SE0901623A1 - Procedure for letting a raw soap from black liquor - Google Patents

Abstract

The present invention comprises a method and a plant ("A") for allowing a mixture of black liquor (20) with raw soap (10) drained from a sieve equipment (11) to be passed through a separation and via a separation. separated and / or concentrated raw soap into a centrifugal separator process for separating pure soap (10d) from black liquor (20), using a white liquor wash (4, (4)), in several successive process steps ("A1"), More specifically, the following process steps are indicated: a. That the raw soap (10a) is fed to a first centrifugal separator ("C1"), within a first process step ("A1") to form a concentrated raw soap, or a first soap (10b) and residues (20b), that the first soap (10b) recovered under "a" above is mixed (B1), smooth first-mixer ("B1"), with an added first white liquor (4), within a second process step <"A2" >. that the mixture, according to "b" above, is fed to a second centrifugal separator ("C2"), to form a purified crude soap, a second soap (10c), and residues (20c), within the second process step ("A2"), that, under "c" above, the second soap (10c) recovered can be mixed (B2) in a second mixer ("B2"), with an added second white liquor ((4)), within the second process step ("A2"), that the mixture, according to "b" or "d" above, can be added to a third centrifugal separator ("C3"), to form the pure soap (10d) and residues ((4), 20d) and that the pure soap ( 10d) can be supplied to a splitting plant known per se (24). It is proposed that Figure 4 be attached to the summary at the time of publication.

Description

The invention intends to thereby reduce and / or eliminate the technical problems associated with the actual soap digestion which have otherwise been found to be relevant in the subsequent digestion process, in order to be able to recover crude tall oil, adapted for a subsequent purification and / or processing process. , not shown and described in this application.

The present invention can be advantageously used in a pulp mill built on the sulphate method, where the contents of a digester are passed over to a sieving equipment or sieving plant, where fibrous products are separated for use in the actual pulp production, while in the boiler formed the barrel liquor, "black liquor" with raw soap proportions, is transferred i.a. to a separating process step with respect to raw soap, here referred to as a first process step.

Black liquor contains not only sodium and calcium, as dissolved salts (eg calcium ions) and lignin substances but also crude soap), where discrete crude soap proportions can be discontinuously or continuously separated and then, in several successive other process steps , have the treated raw soap cleaned of soap and remove the, the raw soap and / or the soap cleaned by washing, containing the black liquor-related residues.

Such a concentrated and clean-washed soap must, via a cleavage process within a cleavage plant, be able to form a crude tall oil and residual products, such as cleavage water with salt and lignin precipitates.

BACKGROUND OF THE INVENTION Methods, arrangements and constructions related to the above-mentioned technical field and with a function and a nature that meets the set requirements are previously known in a number of different embodiments.

As an example of the prior art and the technical field to which the invention relates, mention may be made of a method and a plant, in accordance with the following description related to the accompanying Figures 1 and 2, and with crude soap. separated from the black liquor via a gravimetric separation procedure, and used within a pulp mill, according to the attached figure 1.

The previously known technique for separating and separating raw soap from black liquor and allowing the raw soap to be concentrated and washed in a process step and then having a treated raw soap split into crude tall oil and splitting water, with its salt and lignin precipitates, is also further illustrated in the following, with a reference to the attached fi clock 2, and using a plurality of series-oriented raw soap separating tanks. In the publication HUIBERS, D.T.A. "Tall Oil" (Kirk-Othmer Encycopedia of Chemical Technology. John Wiley & Sons, 2000) shows and describes there a process and arrangement which can be considered to be fully connected to the plant shown in the following Figures 1 and 2 of this application.

Taking into account the peculiarities associated with the present invention, in connection with the use of centrifugal separators, both in the first and in the second process step, the content of the following patent publication should be mentioned as the prior art.

As regards the content of the patent publication US-A-2 227 203, a process is shown and described there, in order to be able to successively distinguish raw soap from black liquor in different process steps, which is initially to be stored in a tank (10).

The process suggests the use of a multi-step evaporation process in an evaporator (11), to a dry matter (TS) of about 40%.

The thus thickened black liquor with raw soap, in the form of saponified components, is fed to a first centrifugal separator (12), which is fed via first separated products, in the form of black liquor, over a connecting evaporation stage (24), with a 70% dry matter content (TS). a recovery boiler in a known manner.

More specifically, it should be considered that other separated products, in the form of the separated raw soap with black liquor, equation and other by-products, are added to a (second) tank (13) for a saponification, however through a time-consuming and energy-consuming special treatment process.

For this purpose, the treatment process indicates that hot (heated) water (15) is added to a tank (13), to dilute and dissolve the raw soap via thermal processes, and then to add to this diluted and hot solution an alkaline solution ( heated solution), to further dilute the solution within the tank (13), in order to precipitate dissolved saponified and / or saponifiable components.

This diluted raw soap in two different sequences, chronologically separated, will now be the subject of a centrifugal separation within a (second) centrifugal separator (16).

The thereby diluted and separated raw soap must then be fed to a new tank (17) with the same treatment process, in two different sequences as in the tank (13), a new centrifugal separation within a centrifugal separator (20), a new tank (21) and a final centrifugal separator (23), for the purpose of precipitating the dissolved saponified and / or saponifiable components to separate a treated raw soap into soap (a pure soap) from the washing liquid (Na 2 SO 4 solution).

In this way, within the different process steps, not only allow hot water (15) to be supplied, to dilute the raw soap and other by-products or residues, within three separate tanks (13, 17, 21) but also, at each tank, adding an alkali solution (14), for further dilution and adjustment of the total "pH" value of the solution, and then separating black liquor from raw soap in four different centrifugal separators (12, 16, 20 and 23), requires one, with today's energy-efficient requirements, relatively high energy supply.

Furthermore, this plant requires measures to take advantage of the large amount of washing liquid required in the various process steps. An evaporation plant would probably be suitable for this.

