FI122169B - Treatment of wood chips for the production of hot pulp - Google Patents

Description

Treatment of wood chips for the production of hot pulp

FIELD OF THE INVENTION

The present invention relates to a hot pulp process and, in particular, to the treatment of wood chips in connection with the production of hot pulp.

BACKGROUND OF THE INVENTION

Thermo mechanical pulp (TMP) is pulp made from wood fibers by processing. Peeled timber is usually first converted into small pieces of wood, chips. In the Hot Hierremas process, wood chips are preheated before the rolling process. Chip milling 10 refers to milling chips, whereby the chips are subjected to mechanical force during a roughing or grinding operation. This softens heat and water vapor, softening the lignin in the wood and other molecular bonds between the fibers, thereby separating the individual fibers. The steam generated can also be used to preheat the chips under pressure or at normal atmospheric pressure. During pre-15 heating, the lignin softens, which allows the fibers to separate from one another and become more intense and longer.

TMP can be used, for example, in the manufacture of newsprint, lightweight coated (LWC) and super calendered (SC) paper and board.

The problem with the above arrangement is that the preparation of heat massage heat consumes quite a lot of energy.

BRIEF DESCRIPTION OF THE INVENTION

It is therefore an object of the invention to provide a method and apparatus implementing the method so as to alleviate the above problem. The object of the invention is achieved by a method, a system, an impregnation device, a dose unit, an optimization unit, a hot pulp and a use which are characterized by what is stated in the independent claims. Preferred embodiments of the invention are claimed in the dependent claims.

The invention is based on the use of one or more ligninous enzymes lysing or otherwise disrupting the wood-based material to pre-treat the wood-based material in an impregnation device o g prior to the actual shredding process. The method comprises recycling the enzyme, wherein the enzyme exiting the impregnator is recycled by means of

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at least partially back to the impregnation device. The system further comprises measuring means for measuring the activity of the enzyme (s). The measurement result is transmitted to control means configured to control the delivery means based on said measurement result.

An advantage of the present arrangement is that it provides a biological method for treating wood-based material prior to actual hot rolling, thereby making the system more environmentally friendly compared to, for example, chemical treatment of wood-based material (Kemi-heat pulp, Chemi-thermo mechanical pulp) with no treatment of the wood-based material prior to the actual hot rolling process.

BRIEF DESCRIPTION OF THE FIGURES

The invention will now be further described in connection with preferred embodiments with reference to the accompanying drawing, in which:

Figure 1 shows a system according to an exemplary embodiment of the present solution.

DETAILED DESCRIPTION OF THE INVENTION

The present solution relates to a method and system for optimizing the pretreatment of fibrous pulp, wood chips and / or other wood-based material using enzymes in an impregnation apparatus. In method 20, enzyme activity can be continuously measured by enzyme-selective sensors (e.g., biosensors or conventional sensors such as pH measurement, or pH sensors). In the process, the enzyme mixture (or at least a portion thereof) is preferably recycled in a impregnator. Recycling may, for example, be performed by recovering the enzyme or enzyme-containing fluid from the bottom of the device and circulating it to the top of the device. In an exemplary embodiment of the present invention, the enzymes are pumped into the impregnator and optimized for the treatment of wood (wood chips, wood chips, etc.) for the production of £ 30 enzyme-thermo mechanical pulp (eTMP). The purpose of dosing the enzyme is to soften the mass or

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^ chips to facilitate the actual hot rolling, thereby reducing the energy cost of producing hot pulp. The enzymes used herein are ligninolytic, pectinolytic and / or otherwise degradative to the wood-based material. Optimizing the amount of enzyme in 3 processes by circulating and dispensing the enzyme mixture to the impregnator is based on measuring the activity of the enzyme in the impregnation tank and / or the recycling pipeline by means of sensors, for example suitable biosensors. The activity of different enzymes can be measured using different Senso-5s, so that the activity of a particular enzyme can be measured separately using a specific sensor specific to that enzyme. For example, a disintegrating enzyme may refer to an enzyme which softens wood cells / wood structure and / or differentiates wood fibers.

