liqueur noire de kraft et de séparation de la lignine de la phase aqueuse. L'étape suivante consiste à traiter la phase aqueuse pour séparer les matières inorganiques et organiques, les matières organiques étant de préférence recyclées vers la boucle de traitement pour être brûlées dans le four de récupération. Les matières inorganiques sont converties en produits chimiques de pâte en évitant le four de récupération et sont transportées vers une préparation de liqueur blanche.
PCT/US1988/003801 1987-11-06 1988-10-31 Procede de recuperation chimique de kraft WO1989004395A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US11815287A 1987-11-06 1987-11-06
US118,152 1987-11-06

Publications (1)

Publication Number Publication Date
WO1989004395A1 true WO1989004395A1 (fr) 1989-05-18

Family

ID=22376789

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1988/003801 WO1989004395A1 (fr) 1987-11-06 1988-10-31 Procede de recuperation chimique de kraft

Country Status (3)

Country Link
AU (1) AU2803389A (fr)
CA (1) CA1312420C (fr)
WO (1) WO1989004395A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005054572A1 (fr) * 2003-12-01 2005-06-16 University Of Florida Research Foundation, Inc. Traitement de liqueur de cuisson epuisee avec separation de la lignine aux fins de la recuperation des produits chimiques alcalins de fabrication de la pate dans la fabrication de pate a papier
RU2617569C2 (ru) * 2014-03-05 2017-04-25 Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "Санкт-Петербургский государственный технологический университет растительных полимеров" Способ кислотно-щелочной переработки черного щелока сульфатного производства целлюлозы
CN115182186A (zh) * 2022-08-01 2022-10-14 贵州赤天化纸业股份有限公司 一种环保节能的生活用纸纸浆的生产方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3986923A (en) * 1973-08-07 1976-10-19 Erco Envirotech Ltd. Removal of dissolved salts from sulphide liquors
SU730914A1 (ru) * 1978-03-01 1980-04-30 Государственный Институт По Проектированию Предприятий Целлюлозно-Бумажной Промышленности Способ обработки целлюлозы
US4470876A (en) * 1982-07-22 1984-09-11 Beaupre Marc F Kraft overload recovery process
US4507172A (en) * 1982-09-16 1985-03-26 St. Regis Paper Company Kraft pulping process

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3986923A (en) * 1973-08-07 1976-10-19 Erco Envirotech Ltd. Removal of dissolved salts from sulphide liquors
SU730914A1 (ru) * 1978-03-01 1980-04-30 Государственный Институт По Проектированию Предприятий Целлюлозно-Бумажной Промышленности Способ обработки целлюлозы
US4470876A (en) * 1982-07-22 1984-09-11 Beaupre Marc F Kraft overload recovery process
US4507172A (en) * 1982-09-16 1985-03-26 St. Regis Paper Company Kraft pulping process

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005054572A1 (fr) * 2003-12-01 2005-06-16 University Of Florida Research Foundation, Inc. Traitement de liqueur de cuisson epuisee avec separation de la lignine aux fins de la recuperation des produits chimiques alcalins de fabrication de la pate dans la fabrication de pate a papier
RU2617569C2 (ru) * 2014-03-05 2017-04-25 Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "Санкт-Петербургский государственный технологический университет растительных полимеров" Способ кислотно-щелочной переработки черного щелока сульфатного производства целлюлозы
CN115182186A (zh) * 2022-08-01 2022-10-14 贵州赤天化纸业股份有限公司 一种环保节能的生活用纸纸浆的生产方法

Also Published As

Publication number Publication date
AU2803389A (en) 1989-06-01
CA1312420C (fr) 1993-01-12

Similar Documents

Publication Publication Date Title
US5034094A (en) Method of converting inorganic materials from kraft pulping liquor into pulping chemicals without passing them through a recovery furnace
US4470876A (en) Kraft overload recovery process
US2057117A (en) Process of making vanillin
US4086329A (en) Integrated chlorine dioxide producing system
US3366535A (en) Process for regenerating waste liquor for reuse in kraft pulping operation
CN115947486B (zh) 一种脱硫废液资源化处理工艺及系统
CN101391848A (zh) 代森类产品生产中含氨废水综合治理的方法
US3746612A (en) Removal of sodium chloride from white pulping liquor
US4239589A (en) Process for oxidation of black liquor
US4138312A (en) Process of recovering sodium carbonate from spent pulping liquors
EP0599917B1 (fr) Production d'hydroxyde de metal alcalin et regeneration des liqueurs noirs
US3751560A (en) Multi-stage process for the preparation of sodium bicarbonate
WO1989004395A1 (fr) Procede de recuperation chimique de kraft
US3733395A (en) Process for producing chlorine dioxide,chlorine and a neutral sulfate salt in the sulfate or kraft process of preparing wood pulp
US3954552A (en) Removal of sodium chloride from pulp mill systems
US4735683A (en) Process for preparation of potassium salts from pulp of lignocellulosic materials
AU671487B2 (en) Reduction of chloride in pulping chemical recovery systems
US3986923A (en) Removal of dissolved salts from sulphide liquors
EP3126569B1 (fr) Procédé de traitemetn d'une solution de lavage usée d'un processus de récupération de lignine
US3996097A (en) Kraft mill recovery system
US2913310A (en) Chemical recovery process
US2774666A (en) Recovery of cooking liquor from spent soda pulping liquors
US4249990A (en) Process for removal of potassium values from pulp mill liquors
US4253911A (en) Process for maintaining a low sodium chloride content in recycled sodium chemicals of sodium-based pulp manufacturing processes
US4131508A (en) Recovery system for oxygen bleaching of pulp

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AU FI JP NO

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE FR GB IT LU NL SE