The: nitions: (The reference numerals in parentheses refer to the embodiment illustrated in Figure 4.) 'Black liquor' (20) is a collective name for a used cooking liquid (sodium hydroxide and / or sodium sulphide) in varying stages of dry matter and in which dissolved salts, 10 Lignin substances and soap products are present and where the soap products here appear in the form of raw soap.

"Raw soap" (10) is the light product which, in a tank or a centrifugal separator, will "float" or be separated from the cooking liquid, in the form of a predominant proportion of black liquor, and which will consist of raw soap proportions and black liquor, in a selected mixing ratio.

"Soap" (10b) is the name given to, in one or more steps treated (washed) and concentrated raw soap parts, to squeeze black liquor products out of the raw soap.

"Pure soap" (10d) is the name given to a raw soap and / or soap treated in one or more washing steps and which is thereby adapted to be added to a cleavage equipment or plant (24).

“Soap of a first quality” (1 Ob) is the name of a first concentration of raw soap carried out within a centrifugal separator, within a first process step (“A1”), with regard to the proportion of soap products and a separation of black liquor.

"First mixture" (B1) is the name given to a mixture of a first concentration or first grade of raw soap (in "porridge or mousse consistency") and an added white liquor (either fresh white liquor or white liquor which appears in one or more subsequent washing steps ) to mix with the added white liquor the proportion of occurring black liquor (20 - 20b) within the available concentrated raw soap (10b).

"Red | out" (8) is the name of a residual product formed within a centrifugal separator ("C2") when a raw soap 10a treated with soap (10b), within a first process step ("A1"), and a smaller proportion black liquor is washed with white liquor (4), where the red color comes from occurring equation precipitates.

"Soap of a second quality" (10c) is the term for a concentration and purification of soap carried out within a centrifugal separator ("C2") from a mixture of a "Soap of a first quality" (10b) and white liquor (4) )). 10 15 20 25 30 "Second mixture" (B2) is the name given to a mixture of solutes further purified and concentrated from solutes (10c) (in "porridge or mousse consistency") and an added white liquor ((4)), to mix with the added white liquor occurring small amounts of black liquor within the soap (10c), of the second quality.

"Clean soap" (10d) is a raw soap and / or soap treated within one or more process steps and cleaned via washing, with distinct small amounts of black liquor and substances dissolved therein.

"Crude tall oil" (24c) is an oil, consisting of fatty acids, resin acids and neutral substances, obtained by adding, within a digestion plant (24), to a pure soap (10d) an acid (24a), such as a sulfuric acid, for to create a solution with a selected pH value (approx. 3.0), "Cleavage water" (24b) is the name of the residual products that the treatment of the pure soap (10d) within the cleavage plant gives rise to.

“Complexing agent” refers to the substances used in a cleavage plant to bind ions, such as sodium and / or calcium ions, in order to reduce the formation of coatings, such as calcium sulphate.

"Flotation tank" ("T") is the name of a tank where black liquor mixed with raw soap and / or soap is added, where the lighter raw soap parts or soap parts float upwards while the heavier black liquor parts sink downwards whereby raw soap parts and / or soap parts can taken out at the upper part of the tank, while heavier black liquor proportions can be taken out at the lower part of the tank, where the take-out can take place continuously and / or discontinuously as needed. A flotation tank is based on the conditions for a gravimetric separation.

DESCRIPTION OF THE PRESENT INVENTION / TECHNICAL PROBLEMS Considered the fact that the technical considerations that a person skilled in the relevant technical field must make in order to be able to offer a solution to one or 10 15 more technical problems posed are partly initially a necessary insight into the measures and / or the sequence of measures to be taken and a necessary choice of the means or means required, the consequent technical problems should therefore, as a result, be relevant in the creation of the present invention.

Taking into account the prior state of the art, as described above, it should therefore be seen as a technical problem to be able to realize the significance of, the benefits associated with and / or the technical measures and considerations that may be required to: in a process and a plant, for separating and concentrating the raw soap from an accessible black liquor through a silo equipment or plant, and in one or more subsequent steps having the raw soap treated into soap in successive process steps , via one or more washing liquids supplied in a second process step, such as in the form of white liquor, can easily separate and separate a clean soap from the available black liquor with mixed raw soap and the other raw soaps containing the residual products and during a reduction of normal energy losses.

There is a technical problem in being able to realize the significance of, the benefits associated with and / or the technical measures and considerations that will be required to create such a first process step, which with a small temperature reduction can separate, separate the raw soap. from the black liquor and concentrate the raw soap, where a separated black liquor can be subjected to a direct supply to an evaporation plant.

There is a technical problem in being able to realize the significance of, the benefits associated with and / or the technical measures and considerations that will be required to allow the, within a second process step, purified raw soap to a pure soap to show improved properties, than previously known separation and washing processes.

There is a technical problem in being able to realize the significance of, the benefits associated with and / or the technical measures and considerations that will be required in order to use one or more series-oriented centrifugal separators, as mentioned in the second process step, between the first process step and the the second process step is allowed to mix the separated raw soap with a selected addition of white liquor and that the mixture thus formed should be able to be fed directly to a centrifugal separator, within the second process step, for a separation and concentration of it with white liquor. washed raw soap or soap from black liquor and residues.

There is a technical problem in being able to realize the significance of, the benefits associated with and / or the technical measures and considerations that will be required to use as a single process step as a single centrifugal separator, however selected with a high flow capacity and / or separation speed, alternatively a tank adapted for a gravimetric separation and a centrifugal separator connected to this tank, with an adapted low flow capacity and / or separation speed.

There is a technical problem in being able to realize the significance of, the advantages associated with and / or the technical measures and considerations that will be required to use, as the said other process steps, a plurality, such as two, series-oriented centrifugal separators, to the constituent first centrifugal separator and the second centrifugal separator mix the separated and washed soap in the first centrifugal separator with an addition of a selected proportion of white liquor and that the mixture thus formed is fed to the second centrifugal separator, for a separation of a again washed and concentrated liquor and residues.

There is a technical problem in being able to realize the significance of, the benefits associated with and / or the technical measures and considerations that will be required to allow a washed soap from a first centrifugal separator or a re-washed soap from the second centrifugal separator, within the second process step, a third process step may be added, such as a cleavage step within a cleavage plant.

