WO2004074415A1 - Recuperation de tallöl brut dans des usines a pâtes alcalines - Google Patents

Recuperation de tallöl brut dans des usines a pâtes alcalines Download PDF

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Publication number
WO2004074415A1
WO2004074415A1 PCT/SE2004/000207 SE2004000207W WO2004074415A1 WO 2004074415 A1 WO2004074415 A1 WO 2004074415A1 SE 2004000207 W SE2004000207 W SE 2004000207W WO 2004074415 A1 WO2004074415 A1 WO 2004074415A1
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WO
WIPO (PCT)
Prior art keywords
tall oil
brine
carbon dioxide
acidulation
soap
Prior art date
Application number
PCT/SE2004/000207
Other languages
English (en)
Inventor
Lennart Delin
Curt Lindström
Lars Stigsson
Original Assignee
Linde Ag
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 Linde Ag filed Critical Linde Ag
Publication of WO2004074415A1 publication Critical patent/WO2004074415A1/fr

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
    • C11B—PRODUCING, e.g. BY PRESSING RAW MATERIALS OR BY EXTRACTION FROM WASTE MATERIALS, REFINING OR PRESERVING FATS, FATTY SUBSTANCES, e.g. LANOLIN, FATTY OILS OR WAXES; ESSENTIAL OILS; PERFUMES
    • C11B13/00—Recovery of fats, fatty oils or fatty acids from waste materials
    • C11B13/005—Recovery of fats, fatty oils or fatty acids from waste materials of residues of the fabrication of wood-cellulose (in particular tall-oil)
    • 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
    • D21C11/0007—Recovery of by-products, i.e. compounds other than those necessary for pulping, for multiple uses or not otherwise provided for
    • 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
    • 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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00—Technologies for solid waste management
    • Y02W30/50—Reuse, recycling or recovery technologies
    • Y02W30/74—Recovery of fats, fatty oils, fatty acids or other fatty substances, e.g. lanolin or waxes

