KR101805162B1 - Organic high density material with improved water resistance and durability and producing method thereof - Google Patents

Abstract

The present invention relates to an organic high density material having improved water resistance and durability, and to a producing method thereof, wherein the organic high density material is produced by the following steps: mixing at least one selected from a group consisting of alkyl ketene dimer (AKD), rosin, lignosulfonate, starch, a calcium agent, silicon dioxide and sodium silicate with wood flour or an organic waste; impregnating extrusion-molded pellets with oil or subjecting the extrusion-molded pellets to surface heat treatment.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic high-density material having excellent moisture resistance and durability,

The present invention relates to an organic high-density material excellent in moisture resistance and durability and a method for producing the same.

Generally, high density materials such as pellets are prepared using lignocellulosic raw materials composed of cellulose, hemicellulose, lignin and other extracts. Such lignocellulosic material is thermoplasticized by thermoplastic lignin due to frictional heat of 120 to 170 ° C which occurs during pellet molding, and functions as an adhesive. When cellulose such as cellulose is softened by moisture and heat, it is used as a high density pellet . Such general organic pellets have hygroscopicity due to hydrophilic cellulose and hemicellulose components. When water is exposed to water in various ways such as moisture in air, the fibers in the densified pellets cause moisture expansion, resulting in destruction of the pellet structure and deterioration of physical properties There are disadvantages. Therefore, it is difficult to apply in an environment where moisture exposure is a concern due to a high density material. In addition, since a wood pellet having high hygroscopicity causes various problems such as a sudden decrease in calorific value due to a high moisture content, .

The high density material to be implemented in the present invention is classified into a pellet or a similar structure and a material to be manufactured at a high density through a high temperature process of an organic material. Particularly, the pellet is mainly used for producing a solid fuel of biomass for cogeneration Is being produced. Such a pellet-shaped material is widely used because it increases the ease of transportation and ease of storage of bulky solid materials. In the case of wood pellets and biomass pellets, which are currently being developed as energy fuels for boilers, the raw materials for producing pellets are generally based on organic raw materials such as wood flour, sawdust, and corn stover. Therefore, There is a weak disadvantage such as structural deformation and strength reduction. This disadvantage is disadvantageous in that it is difficult to apply to a non-fuel application because it is difficult to maintain the pellet structure in the case of exposure to moisture.

Korean Patent No. 1533924 discloses a method for producing wood pellets by recycling waste wood. Korean Patent No. 1007651 discloses a method for producing fuel pellets using wood-based raw materials and wood. However, It is different from an organic high-density material having excellent moisture resistance and durability.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a high-density material for imparting high-value utilization of wood flour or organic waste by using pellets formed by mixing various functional additives into wood flour or organic waste Is subjected to an additional surface treatment such as oil impregnation or heat treatment to provide an organic high-density material excellent in durability and moisture resistance.

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a wood powder or organic waste comprising one or more functionalities selected from the group consisting of bark, AKD (Alkyl ketene dimer), rosin, lignosulfonate, starch, calcium, silicon dioxide, The present invention provides an organic high density material having excellent moisture resistance and durability, which is prepared by mixing additives and extrusion molding.

The present invention also provides an organic high-density material having excellent water resistance and durability, which is prepared by impregnating or heat-treating pellets extruded from wood powder or organic waste.

The present invention also relates to a method for producing wood pellets or organic waste by mixing extruded pellets after mixing at least one functional additive selected from the group consisting of bark, AKD, rosin, lignosulfonate, starch, calcium, silicon dioxide and sodium silicate Oil-impregnated or surface-heat-treated organic high-density material excellent in moisture resistance and durability.

The present invention also relates to a method for producing a wood powder or an organic waste which comprises mixing wood powder or organic waste with one or more selected from the group consisting of bark, AKD, rosin, lignosulfonate, starch, calcium agent, silicon dioxide and sodium silicate, The present invention also provides a method for producing an organic high-density material excellent in moisture resistance and durability.

Also, the present invention provides a method for producing an organic high-density material having excellent moisture resistance and durability, comprising the steps of impregnating oil or impregnating pellets produced by extrusion-molding wood powder or organic waste.

The present invention also relates to a method for producing a wood powder or organic waste by mixing (a) wood powder or organic waste with one or more selected from the group consisting of bark, AKD, rosin, lignosulfonate, starch, calcium agent, silicon dioxide and sodium silicate, Lt; / RTI > And (b) impregnating or heat-treating the pellets prepared in step (a) with oil. The present invention also provides a method for producing an organic high-density material excellent in moisture resistance and durability.

