FI115978B - Process for the recovery of non-fibrous substances from wood material - Google Patents

Description

115978

METHOD FOR THE EXTRACTION OF NON-FIBER MATERIALS FROM RECOVERY WOOD MATERIAL

The present invention is directed to a process for recovering non-fibrous materials from a fibrous wood material that has been subjected to a mechanical pulping process such as so-called. TMP process (Thermomechanical Pulping) or grinding process as defined in the preamble of the attached independent claim 1 10.

The mechanical pulping of wood to produce fibers for paper and board takes place at elevated temperatures, typically above 80 ° C. A high temperature is required to soften the fiber-binding lignin. By raising the temperature, the fibers are separated relatively undamaged. Mechanical pulping is generally accomplished by treating the wood chips in a plate refiner, or by grinding the pieces of wood with a rotating 20 refiner with a suitable abrasive abrasive surface. Grinding of the chips yields hot pulp, TMP (Thermomechanical Pulp). Even more selectively, the fibers are separated by chemically treating the chips before grinding, usually alkaline:. 25 with sulphite or with base only. The aforementioned mechanical • «: pulps are mainly used in tissue products and board. Grinding with a disk refiner is typically performed in two stages, in separate refiners.

• · · 30 High used in mechanical pulping '!!! temperatures cause a significant amount of wood material to dissolve or disperse in process water.

When producing mechanical pulp from spruce (Norway spruce), the most widely used wood species in Northern Europe, *:, about 30 to 50 kg / t of 35 wood materials are released into process water. This Dissolved and Colloidal Material (DisCo) contains 115978 2 mainly hemicellulose, lignin, lipophilic extractives (wood resin) and lignans.

In recent years, paper mills have had to reduce the use of 5 process waters to reduce the amount of wastewater and thus reduce emissions to the receiving water. The now released dissolved and colloidal materials (DisCo materials) accumulate in the process water cycle in paper mills that use little fresh water, i.e. 10 mills with a high water closure rate. Accumulated DisCo materials cause a variety of interferences with the papermaking process. Wood resin can form sticky deposits on the surface of the paper machine equipment and also dramatically weaken the strength of the paper 15. Dissolved lignins consume bleaching chemicals and reduce the brightness of the paper produced.

Lignans and other hydrophilic extracts, such as 20 different stilbenes and flavonoids, also consume bleaching chemicals and can therefore reduce the brightness of the paper when oxidized.

Inorganic salts are also soluble in the production of mechanical pulp. Salts can interfere with pulp bleaching processes using hydrogen peroxide by catalyzing the breakdown of hydrogen peroxide ions. The salts can also promote unwanted growth of bacterial strain * * *. Thus, it is evident 30 that the DisCo "!! removing material from the pulp before bleaching the pulp and making paper would result in many economic benefits., * f *.

* * · * T »35 The solubility of wood in mechanical pulping cannot be substantially reduced by optimizing the pulping process. However, the negative effects of DisCo ingredients on 115978 3 pulp bleaching and papermaking can be avoided if said materials are removed from process waters immediately after the mechanical pulping process.

5

Methods for removing wood resin from mechanical pulps have previously been disclosed e.g. U.S. Patent No. 4,922,989, which proposes turbulence treatment of mechanical pulp at a consistency of 7 to 20%, whereby resin removal is said to improve.

It is also known that the dissolution and dispersion of wood material generally has a minimum at pH of about 5, which is a pH of 15 naturally occurring in mechanical pulping, and that, for example, wood resins and pectins are released significantly more than pH> 7. .

In "Factors affecting resin removal from radiata 20 pine mechanical pulps", Appita J. 1990, 3: 5, 217-221 by Suckling et al. have concluded that high pH values increase the solubility of the resin.

25, Part II: Screw Press Study, Pulp & Paper Canada 92: 9: **, * (1991), 47-51 by J. Alamo, D. Ouchi , J. Paris and J.

• ♦

J "; Wearing propose that the temporal conditions at which pH

> 7, should be used to improve resin removal from * * · chemothermal (CTMP). Figure 2 of the article shows that when the pH of the process water is raised from 4 to 8, the resin removal t '!!! power is improved by about 15%. An alkaline pH is recommended in the caption.