Definitions

  • the present invention relates to an improved method for the recovery of crude tall oil in an alkaline pulp mill without the recycling of sulphurous compounds to the chemical recovery system of the mill.
  • the resin and fatty acids contained in the wood raw material form soaps with the alkaline compounds in the cooking liquor.
  • soaps of resin and fatty acids and neutral components Prior to the final concentration or evaporation of cooking liquor, generally called black liquor in the sulphate or kraft pulping process, the soaps of resin and fatty acids and neutral components are separated from the black liquor, and collected for further treatment. This viscous soap mixture is generally called tall oil soap.
  • weak black liquor (at about 15% solids) is filtered to remove fibres and is thereafter passed into a weak liquor skimmer. Thirty percent (30%) to 70 % of the available black liquor soap is skimmed off in this stage. The black liquor thereafter passes through several stages of evaporative concentration to raise the solids content to 25-30%. The partially concentrated black liquor passes through a second skimmer from which the remaining 30-70% of soap is skimmed off. The black liquor, now substantially free from tall oil soap, finally passes through more stages of evaporative concentration to raise the solids to 60-80% range.
  • black liquor soap is washed degassed (or concentrated) to remove foam and is then settled to decant out excess residual black liquor.
  • the separated tall oil soap is normally acidulated with sulphuric acid to form crude tall oil, which oil can be refined by vacuum fractionation to form tall oil fatty acids and tall oil rosin.
  • the fatty acids and rosin are used in numerous industrial applications, including the preparation of polyamides, rosin resins, adhesive and epoxy compositions.
  • the acidulation process comprised the addition of sulphuric acid (H2S04) to the tall oil soap to produce crude tall oil and a waste stream containing dissolved organic matter and sodium sulphate
  • the waste brine contains a substantial fraction of sodium compounds and can therefore neither be disposed of in conventional boilers, such as bark or power boilers, nor can it be incinerated in the lime kiln risking operational disturbances due sodium compound fusing and smelting.
  • Pulp mills have been forced in recent years to upgrade their chemical recovery systems so that there is or will be less and less sulphur loss through the stacks and effluent streams in general and it appears that the various governmental regulations mandating such recovery will be made more stringent in the future.
  • Sulphuric acid acidification of tall oil soap introduces sulphur into the mill liquor cycle placing an increased burden on the chemical recovery systems employed.
  • crude tall oil can be prepared from tall oil soap without the need for recycle of sulphur chemicals to the recovery cycle of a pulp mill.
  • the method of the present invention as defined by appended claim 1 is thus carried out by contacting an aqueous solution containing tall oil soap with carbon dioxide in two or more stages in reactors operated at or above atmospheric pressure forming an emulsion comprising crude tall oil intermediate and a sodium bicarbonate brine wherein at least a portion of said brine is separated from the crude tall oil intermediate after each stage.
  • the method can be carried out in batch or in continuous equipment in one or more reactors, preferably with optional counter-current or co- current washing of partially acidified tall oil soap after each brine separation/acidulation stage.
  • the substantially sulphur free sodium bicarbonate brine comprising alkali and organic matter is recycled to the mill chemical recovery system without affecting the sulphur balance.
  • the separated crude tall oil intermediate fraction is thoroughly washed and thereafter finally reacted with an acid or other chemical compound capable of transforming crude tall oil intermediate to crude tall oil and sodium salty brine.
  • the crude tall oil formed is separated from the sodium salty brine, which brine mainly comprises soluble and non-toxic sodium salts and therefore can be disposed of externally from the mill liquor cycle.
  • FIG. 1 illustrates one embodiment of the present invention in the form of a schematic flow diagram of a crude tall oil recovery system in an alkaline pulp mill.
  • the present invention thus relates to a method for the production of crude tall oil in a pulp mill, comprising the acidulation of tall oil soap with carbon dioxide in two or more reaction steps.
  • the method can be carried out in batch or in continuous equipment in one or more reactors with optional counter-current or co-current washing of partially acidified tall oil soap after each brine separation/acidulation stage.
  • a crude tall oil intermediate fraction and a sodium bicarbonate brine is formed after each reaction step.
  • the brine is recycled to the mills chemicals recovery.
  • the crude tall oil intermediate obtained after a final treatment with carbon dioxide is effectively washed and thereafter reacted with an acid capable of transforming crude tall oil intermediate to crude tall oil and a sodium salty brine.
  • the crude tall oil is separated from the sodium salty brine which brine is not recycled to the mills chemical recovery system.
  • wood chips comprising cellulose, extractives and lignin, and white liquor comprising NaOH are added to a digester and heated according to a predetermined schedule of temperature and time in order to dissolve a significant portion of the lignin into the cooking liquor.
  • the extractives are saponified by the alkaline cooking liquor, thereby forming sodium salts of resin acids.
  • These salts commonly referred to as “tall oil soap” are suspended in the cooking liquor, which is normally called “black liquor”, along with lignin and various carbohydrate degradation products. Black liquor comprising used chemicals and dissolved lignin is extracted from the digester.
  • the cooked pulp material is passed to a brown stock filter/washer, wherein the pulp product ("brown stock”) is separated from entrained black liquor substances, and then washed and carried forward to further processing in a bleaching plant or board mill.
  • the dilute black liquor known as weak black liquor, which contains dissolved tall oil soap and lignin
  • a weak black liquor storage facility 1 wherein the tall oil soap is separated from the black liquor by any suitable method known to the industry.
  • the tall oil soap is brought to a first acidulation stage 2.
  • the remaining weak black liquor in storage facility 1 is then concentrated in a series of evaporators 3 wherein more tall oil soap 4 may be recovered and brought to carbon dioxide acidulation stage 2.
  • a stream of concentrated black liquor 5 is discharged to a recovery furnace for recycle/conversion to new cooking liquor.
  • the tall oil soap is acidulated (acidified) , at or above atmospheric pressure, in two or more acidulation stages 2 and 8 by contacting the tall oil soap with carbon dioxide (C0 2 ) 7 to form an emulsion comprising partly acidulated tall oil soap and a sodium bicarbonate brine.
  • the reaction proceeds as follows:
  • the sodium bicarbonate brine is separated from the partly acidulated tall oil soap in a brine separation step 9 arranged prior to further acidulation of the partly acidulated soap in a second acidulation stage 8.