In addition, the present invention provides an organic high-density material having excellent moisture resistance and durability produced by the above method.

The present invention has developed a functional high density material having high durability and moisture resistance based on wood or organic waste organic wastes. The organic high-density material of the present invention devises various methods for enhancing and strengthening the water resistance property. In particular, by applying the additives having the curing properties and the additives having the hydrophobic property and developing the techniques such as the oil impregnation or the surface heat treatment, It is possible to produce an organic high-density material having enhanced water resistance which can be applied to the field. In addition, the organic high-density material of the present invention can impart certain porosity to the interior of the soil due to its resistance to moisture when it is applied for soil improvement such as artificial soil, sulfur waste paper, and landfill.

1 is a graph comparing the durability (%) of pellets after 30 minutes of impregnation of wood pellets, softwood bark-added pellets, and hardwood bark added pellets with moisture.
FIG. 2 is a photograph showing changes in properties of wood pellets, softwood bark-added pellets, and hardwood bark added pellets according to impregnation time in water.
Fig. 3 is a graph showing the results of the analysis of wood powder (Control), AKD added pellets (AKD) in wood powder, rosin added pellets (rosin) in wood powder, lignosulfonate added pellets (lignosulfonate) (%) Of the starch (starch).
Fig. 4 is a graph showing the results of the analysis of wood powder (Control), AKD added pellets (AKD) in wood powder, rosin added pellets (rosin) in wood powder, lignosulfonate added lignosulfonate (lignosulfonate) (A) shows the results after 10 minutes of impregnation, and (B) shows the results after 20 minutes of impregnation. x: Structure destruction.
5 is a graph comparing the shrinkage percentage (%) of the pellets with the surface heat treatment conditions.
6 is a graph comparing the durability (%) of the pellets according to the surface heat treatment conditions.
FIG. 7 is a graph comparing changes in durability (%) with time of moisture impregnation of the pellets produced by different surface heat treatment conditions.

In order to accomplish the object of the present invention, the present invention provides a wood flour or an organic waste which comprises a wood flour, an alkyd ketene dimer, a rosin, a lignosulfonate, a starch, a calcium agent, a silicon dioxide and a sodium silicate The present invention provides an organic high-density material having excellent moisture resistance and durability, prepared by mixing the above-mentioned functional additive and extrusion molding.

The present invention also provides an organic high-density material excellent in moisture resistance and durability, prepared by impregnating or heat-treating pellets extruded from wood powder or organic waste.

The present invention also relates to a process for producing wood pellets or organic wastes by mixing extruded pellets after mixing at least one functional additive selected from the group consisting of bark, AKD, rosin, lignosulfonate, starch, calcium, silicon dioxide and sodium silicate Oil-impregnated or surface-heat-treated organic high-density material excellent in moisture resistance and durability.

In the organic high-density material of the present invention, the organic waste may be at least one selected from the group consisting of agricultural by-products, paper sludge, food waste, forestry by-products and animal manure, but is not limited thereto. The agricultural by-products may be cornstalks, yams, rice hulls, rice bran, rice straw, emptive fruit bunch, oil palm, oil meal, food waste may be bean curd, coffee bean, oyster shell, Forestry by-products may be, but are not limited to, residues of residual phytoncide from trees, decaying leaves.

In the organic high-density material of the present invention, the bark may be a hardwood bark or a coniferous bark. The bark may be prepared by mixing the bark with wood powder or organic waste at a weight ratio of 40 to 60: 40 to 60, 50: 50 weight ratio. The high-density material added with the bark was excellent in moisture resistance and durability.

In the organic high-density material of the present invention, the AKD (Alkyl Ketene Dimer) is covalently bonded to a hydroxyl group of an organic material having hydrophilicity, which has been applied to various paper products such as printing paper and wrapping paper, When the heat is applied at 100 ° C or more as an additive, it spreads widely on the surface and the hydrophobic development effect is further improved. It can be added in an amount of 2 to 4%, preferably 3%, based on the weight of the wood or organic waste.

In addition, in the organic high-density material of the present invention, the rosin may be added as a vegetable extract in an amount of 2 to 4%, preferably 3%, based on the weight of the wood or organic waste. The addition of the rosin can further improve the durability and moisture resistance of the high-density material. In particular, since the shape can be maintained even when exposed to moisture for a long time, even when the external environment is exposed or the moisture is high, The performance structure can be maintained for a certain period of time.

In addition, in the organic high-density material of the present invention, the lignosulfonate serves as an adhesive for increasing the strength of the high-density material, and may be added in an amount of 2 to 4%, preferably 3%, based on the weight of the wood or organic waste.