Hot pulp production consumes quite a lot of energy. In an exemplary embodiment of the present solution, it may be possible to reduce the energy consumption of TMP manufacturing by up to 24% by using enzymes and enzyme recycling in the system. In addition, the use of enzymes for chip / pulp pre-treatment may have other effects that improve the properties of the enzyme hot pulp (eTMP) to be manufactured, for example, by reducing the amount of pulp needed to produce paper. The present solution makes it possible to reduce paper production costs and thus make paper production more profitable. In other words, the present solution may significantly reduce the energy consumption of the TMP process, may have a positive effect on the properties of the eTMP stock and / or may minimize the amount of debris during the massage.

Figure 1 illustrates system S according to an exemplary embodiment of the present solution. Referring to Figure 1, the components of system S according to the exemplary embodiment of the present solution include a "fresh" enzyme (mixture) dosing unit EAS, an-25 dosing pump P1 and dosing tube L) an enzyme (s) for measuring the activity, and a recycling unit (including, for example, a recirculation pump P2 and / or a recirculation pipeline L2) for circulating the enzyme-containing liquid into the impregnation vessel I2. Sensors (i.e., sensor. Rit) A may comprise biosensors 30 and / or existing biosensors and / or conventional sensors specifically developed for the present solution. The amount of enzyme to be dosed can be automatically calculated by the optimization unit

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£ O based on parameters. The optimization unit O communicates with the sensors cd A and the enzyme dosing unit EAS to enable the optimization unit g to control the dosing means EAS, P1 from the information received from the sensors. 35 on the ground. The optimization unit O may also be configured to control the O1 enzyme recycling means P1 based on information received from the sensors A. In addition, the optimization unit O may be connected to a factory / plant process control and / or the Internet. The optimization unit O may be configured to use the data it receives from the process control and / or the Internet to control the dosing and / or recycling means. In addition, the optimization unit O5 may be configured to transmit parameters related to process control and / or the Internet to control dosing and / or recycling means. Appropriate dosing of the enzyme is performed by the enzyme dosing unit based on parameters transmitted by the EAS optimization system O. An enzyme dosing unit EAS may be connected to a dosing pump P1 for pumping enzyme (s) to impregnation device I2 (e.g., via dosing / recycling piping L1 + L2).

Thus, an exemplary embodiment of the present solution comprises an enzyme activity control unit O and a recirculation pump P2 for processing the enzyme. The enzyme (s) can be introduced into the impregnation vessel I2 via a dose-15 roll pump P1 via a recirculation pump P2 for better mixing. The system comprises an enzyme dosing pump P1 and an enzyme dosing line L1 (e.g. one pump and / or one line per enzyme), a recirculation pump P2 (and a possible recirculation line L2) for an impregnation device (e.g. an impregnation container I2) top), sensors A to measure enzyme activity (for example, one sensor A per enzyme) and to control and optimize the enzyme dosing of the computer / logic unit O.

In an exemplary embodiment of the present solution, dosage delivery devices EAS, P1 are configured to deliver one or more ligninolytic or otherwise degradable enzymes to wood-based material (such as wood chips and / or fibrous pulp) from the EAS, P1 impregnating delivery device. In the method, at least a portion of the liquid containing one or more ligninolytic or other enzymes that degrade the wood-based material is recirculated through the rags P2 through the rags P2 | to impregnation device I2. Measuring means A is configured to measure the activity of one (j) or more of the ligninolytic or otherwise degradable enzymes in the liquid 35 contained in the impregnator I2 and / or in the liquid supplied to the impregnator I2. The guiding

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The lines 0 are configured to control dosing means EAS, P1 based on measurement information of the activity of one or more ligninolytic or otherwise affecting wood-based material received from the measuring means A to maintain the enzyme activity in the impregnating device 12 at enzymatic impounding.

Further, system S according to an exemplary embodiment of the present solution may comprise a pre-steaming tank C1 into which wood chips (and / or fibrous pulp and / or other similar wood-based material) are fed to moisten the wood chips. The pre-steamed wood chips are conveyed, for example, via the RT conveyor K1, the rotary valve V and the conveyor K2 (horizontally) to the press impregnation device 11 (impregnation screw). The press impregnation device 11 is configured to squeeze excess moisture from the wood vapor impregnated wood chips prior to feeding the wood chips to the vertical impregnation device 11, which impregnates the wood chips with an enzyme or enzyme mixture according to the present solution. The wood chips impregnated with the enzymes are recovered, for example, from the top and / or the middle of the impregnation device and are transported, for example, by a screw conveyor K3 to a storage tank C2 for temporary storage. The impregnated wood chips from the storage tank C2 are delivered to the buffer tank / press C3 for smooth 20 refining and from there to the primary rolling and / or the actual chipping process (chipping milling). The enzyme solution can be left in the impregnator after impregnator I2 (not shown).