There is a technical problem in being able to realize the significance of, the benefits associated with and / or the technical measures and considerations that will be required to have a procedure created, constructed by a number of process steps, and a procedure adapted for the implementation of the procedure. compact plant, which in the series-oriented process steps, via centrifugal separators, can gradually reduce (and eliminate) the presence of calcium and lignin in the washing treatment of crude soap 10 15 20 25 30 to soap, so as to be washed, preferably in several steps to be able to form a clean soap for the cleavage plant.

There is a technical problem in being able to realize the significance of, the benefits associated with and / or the technical measures and considerations that will be required to reduce (or eliminate) the technical problems which in the prior art usually occur in the cleavage process, by precipitated salts therein (eg calcium sulphate).

There is a technical problem in being able to realize the importance of, the benefits associated with and / or the technical measures and considerations that will be required to create a procedure and a facility with distinct, continuously operating and mutually coordinated and dimensioned, first , second and third process steps, preferably with intermediate leveling tanks.

There is a technical problem in being able to realize the significance of, the benefits associated with and / or the technical measures and considerations that will be required to allow a procedure and / or a facility to be used in at least one, or in each case a few, process steps, as described in more detail below.

There is a technical problem in being able to realize the significance of, the benefits associated with and / or the technical measures and considerations that will be required to allow the various series-oriented centrifugal separators, within the second process step, to separate sequential proportion by proportion. black liquor from the soap with white liquor, and by means of utilized white liquor having the soap washed, with respect to black liquor and in black dissolved or substances, to form residues, from a first centrifugal separator within the second process step, in the form of a " red liquor ”, for use in one or more subsequent processes or process steps.

There is a technical problem in being able to realize the significance of, the benefits associated with and / or the technical measures and considerations that will be required to allow residual products, obtained from one or more centrifugal separators comprising process steps, to be added directly to an evaporation plant. . There is a technical problem in being able to realize the significance of, the benefits associated with and / or the technical measures and considerations that will be required to allow an added second white liquor, within one, a centrifugal separator comprising, other process steps may consist of a fresh white liquor.

There is a technical problem in being able to realize the significance of, the benefits associated with and / or the technical measures and considerations that will be required for the soap to be treated within it, comprising several centrifugal separators, the second process step towards and to one, after washing process in white liquor, pure soap may be driven so far in the cleaning or washing process that the clean soap will contain very small amounts of residual products, such as black liquor with impurities present in the black liquor, such as e.g. lignin.

There is a technical problem in being able to realize the significance of, the benefits associated with and / or the technical measures and considerations that will be required to create such conditions, within the first process step and the first centrifugal separator, that a higher proportion of and a higher concentration of raw soap than has been offered in a tank for gravimetric separation and thereby separate a black liquor purified from raw soap, containing a smaller proportion of raw soap.

SOLUTION The present invention is based on the prior art initially indicated, in a process or a plant, for separating and concentrating raw soap from black liquor from an available mixture of black liquor and raw soap, in a first process step and in a subsequent second process steps have a white soap-treated raw soap washed into soap, thereby removing contaminants from the available raw soap and / or soap, whereby a pure soap produced via the second process step will be adaptable to, within a third process step , be subject to a direct cleavage to crude tall oil and residual products, such as to e.g. cleavage water.

In order to be able to solve one or more of the above-mentioned technical problems, the present invention more particularly discloses that the prior art should be supplemented with the use of a number of soap washing sequential process steps, according to the characterizing parts of claims 1 and 9. As proposed embodiments, falling within the scope of the basic idea of the present invention, in addition, the peculiarities specified in subclaims 2 to 8 and subclaims 9 to 26, respectively, are indicated.

ADVANTAGES The advantages that can mainly be considered to be characteristic of the present invention and the special significant characteristics indicated thereby are that this has created conditions for, from an available mixture of black liquor and raw soap, in a first process step to roughly separate and concentrate the lighter raw soap from the heavier black liquor and in a subsequent second process step have a thus separated raw soap and / or a soap-treated raw soap washed with white liquor, thereby removing black liquor-related contaminants from the available and treated raw soap to soap, the pure soap produced via the second process step being adaptable in order, within a third process step, to be subjected to a cleavage, by means of an added acid, into crude tall oil and residual products, such as e.g. cleavage water.

In particular, the invention provides for the use of one or more series-oriented centrifugal separators as said second process step, for mixing the separated and concentrated raw soap with a selected addition of white liquor between the first process step and the second process step, after which the mixture thus formed must be fed directly to a centrifugal separator, within the second process step, for the separation of a soap washed with white liquor and concentrated from black liquor-related residues.

What can primarily be considered as characteristic of a method according to the present invention is stated in the characterizing part of the following claim 1, while a plant, for carrying out the method, is stated in the following The characterizing part of claim 9.