In addition, in the organic high-density material of the present invention, the starch may be a vegetable starch or an oxidized starch (starch glue), which is characterized by further enhancing the durability and moisture resistance of the high-density material by the addition of the starch. The starch may be added in an amount of 1 to 3% based on the weight of wood flour or organic waste.

In addition, in the organic high-density material of the present invention, the calcium material may preferably be calcium oxide (CaO) or calcium carbonate (CaCO ₃ ), which is evaporated during the hot-pressing of the pellet by the addition of the calcium material The strength and moisture releasing resistance can be increased by the property of curing by reacting with moisture.

In addition, in the organic high-density material of the present invention, an alkali metal salt is added to the basic raw material composition containing minerals in wood or organic wastes to induce the inorganic hardening reaction due to the heat and moisture generated in the pellet molding, And can be produced as highly resistant pellets. The inorganic material may be calcium carbonate or silicon dioxide, and the alkali metal salt may be calcium oxide or sodium silicate. The wood powder or the organic waste and the inorganic material may be mixed in a weight ratio of 70 to 90:10 to 30, preferably 80:20. In addition, the alkali metal salt may be added in an amount of 2 to 4%, preferably 3%, based on the weight of the basic raw material composition.

In addition, an alkaline metal salt may be added to the basic raw material composition containing an inorganic substance in the wood powder or the organic waste, and the alkaline salt may be additionally added to the pellet after the pellet is formed. Specifically, the alkali metal salt may be added to the hydrolyzed basic raw material composition by adding 1 to 5% of alkali salt to the basic raw material composition, adjusting the water content to 40 to 60%, and reacting for 2 to 4 hours to prepare pellets This is because the content of alkoxide which can cause an inorganic reaction (polycondensation reaction) through alkaline activation treatment is increased, so that more inorganic curing reaction can be generated and the water resistance can be further enhanced.

Further, in the organic high-density material of the present invention, the oil impregnation may preferably be impregnated with oil at 15 to 25 ° C for 30 seconds to 7 minutes, then dried at a temperature of 90 to 110 ° C for 2 to 5 hours Can be processed. The prepared pellets were impregnated with the oil at room temperature under the same conditions as described above, so that the water resistance and the strength properties of the pellets could be further improved.

Further, in the organic high-density material of the present invention, the oil impregnation can further improve the durability and moisture resistance of the pellets by changing the drying conditions after impregnation. The changed drying conditions are heat treatment and drying at a temperature of 110 to 290 ° C for 30 seconds to 3 minutes. In this case, the content of residual oil in the pellets is lowered. If the drying is performed at a temperature of 90 to 110 ° C for 2 to 5 hours The durability and moisture resistance were further increased.

In the organic high-density material of the present invention, the surface heat treatment may preferably be performed at 270 to 330 ° C for 3 to 15 minutes, more preferably at 300 ° C for 10 minutes. By changing the surface structure of the pellets produced through the above-described heat treatment, moisture resistance and surface porosity can be imparted. In the above conditions, the heat resistance can increase the moisture resistance without lowering the strength of the pellets, The surface hydrophilicity of the OH group, which is a hydrophilic group on the surface, is bonded to the surrounding hydrophilic group just before it is burned with water and carbon dioxide, and microvoids are generated as volatile components on the surface dissipate. However, if the heat treatment conditions exceed the above range, there is a problem that the strength of the pellets is greatly reduced due to thermal decomposition, and when the heat treatment conditions are less than the above range, the effect of increasing the moisture resistance is insufficient.

The application field of organic high density material having moisture resistance is applicable to surface cover such as desolation and artificial landscaping paper. It can be used as soil covering material such as restoration paper, waste paper, mine paper, and porosity of artificial soil. It can be applied to materials. In particular, it can be easily transported and stored by adjusting the shape and size of the structure variously, and it is possible to put a fixed amount at the time of application, and even when it is exposed to the outside, it can maintain a certain form due to moisture resistance, After one year or so, it breaks down and biodegrades, so it does not have problems such as disposal or disposal after application.

The present invention also relates to a method for producing a wood or organic waste by mixing at least one selected from the group consisting of bark, AKD (Alkyl ketene dimer), rosin, lignosulfonate, starch, calcium preparation, silicon dioxide and sodium silicate, The present invention also provides a method for producing an organic high-density material having excellent water resistance and durability.

The present invention also provides a method for producing an organic high-density material excellent in moisture resistance and durability, comprising the steps of impregnating oil or impregnating pellets produced by extrusion-molding wood powder or organic waste.