* »·

However, to our knowledge, processes to recover other non-fibrous wood material components, such as water-soluble components 115978 4, have not been developed to date.

Therefore, it is an object of the present invention to provide a method for minimizing the above-mentioned problems.

Thus, it is an object of the invention to provide an improved method for removing impurities such as wood resins and aromatic compounds, which impurities can have adverse effects on both the performance of the paper machine and the quality of the paper.

It is also an object of the invention to provide a method for recovering valuable soluble and colloidal materials from process pulping processes of mechanical pulping.

Accordingly, it is an object of the invention to provide a process for isolating from a process water for later use moderately pure component fractions which may have a beneficial effect on paper strength.

It is a further object of the invention to provide a process for recovering valuable aromatic compounds, *: ': which can be used in the preparation of bioactive compounds in the pharmaceutical and food industry.

• 4 I I

needs.

The present invention relates to a process for the recovery of non-a fibrous materials from wood which is subjected to mechanical processing. in the pulping process, as mentioned in the characterizing part of independent claim 1 a.

Il I I

I * I · *, 35 The process of the invention can advantageously be used to recover valuable non-fibrous materials from wood material for later use. Thus, the present invention provides a means of isolating certain valuable components and groups of components, such as bioactive compounds and glucomannans, by separate extraction from wood material or process waters such as wash waters, dilution waters, or recirculated waters to which said compounds have been extracted.

The method can also be used to reduce the concentration of unwanted non-fibrous materials in process waters that are detrimental to pulp and papermaking processes. The present invention provides a means to reduce the concentration of dissolved and colloidal components, particularly in liquids from mechanical pulping and papermaking processes.

According to the present invention, various valuable non-fibrous components are readily recovered from wood material in mechanical pulp and paper 20 manufacturing processes and separated into relatively pure fractions for later use. After separation, said pure fractions can be recycled to the papermaking process or used ... for other purposes, for example in the pharmaceutical industry.

Components or groups of components which * 'can be recovered by the process of the invention; relatively pure fractions are wood resins,: ·: aromatic substances such as lignans, lignin, stilbenes, · * ". flavonoids, wood polysaccharides and salts.

30 • ·

For the extraction and recovery of some valuable compounds such as lignan hydroxymatairesinol (HMR) in its natural form, the pH of the entire mechanical pulping process is preferably maintained at pH <7, * 35 preferably at pH 4-6 until the lignans are extracted and recovered.

t 115978 6

The present invention is particularly suitable for separating non-fibrous material from wood material which is subjected to processes for the production of heat-pulp (TMP). Recovery of dissolved and colloidal materials (DisCo) in TMP processes is particularly easy because the DisCo materials can be washed from the wood material at relatively low preferred pH levels in the range of pH 5 and at preferred temperatures below 90 ° C. in the pulping process, the temperature may be temporarily higher. Further, valuable substances are recovered by using relatively small amounts of water to obtain a high concentration of recovered substances in the liquid fraction.

In the TMP process utilizing the present invention, non-fibrous materials can be extracted from the wood material into a liquid fraction in an extraction apparatus in a separate extraction step. In contrast, in some TMP-20 processes, where wood material is treated at suitably low pH levels of about 4-6 and high temperatures, valuable recoverable materials, such as water-soluble aromatic components, are soluble and dispersed in the liquid fraction as such. • 25 concentrations to separate these materials without separate extraction in the extraction apparatus. the extraction step. Valuable materials can be recovered, * <, from process waters, such as wash waters, dilution waters, or recycled waters, either removed from the pulp, paper mill or left in its process cycle.

* · · · ;;; At low pH levels, for example, temperature is not as important for the recovery of HMR '···' as at higher pH levels; Therefore, high temperatures can be used at lower pH levels. At higher pH-35 levels, low temperatures should be used.

> I t I I

The extraction of the non-fibrous material from the wood material now according to the present invention is preferably carried out in an extraction apparatus in which the non-fibrous material obtained from the wood material dissolves and disperses in the water fraction when water is mixed with the pulp.