The present enzyme pretreatment solution is based on the idea of treating wood chips with an enzyme mixture before chipping the wood chips in the TMP process. Enzyme treatment can be performed at normal temperature or at elevated temperature (such as about 60 ° C). The purpose of the pretreatment is to improve the properties of the mechanical pulp obtained during the pulp and to save energy during the rolling process. Enzyme treatment makes it possible to produce a higher level of mechanical pulp in a more cost-effective manner and with a lower amount of chemicals than in prior art. In the present rat-

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means for dispensing and measuring the required enzyme mixture

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cd In order to adapt the present solution to the different mills, l'- g of the wood chips samples / 2 35 fiber pulp samples (used at that mill) may first be tested under laboratory conditions and / or in pilot equipment. Thus, enzyme treatment can be pre-optimized 6 specifically for different mills. For each case, the most appropriate enzyme combination is sought by testing wood chips. Once the information for the enzyme mixture and control parameters is ready, the enzyme mixture and the optimization unit O, including the control parameters, can be supplied to the factory for trial use. In Test-5, the chips are processed into mechanical pulp, whereby the resulting pulp can be tested by laboratory measurements for, for example, fiber length distribution, brightness and / or roughness. Based on test use and measurement results, the final factory scale enzyme mixture and composition of the mixture can be selected. Thus, it is possible to provide a factory-scale enzyme mixture composition for 10 customer and factory specific types of chips. At the same time, it is possible to set the control parameters of the optimization unit (i.e., the enzyme activity control unit O) which controls the dosing of the enzyme to dispense a suitable enzyme mixture for the chip. The parameters are stored in the memory units, and the parameters are used in the programs of the optimization unit O. The programs can be installed as part of the factory process. In addition to the factory scale, the enzyme activity control unit O may also be implemented as a laboratory or pilot scale formula suitable for pre-optimizations.

According to an exemplary embodiment of the present solution, it is also possible that instead of / in addition to the recycling means P2, L2 connected to the impregnation device I2, the system comprises the "internal" recycling of the enzyme in the impregnation device I2. This may mean, for example, efficient mixing of the enzyme-containing liquid within the impregnation device I2. It is also possible that the system will measure the activity of the enzyme, but not the recycling of the enzyme. If system S does not have '' external 'recycling (via L2 and P2) of the enzyme-containing liquid 25, the activity of the enzyme is measured from impregnator I2.

The optimization unit O according to an exemplary embodiment of the present solution comprises means for receiving a signal from the measuring means A for measuring the activity of one or more ligninolytic, pectinolytic and / or other wood / wood cell enzymes, such as hemicellulase, and measuring information. / £ or in the feed stream of impregnator I2, means for generating a signal to the left to receive measurement information describing the activity of said enzyme from measuring means A and means for transmitting the signal to the enzyme? 35 for dispensing means EAS to the impregnation device I2 of said enzyme to control dosing based on said information to maintain the activity of the enzyme 7 in the impregnating device 12 at a predetermined level. The optimization unit O may further comprise means for transmitting a signal to the enzyme recycling means P2 in said enzyme impregnation device 12 on the basis of measurement information describing said enzyme activity to maintain the enzyme activity in the impregnation device 12 at a predetermined level. The enzyme dispensing unit EAS according to an exemplary embodiment of the present solution comprises means for receiving a signal from the control means A regarding the activity of said enzyme in the impregnation device 12 and / or in the feed stream of the impregnation device 12.