The present invention also relates to

(a) mixing wood flour or organic waste with one or more selected from the group consisting of bark, Alkyl ketene dimer, rosin, lignosulfonate, starch, calcium agent, silicon dioxide and sodium silicate, Lt; / RTI > And

and (b) impregnating or heat-treating the pellets prepared in step (a) with oil. The present invention also provides a method for producing an organic high-density material having excellent water resistance and durability.

The method for producing an organic high-density material of the present invention, more specifically,

(a) mixing wood powder or organic waste with one or more selected from the group consisting of bark, AKD, rosin, lignosulfonate, starch, calcium agent, silicon dioxide and sodium silicate, followed by extrusion molding to produce pellets; And

(b) impregnating the pellet produced in step (a) with oil at 15 to 25 ° C for 30 seconds to 7 minutes or surface-treating the prepared pellet at 270 to 330 ° C for 3 to 15 minutes , ≪ / RTI >

More specifically,

(a) mixing wood powder or organic waste with one or more selected from the group consisting of bark, AKD, rosin, lignosulfonate, starch, calcium agent, silicon dioxide and sodium silicate, followed by extrusion molding to produce pellets; And

(b) impregnating the pellets prepared in step (a) with oil at 20 ° C for 1 to 5 minutes or surface-treating the prepared pellets at 300 ° C for 10 minutes.

The oil impregnation of step (b) of the present invention may further include heat treating and drying the oil-impregnated pellets at a temperature of 110 to 290 ° C for 30 seconds to 3 minutes, but the present invention is not limited thereto.

The present invention also provides an organic high-density material excellent in moisture resistance and durability produced by the above method.

Hereinafter, the present invention will be described in detail with reference to examples. However, the following examples are illustrative of the present invention, and the present invention is not limited to the following examples.

1. Manufacture of organic high-density materials

Functional additives were mixed in wood flour and extrusion molding was performed to produce high density pellets and cut to a certain size. Further, the produced pellets were impregnated with oil (soybean oil) and then dried in a drier at 100 ± 5 ° C for 3 hours. Alternatively, the prepared pellets were subjected to an additional surface treatment such as heat treatment at a high temperature to prepare a high density material.

2. Durability measurement

The durability according to the raw materials was measured by weighing the pellets excluding the fine particles separated when the vibration of 300 rpm was applied. That is, the higher the% durability, the higher the durability and the higher the moisture resistance.

Durability (%) = (dry weight (g) / pellet dry weight (g) of pellet after applying vibration) x 100

Example  1: Characterization of pellets by raw material blending

(1) Applicability analysis according to compositional characteristics of ingredients

Depending on the composition of the raw material, the moisture resistance of the manufactured pellets is greatly influenced. In the case of wood flour, it is composed of holocellulose having a hydrophilic group of 55-75%. As a result, hydrophilic pellets are generally produced. As a result, moisture and shape retention tend to decrease. In order to compensate for this, it is expected that the addition of the lignin, wax and fat content of the bark increases the bond strength by lignin and the moisture resistance by the natural hydrophobic ingredient in the raw material.

Chemical composition of raw materials (%) division Hot water extract Alcohol benzene Holocellulose Lignin Ash Wood flour softwood 1-2 0.5-1 55-75 25-35 1-3 Hardwood 1-4 1-2 55-75 15-25 1-3 fell softwood 4-7 2-3 40-55 35-45 4-10 Hardwood 5-7 1-4 47-57 36-39 4-10

(2) Durability change of the pellets produced by the raw material mixture

The durability changes after 30 minutes after impregnation of the pellets prepared by mixing the 100% wood pellets with the wood pellets and the wood pellets in a weight ratio of 1: 1 are shown in FIG. The durability of pellets containing 100% wood flour and wood flour and bark was reduced by exposure to water for 30 minutes, but the pellets containing wood flour and bark were more durable than wood flour 100%.

(3) Influence of water content on the pellets

The durability change of the prepared pellet with time of moisture impregnation is shown in Fig. In the case of wood pellets, the structure was swelled after 6 hours of impregnation and the water resistance was low. However, when the pellets were prepared by adding coniferous and hardwood bark, the pellet shape was maintained even after 6 hours. It is believed that the pellet containing the high bark lignin, which is constituted by pellets, is self-hydrophobic and does not swell in water, so that it maintains its structure. It is observed that when the pellets are made into water, the water resistance can be increased.