  • the partially acidulated tall oil soap may be washed for removal of impurities prior to charging the soap to a second acidulation stage.
  • the brine, which contains substantially no sulphur compounds is discharged by line 12 to a pressurized carbon dioxide flash tank 10, suitably at a pressure in the range from about 0,1 MPa up to about 3 MPa.
  • the flashed off pressurised carbon dioxide stream 6 is partly or fully used for acidulation purposes in the mill 19, including use in tall oil soap acidulation stages 20.
  • the brine from flash tank 10 is thereafter recycled to the mill chemical recovery system through conduit 11.
  • the tall oil intermediate is separated from the bicarbonate brine in a tall oil intermediate separation stage 13.
  • the bicarbonate brine 14 contains sodium but substantially no sulphur compounds and is transferred to the carbon dioxide flash tank 10 and combined for discharge to chemical recovery in through line 11.
  • the separation in brine separation step 9 and tall oil intermediate separation stage 13 may be performed at atmospheric pressure or above by decanting, by gravity separation, centrifugation, coalescation and/or other means as will be readily apparent to those skilled in the art once armed with the present disclosure.
  • a solvent may be employed to promote effective separation of the two phases, however, preferably the separation process is carried out in the absence of a solvent.
  • a substantial part of the sodium bicarbonate brine is advantageously removed in brine separation step 9 and tall oil intermediate separation stage 13, preferably at least about 50% of the total bicarbonate remaining when entering each separation step/stage 9, 13. Most preferably substantially all bicarbonate is removed by the separation 9, 13.
  • the sodium bicarbonate brine recovered after a carbon dioxide treatment step may also contain some other components, such as sodium lignate salts and organic material entering the process with the soap as black liquor entrainments .
  • the crude tall oil intermediate recovered from the tall oil intermediate separation stage 13 should be thoroughly washed and/or cleaned from organic and inorganic impurities in order to obtain a pure tall oil intermediate.
  • Such washing and/or cleaning is performed by treatment with an aqueous solution or an organic solvent in one or more stages following the tall oil intermediate separation step 13 (such wash steps not shown in Fig 1) .
  • Used wash liquid can be recycled to a partially acidulated soap washing stage following a first soap acidulation stage (counter-current washing) and/or be combined with the bicarbonate brine solution 14 and thus be recycled to the chemical recovery system of the mill.
  • the tall oil intermediate Prior to final acidulation of the tall oil intermediate, the tall oil intermediate may be treated, preferably by heat treatment, in order to remove carbon dioxide. Such treatment will decrease the use of acid in a final tall oil intermediate acidulation stage.
  • the tall oil soap In order to achieve an effective conversion of tall oil soap to crude tall oil intermediate, the tall oil soap should be dissolved in an aqueous solution in acidulation stages 2 and 8.
  • the water to tall oil soap ratio of the aqueous tall oil soap solution is preferably between about 0.5:1 to about 2:1, although higher or lower ratios may be used.
  • the degree of conversion of tall oil soap using carbon dioxide in the practise of the present invention measured as percentage of complete conversion to crude tall oil is in the order of 30 to 80 %, preferably over 50 %.
  • the pressure used in the various acidulation reactors and separation steps of the present invention may vary from atmospheric to several bars over pressure, however pressures around atmospheric is preferred for a first carbon dioxide acidulation stage.
  • a following or final carbon dioxide acidulation stage is advantageously operated at a pressure ranging from about 0,1 to about 3 MPa.
  • the pressure in the first carbon dioxide acidulation step is lower than or equal to the pressure in the second carbon dioxide acidulation step.
  • the carbon dioxide employed in the first acidulation steps of the present invention may be in any form, for example, liquid, solid or gaseous, although preferably gaseous or liquid carbon dioxide should be used.
  • carbon dioxide may be recovered internally for use in the process by thermal treatment of a bicarbonate brine separated from a crude tall oil intermediate fraction in carbon dioxide flash tank 10. Such internally recovered carbon dioxide is transferred in lines 6.
  • carbon dioxide can be added to tall oil soap prior to the first acidulation step in weak black liquor storage or in another suitable vessel, in order to improve efficiency of tall oil soap recovery from black liquor.
  • Carbon dioxide may be added in one or more stages to the soap solution during skimming to facilitate recovery of pure soap combined with addition of carbon dioxide in a separate acidulation step as may be desired to obtain a high conversion. Carbon dioxide may be added as stoichiometric equivalent to the reactive groups in tall oil soap and its entrained black liquor solids, however, in order to increase conversion rate it has been found that better performance can be obtained with excess carbon dioxide. Flashing of part of the carbon dioxide or solid to the gas will accelerate the reaction by providing vigorous mixing.
  • the crude tall oil intermediate recovered from the final separation stage 13 may then be removed from the mill or upgraded on site to crude tall oil.
  • the upgrade of crude tall oil intermediate to crude tall oil comprises one or more reaction or acidulation steps 15 which can be performed externally from the mill or on site.
  • a salty brine is formed which is separated from the crude tall oil in a separation stage 16.
  • the separation in separation stage 16 may be performed at atmospheric pressure or above by decanting, by gravity separation, centrifugation, coalescation and/or other means as will be readily apparent to those skilled in the art once armed with the present disclosure.
  • An acid or other reactive compound is charged through line 18 to the final acidulation stage 15 wherein tall oil intermediate is converted to crude tall oil.
  • the acid used in step 15 is selected from at least on of an inorganic strong acid, a strong mineral acids, boric acid, acetic acid, formic acid and/or organic acids. If sulphuric or hydrochloric acid is used, the salty brine, which will be formed along with the crude tall oil, will contain dissolved sodium chloride or, as the case may be, sodium sulphate.
  • the salty aqueous brine stream 17 is disposed of externally from the chemical recovery system of the mill. Such disposal may be discharged to a secondary waste water treatment plant in the mill or sewering. Alternatively the salts can be recovered and exported as useful chemicals.
  • the crude tall oil is produced in high quality as measured by standard quality methods such as acid number. Acid number of the tall oil thus produced and expressed as grams of KOH per gram is suitably higher than about 130 for Scandinavian pine wood.
  • the present invention thus addresses the long felt need in the pulping industry to reduce sulphur inventory build up and emission of odorous sulphurous.
  • the present invention provides a method for the production of crude tall oil from tall oil soap in pulp mills which is operated using a an alkaline process substantially free from sulphur chemicals such as the soda process.

