EP1252388B1 - Use of a compound for reducing and/or avoiding the build up of wood components - Google Patents

Abstract

The invention relates to a method for avoiding and/or reducing the deposition of volatile and non-volatile wood components in gas-bearing systems, whereby at least one of the volatile wood components, at least partly, condenses in the gas-bearing system and the gas contains at least one compound with a similar condensation profile to the volatile wood component and which at least reduces the deposition of volatile wood components or the reaction products thereof. The invention further relates to a method for reducing and/or avoiding the deposition of wood components on machines and/or equipment components for the production of wood fiber materials from wood chippings, in which the shredding of the wood is achieved in the presence of a compound which forms a film on the surfaces of the above machines and/or equipment components and at least reduces the deposition of volatile wood components and/or the reaction products thereof.

Description

The present invention relates to the avoidance and / or reduction of deposits of volatile and non-volatile wood constituents in gas-carrying systems, the volatile wood constituents at least partially condensing in the gas-carrying systems.
The present invention further relates to the reduction and / or avoidance of deposits of wood constituents on machines and / or system parts for the production of wood fibers from wood chips.

When processing wood, producing and processing pulp and / or the manufacture of paper, cardboard or molded fiber often become volatile Free wood constituents, which then condense in gas-carrying systems and solid there Form deposits. These deposits increase z. B. the pressure loss of the pipelines, the separation performance of any existing ones is reduced Cyclones and control devices are blocked so that the gas lines are opened and have to be cleaned with high-pressure units, for example. This cleaning is very expensive and disrupts the respective manufacturing process.

EP-A-0 334 098 describes a method for reducing deposits in Equipment for the evaporation of waste liquors from wood pulp production by Sulfite waste liquor low molecular weight polyacrylic acid is added. The deposits are gypsum or silicate deposits that fail during the process.

US-A-5 762 757 describes a method of preventing deposits organic pulp ingredients such as pitch and sticky Contamination in pulp or paper making systems by a anionic surfactant from the group of Dinonyl sulfosuccinates or a mixture of Dioctyl sulfosuccinate and didecyl sulfosuccinate are either added to the pulp or is applied to the surface of the system.

DE-A-27 35 300 A describes a method for the aftertreatment of vapor condensate for the distillative removal and burning of steam-volatile oxygen-consuming substances, from liquids and wet combustion non-volatile components. Part of the substances present in the wood are volatile in water and are present in the vapor condensate. In the process the substances are burned at over 1000 ° C.

WO-A-98/33970 describes a process for the production of fibrous materials for the Production of pulp, paper or wood-based panels, in which the Pretreatment for impregnating dicarboxylic acid dialkyl esters and / or one or several fatty acid polyol mono, di, tri and / or higher polyesters and / or Polyester-polyether copolymers are added. These components clean the Primary fibers from resin components and other wood constituents and cause one higher yield and better optics.

The present invention is therefore based on the object of a method for To provide with the deposition of volatile and / or non-volatile Wood ingredients in gas-carrying systems is at least reduced.

• ein ähnliches Kondensationsverhalten aufweist wie die flüchtigen Holzinhaltsstoffe,
• Ablagerungen von flüchtigen Holzinhaltsstoffen und/oder deren Reaktionsprodukten zumindest vermindert.

The object is achieved according to the invention by using a compound for avoiding and / or reducing deposits of volatile and non-volatile wood constituents in gas-carrying systems, at least some of the volatile wood constituents at least partially condensing in the gas-carrying systems and the gas at least the compound contains that

• has a condensation behavior similar to that of the volatile wood constituents,
• Deposits of volatile wood constituents and / or their reaction products are at least reduced.

Volatile wood constituents in the sense of the invention are all wood constituents that Temperatures above 20 ° C have a vapor pressure. reaction products Within the meaning of the invention are any products that contain the volatile wood constituents after the condensation, e.g. B. by polymerization.

Because the condensed volatile wood components and their reaction products often form a sticky film on the surfaces of the gas-carrying systems, the deposits usually have non-volatile wood constituents, e.g. B. fine Wood particles, which separate from the gas stream and sticky films adhere.