5 The pulp material should be handled in a relatively dilute extraction apparatus. In most cases, this requires dilution of the bulk material before the extraction process. The diluent, typically water, may be added to the direct extraction apparatus, or may be mixed with the pulp material prior to its introduction into the extraction apparatus. The TMP pulp obtained from the pulverization step of the papermaking process having a dry matter content of about 5 to 50%, typically 20 to 40%, and more typically 30 to 40% should preferably be diluted by adding water to a dry matter content of about 0.5 to 20%. , typically 0.5 to 15%, more typically 0.5 to 10%, before the pulp is processed in the extraction apparatus.

In the extractor, non-fibrous materials such as small particles containing wood resin and water-soluble components containing aromatic compounds, salts, and polysaccharides are dispersed and soluble in the liquid fraction of the diluted bulk material. That part of the liquid fraction *: ··: of which dissolved and colloidal non-fibrous matter | It is desirable to separate and recover, preferably by squeezing • I · · from other pulp material, but in some ··· processes it can be separated by centrifugation or even, by filtration of the coarse material.

, 30 According to the present invention, water-soluble * ;;; the extraction of the aromatic compounds should preferably be carried out at pH <7, more preferably at pH 4-6. Therefore, ·; · in pulping processes such as CTMP processes, f ”; where the pH of the pulp suspension is higher, the pH of 35 should be lowered so that a suitable pH is obtained for the extraction process. A suitable acid may be added to the pulp suspension to achieve the desired pH.

8 115978

Potentially valuable soluble and colloidal materials (DisCo) released from wood material into process water during mechanical pulping include, for example, wood resins, water-soluble aromatic compounds, salts, and polysaccharides.

The main component groups of wood resin, i.e. fatty acids, resin acids and sterols, are commercially produced chemicals that have so far been recovered only in sulphate pulp mills in the form of tall oil soap.

Tall oil soap has been acidified and distilled to give a pure fraction of fatty acids and resin acids. Sterols have been recovered from either pine soap or 15 tall oil pitch, which is formed as a residue from the distillation of tall oil. The recovery of wood resin also in mechanical pulp mills, which is made possible by the present invention, is a significant addition to current tall oil production. Wood resins, as well as their 20 most important components, triglycerides and steryl esters, obtained from the process utilizing the present invention, can be used as such in a variety of applications.

Of the water-soluble aromatic compounds, in particular, · · · · * * lignans are potentially valuable bioactive components for medical purposes due to their antioxidant and anticarcinogenic properties. * *. applications and health foods.

In particular, this applies to lignans from softwood species such as Norway spruce (Norway spruce), in which the main component is the highly bioactive compound i t · hydroxymatairesinol (HMR). The isolation and isolation of HMR on an industrial scale is made possible by the present invention. In particular, isolation at a pH below pH 7, preferably between pH 4 and pH 6, improves the yield.

»* 115978 9

The low molecular weight lignin present in mechanical pulping solutions is a pure, sulfur-free and reactive lignin, which may be a valuable addition to the currently produced lignin products.

Especially dissolved hemicelluloses from polysaccharides, with glucomannans as the dominant component, are useful because they stabilize the colloidal dispersion of wood resin and other non-water-soluble sticky materials by an ethereal mechanism. In addition, they reduce the tendency of such sticky particles to precipitate by forming a hydrophilic gel around the particles which makes them less sticky (adhesive). Further, hemicelluloses also reduce or even eliminate the negative effects of wood resin on paper strength.

The non-fibrous components, by means of a typical embodiment of the present invention, can be extracted from the wood material in mechanical pulping processes in a separate extraction step where the non-fibrous components are extracted as dissolved and colloidal *: · *: components into Pesul.

• 25 Detergent Separated from Fibrous Wood Material: Can be Concentrated Prior to Its Different Components ·· *. bathing. Thereafter, the washing solution obtained from the extraction step is first typically treated to recover finely divided particles such as wood resin dispersed therein. Wood resin can be separated from solution ** ·: by microfiltration, ultrafiltration or micrototation. After removal of the wood resin ·· and other finely divided particles from the washing liquid, the remaining solution contains mainly ·, 35 water and water-soluble components. The solution ···· can then be treated to separate the water-soluble aromatic components contained therein.

115978 10

The water-soluble components can be isolated in relatively pure fractions by optimizing the pH and temperature of the liquid and using appropriate process steps to remove each of the individual components or groups of components.