The goal is to develop a system configured to measure, control, and dispense the correct enzyme mixture for the eTMP process. 15 Dosage and correct / optimized enzyme mixture will reduce enzyme consumption and operating costs of enzyme treatment. Enzymes are to be administered in an amount sufficient to achieve the desired softening effect of wood chips. However, the amount of enzyme is optimized so that the enzyme is not used excessively, i.e., it is desired to avoid excess enzyme dosing as the enzymes are typically quite expensive. Therefore, the enzyme is also recycled in the process and it is desired to find the most suitable enzyme or enzyme mixture for each type of chips / fiber. Pilot tests can be used to check the performance of the system and the enzyme mixture and, in continuous operation, to verify the energy saving potential. Simultaneously, the enzyme activity control unit O testing unit and the sensors A can be technically tested in each production environment. Suitable devices for the eTMP process can be developed and provided. The enzyme activity control unit O is installed in the process equipment and the dosing and measurement processes are integrated into the process machinery.

i ^ L. The development of the enzyme activity control unit O is performed in relation to the development of the eTMP process. The pilot units can already be tested during the pilot times of the eTMP process, and therefore the development schedule of the enzyme activity control unit g closely follows the evolution of the eTMP process. Table 1 illustrates the steps of eTMP process design.

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table 1

Project Phase__Activity_ Preliminary Design of Enzyme Activity Control Unit __ Development of an Enzyme Activity Control Unit - Development of an Enzyme Activity Control Unit (Preparation of Measurement and Results for the Development of an Enzyme Activity Control Unit ((Bio) Enzyme Activity Control Unit ( control unit pilot scale unit development for test development background __ pilot scale unit control enzyme activity control unit factory scale test unit development - enzyme activity control unit production scale testing - enzyme line activity measurement unit __ activity mixing control unit __- mixing dosing and preparation - Continuous Development and Improvement Based on Experimental Development_of Enzyme Activity Control- Commercial Distribution eTMP and Enzyme Developmental Activity Control Unit

Suitable enzyme (s) are developed and final chipping to mechanical pulp (pilot plant) eTMP is performed. Enzyme dosing parameters are encoded by the optimization unit through test facility testing. An-x lifting system is designed and built. The dosing system may be similar to each pilot plant and the parameters of the dosing systems may also be the same. The capacity of the dosing system is dimensioned according to the pilot process. In the arrangement, the enzyme activity control unit O is constructed and encoded. It is contemplated that the optimization unit O comprises a portion of the enzyme activity control unit O containing information on the use and mixing of enzyme 9 in the production of TMP. The delivery of the optimization unit O may include the following articles: hardware: 5PLC logic (for example, Siemens S7) internet connection process inputs to the enzyme activity control unit and process outputs from the enzyme activity control unit - client interface 10 software to process control software Program for Enzyme Activity Control 15 Program for Remote Control and Update Protection Protocol

According to an exemplary embodiment of the present solution, it is possible to make different mixtures of enzymes for different species of wood. After laboratory testing of the enzyme mixtures 20, the recipe information for the enzyme mixture can be transferred to the customer's pilot plant. In order to ensure the efficacy of the mixture at the pilot plant, the scale change between the various enzyme activity control devices must be correct. The device may comprise measuring means for evaluating the efficacy of the enzyme mixture. The information is programmed on the device to optimize the recipe. For example, five to ten different types of enzymes can be used in Tes-25. The key steps in determining the correct recipe may include, for example, the following steps: o · protocol for mixing enzymes rL · measurement method for evaluating enzyme potency o ^ 30 · scaling between pilot plant and client plant · · programming unit O σ> 1 ^.

o The principle of the chips impregnation system is to fill the wood cells with ent-35 mixture. This can be achieved by appropriate process means in a manner where-

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The cells are first filled with water in the pre-steaming vessel C1, and then the cells are mechanically depressed and the cells are filled with an enzyme mixture in impregnator I2. Recirculation pump P2 recycles the enzyme mixture and excess water back to the impregnation tank I2. The main impregnation occurs during flow through the storage tank C2 and partially through the buffer tank C3. For example, the flow of chips through the system may take from one to two hours. After that, the wood chips can be fed for trimming.

The purpose is to prepare the enzyme mixture according to a specific protocol, whereby a database of the supplied mixtures and their associated process parameters can be created and maintained.

In the present solution, enzyme activity assays can be analyzed using state-of-the-art analyzers and a modern laboratory. Raw material sampling may also be performed to monitor quality in accordance with the raw material supplier's specifications.