According to the invention, the connection has a similar condensation behavior like the wood ingredients; d. H. the connection and the wood constituents condense preferably at the same point in the gas-carrying system and preferably form there a movie.

The compound is preferably a dicarboxylic acid ester. Is particularly preferred the dicarboxylic acid ester is a dicarboxylic acid dialkyl and / or diisoalkyl ester of C2-C12 Dicarboxylic acids with C1-C13 n- and / or iso-alkanols such as di-n-butyl oxalate, di-n-butyl malonate, Di-n-butyl succinate, di-n-butyl glutarate, di-n-butyl adipate, di-n-butyl suberate, Di-n-butyisebacate, dimethyl adipate, di-n-propyl adipate, diisopropyl adipate, Diisobutyl adipate, di-tert-butyl adipate, di-isoamyl adipate, di-n-hexyl adipate, di- (2-ethylbutyl) adipate, Di- (2-ethylhexyl) adipate, diisodecyl adipate and dimethyl phthalate, Diethyl phthalate, di-n-butyl phthalate, diisobutyl phthalate, di (2-ethylhexyl) phthalate and Diisodecyl phthalate and the corresponding terephthalic acid esters and diesters C9 dicarboxylic acid (trimethyladipic acid) and dodecanedicarboxylic acid.

However, the compound is very particularly preferably a di-n-alkyladipic acid ester and / or a di-iso-alkyl adipic acid ester. The most preferred is the compound n-dibutyl adipate.

• Holzverarbeitungsanlage, insbesondere einer Anlage zur Herstellung von Holzfaserstoff und/oder Holzfaserplatten,
• Anlage zu Herstellung von Zellstoff,
• Zellstoffverarbeitungsanlage,
• Papier- oder Kartonherstellungsanlage und/oder
• Anlage zur Herstellung von Teilen oder Gegenständen aus Formfasem.

The use according to the invention is suitable for avoiding and reducing deposits of volatile or non-volatile wood constituents in gas-carrying systems of any kind. However, the gas-carrying systems are preferably part of:

• Wood processing plant, in particular a plant for the production of wood pulp and / or wood fiber boards,
• Plant for the production of pulp,
• Pulp processing plant,
• Paper or cardboard manufacturing plant and / or
• Plant for the production of parts or objects from shaped fibers.

The gas-carrying system is very particularly preferably part of a plant for the production from Thermo-Mechanical-Pulp (TMP) or a wood chip refiner system, as described in WO-A-96/41914, which is hereby introduced as a reference becomes.

The gas that flows through the gas-carrying lines can be any gas be, but preferably has water vapor.

The compound is preferably metered into the gas in gaseous form. The specialist realizes that the compound can also be metered into the gas in the liquid state can and then there is converted into a gaseous state. The dosage is preferably carried out continuously.

The dosage of the compound depends on the concentration of the volatile wood constituents in the gas and the gas volume flow. The is preferably Concentration 100-5000 ppm, particularly preferably 200-2000 ppm and very particularly preferably 300-1000 ppm.

The compound is preferably metered into the gas in such an amount that there are no deposits of volatile or non-volatile compounds and / or form their reaction products on the surfaces of the gas-carrying systems or that deposits already formed detach and / or dissolve again. Accordingly the dosage of the compound is preferably regulated automatically. The pressure loss in the pipelines is preferably used as the control parameter the gas-carrying system and / or the degree of separation of cyclones, which are in the gas-carrying system. Are also preferred as Control parameters also the gas volume flow and the concentration of volatile Wood ingredients used in the gas or the area coverage.

Because the above manufacturing process is usually in the presence of Water are carried out and the water is at least partially evaporated the compound in another preferred embodiment of the invention Process dosed directly into the water. In this case, the connection also be steam-volatile.

The present invention has the advantage that the gas-carrying systems are less common must be cleaned and the systems therefore have a longer operating time. There z. B. Cyclones are no longer added by deposits, their separability remains receive. Existing deposits are reduced.

Another object of the present invention is to provide a method to reduce and / or avoid deposits of wood constituents on machines and / or system parts for the production of wood fibers Wood chips (wood chips).

• auf den Oberflächen der Maschinen und/oder Anlagenteile einen Film bildet und
• Ablagerungen von flüchtigen Holzinhaltsstoffen und/oder deren Reaktionsprodukten zumindest vermindert.