BRIEF DESCRIPTION OF THE FIGURES Basic conditions, behavior within a pulp mill according to the sulphate method, and a previously known process with associated tank plants, in order to extract a concentrated raw soap from a black liquor produced in a boiler and currently proposed embodiments of the methods and plants, exhibits the significant features associated with the present invention will now be described in more detail, by way of example, with reference to the accompanying drawings, in which; Figure 1 schematically shows certain parts within a pulp mill operating on the sulphate method, where a black liquor is separated from the fibrous pulp, within a screen plant, as a used cooking liquid from cellulose fibers, Figure 2 schematically shows a known time-consuming process for via a gravimetric separation within a number of flotation tanks allows an increasingly concentrated and purified raw soap to be recovered. Figure 3 illustrates in principle two embodiments of the present invention, in which Figure 3A shows an embodiment with a gravimetric tank or a flotation tank and a connected centrifugal separator, as a first process step. , while Figure 3B shows an embodiment with a single centrifugal separator, as a first process step, while a subsequent raw soap to soap washing second process steps uses one or more centrifugal separators, Figure 4 schematically shows a plant of a first ”embodiment, with a wash operating on the countercurrent principle process, in accordance with the teachings of the present invention, to in different process steps, related to a process with an initial gravimetric purification step and with a centrifugal separator followed, within a first process step, according to Figure 3A, and with a number of centrifugal separators, which A second process step, stepwise cleaning a raw soap treated soap, containing different grades of black liquor, with white liquor to extract a pure soap, adaptable for a treatment via a cleavage process within a cleavage equipment or plant, Figure 5 shows in exemplary graphs the equation reduction as a function of the wash liquor or white liquor flow, Figure 6 schematically shows a plant of a “second” embodiment, with a washing process operating on the cross-flow principle, in accordance with the instructions of the present invention, to in different process steps, related to a process with an initial gravimetric purification step and with a connected centrifuge separator, within a first process step, according to Figure 3A, and with a number of centrifugal separators, as a second process step, stepwise having a raw soap treated with soap, containing different degrees of black liquor, with white liquor to extract a pure soap, adaptable to a treatment soap. Figure 7 schematically shows a plant of a "third" embodiment, with a washing process operating on the countercurrent principle, in accordance with the instructions of the present invention, in order to in different process steps, related to a process, take place via a cleavage process within a cleavage equipment or plant. with only centrifugal separators within a first process step, mechanically separate and concentrate a raw soap from black liquor and in different process steps, according to Figure 3B, have the raw soap treated into soap, containing different grades of black liquor, with white liquor to extract a pure soap, adaptable for a treatment via a cleavage process within a cleavage equipment or plant and Figure 8 shows diagram a plant of a "fourth" embodiment, with a washing process operating on the cross-flow principle, in accordance with the instructions of the present invention, in order to allow mechanical separation and cone to be separated and reconstituted in different process steps, related to a process with only centrifugal separators - center a raw soap from black liquor and in different process steps, according to figure 3B, have the raw soap treated into soap, containing different degrees of black liquor, with white liquor to extract a pure soap, adaptable for a treatment via a cleavage process within a cleavage equipment or plant , lO 15 20 25 30 DESCRIPTION OF A PART OF THE PAPER FACTORY ACCORDING TO THE SULPHATE METHOD.

Figure 1 shows a utilization of a boiler to which wood chips "Ka" and white liquor "Kb" are added in a known manner.

The chippings "Kc" boiled in a liquefied bath "Kd" with boiling liquid are fed to a silo equipment or plant 11, where boiled cellulose fibers 11 'are separated and through the silo equipment 11 light liquor passes, in the form of so-called black liquor 20, with a smaller part of raw soap parts 10, where the cellulose fibers 11 'are transported further in a known manner for pulp production.

The black liquor 20 and crude soap portions 10 can be treated as an initial mixture in a plurality of process steps 12, to be able to recover from raw liquor 20 separated raw soap shares 10, which will be described in more detail as a known method and a plant for this, with a reference to figure 2, and according to the instructions of the invention, with a reference to e.g. Figures 3A, 4, 5 and 6 but also to Figures 3B, 7 and 8.

Within process step 12, in Figures 1 and 2, the mixture of black liquor and raw soap (20, 10) is separated by a gravimetric separation, where a concentrated black liquor portion 20a is fed to an evaporator 13, in which water is evaporated and the black liquor portion 20a is concentrated from process step 12 to a black liquor concentrate 13a.

This concentrated black liquor 13a is fed to a recovery boiler 14, where organic wood substances 14a are burned while inorganic substances accumulate as a lower melt 14b.

The inorganic substances 14b are mixed with water 15a, in a mixer 15, to form a so-called green liquor 15b. The green liquor 15b is mixed, in a mixer 16, with burnt lime 16a, which gives calcium carbonate 16b (mesa), which is fed to a lime kiln 17. The green liquor 15b is converted in the mixer 16 to white liquor "Kb", for use in the cooker "K" via a line 16c.

DESCRIPTION OF A KNOWN SYSTEM FOR SEPARATING AND CONCENTRATING RAW SOAP PARTS FROM SVARTLUT, ACCORDING TO FIGURE 2.

Figure 2 now illustrates a plant 12, where a mixture of black liquor and raw soap parts (20 + 10) is fed to a separation or leveling tank "T" in order to cause a proportion of thickened raw soap 10a to separate or separate via a gravimetric separation. up from the proportion of black liquor 20a, which in turn sinks downwards and is led, via a line 20a ', to the evaporator 13 and the recovery boiler 14.

Within the tank “T” a first separation step takes place and discontinuously the raw soap 10a is removed from the upper part of the tank “T”, via a line “T1”.

Raw soap 10a is further concentrated and separated from proportions of black liquor in the three tanks 21, 22 and 23 shown in series, all intended to create a successive thickening of the raw soap, 10a to || 10e, towards the upper portions of the tanks for a flotation. - of raw soap.

Figure 2 illustrates here three such thickening tanks 21, 22, 23, where further separation steps are performed to separate further thickened raw soap 10e with small proportions of residual products and black liquor, assigned the reference numeral 20b and which is fed to the evaporator 13.

The crude soap 10e is fed to a digestion plant 24 where the crude soap is mixed in a mixer with an acid, such as sulfuric acid, 24a, to allow the crude soap 10e to be split into crude pine oil 24c and digestion water 24b, but also containing salt and lignin precipitates.

Via drain pipes 20b ', residual products within the tanks 21, 22, 23. Removal of the process described here are discontinued with a repetition time of about one to two times per week, in the case of a separation of raw soap 10a from the black liquor 20a in the container or THE DESCRIPTION OF THE EMBODIMENTS PROPOSED NOW It should be pointed out at the outset that in the following description, of a presently proposed embodiment, which exhibits the significant features associated with the invention and which is clarified by the drawings shown hereinafter, had chosen terms and a special terminology for the purpose of clarifying the idea of the invention in the first instance.

In this context, however, it should be borne in mind that the terms chosen here should not be construed as limiting only the terms used and chosen here, but it should be understood that each term thus chosen should be interpreted so as to include all technical equivalents that operate on the same or essentially the same way, in order to be able to achieve the same or substantially the same intention and / or technical effect.