The present solution employs sensors A for analyzing the enzyme activity impregnator I2 and for recycling L2, L1 + L2. Sensors A which are selective for the particular online enzyme combinations can be utilized in the present solution. Therefore, attention has been paid to the purity of the recycle solution to provide a reliable measurement of enzyme activity.

The present solution encompasses the development of an enzyme activity control unit O including the design, installation and implementation of an EAS, P1 dosing system.

The development of the optimization unit O includes design, fabrication, programming and implementation according to the parameters of the optimization calculations and laboratory tests. The present solution comprises encoding and setting parameters for metering for controlling the metering unit EAS.

A laboratory-scale pilot process can be built by purchasing o or leasing process equipment. Delivered enzyme mixtures for pilot and

rL for daste testing. Analysis and enzyme activity sensor A are required

0 ^ 30 development, fiber analysis and abrasion testing, fiber and particle technology laboratory, ^ process equipment, laboratory and / or pilot dosing equipment EAS, implementation and

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£ startup, optimization unit O, logic (eg Siemens S7), design, 01 installation, programming. In factory testing, for example, enzymes may be consumed in g about 1000 kg / day.

? 35 The enzyme mixture should function technically in the impregnation system.

In the present solution, the most effective blend for different types of wood chips can be found and selected. In the present solution, a reliable method and / or development / testing process can be developed to produce an optimal enzyme mixture.

The principle of the process is that the wood cells are filled with water, the water is squeezed out and replaced by a mixture of enzymes in the wood cells (the so-called '' fungal effect ''). The enzyme-lignin reaction occurs in a storage tank and this step takes about 0.5 to 1 hour. The storage tank is dimensioned for a mass flow such that it is capable of continuous process. This requires collaboration and testing with the equipment supplier.

Various ligninolytic (i.e., wood-lignin-degrading and / or softening and / or other wood-cell and fiber-acting enzymes such as pectinases, laccases, resinases, hemicellulases and / or cellulases depending on the wood species, In their chemical composition, enzymes are typically naturally occurring proteins.

The amount of enzyme used depends on the type of wood and the quality of the raw material and on the enzyme used. In the exemplary embodiment, the enzyme is used in an amount of about 1 to 3 liters / 1000 kg of dry matter.

Temperature, pH 20 and reactor volume may be used as process parameters. In an exemplary embodiment, the pressure is essentially atmospheric pressure. For example, in eTMP, the temperature, pH, and process specificity for a particular type of wood chips may change as compared to the cTMP process and / or the '' just 'TMP process.

In addition to the amount of enzyme, the activity of the enzyme depends on the nature of the enzyme. Enzymes are catalysts, i.e. they can carry out several reactions in succession. Some of the enzymes present in the eTMP process are inactivated, i.e. become inactive, because they are protein molecules. Some of the ent-o causes are exited from the process in the wood chips going to the storage tank C2.

ri. The enzyme activity is affected by the process conditions and the enzyme activity is not necessarily directly proportional to the enzyme concentration. For example, enzyme activity can be determined by standard methods according to the Ec classification. However, standard determination takes place under standard conditions that do not directly apply to practical process conditions, so for practical process conditions, the methods for determining activity? 35 optimized according to the present solution process-by-process. This

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For example, it means that for each process an appropriate level of 12 enzyme (s) can be determined which is sufficient to provide sufficient enzyme impregnation of the wood chips in the process. This also means that it is possible to avoid excessive use of the enzyme, thus saving on the consumption of the enzyme.

5 Different types of sensors A can be used in the present solution. Sensors A are based on the idea of measuring the effect of enzyme activity on the concentration of various volatile compounds, such as volatile aldehydes, organic acids, alcohols, in the gasified (evaporated) aqueous phase. In addition, immobilized substrates (such as various sugars), whose degradation rate is measured by measuring the appearance of degradation end products during the degradation reaction, can be used as sensors.

The present solution can be thought of as applicable not only to eTMP but also to other industrial processes based on enzymatic reactions (enzyme solution treatment or pure enzyme treatment), such as industrial (e.g. pulp, paper, food and / or chemical) and waste (e.g. / or landfill sites).

An advantage of the present solution is that the composition and dosage of the enzyme mixture can be (pre) optimized for each plant individually.