This object is achieved according to the invention with the use of a compound for reducing and / or avoiding deposits of wood constituents on machines and / or system parts for producing wood fiber materials from wood chips, in which the fiberization of the wood takes place in the presence of at least one compound which:

• forms a film on the surfaces of the machines and / or system parts and
• Deposits of volatile wood constituents and / or their reaction products are at least reduced.

Deposits in the sense of the invention are any deposits of wood constituents in gas-carrying systems and / or on other systems or Machine parts that are used for the production of wood fiber materials.

The compound is preferably a dicarboxylic acid ester. Is particularly preferred the dicarboxylic acid ester is a dicarboxylic acid dialkyl and / or diisoalkyl ester of C2-C12 Dicarboxylic acids with C1-C13 n- and / or iso-alkanols such as di-n-butyl oxalate, di-n-butyl malonate, Di-n-butyl succinate, di-n-butyl glutarate, di-n-butyl adipate, di-n-butyl suberate, Di-n-butyl sebacate, dimethyl adipate, di-n-propyl adipate, diisopropyl adipate, Diisobutyl adipate, di-tert-butyl adipate, di-isoamyl adipate, di-n-hexyl adipate, di- (2-ethylbutyl) adipate, Di- (2-ethylhexyl) adipate, diisodecyl adipate and dimethyl phthalate, Diethyl phthalate, di-n-butyl phthalate, diisobutyl phthalate, di (2-ethylhexyl) phthalate and Diisodecyl phthalate and the corresponding terephthalic acid esters and diesters C9 dicarboxylic acid (trimethyladipic acid) and dodecanedicarboxylic acid.

However, the compound is very particularly preferably a di-n-alkyladipic acid ester and / or a di-iso-alkyl adipic acid ester. The most preferred is the compound Di-n-butyl adipate.

The esters can be used alone or in combination with water-soluble or water-insoluble ones Solvents as water-free or water-containing solution or as water-containing Dispersion, preferably emulsion, are used. Suitable solvents are n- and iso-alkanols, liquid hydrocarbons, acetone and others known solvents, in particular natural oils or modified natural oils, such as beet oil methyl ester.

Nonionic, ionic and Amphoteric, especially nonionic, surfactants are used as emulsifiers.

Suitable nonionic emulsifiers are, for example, oxalkyl ethers, preferably Oxethylates and / or terminally blocked oxethylates of fatty alcohols and Fatty acids or oils. As anionic emulsifiers are alkyl and / or Aryl sulfonates, α-olefin sulfonates, α-sulfofatty acid esters, sulfosuccinic acid esters and Alkyl sulfates and ether sulfates as well as carboxymethylated oxethylates and soaps suitable. The preparation of the preferably stable emulsions is known. For example, the hydrophobic phase in the aqueous emulsifier-containing phase registered and dispersed with stirring and pumping.

The plant for producing wood fiber materials preferably has at least a refiner on how he z. B. from WO-A-96/41914 or from WO-A-96/35016 is. These patent applications are hereby introduced for reference.

The diacid carboxylic ester is preferably used together with the clear filtrate dosed into the refiner. The metering is preferably carried out continuously.

In a preferred embodiment, the dicarboxylic acid ester concentration is in the first refiner 100-5000 ppm, particularly preferably 200-2000 ppm and whole particularly preferably 300-1000 ppm.

The use according to the invention is suitable for machines and systems for Wood fiberization of any kind. The machines and / or systems are preferred however part of the TMP process or a process as described in WO-A-96/41914 is described.

With the present invention, the runtimes of machines and systems succeed extend considerably to the production of wood fiber materials. The plants are easier to regulate and the service life of the refiner's grinding set can be extended become. The method according to the invention can be integrated into existing systems become. Deposits already present are removed by the inventive Use reduced.

The invention is explained below with reference to FIG. 1 . The explanations are only examples and do not restrict the general idea of the invention.