Figure 3 illustrates in principle two embodiments of the present invention.

Figure 3A shows a first embodiment with a gravimetric tank "T" and a tank-connected centrifugal separator "C1", of a first process step "A1".

Figure 3B shows a second embodiment, with a single centrifugal separator "C1a", of a first process step "A1. Figure 3 shows the basic structure of a method and a plant for from an available mixture of black liquor and raw soap (20 + 10), in a first process step ”A1 having raw soap 10b (10b1) separated from black liquor 20b (20b1) and in a subsequent second process step“ A2 ”(“ A21 ”) having the raw soap 10b (10b1) treated washed with soap 10c, 10d (10c1) , 10d1) with white liquor 4, ("Kb") to thereby successively have b | .a. black liquor-related contaminants from the available raw soap 10b, (10b1). The soap 10c (10c1), 10d (10d1) produced via the second process step "A21" is adaptable to, within a third process step "A3", be subjected to a cleavage into crude tall oil 24c and residual products, such as splitting water 24b.

Here it is indicated that as mentioned the second process step "A21" one or more series-oriented centrifugal separators "C2", ("C2a"); "C3", ("C3a") are used, whereby between the first process step "A1" and the second process step the separated the raw soap 10b (Figure 3A) with a selected addition of white liquor 4 ("Kb") and that the mixture thus formed is fed to a centrifugal separator "CZ" within the second process step "A2", for a separation of one with white liquor washed soap 10c from residual products 20c.

As said first process step "A1", a single centrifugal separator "C1a" is used, according to Figure 3B, with a high flow capacity and / or separation speed, alternatively a tank "T" adapted for a gravimetric separation and a connected centrifugal separator "C1" , according to Figure 3A, with a significantly lower flow capacity and / or separation rate.

Figure 3 then illustrates that as the said second process steps "A2", "A21" two series-oriented centrifugal separators "C2", "CS" are used and between the first centrifugal separator "CZ" and the second centrifugal separator "G3" the one with the first centrifugal separator is mixed separated and washed the soap 10c with an addition of a selected proportion of white liquor (4) and that the mixture thus formed is fed to the second centrifugal separator "C3", for a separation of a again washed soap 10d and residual products 20d.

The washed soap 10c from the first centrifugal separator "C2" or the re-washed soap 10d from the second centrifugal separator "C3", within the second process step "A21", is fed to the final third process step "A3". Figure 3 shows in parentheses examples of the values for current flows in m3 / h. Figure 3 has not indicated the presence of any equalization tanks or buffer tanks, for clarification purposes only. Such tanks can be placed in depending on needs and location.

With reference to the appended Figures 4, 5 and 6 and Figures 7 and 8, not only is the present invention shown as a plant “Aa” and “Ab” but also the significant properties associated with the invention, with respect to the procedure with different process steps "A1", "A21" and "A3", has been concretized, by the now proposed and in the following details described in more detail.

Thus, Figure 4 shows a method, according to the invention and a plant adapted for this purpose, adapted for a washing process operating on the countercurrent principle.

For this purpose, a method is provided for separating raw soap 10a from a mixture of black liquor and raw soap (20 + 10) and via a tank according to Figure 3A and in several successive process steps "A21", and via added washing liquid, in the form of white liquor 4, have the raw soap 10a, 10b treated to soap 10c, 10d and to form a clean soap 10d and via the washing successively have the raw soap and the soap containing residual products removed, primarily black liquor parts 20b, 20c, 20d.

A first centrifugal separator "G1" within the first process step "A1" is, in Figure 4, adapted to form a saponified black liquor, designated 20b, and a proportion of concentrated raw soap, designated 10b, in the form of a "porridge or mousse consistency" .

A portion or all of this concentrated raw soap 10b is fed to the second process step "A2" and mixed in a first mixer "B1" with a supplied first washing liquid 4, in the form of, in a subsequent washing step (centrifugal separation), a separated and here useful, white liquor (4), to form a first mixture Bl.

A portion or all of the first mixture B1 is fed, via a line 5, a second centrifugal separator "G2" within the second process step to form a, to 10 a dilute (8) diluted, black liquor portion 20c and a portion partially additional cleaned soap 1 Oc.

A portion or all of the partially cleaned and cleaned soap 10c, of the second grade, is mixed with an added second washing liquid, in the form of white liquor (4), to a second mixture B2 in a second mixer "B2".

A portion or all of the second mixture B2 is fed, via a line 9, a third centrifugal separator "C3" within the second process step "A21" to form a pure soap 10d and the white liquor (4) used as washing liquid, however containing minor proportions black liquor residues 20d and here an extremely small proportion of pure soap.

As proposed embodiments, falling within the scope of the present invention, it is indicated that the separated white liquor (4) within the second process step "A21" can be supplied as a first washing liquid 4 to the mixer "B1".

It is further indicated that the process steps “A1”, “A2”, (“A21”) and “A3” can advantageously be carried out as a continuously operating process, whereby the individual units described above consist of whole units, however with non-illustrated equalization tanks.

Referring to Figure 5, under "A" the lignin reduction is shown as a function of the wash liquor flow "f" in a single wash separation and where the upper curve is valid for a lignin separation at 90% by volume soap and the lower curve is valid for a lignin separation at 85 volumes -% soap, and where the separation reaches up to 90%.

Figure 5 is shown under "B" the lignin reduction as a function of the wash liquor flow "f" in two washing separations and where the upper curve is valid for a lignin separation at 90% by volume soap and the lower curve is valid for a lignin separation at 85 volume% soap, and where the separation reaches almost 100%.

The lignin reduction in the black liquor soap depends on how concentrated the soap becomes during the first and second separation. 10 15 20 25 30 20 A measure of the concentration of the soap is when the solid soap phase is measured in a centrifuge tube after centrifugation in a laboratory centrifuge at 3000 rpm and 3 minutes and is set in relation to the entire volume of the centrifuge tube. The concentration of the soap after a separator is 85 - 100% by volume.

The laboratory centrifuge can advantageously consist of a centrifuge where samples are analyzed by a spin test in a "Hotspin", model Mk-5-230-0.