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  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Chemical & Material Sciences (AREA)
  • Paper (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Organic Chemistry (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

La présente invention concerne un procédé amélioré permettant de récupérer du tallöl brut dans une usine à pâte à base de sodium, sans recycler les composés sulfureux vers le système de récupération de substances chimiques de l'usine. Ce procédé consiste : à traiter du savon au tallöl avec du dioxyde de carbone (7) dans une première étape d'acidulation, pour former une émulsion de savon au tallöl partiellement acidifié et une saumure de bicarbonate de sodium ; à séparer (9) une fraction contenant le savon au tallöl partiellement acidifié d'une suspension aqueuse comprenant le bicarbonate de sodium ; à recycler cette suspension aqueuse comprenant le bicarbonate de sodium vers le système de récupération de substances chimiques de l'usine à pâte ; à traiter davantage le savon au tallöl partiellement acidifié avec du dioxyde de carbone pour former un produit intermédiaire de tallöl qui est ensuite lavé et mis en réaction avec un acide dans une étape d'acidulation finale (15) pour former un mélange de tallöl brut et de saumure ; et, enfin, à séparer (16) cette saumure du tallöl et à l'évacuer à l'extérieur (17) du système de récupération de substances chimiques de l'usine à pâte.
PCT/SE2004/000207 2003-02-18 2004-02-17 Recuperation de tallöl brut dans des usines a pâtes alcalines WO2004074415A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE0300434-8 2003-02-18
SE0300434A SE0300434D0 (sv) 2003-02-18 2003-02-18 Crude tall oil recovery in alkaline pulp mills