Example  2: Technology for imparting moisture resistance of pellets by applying functional material

Using wood powder as a base material, the functional material was mixed and agitated to prepare a raw material, and pellets were produced (Table 2). Rubber rosin obtained by distilling turpentine oil from rosin is softened at 70 to 80 ° C and dissolved at 120 to 130 ° C to soften and dissolve in pellet molding and is fixed on each surface after pelletization to impart hydrophobicity to pellets and strength . In addition, AKD (Alkyl ketene dimer) is applied as an additive that removes hydrophilicity through covalent bonds with hydroxyl groups of hydrophilic organic substances, increases rigidity and does not impair flexibility. Since the AKD in the emulsion state reacts with the hydrophilic group at a temperature of 80 ° C or higher, the hydrophobic surface modification effect can be expected by strongly binding with the pellet raw material by the heat of 120 ° C or more generated in the pellet molding. Lignosulfonate is a lignin derivative produced by the reaction of lignin in fibrous raw material with a sulfite ion and sulfurous acid in the digestive juice due to sulfite digestion or the like, and is easily bonded to the lignocellulosic raw material since it is hydrophilic in the dissolved state , It has an effect of strengthening the pellet due to its strong point-bonding force and increasing the flexibility of the raw material upon pelletization, thereby increasing the workability. In addition, it is applied as an additive for improving hydrophobicity and improving the process by curing by cooling after thermo-setting and reducing hydrophobicity.

Manufacture of pellets mixed with functional materials division Raw material additive AKD rosin Lignosulfonate Oxidized starch Control Wood flour 100 Not added AKD 3% rosin 3% Lignosulfonate 3% Oxidized starch 3%

As a result of producing the pellets by applying the additives for moisture resistance, rosin, lignosulfonate, oxidized starch and AKD added pellets act as a binder for improving the strength compared to the pellet without additives, (Fig. 3). ≪ tb > < TABLE >

The durability changes of the pellets treated with each additive were measured. As a result, the AKD and rosin - added pellets exhibited increased water resistance at a similar level, and the lignosulfonate - added pellets showed the highest water resistance. In addition, the oxidized starch-added pellets had excellent effect as a binder for improving durability, but the water resistance resistance effect showed lower water resistance than the lignosulfonate-added pellets. As a result, it is expected that the application of the lignosulfonate can improve the durability change by about 20 to 30% by moisture (FIG. 4).

Example 3 Evaluation of Moisture Resistance Properties of Pellets Prepared by Application of Inorganic Curing Bonding Technology

(1) Evaluation of moisture resistance of pellets by simple addition of inorganic hardener

The pellet can be produced as a pellet having high water resistance by constituting the bond forming the structure of the pellet with a water-resistant decomposable bond through inorganic curing. Particularly, the calcium hardening characteristics using calcium salts (calcium silicate, hemihydrate gypsum, calcium oxide, paper sludge, etc.) react with water to generate heat and harden by hydration reaction, are used for strong inorganic hardening such as concrete by cement It is possible to produce pellets of high density and high moisture resistance when applied to pellets. In addition, the silicon-based curing is strongly cured by forming an inorganic material such as silicon dioxide and hydrolysis due to the addition of sodium silicate and crosslinking with other inorganic particles, and by applying an additional inorganic material and a sodium silicate curing agent, And can be produced as pellets having improved water resistance.

In the present invention, pellets were prepared by mixing wood and additional inorganic raw materials (calcium-calcium carbonate, silicon-rice husk (silicon dioxide, SiO ₂ )) and applying additives to exhibit curing properties (Table 3) The change of frictional heat of pellet molding due to inorganic additives was measured by attaching a temperature sensor to the surface of the molding machine. The durability of the prepared pellets and the durability of each pellet after impregnation for 10, 20, 30 minutes in water were measured to evaluate the improvement of water resistance (durability according to water exposure).

Conditions of raw material composition of inorganic hardener added pellets division Raw material additive Main ingredient Supplementary material Wood flour pellets Wood flour 100 - - Calcium Binder Pellet # 1 Wood flour 80 Calcium carbonate 20 Calcium hydroxide 3% Calcium Binder Pellet # 2 Wood powder 70 Calcium carbonate 30 Calcium hydroxide 10% Silicon Binder Pellet # 1 Wood flour 80 Rice cakes 20 Sodium silicate 3% Silicon Binder Pellet # 2 Wood powder 70 Rice cakes 30 Sodium silicate 10%

Changes in durability and moisture resistance depending on the type of inorganic hardened pellets division durability Water resistance (durability due to water exposure) Frictional heat change
(° C) 10 minutes 20 minutes 30 minutes Wood flour pellets 98.0 46.5 Destruction of structure Destruction of structure 145-160 Calcium Binder Pellet # 1 99.7 59.5 38.4 25.6 155-175 Calcium Binder Pellet # 2 96.3 63.2 43.7 33 180-185 Silicon Binder Pellet # 1 99.4 60.8 45.6 31.5 170-180 Silicon Binder Pellet # 2 93.8 71.1 53.5 39.3 190-200