According to a typical embodiment of the present invention, the process steps of separating the desired components or groups of components from the extraction liquid 10 or from a liquid fraction such as process water, wash water or recirculating water to recover non-fibrous materials from the wood material to be processed

Compression or filtration to separate most of the liquid fraction from the pulp suspension or process water in the mechanical pulp or paper making process.

20 - Extraction, filtration or flotation to remove the insoluble colloidal wood resin from the above liquid fraction.

• · '' - Removal of aromatic components from the liquid fraction using sorbents for the aromatic components, • 25 aromatic ion exchange resins or column or: liquid chromatography.

···, - To remove salts of dialysis or osmosis from the liquid fraction. Dialysis removes salts and leaves 30 fractions of water-soluble polysaccharides, provided that the wood resin and aromatic compounds have been removed previously.

··· According to a preferred embodiment of the present invention, the wood resin free solution may be mixed with *. 35 acrylate or divinylbenzene-polystyrene resin ···· macroreticular particles to provide sorption of aromatic substances such as lignans, stilbenes, 115978 11 flavoinoids and lignins. The acrylate or resin eluent containing absorbed aromatics is separated from the solution, the remaining eluate solution containing mainly water-soluble salts and polysaccharides such as hemicellulose. The aromatic substances are recovered from the acrylate or resin eluent by means of a polar solvent such as acetone, ethanol or methanol. Aromatic agents can be separated from the eluent with a strong alkaline solution if there is no need to recover the lignans without causing a chemical deformation.

The aromatic compounds can be further subdivided into fractions containing either lignans or lignin. This can be accomplished, for example, by extraction with methyl tert-butyl ether (MTBE), dialysis, reverse osmosis, or chromatographic techniques.

In order to separate and isolate the lignans from the process fluids without altering the chemical composition in which they are present in the wood material, a pH of between 4 and 6 is preferably maintained until the lignans are separated. Outside this pH range ·; ··: lignans undergo a number of chemical deformations.

, ···. In the following specific examples, the process of the present invention is described with reference to the accompanying drawings, in which: FIG. 1 shows an exemplary schematic diagram of the fractionation of soluble and colloidal compounds in mechanical fluids and paper making processes; FIGURE 2 shows the amount and composition of dissolved lignans separated from process liquids at various pH levels at 12-15978 at 90 ° C; FIGURE 3 shows the amount and composition of dissolved lignans separated from process fluids at various pH levels at 5 ° C to 60 ° C; FIGURE 4 shows the amount and composition of lipophilic extractants at various pH levels; FIGURE 5 illustrates the amount and composition of dissolved and dispersed hemicellulose at various pH-10 levels, and FIGURE 6 illustrates an exemplary schematic diagram of a system where the present invention is applied.

Figure 1 shows an exemplary schematic diagram of the fractionation of soluble and colloidal compounds in liquids 10 of mechanical pulp and paper.

Such process fluid 10 may be a 20-dilute solution from an extraction apparatus in which non-fibrous compounds are extracted from wood material, or process water from a mechanical pulp and paper: manufacturing process, such as washing water, dilution water ·: * ·, or circulation water.

: 25: In order to isolate relatively pure fractions from all * ·· major non-fibrous components or Group III components present in pulp and paper ** 'manufacturing solutions, it is advantageous for the subsequent fractionation of the dissolved components initially ···! separates solids such as fines and '... · colloidally dispersed wood extracts.

1111. "·. Thus, in the first separation step 12, the fraction 35 of the fibers and larger particles is separated from the liquid 35 by compression, filtration or other suitable means. The separated fibers and larger particles 115978 13 14 can be recycled to the pulp and paper making process. The remaining liquid fraction 16 still contains finely dispersed fibrous material and colloidally dispersed wood extracts such as wood resin (pitch). These particles are separated from the liquid in a second separation step 18 using appropriate separation techniques such as microfiltration, ultrafiltration, flotation, centrifugation or extraction. The solid reject 20 can either be destroyed or reused 10.

The secondary fraction 22 of the second separation step 18 contains components dissolved in the broth, such as water-soluble aromatic compounds, salts and polysaccharides. Said components or groups of components can be fractionated on the basis of their molecular properties, i.e. size, hydrophobicity, ionicity, volatility, etc.