In the exemplary embodiment of the present solution, the circulation and dosing of the enzyme is pump-based, since the pump can provide accurate dosing, but other dosing modes such as gravity may be used.

Accordingly, the present invention provides a method of pre-treating chips with one or more enzymes using 25 sensors (s) to measure the activity of the enzyme (s) and to recycle the pump and lines in the impregnation tank to homogenize the enzyme-containing liquid and reduce enzyme consumption. The items and functions shown in the figure are simplified and are only intended to illustrate the idea of the present solution. The functions described in Fig. 1 ^ 30 above are not in absolute chronological order, and some of the steps / positions may be performed simultaneously or in a different order than the given one. order. Other operations can also be performed between steps / points

Co or steps / points. Some of the steps / points or parts of the steps / points may also be omitted or integrated or replaced with the corresponding step / point or part of the step / point. Device functions illustrate a procedure that may be implemented in one or more physical or logical units. Signaling messages are exemplary only and may even include multiple discrete messages to send the same information. The messages serve only as examples and may contain only some of the above information. In addition, the messages may contain other information.

In addition to prior art tools, the system or network nodes of the system that implement the functionality of the present solution comprise means for performing optimization of the enzyme dosage described above. Existing network nodes and user terminals comprise processors and memory that can be utilized in the functions of the present solution.

Changes necessary to implement the present solution may be made by routines embedded in software routines and / or routines contained in application-specific integrated circuits (ASICs) and / or programmable circuits such as EPLDs (electrically programmable logic device) or FPGAs (field programmable gate array). updates or additions.

It will be obvious to a person skilled in the art that as technology advances, the basic idea of the invention can be implemented in many different ways. The invention and its embodiments are thus not limited to the examples described above, but may vary within the scope of the claims.

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Claims (29)