As shown in Table 4, the durability of each of the pellets showed a tendency that the durability of the calcium phosphate pellets # 1 and the silicon binder pellets # 1 was increased but the durability thereof was lower than that of the calcium phosphate pellets # 2 and the silicon binder pellets . This is due to the friction between the raw materials and the frictional heat passing through the pellet mold during the production of the pellets due to the addition of the excessively applied inorganic material, resulting in a large amount of fine powder as the pellet forming temperature increases. This phenomenon affects the wear of the pellet molding equipment. Therefore, it is considered that the inorganic raw materials should be applied within 20% of the main raw materials in consideration of operational suitability and equipment life. The water resistance improvement effect was found to increase the moisture resistance by forming an inorganic bond with a water-impermeable property, with all of the inorganic hardened pellets exhibiting a durability of at least 25% after 30 minutes of water exposure.

(2) Induction of inorganic hardening (alkali activity) Evaluation of moisture resistance by pretreatment

A new method capable of synthesizing an inorganic material such as amorphous ceramics, crystallized glass or ceramics from a starting material of a metal alkoxide (M (OR) n, M: metal, R: alkyl group) By applying the principle of the law, we tried to devise a method that can promote the silicon curing reaction.

In the present invention, rice husk as a silicate material is mixed in the raw material, followed by agitation and reaction at a water content of 50% for 3 hours by applying an alkali such as sodium hydroxide (NaOH) to elute the silicate in the form of a sol. In addition, by adding sodium silicate additionally, pellets were prepared from a raw material having abundant silicate, rather than simply adding sodium silicate, to induce stronger silicon curing bonds.

Conditions for raw material composition of inorganic hardening induction pretreatment pellets division
Raw material additive Treatment with alkali active Main ingredient Supplementary material Wood flour pellets Wood flour 100 - - - Silicon Binder Pellet # 1 Wood flour 80 Rice cakes 20 Sodium silicate 3% Untreated Silicon cure inducing pellets Wood flour 80 Rice cakes 20 Sodium silicate 3% 3% sodium hydroxide added to the raw material,
50% moisture control,
Stirring reaction for 3 hours

Changes in durability and moisture resistance of pellets with or without inorganic curing alkali treatment division durability Water resistance (durability due to water exposure) Frictional heat change
(° C) 10 minutes 20 minutes 30 minutes Wood flour pellets 98.0 46.5 Destruction of structure Destruction of structure 145-160 Silicon Binder Pellet # 1 99.4 60.8 45.6 31.5 170-180 Silicon cure inducing pellets 99.5 80.4 63.7 49.6 160-170

In the case of silicon curing induced pellets through alkaline activation treatment, the water resistance of the pellets was more increased than that of the conventional silicon curing agent added pellets (Table 6). This is because the content of alkoxide which can generate an inorganic reaction (polycondensation reaction) through the alkali activation treatment is increased, resulting in more inorganic curing reaction. In addition, due to the high water content and the alkaline activation treatment that dissolves the inorganic particles, a more flexible raw material is formed and the frictional heat is generated to a degree similar to that of ordinary wood pellets. Therefore, the wear of the equipment and the durability of the pellet hardly occur, It was judged that it could be applied as an increased method.

Example  4: Application of oil surface treatment process Pellet  Analysis of moisture resistance effect

(1) Oil surface treatment method

Techniques for increasing the water resistance of pellets through post-treatment processes include surface treatment techniques using oils that are viscous and flammable and are not soluble in water. Such an oil surface treatment proceeds to a process of removing and drying residual oil after impregnating (immersing) in oil for a short period of time, and coating with an oil component on the surface thereof to suppress moisture penetration.

In order to analyze the effect of the oil surface treatment on the increase of water resistance, pellets were prepared from wood flour (rubber tree) as a raw material without adding a binder or other additives. Each pellet was treated at room temperature for 1 to 15 minutes The oil was impregnated with vegetable oil (soybean oil) and placed on a mesh of 8 mesh size for 3 hours. The remaining oil was freely dropped off and then dried in a hot air drier at 100 ± 5 ° C for 3 hours to complete the post-treatment process.