The concentration of the soap after normal tank separation is about 80 - 90% by volume.

The process steps can be considered to be as follows, with reference to Figures 3A and 3B; a.

Black liquor and the raw soap (20 + 10) must be fed to a first centrifugal separator "C1", "C1a" within a first process step "A1" to form a first concentrated raw soap 10b, 10b1 of a first quality (light phase) and residues (heavy phase), in the form of separated black liquor 20b (20b1), containing particles and solutes, such as calcium salts and lignins.

The first raw soap 10b (10b1) recovered under "a" above is mixed with B1, a first mixer "B1", with an added first white liquor 4, within a second process step. The mixture B1, according to "b" above, is fed to a second centrifugal separator. C2 ”, (“ C2a ”) within the second process step“ A2 ”, to form a second concentrated, whitewashed and washed soap 10c (10c1) of a second quality (light phase) and residues (heavy phase), in in the form of a mixture (8) of white liquor and black liquor 20c (20c1), containing particles and solutes, such as e.g. calcium salts and lignin substances, The second concentrated soap 10c (10c1) recovered under 'c' above may then be subjected to a mixture into a second mixture B2 in a second mixer "BZ" with an added second white liquor (4), within the second process step The mixture B2, according to "d" above, is fed to a third centrifugal separator "C3", "C3a" to form a pure soap 10d (10d1) (light phase) and residues (heavy phase), in the form of a mixture, with a predominant proportion white liquor (4), and a small proportion of raw soap (10d) and black liquor 20d (20d1), containing particles and solutes, such as e.g. calcium salts and lignins. The pure soap 10d (10d1) is supplied to a digestion plant 24, where an added acid 24a is mixed with the pure soap 10d (10d1) to via a third process step "A3" in the form of a digestion process. let form a crude tall oil 24c and residues in the form of b | .a. cleavage water 24b.

It is further indicated in Figures 4 and 7 that the residual products, under "e" above, consist of white liquor (4), and are added, under "b" above, as the first added white liquor 4 and / or a white liquor stream is fed to a boiler or to an evaporator 13.

Via the various centrifugal separators "C1" and "C2", sequences of black liquor 20b, red liquor 20c (8) are sequentially separated from the raw soap 10b, with calcium and lignin, in different process steps by washing with white liquor 4, to form a red liquor contaminated with black liquor (s).

The residual products 20b, obtained under 'a' above, can be fed to an evaporation plant 13.

The residual products 20c, (8), obtained under "c" above, can be fed to an evaporator 13, or a boiler. The white liquor (4) added under "d" above can, as an alternative, be a newly produced and / or fresh white liquor "Kb".

The produced raw soap 10, 10a, the concentrated raw soap 10b, the white liquor treated and washed raw soap for soap 10c and for pure soap 10d should be operated according to the instructions of the invention so far that the pure soap 10d contains very small amounts of residues, which can be controlled via the volume of added washing liquid (4, (4)) in relation to the volume and concentration of recovered raw soap 10, 10a resp. 10b and its impurities.

A second embodiment of the present invention, operating on the cross-flow principle, is shown and described in Figure 6, with a direct reference to the embodiment according to Figures 4 and 5. Thus, Figure 6 schematically shows a plant of a "Second" embodiment, in accordance with the teachings of the present invention, so that in various process steps, related to a centrifugal separator process and an initial gravimetric separation step, stepwise separating and cleaning with white liquor washing a mixture of black liquor with crude soap 10a for to extract a pure soap 10d.

The description of Figure 6 corresponds to the description of Figure 4, but with the difference of the supply of white liquor 4.

Figure 7 shows an alternative method according to the invention and an alternative adapted for this purpose, a “third”, plant “Aa”, structured with a washing process operating on the countercurrent principle.

For this purpose, a method and a plant are indicated for removing directly from a mixture of black liquor and raw soap (20 + 10) drained via a screen equipment 11 and via mechanically active separation steps “A1”, “A2”, “A21”, “A3 only "Separate raw soap 10 from the black liquor 20 in several successive process steps built up on centrifugal separators" C1a "," C2a "and" C3a ", and via added washing liquids 4, (4), in the form of white liquor, have it separated or separated out a clean soap 10d1 from black liquor 20 with residual products.

This method is based on the use of a number of process steps, also referred to here as "A1", "A21" and "A3", where a raw soap 10 mixed with black liquor 20, stepwise and preferably continuously, must be separated and purified via a number of centrifugal separators. to produce said pure soap 10d1.

More specifically, it is indicated here that the black liquor with the raw soap from the screen equipment 11 is directly fed to a separator stage "A1" comprising a first centrifugal separator "C1a".

The supplied black liquor 20 with raw soap 10 is separated directly in a first separator stage "C1a" to distinguish a concentrated raw soap 10b1, with a higher concentration, than that obtained from the tank ("T" 21, 22 and 23 in Figure 2). and with a lower concentration of soap within the separated black liquor 20b1 than the mixture 20a, 20b obtained from the tank 23 in Figure 2.

The raw soap 10b1 thus separated and concentrated is washed, in the same manner as shown and described in Figure 4, by means of white liquor 4 in a first mixer "B1", and separated in a second centrifugal separator "C2a".

A separated and concentrated soap 10c1 is mixed in a second mixer "BZ" with white liquor (4) and fed to a third centrifugal separator "C3a" for, among other things, the formation of pure soap 10d1 with ever smaller black liquor parts 20b1, 20c1 and 20d1.

A "fourth" embodiment of the present invention operating on the cross-flow principle "Ab" is shown and described in Figure 8, with a direct reference to the embodiment, according to Figure 6.

By using a mechanically operating separator unit "C1a", fed directly from the screen equipment 11, a significantly faster separation step "A1" is indicated than that which can be offered via a gravimetric separation within a tank "T" or one within several tanks 21, 22, 23. .

However, the invention requires that the first centrifugal separator "C1a" be dimensioned for a significantly larger separation capacity than one or more of the subsequent centrifugal separator units "C2a" and "C3a" within the series-oriented process steps. or thereabouts.