A process for treating a wood-based material in an impregnation device (I2) for producing a thermomechanical pulp, characterized in that the method comprises dispensing one or more ligninolytic or otherwise degradable enzymes on the wood-based material into the dispensing means (EAS, P1), (I2) for feeding; recycling means (P2) for recirculating at least a portion of the fluid containing said enzyme exiting the impregnating device (I2) to the impregnating device (I2); measuring means (A) for measuring the activity of said enzyme in the impregnating device (I2) and / or in the feed stream of the impregnating device (I2); and controlling the dispensing means (E), the control means (O) based on measurement information received from the measuring means (A) to describe the activity of said enzyme in an impregnation device (I2) to maintain a level sufficient to impregnate the woody material with the enzyme. Method according to Claim 1, characterized in that the delivery of the enzyme from the delivery means (EAS, P1) to the impregnation device (I2) is effected via the recycling means (P2). Method according to claim 1 or 2, characterized in that the control means (O) controls the recycling means (P2) based on the measurement information received from the measuring means (A) describing the enzyme activity in the impregnation device (I2) to maintain a level of sufficient wood material. impregnation with o enzyme. i ^ L. 4. A method according to claim 1, 2 or 3, characterized in that said enzyme comprises pectinase, laccase, resinase, hemicellulase and / or cellulase. X The method according to any one of claims 1 to 4, characterized in that information about the measured enzyme activity is transmitted from the measuring means (A) to the control means (O). A method according to any one of claims 1 to 5, characterized in that the recycle stream of enzyme-containing impregnation device (I2) is recovered from the lower part of the impregnation device (I2). 15 Method according to one of claims 1 to 6, characterized in that the feed stream of the impregnating device (I2) containing the enzyme is supplied to the upper part of the impregnating device (I2), A method according to any one of claims 1 to 7, characterized in that the method comprises impregnating the wood-based material with water in a press impregnation device (11), wherein the excess water is squeezed out before the wood-based material is fed to the enzyme impregnator (I2). Method according to one of claims 1 to 8, characterized in that the wood-based material is fed to the impregnation device (I2) at the lower part of the impregnation device; and recovering the wood-based material from the impregnator at the top of the impregnator. Method according to one of claims 1 to 9, characterized in that said wood-based material comprises wood chips and / or fibrous pulp. The method according to any one of claims 1 to 10, characterized in that the activity of the enzyme is measured by means of one or more enzyme-selective sensors. A method according to claim 11, characterized in that sugar is used as said sensor, wherein the measurement of enzyme activity is based on the measurement of the rate of degradation of said sugar. 13. A method according to claim 11 or 12, characterized in that said volatile compound comprising volatile aldehyde, volatile organic acid and / or volatile alcohol is used as said sensor, wherein the measurement of the activity of the enzyme is based on the concentration of the volatile compound affecting the enzyme activity. for gaseous aqueous phase measurement. sj- ^ 14. System (S) for treating wood-based material with ter- | for the production of a mechanical pulp, which system comprises an impregnator (I2), characterized in that it further comprises a g dispenser (EAS, P1) configured to deliver two or more ligninolytic or otherwise degradable enzymes. an impregnation device (11) for feeding; Recycling means (P2, L2) configured to feed at least a portion of the effluent from the impregnation device (I2) containing said enzyme back to the impregnation device (I2); measuring means (A) configured to measure the activity of said enzyme in the impregnator (I2) and / or in the feed stream of the impregnator (I2); and control means (O) configured to control said dispensing means (EAS, P1) based on information received from said measuring means (A) describing the activity of said enzyme to maintain an enzyme activity impregnation device (I2) at a level sufficient to provide sufficient wood material. 14 PATENT CLAIMS ET System according to claim 14, characterized in that it is configured to supply the enzyme from the dispensing means (EAS, P1) to the impregnation device (I2) via the recycling means (P2, L2). System according to Claim 14 or 15, characterized in that the control means (O) are configured to control the recycling means (P2) based on the measurement information received from the measuring means (A) describing the enzyme activity to maintain the enzyme activity in the impregnation device (I2). impregnation of wood-based material with an enzyme. The system according to claim 14, 15 or 16, characterized in that said enzyme comprises pectinase, laccase, resinase, hemicellulase and / or cellulase. A system according to any one of claims 14 to 17, characterized in that the measuring means (A) is configured to transmit to the control means (O) information on the measured activity of one or more enzymes. CM A system according to any one of the preceding claims 14 to 18, characterized in that it is configured to recover the recycle stream of the enzyme-containing impregnation device (I2) by impregnating | at the bottom of the device (I2). No, A system according to any one of claims 14 to 19, characterized in that it is configured to supply recyclable material. at the top of the feed stream impregnating device (I2) containing the enzyme-containing impregnation device (I2). 17 A system according to any one of claims 14 to 20, characterized in that it is configured to impregnate the wood-based material with water in a compression impregnation device (11); and squeeze out excess water before feeding the wood-based material to the enzyme impregnation device (I2). A system according to any one of claims 14 to 21, characterized in that it is configured to feed a wood-based material to the impregnating device at the bottom of the impregnating device; and recovering the wood-based material from the impregnator at the top of the impregnator. A system (S) according to any one of claims 14 to 22, characterized in that the recycling means (P2) comprise a pump and / or a recycling pipeline (L2). System (S) according to any one of claims 14 to 23, characterized in that the control means (O) are configured to communicate with the process control unit and / or the Internet for controlling the impregnation process of the wood-based material. A system according to any one of claims 14 to 24, characterized in that said wood-based material comprises wood chips and / or fibrous pulp. A system according to any one of claims 14 to 25, characterized in that it is configured to perform measurement of enzyme activity by one or more enzyme-selective sensors. The system of claim 26, characterized in that it is configured to use sugar as said sensor, wherein the measurement of enzyme activity is based on measuring the rate of degradation of said sugar. A system according to claim 26 or 27, characterized in that it is configured to use, as said sensor, a volatile compound comprising volatile aldehyde, volatile organic acid? and / or volatile alcohol, wherein the measurement of the enzyme activity is based on measuring the effect of the enzyme activity on the volatile compound concentration in the aqueous gas phase. 18 An impregnation device (I2) for treating a wood-based material, characterized in that it is configured to receive fresh, one or more ligninolytic or otherwise degradable enzymes from the dosing means (EAS, P1); receive recycled, one or more ligninolytic or otherwise degradable enzymes from the recycling means (L2, P2); impregnating the wood-based material fed to the impregnator with said enzyme; and to supply wood-based material impregnated with said enzyme for further processing. δ cv i h- · o X Χ CL O) h- · o m o δ (M 19