Processing conditions of oil surface treated pellets division Raw material Oil impregnation conditions Holding temperature Impregnation time Wood flour pellets 100% wood flour - - Oil Impregnated Pellet # 1 20 ± 5 ° C 1 minute Oil Impregnated Pellet # 2 5 minutes Oil Impregnated Pellet # 3 7 minutes Oil Impregnated Pellet # 4 10 minutes Oil Impregnated Pellet # 5 15 minutes

(2) Evaluation of pellet characteristics by oil surface treatment conditions

The weight change ratio before and after post-treatment was measured to determine the amount of retention that could be caused by oil impregnation time conditions. A 5 g pellet sample was connected to a Sohxlet glass tube with 150 ml of n-hexane solvent for 4 hours The oil adsorption rate was measured by heat extraction. The durability and moisture resistance of the pellets according to the oil surface treatment were evaluated. The results are shown in Table 8.

Characteristics of pellets by oil surface treatment conditions division durability Water resistance (durability due to water exposure) Weight change
(%) Oil adsorption rate (%) 10 minutes 20 minutes 30 minutes Wood flour pellets 98.0 46.5 Destruction of structure Destruction of structure 0 0 Oil Impregnated Pellet # 1 97.7 69.2 41.0 25.9 +4.11 1.05 Oil Impregnated Pellet # 2 98.0 66.1 41.6 27.6 +4.46 0.80 Oil Impregnated Pellet # 3 97.1 66.8 43.4 26.2 +5.69 2.05 Oil Impregnated Pellet # 4 97.3 64.3 42.8 23.1 +6.10 3.84 Oil Impregnated Pellet # 5 95.8 63.8 40.7 22.6 +8.33 4.80

As a result, as shown in Table 8, it was confirmed that the oil-impregnated pellets showed a durability of about 25% even after 30 minutes of water exposure, thereby increasing moisture resistance, compared to wood pellets whose structure was destroyed by moisture exposure for 20 minutes. However, when the oil impregnation time was increased, the weight of the pellets was increased due to the increase of the amount of adsorbed oil, whereas the effect of improving the water resistance was not remarkable. It was confirmed that the oil resistance on the surface of the pellet was expressed by the oil remaining on the surface of the pellet, but there was no proportional correlation between the amount of residual oil and the resistance to moisture. After the oil surface treatment, It was judged desirable to impregnate it.

(3) Heat treatment after oil coating

After the oil surface treatment, there is a disadvantage in that the residual oil on the surface is adsorbed through hot air drying at 100 캜, whereby the residual oil is eluted. In order to compensate for these disadvantages, it is possible to apply a puffing effect by applying oil at a temperature of 150 to 250 ° C. for a short time through an electric furnace after applying oil as in an oil surface treatment method. This method is an excellent process in terms of deterioration of the grease and process efficiency, and the inventor named this post-processing method as "oil coating-heat treatment" post-processing.

In the present invention, the pellets made of wood powder were impregnated with vegetable oil at room temperature for 3 minutes to coat the oil on the surface of the pellets, and the remaining oil was freely dropped on the mesh of 8 mesh size for 3 hours. Then, it was heat treated in an electric furnace at 150 to 250 ° C for 1 to 5 minutes to complete the oil coating-heat treatment. After that, the durability and moisture resistance of each treated pellet were measured. Since the remaining amount of retention may differ depending on the heat treatment conditions after oil coating, the weight change ratio before and after post-treatment was measured. - The effect of oil coating-heat treatment after oil coating-heat treatment was evaluated by measuring the oil adsorption rate by heating for 4 hours by connecting it to Sohxlet glass tube with 150 ml of hexane solvent.

Oil coating - Heat treatment condition division Raw material Heat treatment condition Electric furnace temperature Drying time Wood flour pellets 100% wood flour - - Oil Coating - Heat Treatment Pellet # 1 150 ℃ 1 minute Oil coating - Heat treated pellet # 2 150 ℃ 5 minutes Oil coating - Heat treated pellet # 3 200 ℃ 1 minute Oil coating - Heat treated pellet # 4 200 ℃ 5 minutes Oil coating - Heat treated pellet # 5 250 ℃ 1 minute Oil coating - Heat treated pellet # 6 250 ℃ 5 minutes

Oil coating - Pellet properties by heat treatment division durability Moisture resistance Weight change
(%) Oil adsorption rate (%) 10 minutes 20 minutes 30 minutes Wood flour pellets 98.0 46.5 Destruction of structure Destruction of structure 0 0 Oil Coating - Heat Treatment Pellet # 1 96.6 55.6 39.1 33.7 +1.71 1.23 Oil coating - Heat treated pellet # 2 95.3 60.2 41.9 38.6 -0.16 0.67 Oil coating - Heat treated pellet # 3 97.4 64.4 53.0 43.5 +1.63 0.94 Oil coating - Heat treated pellet # 4 95.7 59.0 36.9 30.1 -0.45 1.00 Oil coating - Heat treated pellet # 5 96.1 66.8 51.7 49.0 +1.30 0.78 Oil coating - Heat treated pellet # 6 93.9 58.3 36.3 29.5 -2.27 -0.34