Aromatic compounds such as lignins and lignans can be separated from the accretion fraction 22 in the third separation step 24 by using absorbents, aromatic ion-exchange resins, column or liquid chromatography, ... dialysis, reverse osmosis or membrane filtration to give # 25 as eluent, and e «» lignans can be recovered, for example, by treating:. The eluate 28 of step 24 contains salts and polysaccharides. The hemicellulose can be separated from the salts at step 30 using dialysis or reverse osmosis. The salts are separated into the permeate 32 of step 30. The polysaccharides are recovered from the concentrate 34 of step 30.

Process conditions are of considerable importance in order to, V. The components can be isolated in their "natural" form, that is, in the form in which they are present in the wood material. It has now surprisingly been found that kkkt 115978 14 for separating and isolating lignans from process fluids without altering the chemical composition in which they are present in wood material, pH between 3.0 and 6.7 is preferred throughout the 5 pulping processes, or at least as long as the lignans are extracted and separated liquid. Outside this range, lignans undergo numerous chemical deformations.

10 TEST 1

The purpose of the experiment was to find out the components that are separated from the DisCo solution at different pH levels.

After the first milling step, hot pulp (TMP) was sampled at a pulp and paper mill producing TMP from spruce. These samples were used to make DisCo solutions containing dissolved and colloidal (DisCo) materials by mixing with 20% pulp of distilled water, followed by centrifugation to separate the fibers. Stirring was carried out at 90 ° C at pH 3, 4, 5, 6, 7 and 8, 10, 30, 60, and 180 minutes each using a vibratory mixer. The lignans contained in the DisCo solutions after centrifugation at 500g (30 min): 25, lipophilic extracts and polysaccharides were analyzed by gas chromatography.

The composition of lignans dissolved in DisCo solutions was strongly dependent on the pH used during pulping.

. The results are shown in Figure 2. At pH 3-5, the composition was practically constant. But at pH> 6, hydroxymatairesinol (HMR) decreased, ··, significantly. At pH 7 and 8, the HMR concentration '·' 35 was dramatically lower than at pH <7.

Conidendric acid concentration;> · increased directly proportional to the decrease in HMR, meaning that the total concentration of 115978 lignans remained virtually constant. The experiment suggests that HMR was converted to conidendric acid and therefore it is very important to select the correct pH for pulping to ensure high recovery of recovered 5 HMR.

Figure 2 also shows that HMR can be converted to conidendric acid if mixing is continued for 180 minutes at pH 5 and 6.

10

Figure 3 shows the results of a corresponding experiment in which the treatment was carried out at 60 ° C. It can be seen that at this lower temperature a higher concentration of HMR was obtained. Also, the longer mixing time does not seem to be particularly affected at pH 5 and 6.

Figure 4 shows that the composition of lipophilic extractives in DisCo solutions was only slightly dependent on pH but that the amount of extractants dispersed in the aqueous phase was highly influenced by pH. Higher pH increased the solubility of the extracts. At pH 8, the amount of lipophilic extractives was about five times that of pH 3. This can be:. 25 explains that at higher pH, * · », ·,; fatty acid and resin acid soaps, the soaps being able to act as dispersants for other lipophilic h; extractives.

Figure 5 shows that the amount of dissolved and dispersed: hemicellulose remained fairly constant throughout pH range 3 to 7. However, the amount of glucomannan decreased significantly at pH 8, whereas that of dissolved pectin

Iti *, ·> ·, the number increased. Under initial conditions, the organic glucomannans are deacetylated, whereby the water solubility of the glucomannans is reduced, which in turn results in their precipitation on the pulp fibers. Under the same conditions, 11597816 pectins were demethylated, resulting in higher solubility of the sodium salts of polygalacturonic acids formed.

5 EXPERIMENT 2

The purpose of the experiment was to determine the separation of different groups of components and their yield from DisCo solution.

The first portion of the DisCo solution was filtered through a 0.1 µm membrane filter under vacuum at 90 ° C. About 85% of the wood resin dispersed in the DisCo solution was removed from the DisCo solution along with the reject to be removed from this step. More than 90% of the lignans and lignin were recovered in the filtrate, as were 85% of the dissolved polysaccharides.