The present invention teaches the use of e.g. "First", "second" ........ .. means for moving (pumping) black liquor and white liquor diluted black liquor with ever smaller proportions of raw soap and soap with small amounts of black liquor and / or white liquor from a process step to a subsequent one. Such agents are admittedly not specified in the embodiments shown, but may consist of pump units for a fluid (black liquor and raw soap, white liquor, red liquor, etc.). The invention is of course not limited to the above-mentioned exemplary embodiment, but may undergo modifications within the scope of the inventive concept illustrated in the appended claims.

Special consideration should be given to the fact that each displayed unit and / or circuit can be combined with any other displayed unit and / or circuit within the framework in order to be able to achieve the desired technical function.

Claims (27)

10 15 20 25 30 25 P09-0405 PATENT REQUIREMENTS A process for separating the raw soap from black liquor and / or concentrating the raw soap from an available mixture of black liquor (20) and raw soap (10), and in a subsequent second process step ("A2"), in a first process step. "A21") has the raw soap treated with white liquor (4, (4)) as a soap, in order to remove contaminants from the available raw soap, the pure soap produced via the second process step being adaptable to, within a third process step ("A3"), be subjected to a digestion of crude tall oil (24c) and residual products, such as, for example, digestion water (24b), characterized in that, as said second process step ("A2", "A21), ') One or more series-oriented centrifugal separators ("C2", "C3") are used, that after the first process step ("A1") and within the second process step ("A2") the separated and concentrated raw soap is mixed with a selected additive of white liquor (4) and that the mixture thus formed is fed to a centrifugal separator ("C2") within the t second process step ("A2"), for a separation of a white liquor washed and treated soap from black liquor-related residues. Method according to claim 1, characterized in that a centrifugal separator ("C1a") is used as said first process step, with a high flow capacity and / or separation speed, alternatively a tank ("T") adapted for a gravimetric separation and a connected centrifugal separator ("C1"), with a significantly lower flow capacity and / or separation speed. Method according to claim 1, characterized in that two series-oriented centrifugal separators ("C2", "C3") are used as said second process step ("C2"), that between the first centrifugal separator ("C2") and the second centrifugal separator ("C3") the mixed and washed soap (10c) separated in the first centrifugal separator is mixed with an addition of a selected proportion of white liquor ((4)) and the mixture thus formed is fed to the second centrifugal separator ("C3"), for a separation of a re-washed soap (10d) from black liquor-related residues. A method according to claim 1 or 3, characterized in that the washed soap from the first centrifugal separator or the re-washed soap from the second centrifugal separator, within the second process step, is fed to the third process step. Process according to Claim 1 or 3, characterized in that the mixture of black liquor (20) and raw soap (10) is fed to a first centrifugal separator ("C1"), within the first process step, to form a concentrated raw soap. (10b), of a first quality (light phase), and residues (heavy phase), in the form of black liquor (20b) with i.a. containing particles and solutes, such as e.g. calcium salts and lignin substances, that, under 'a' above, the first and concentrated raw soap (10b) recovered is mixed (B1), in a first mixer ('B1'), with an added proportion of first white liquor (4), that the mixture (B1 ), according to "b" above, a centrifugal separator ("C2") is fed, within the second process step, to form a second-grade soap (10c), a second-grade soap (10c), and residues (heavy-phase) ), in the form of a mixture (20c) of white liquor and black liquor, containing, inter alia, particles and solutes, such as calcium salts and lignins, that, under 'c' above, the second soap was recovered ( 10c) may be subjected to a mixture (B2), in a second mixer ("B2"), with an added proportion of second white liquor ((4)), that the mixture (B2), according to "d" above, is then added to a third centrifugal separator ("C3"), in the second process step, to form a pure soap (10d) (light phase) and residues (heavy phase), in the form of a mixture with a predominant proportion of white liquor (20d) and a min dre share of soap and black liquor, with bla. containing particles and solutes, such as e.g. calcium salts and lignin substances and that the pure soap (10d) is added to the third process step, in the form of a digestion equipment or plant (24), where an added acid (24a), (usually sulfuric acid) is mixed with the pure soap ( 10d) to form a crude tall oil (24c) and residual products via a cleavage process, e.g. in the form of splitting water (24b). Method according to one of the preceding claims, characterized in that, via different series-oriented centrifugal separators, within the second process step, sequences of black liquor are sequentially separated from the soap with white liquor, calcium and lignin and that the soap is washed with the aid of utilized white liquor. , with respect to black liquor and components or substances dissolved in the black liquor, for the formation of residues, from a first centrifugal separator, in the form of a 'red liquor' (20c), for use in one or more process steps. Process according to Claim 5, characterized in that the residual products obtained under "e" above are fed, under "b" above, as a first white liquor, or alternatively a boiler ("K") and / or a evaporation plant (13). Process according to Claim 1, characterized in that the black liquor with raw soap is fed to a single centrifugal separator ("C1a"), within the first process step ("A1"), which is dimensioned for a considerably greater flow capacity and / or separation speed than one or more of the subsequent centrifugal separators, within the second process step ("A2", "A21"). Plant, adapted to carry out the procedure specified in any one of the preceding claims 1 to 8, to separate from an available mixture of black liquor and raw soap (10), in a first process step ("A1") raw soap from black liquor and in a subsequent second process step have a concentrated raw soap washed with white liquor to thereby remove contaminants from the available raw soap, the pure soap (10d) produced via the second process step being adaptable to within a third process step (" A4 ') be subjected to a cleavage into crude tall oil (24c) and residual products, such as cleavage water (24b), characterized in that said second process stage uses one or more series-oriented centrifugal separators, that after the first process stage and within the second process stage mix in a mixer the separated and concentrated raw soap with a selected addition of white liquor and that the mixture thus formed is fed to a centrifugal separator ("C2"). ) for the separation of a washed raw soap into soap from black liquor-related residues. Plant according to claim 9, characterized in that said first process step is adapted to use a centrifugal separator, with a high flow capacity and / or separation speed, alternatively a tank adapted for