It has been confirmed that the water resistance after oil coating-heat treatment improves (Table 10). The improvement in moisture resistance was further enhanced as compared with the above-described oil surface treatment method, and it was judged to be a method capable of alleviating the secondary pollution caused by the residual oil due to the low oil adsorption rate. However, in case of drying for 5 minutes or longer in oil coating-heat treatment, weight reduction due to pyrolysis and lowering of durability are caused, and oil coating-heat treatment is performed at a heat treatment time within 5 minutes and at a heat treatment temperature of 150 to 250 ° C Respectively.

Example  5: Moisture resistance application technology through application of surface heat treatment process

The surface heat treatment process is a process of modifying the surface of the pellet by applying heat energy to the pellet at a predetermined temperature (200 to 350 ° C) for a short time (2 to 10 minutes). In this surface heat treatment process, the free energy existing in the pellet After the water is completely dried, the water resistance of the surface of the pellet due to drying shrinkage may be increased by binding to the adjacent hydroxyl group to lose hydrophilicity. However, when the surface heat treatment process is excessively applied, the shrinkage ratio is greatly increased, and the durability is reduced due to the inhibition of the structural bonding.

(1) Shrinkage analysis of pellets by surface heat treatment process

As a result of analyzing the shrinkage rate of the pellets produced by varying the heat treatment temperature and time, the shrinkage tends to increase as the heat treatment condition is increased by the surface heat treatment. In particular, the volume shrinks by up to 10% at 350 ° C for 10 minutes under heat treatment conditions, and it is estimated that the removal of hydroxyl groups has progressed somewhat during the drying shrinkage process, resulting in a decrease in physical properties (FIG.

(2) Durability change of pellets according to surface heat treatment process conditions

The durability change of the pellets produced by varying the heat treatment temperature and time showed a tendency similar to the shrinkage rate, and the drying shrinkage due to the actual heat treatment affects the durability and the heat treatment should be applied at a temperature of 200 to 300 ° C or less (Fig. 6).

(3) Analysis of moisture resistance effect of pellets according to surface heat treatment process conditions

The durability changes of the pellets subjected to the surface heat treatment were analyzed according to the water exposure time. Existing wood pellets showed complete dissociation of the pellet structure by 20 minutes exposure, but the heat treated pellets showed a durability of at least 30%, indicating that the improvement in moisture resistance was evident. The pellets heat-treated at 200 ° C showed complete dissociation by water exposure for 30 minutes, and the effect of improving the moisture resistance was lower than that of other conditions. The pellets heat-treated at 300 ° C for 10 minutes showed the highest improvement in moisture resistance (FIG. 7) .

Claims (11)

delete Wood powder; Or organic wastes of paper sludge, forestry by-product or livestock manure; oil-impregnated pellets, dried at 150 to 250 ° C for 0.5 to 3 minutes or surface-treated at 270 to 330 ° C for 5 to 10 minutes Organic high density pellets with excellent moisture resistance and durability. Wood powder; Or at least one functional additive selected from the group consisting of AKD (Alkyl ketene dimer), lignosulfonate, starch, calcium fertilizer and silicon dioxide is mixed with organic waste of paper sludge, forestry by-product or animal manure, The pellets are impregnated with oil and dried at 150 to 250 ° C for 0.5 to 3 minutes or surface-treated at 270 to 330 ° C for 5 to 10 minutes. The pellets are excellent in moisture resistance and durability. delete delete delete delete delete Wood powder; Or organic wastes of paper sludge, forestry by-product or animal manure; oil-impregnated pellets, followed by drying at 150 to 250 ° C for 0.5 to 3 minutes or surface heat treatment at 270 to 330 ° C for 5 to 10 minutes The method of manufacturing an organic high-density pellet having excellent water resistance and durability. (a) wood flour; Or an organic waste of paper sludge, forestry by-product or animal manure is mixed with at least one selected from the group consisting of AKD (Alkyl ketene dimer), lignosulfonate, starch, calcium material and silicon dioxide, Producing; And
(b) impregnating the oil with the pellets produced in step (a), and then performing the surface heat treatment at 150 to 250 ° C for 0.5 to 3 minutes or at 270 to 330 ° C for 5 to 10 minutes By weight based on the total weight of the pellets. delete

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