A second portion of the DisCo solution was treated in a microflotator. 20 bentonites and polyacrylamide (PAM) were used as flotation chemicals. The combination of bentonite and anionic PAM. Resulted in a 20% decrease in wood resin removal. Virtually no lignans, lignin or polysaccharides were lost. The low ... flotation efficiency is probably due to the low concentration of wood resin in the tested DisCo *> 25 solution.

Concentrated DisCo solutions would probably achieve: · · better removal results also by flotation.

The filtrate obtained from the filtration of the wood resin was counted through 30 hydrophobic interactive resin layers (XAD-7) at pH 5 to recover the aromatic substances. The adsorbed onto the resin was eluted with ··· acetone or methanol. The yield of lignans was over 95,. *%, And the yield of lignin was up to 80%. The recovered lignans 35 and lignins could be fractionated by extraction with methyl tert-butyl ether (MTBE).

t · 115978 17

Separation of hemicellulose was performed on the DisCo solution after removal of the wood resin. Separation was performed by ultrafiltration through membranes with 3, 10 or 30 kD molar cut-offs. Filtration 5 was performed by centrifugal force. The best yield, over 80% of hemicellulose, was obtained on a 3 kD membrane.

The high content of wood resin in the DisCo solution used in the ultrafiltration test resulted in slow filtration. Better resin removal by either microfiltration or 10 efficient flotation followed by an XAD-7 treatment step to remove lignan and lignin should result in more efficient ultrafiltration of hemicellulose.

Further, it has surprisingly been found that the size of wood chips influences the extraction of valuable lignans such as HMR. Potentially valuable lignans, especially the proportion of hydroxymatairesinol (HMR) in them, can be extracted into water and recovered in high yield from relatively 20 coarse TMPs in the pH range 4-6. The roughness of the TMP can be expressed as the Canadian Standard Freeness Number (CSF). Typically, the CSF value of the TMP pulp after the first grinding step is higher than 300. In this step, the TMP pulp roughness allows effective compression, i.e., the separation of the solution from the solid wood material.

The effect of pH on HMR yield seems to be due to different steps or isomerization of HMR at different pH levels. At pH levels above 5, the yield of HMR appears (.. »t to decrease due to the isomerization and condensation reactions * · leading to the HMR isomer and conidendric acid). Even at pH below 3, condensation appears : ^ conidendric acid.

. ·! ·. 35

Figure 6 schematically illustrates an exemplary ** ·· * system in which the DisCo solution is taken from the first 18 milling steps of the TMP process> 115978. Figure 6 shows the first and second grinding steps 40, 42 of the TMP process.

Coarse TMP having a dry solids content of 35% is fed from the first milling step 40 via line 44 to 5 extraction apparatus 46. Water 48 is fed to the extraction apparatus to dilute TMP to a solids content of 5%. The TMP treated in the extraction apparatus 46 is removed through line 50 to a screw press 52, from which 35% TMP in dry matter is fed through line 54 to another 10 milling step 42. DisCo solution separated from TMP in a screw press is fed through line 56 for subsequent treatment, e.g. An important advantage of extracting coarse TMP, for example 15 TMP from the first grinding step, instead of the final paper grade TMP, is that the extraction solution is extruded more efficiently, for example by using a screw press.

If, in one exemplary extraction process using the system described above, 17.1 m 3 of water per tonne of TMP is added to the extraction apparatus, and a screw extruder would yield 17.1 m 3 of a DisCO solution, DisCO-j; a solution containing 1.5 kg of lignans, 5.8 kg of lignin, 17.9 kg of hemicellulose and 4.3 kg of resin in a yield of »; ·. 25 could yield 45 tonnes of pure HMR per 100,000

* · I

*! 1 'tons of pulp.

The present invention provides a process for separating various * <·· 'valuable non-fibrous components, such as bioactive HMR, in the desired form and in high yield, allowing the use of the components! It |! on an industrial scale. The pH and temperature levels play an important role in the recovery process. In addition, separation of the resins from DisCo solutions prior to separation of lignans and hemicellulose improves the separation of valuable components.

• »115978 19

The present invention is not intended to be limited to the embodiment described in this specification, but encompasses all methods according to the appended claims.