a gravimetric separation and a centrifugal separator coupled to this tank, with a selected lower or low flow capacity and / or separation rate. 10 15 20 25 30 28 Plant according to claim 9, characterized in that said second process step uses one or more, such as two, series-oriented centrifugal separators, that between the first centrifugal separator and the second centrifugal separator, the separator separated in the first centrifugal separator is mixed and washed. the soap with an addition of a selected proportion of white liquor and that the mixture thus formed within the mixer is adapted to be fed to the second centrifugal separator for a separation of a again washed soap from residual products. Plant according to claim 11, characterized in that the washed soap from a first centrifugal separator or the re-washed soap from a second centrifugal separator, within the second process step, are adapted to be fed to the third process step. Plant according to one of the preceding claims 9 to 12, characterized in that a. Black liquor (20) with raw soap (10) is adaptable to be supplied by a first means with a first centrifugal separator ("C1"), within the first the process step, for forming a concentrated raw soap, a first soap (10b), of a first quality (light phase), and residues (heavy phase) in the form of black liquor (20b), with i.a. containing particles and solutes, such as e.g. calcium salts and lignins, b. that the first soap (10b) recovered under 'a' above is adaptable to be added and mixed by a second agent, in a first mixer ('B1'), with an added proportion of first white liquor (4), c. that the mixture (B1), according to "b" above, is adaptable to be supplied by a third agent with a second centrifugal separator ("C2"), within the second process step, to form a treated raw soap to soap, a second soap (10c), of a second quality (light phase), and residues (heavy phase), in the form of a mixture (20c) of white liquor and black liquor, containing, inter alia, particles and solutes, such as t. eg calcium salts and lignin substances, d. that the second soap (10c) recovered under "c" above is adaptable to be added and mixed by a fourth agent, in a second mixer ("B2"), with an added second white liquor ((4)), 10 15 20 25 30 29 e. that the mixture (B2), according to "d" above, is adaptable to be supplied by a fifth agent to a third centrifugal separator ("C3"), within the the second process step, to form a pure soap (10d) (light phase) and residual products (heavy phase), in the form of a mixture with a predominant proportion of white liquor (4) and a smaller proportion of soap and black liquor, with i.a. containing solutes, such as e.g. calcium salts and lignin substances and f. that the pure soap (1 Od) is adaptable to be added by a sixth agent to the third process step, in the form of a cleavage plant (24), where an added acid (24a) (usually sulfuric acid) is adapted for a mixture with the pure soap (10d), to form a crude tall oil (24c) and residual products via a cleavage, e.g. in the form of splitting water (24b). Plant according to claim 13, characterized in that the residual products separated under "e" above are adaptable to be supplied by a seventh agent, under "b" above, as the first added white liquor (4) and / or adapted to be supplied with a white liquor stream to a boiler ("K"), or to an evaporator (13). Plant according to claim 9, characterized in that via the different centrifugal separators, within the second process step, proportions of black liquor are intended to be sequentially subjected to a separation from the soap, with white liquor, calcium and lignin, and that by means of used white liquor, the soap is adapted to be washed, with respect to black liquor and components or substances dissolved in the black liquor, to form residues, from a first centrifugal separator, in the form of a "red liquor" (20c), for a later use within a or multiple process steps. Plant according to one of the preceding claims 9 to 13, characterized in that residual products obtained under "a" above are adapted to be supplied directly by an eighth agent to an evaporation plant (13). Plant according to any one of the preceding claims 9 to 13, characterized in that residual products, obtained under "c" above, are adapted to be supplied by a ninth agent to a digester ("K") and / or an evaporator ( 13). 10 15 20 25 30 30 Plant according to any one of the preceding claims 9 to 13, characterized in that residual products obtained under "e" above are adapted to be supplied by one tenth agent, under "b" above, as a first white liquor (4 ), or be supplied with a boiler ("K") and / or an evaporator (13). Plant according to one of the preceding claims 9 to 13, characterized in that the second white liquor ((4)) supplied under 'd' above is adaptable to correspond to a produced white liquor. Plant according to claim 13, characterized in that the first white liquor (4) added under "b" above is adaptable to form a mixture of white liquor and black liquor and / or from separated residues, under "e" above, containing dissolved impurities, such as calcium salts and lignins. Plant according to Claim 9 or 13, characterized in that the first white liquor (4) added by an eleventh agent is adapted to consist of a produced white liquor. Plant according to claim 9, characterized in that the soap treated in process steps into a pure soap (1 Od) is adaptable to be operated so far that the pure soap will contain very small amounts of residual products, such as in the form of black liquor, with dissolved substances, such as dissolved salts (eg calcium ions) and lignins. Plant according to claim 9, characterized in that a first centrifugal separator ("C1a"), within a first process step ("A1"), among a plurality of successive process steps, each using a continuous or semi-continuous centrifugal separator process and to which a drained black liquor from a digester ("K") with crude soap is added directly, is adapted to have a concentrated crude soap (10b1) separated from residues, in the form of black liquor (20b1), within this first centrifugal separator. containing dissolved impurities, such as calcium and lignin Plant according to Claim 23, characterized in that the black liquor is fed to a single centrifugal separator ("C1a"), within the first process step, which is dimensioned for a considerably greater flow capacity and / or separation rate than one or more of the subsequent centrifugal separators. (“C2a”, “C3a”), within the second process step. Plant according to claim 24, characterized in that the first centrifugal separator ("C1a") is dimensioned with a flow capacity which by a factor, preferably between 1 and 10, exceeds the flow capacity of one or more of the subsequent centrifugal separators ( "C2a", "C3a"). Plant according to Claim 25, characterized in that each of the centrifugal separators ("C2a"; "C3a") as in the flow direction, in order to be able to separate and concentrate raw soap in a number of process steps and to treat raw soap and soap with white liquor to successively refined grades, considered after being said, said first centrifugal separator ("C1a") are selected from each other with the same or at least substantially the same flow capacity and / or separation speed. Plant according to Claim 9, characterized in that a flotation tank acting on the flotation principle is introduced between all or selected process steps as a buffer tank.