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1637582A1 (fr) * 2004-09-21 2006-03-22 Linde AG Procédé de récupération de tall oil ou de carburant tall oil
WO2011081587A1 (fr) * 2009-12-30 2011-07-07 Hofstedt Anders Goeran Procédé de séparation de fractions concentrées de savon à l'huile de pin à partir d'un mélange de liqueur noire et de savon à l'huile de pin, et dispositifs convenant pour le savon à l'huile de pin concentré et/ou la liqueur noire séparée
US8338633B2 (en) 2007-05-15 2012-12-25 Forchem Oy Method of processing tall oil
EP2776621A4 (fr) * 2011-11-11 2015-06-24 Valmet Power Ab Procédé de séparation de la lignine à partir de liqueur noire comprenant de multiples étapes d'acidification
US10087394B2 (en) * 2015-07-08 2018-10-02 Upm-Kymmene Corporation Method and system for reducing residual soap in crude tall oil
EP3572581A1 (fr) * 2018-05-01 2019-11-27 Kraton Polymers LLC Compositions de savon de liqueur noire désulfurées et leurs procédés de production
EP3494256A4 (fr) * 2011-05-24 2020-03-18 Liquid Lignin Company, LLC Procédé de traitement de lignine

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3901869A (en) * 1974-01-11 1975-08-26 Westvaco Corp Acidification of tall oil soap
US4075188A (en) * 1976-02-02 1978-02-21 Westvaco Corporation Recovery of crude tall oil
US5283319A (en) * 1993-06-23 1994-02-01 Union Camp Corporation Process and control strategy for the recovery and use of excess carbon dioxide discharge from a high pressure carbon dioxide acidulation process
US5286845A (en) * 1992-05-20 1994-02-15 Union Camp Corporation Acidification of tall oil soap using carbon dioxide
US6172183B1 (en) * 1996-12-30 2001-01-09 Aga Aktiebolag Process and apparatus for the cleaning of crude tall oil soap

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3901869A (en) * 1974-01-11 1975-08-26 Westvaco Corp Acidification of tall oil soap
US4075188A (en) * 1976-02-02 1978-02-21 Westvaco Corporation Recovery of crude tall oil
US5286845A (en) * 1992-05-20 1994-02-15 Union Camp Corporation Acidification of tall oil soap using carbon dioxide
US5283319A (en) * 1993-06-23 1994-02-01 Union Camp Corporation Process and control strategy for the recovery and use of excess carbon dioxide discharge from a high pressure carbon dioxide acidulation process
US6172183B1 (en) * 1996-12-30 2001-01-09 Aga Aktiebolag Process and apparatus for the cleaning of crude tall oil soap

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1637582A1 (fr) * 2004-09-21 2006-03-22 Linde AG Procédé de récupération de tall oil ou de carburant tall oil
WO2006032670A1 (fr) * 2004-09-21 2006-03-30 Linde Aktiengesellschaft Procédé de récupération d'huile de pin ou de carburant à base d'huile de pin
US8338633B2 (en) 2007-05-15 2012-12-25 Forchem Oy Method of processing tall oil
WO2011081587A1 (fr) * 2009-12-30 2011-07-07 Hofstedt Anders Goeran Procédé de séparation de fractions concentrées de savon à l'huile de pin à partir d'un mélange de liqueur noire et de savon à l'huile de pin, et dispositifs convenant pour le savon à l'huile de pin concentré et/ou la liqueur noire séparée
EP3494256A4 (fr) * 2011-05-24 2020-03-18 Liquid Lignin Company, LLC Procédé de traitement de lignine
EP2776621A4 (fr) * 2011-11-11 2015-06-24 Valmet Power Ab Procédé de séparation de la lignine à partir de liqueur noire comprenant de multiples étapes d'acidification
US10087394B2 (en) * 2015-07-08 2018-10-02 Upm-Kymmene Corporation Method and system for reducing residual soap in crude tall oil
EP3572581A1 (fr) * 2018-05-01 2019-11-27 Kraton Polymers LLC Compositions de savon de liqueur noire désulfurées et leurs procédés de production
US11034914B2 (en) 2018-05-01 2021-06-15 Kraton Polymers Llc Desulfurized black liquor soap compositions and processes for producing

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Publication number Publication date
SE0300434D0 (sv) 2003-02-18

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