FIG. 1 shows a process flow diagram for the production of thermo-mechanical pulp (TMP). Cleaned wood chips are conveyed to the 1st refiner stage and mechanically broken down there in the presence of clear filtrate and 330 ppm TALLOFIN® TMP. TALLOFIN® TMP is a product of Stockhausen GmbH & Co. KG, which contains 40% by weight di-n-butyl adipate and 60% by weight of a nonionic emulsifier. The TALLOFIN® TMP is dosed into the clear filtrate before it flows into the refiner. The very high energy input creates temperatures of up to 200 ° C and pressures of 2-3 bar in the refiner (up to 22 MW), so that a considerable part of the water evaporates in the refiner. The steam is removed from the refiner through steam lines and fed to heat recovery. In addition to volatile and non-volatile wood constituents, the steam also contains a certain proportion of di-n-butyl adipate, so that the steam lines, the cyclones and the regulating elements in the steam lines have no or only slight deposits. But even in the refiner itself, no or to a much reduced extent deposits of wood constituents form, so that it has to be cleaned less frequently and the service life of the grinding set is increased.
After defibration in the first refiner, the wood fibers are mechanically comminuted again in the second refiner stage before they are then subjected to the further treatment known to the person skilled in the art. Large quantities of steam are also generated in the second refiner stage, which are then used for heat recovery. In addition to volatile and non-volatile wood constituents, the steam also contains a certain proportion of di-n-butyl adipate, so that the steam lines, the cyclones and the regulating elements in the steam lines have no or only slight deposits. But even in this refiner itself no or to a greatly reduced extent deposits of wood constituents form, so that this has to be cleaned less frequently and the service life of the grinding set is increased.

Claims (14)

1. Use of a compound for preventing and/or reducing deposits of volatile and non-volatile wood constituents in gas-conveying systems in the processing of wood, the production and processing of pulp and/or the manufacture of paper, cardboard or moulded fibres, where volatile wood constituents at least partially condense in the gas-conveying systems, characterised in that the compound:

   has similar condensation characteristics to the volatile wood constituents,

   at least reduces deposits of volatile wood constituents and/or the reaction products thereof and

   the compounds are metered into the gas or into an aqueous phase which is formed during the processing of wood, the production and processing of pulp and/or the manufacture of paper, cardboard or moulded fibre.
2. Use according to claim 1, characterised in that the compound is a dicarboxylic acid ester.
3. Use according to claim 2, characterised in that the dicarboxylic acid ester is a di-n-alkyladipic acid ester and/or a diisoalkyladipic acid ester.
4. Use according to claim 2, characterised in that the dicarboxylic acid ester is dibutyl adipate.
5. Use according to one of claims 1 to 4, characterised in that the gas-conveying system is part of a:

   wood processing plant, particularly a plant for producing wood fibre and/or wood fibre board,

   plant for producing pulp,

   pulp processing plant,

   paper or cardboard manufacturing plant and/or

   plant for producing parts and/or objects made of moulded fibres.
6. Use according to one of claims 1 to 5, characterised in that the gas comprises water vapour.
7. Use of a compound for reducing and/or preventing deposits of wood constituents on machines and/or parts of equipment for the manufacture of wood fibre from wood chips, characterised in that the shredding of the wood into fibres takes place in the presence of at least the compound which

   forms a film on the surfaces of the machines and/or equipment parts and

   at least reduces deposits of volatile wood constituents and/or the reaction products thereof.
8. Use according to claim 7, characterised in that the compound is a dicarboxylic acid ester.
9. Use according to claim 8, characterised in that the dicarboxylic acid ester is a di-n-alkyl adipic acid ester and/or a diisoalkyl adipic acid ester.
10. Use according to claim 8, characterised in that the dicarboxylic acid ester is dibutyl adipate.
11. Use according to one of claims 7 to 10, characterised in that the machine and/or equipment parts for producing wood fibres from wood chips comprise at least one refiner.
12. Use according to claim 11, characterised in that the dicarboxylic acid ester is measured into the first refiner preferably together with the clear filtrate.
13. Use according to claim 11 or 12, characterised in that the concentration of the dicarboxylic acid ester is 100-5000, preferably 200-2000 ppm, most preferably 300-1000 ppm.
14. Use according to one of claims 7 to 13, characterised in that the machines and/or equipment parts are components of a plant for producing thermomechanical pulp.

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