5

Claims (17)

20,11978 A process for recovering non-fibrous materials from wood material which is subjected to a mechanical pulping process such as a TMP process or a grinding process comprising the steps of: - extracting non-fibrous materials such as wood resins, aromatic compounds, salts and polysaccharides; and recovering said non-fibrous materials from said liquid fraction, characterized in that the recovery of non-fibrous materials comprises the step of separating said aromatic compounds from said liquid fraction and of said liquid fraction. the pH of the liquid fraction is maintained at pH <7, preferably between pH 3 and pH 6.7, typically between pH 4 and pH 6, during the extraction and recovery process until the aromatic compounds are isolated. The process according to claim 1, characterized in that the non-fibrous components are extracted from said wood material prior to being treated with a pH · ·; · At a pH above pH 7, preferably prior to treatment at a pH above pH 6. • · «t«, ·· *, 30 3. A process according to claim 1 or 2, characterized in that said liquid fraction comprises recovering water-soluble aromatic compounds by means of separation means to obtain an eluent fraction containing water-soluble aromatic compounds and 35 eluate fraction. The method according to claim 3, characterized by 115978, wherein said separation means employ aromatic ion exchange resins, other aromatic component sorbents, liquid or column chromatography or other suitable processes for separating water-soluble aromatic compounds from other compounds. A process according to claim 3, characterized in that the process comprises further treating said eluent fraction 10 to separate lignans from other water-soluble aromatic compounds contained in the fraction, said further treatment comprising chromatographic methods, extraction fractionation, treatment with a polar solvent or other suitable means. 15 A process according to claim 5, characterized in that the process comprises further treating the lignan fraction separated from the water-soluble aromatic compounds to separate the hydroxymatairesinol (HMR) from the other lignan fraction compounds. Process according to claim 1 or 2, characterized in that: - the liquid fraction contains: 25 process water from the TMP process, and - · · · - in addition, the dispersed substances such as small particles or wood resin are separated from the process water. by filtration, flotation, or any other suitable mechanical or physical-physical method. 30 • ;; j A process according to claim 7, characterized in that the dispersed materials are separated from the process water before the aromatic compounds are separated off. * · · Process according to Claim 3, characterized in that polysaccharides such as hemicellulose are separated from the eluate by dialysis, reverse osmosis, nanofiltration, a spinning process or any other suitable method known per se. Process according to claim 1 or 2, characterized in that the non-fibrous materials are separated from the wood material which is processed in the refiner in the process of making TMP pulp. Method according to claim 10, characterized in that the pulp suspension is removed from the first refining step of the refiner, - the pulp suspension is fed to the extraction apparatus, a pulp suspension portion and a solution portion containing colloidal and * non-fibrous materials extracted from the wood material to be treated in the pulping process, ·; ·· - the solid pulp suspension portion is fed to the second • 25 stages of the refiner, and: - water-soluble aromatic compounds. part of the solution. A method according to claim 11, characterized in that the pulp fed to the t * · - extractor is diluted by adding water to the · ··· pulp fed to either the extraction apparatus or the apparatus. * _ 35 The method according to claim 12, characterized in that the pulp suspension '' fed to the extraction apparatus is diluted from a consistency of about 5 to 50%, typically 20 to 115578 40%, more typically 30 to 40%, to a consistency of about 0.5 to 20%, typically 0.5 15%, more typically 0.5-10%, and the pulp suspension removed from the extraction apparatus is divided into a liquid portion and a high consistency pulp suspension-5 portion having a consistency of about 5-50%, typically 20-40%, more typically 30-40%. 14. A method according to claim 11, characterized in that the lignans, including hydroxymatairesinol 10, are separated from the liquid portion. Method according to claim 10, characterized in that the wood material is fed to the refiner in the form of chips having a Canadian Standard Freeness (CSF)> 300. Process according to claim 1, characterized in that in the process involving mechanical pulping processes at a pH of> 7, the pH of the liquid fraction is adjusted to be <7, typically 20 to 4, before the water-soluble aromatic extracting the compounds from the wood material to the liquid fraction. Process according to claim 1 or 2, characterized in that said liquid fraction is separated from: - said wood material by compression. • · · 1> i I „115978