KR100754890B1 - Method for Making Pulp Using Rhodophyta - Google Patents

Abstract

The present invention relates to a method for producing pulp using red algae, and more specifically, red algae are immersed in an acidic solution for a predetermined time, washed with water and then dehydrated, and the dehydrated red algae are immersed in an extraction solvent for a predetermined time. After extraction, the extracted gel and residue in a multi-stage bleaching process, and collected by fibrosis relates to a method for producing red algae pulp.

The present invention is specifically presented for the bleaching process of red algae, it is possible to produce a high whiteness pulp using red algae, there is an advantage that the chemicals used during the bleaching process is also environmentally friendly compared to the conventionally used drugs.

Red algae, pulp, bleach

Description

Method for Making Pulp Using Red Algae {Method for Making Pulp Using Rhodophyta}

1 is a schematic diagram showing a process of making pulp using red algae.

The present invention relates to a method for producing pulp using red algae, and more specifically, red algae are immersed in an acidic solution for a predetermined time, washed with water and then dehydrated, and the dehydrated red algae are immersed in an extraction solvent for a predetermined time. After the extraction, the extracted gel and the residue in a multi-stage bleaching process, and collected and fibrous to a method for producing red algae pulp.

Generally, fibers obtained by mechanically or chemically treating a plant raw material are called pulp. In fact, in addition to wood, cotton, hemp, flax, jute, german hemp, manila hemp, cedar, gingko, straw, esparto, bamboo and bagasse are used as pulp feedstocks. However, the requirements to be provided as industrial raw materials should be abundant in quantity, easy to collect, transport and store, inexpensive and excellent in quality.

Wood, which is a major pulp feed material, is mainly composed of cellulose, hemicellulose, and lignin, and these components constitute the cell wall and the intercellular layer and are present in more than 90% of all species. Subcomponents include resins, essential oils, fats and oils, extracts such as tannins and flavonoids, and other inorganic substances. Among them, cellulose is present in the largest amount of organic compounds present in nature, and is the main component of the plant cell wall. Cellulose is a polymeric material that is insoluble in water, dilute acids and alkalis at room temperature. In order to industrially use wood cellulose, it is used as wood sugar by manufacturing paper through hydrolysis, bleaching, refining, etc., or by hydrolyzing wood, and making and using cellulose derivatives through various chemical treatments. Doing. Various operations are performed from the raw material to the pulp, but it can be largely classified into preparation of pulp raw material, pulping, and purification of pulp.

In the process of processing a wood raw material in the state which is easy to pulp, there are operations, such as cutting, peeling, and sorting, and this is performed suitably according to the kind of raw material. The process of obtaining fibers from the raw material after the preparation process is called a pulping process and is the most important process in pulp production. Fibers can be obtained by destroying the composite intercellular layer of wood, which is a pulp material, with a wood mill or by softening it with water vapor and then breaking it using physical force. The pulp obtained by simple mechanical treatment without chemical treatment is called mechanical pulp. Mechanical pulp has a high yield and low production cost, but it is not suitable as a raw material of high grade paper because of its high content of lignin.

Treatment of the pulp feedstock with ligignin chemicals dissolves the complex intercellular layer and dissociates it into fibrous form. Pulp prepared in this way is called chemical pulp. In the manufacture of chemical pulp, not only the lignin in the intercellular layer of the raw material, but also most of the membrane lignin is removed, and at the same time, many hemicelluloses are dissolved and some cellulose is degraded. Chemical pulp has high quality, i.e., high purity of cellulose, but has a disadvantage of low yield and high production cost compared to mechanical pulp. Chemical pulp production methods include sulfurous acid method, soda method and sulfate method. The selection process is a process of washing and screening fibers obtained from the raw material after the pulping process to remove parts and contaminants that are not completely pulped, and then bleaching as necessary. Specific refinement treatments are performed for those requiring high quality, such as rayon pulp.

The above is the description about the general process of manufacturing pulp from wood raw materials. However, as the depletion of wood resources around the world becomes severe, the task of the industry is to produce paper stock pulp while protecting forests and the environment. As a solution to this problem, a technique for producing paper pulp from non-woody plant fibers mainly on first and second year plants has attracted attention.

Non-woody plants that can be used as a raw material for papermaking include bark, flax, hemp, cotton, manila hemp, rice straw, bagasse and the like. In general, non-woody plants are high in pectin, hemicellulose, minerals, low in lignin, and chemical, semi-chemical, and mechanochemical methods are used when pulping, with very mild conditions compared to wood. Unbleached or bleached pulp can be obtained.

Non-wood pulp has different properties depending on its fiber type, chemical composition, and the type and amount of non-fibrous cells. Therefore, the paper made by non-wood pulp alone or by proper blending with wood pulp can easily control the strength, durability, electrical characteristics, gloss, dimensional stability and printing performance, which can be used for various purposes. Therefore, the use range is also wide. However, the conventional non-wood pulp has to go through a difficult process, and there is a problem that the environment is polluted because toxic chemicals are used even when producing pulp.

Accordingly, the present inventors have introduced a pulp and paper manufacturing method using the red alga in the "pulp and paper made with red algae and the manufacturing method thereof" of the application No. 10-2004-0092297. When pulp and paper are manufactured using red algae, production costs are very low, and the use of chemicals for lignin removal and bleaching is significantly reduced, thereby preventing environmental pollution. However, the invention has been described only for the method of preparing pulp through the extraction process of water, ethyl alcohol, methyl alcohol, acetone and ketones, and has not been specifically described for the bleaching process. There was a difficulty in increasing the whiteness of the paper.

Therefore, the present inventors have continued research on the pulp manufacturing method, as a result of developing a bleaching process of red algae according to the thickness of the red algae shell, it was confirmed that in each case can be produced pulp with a high degree of whiteness To complete.

After all, an object of the present invention, immersed red algae in an acidic solution for a predetermined time, and then dehydrated after washing with water, the dehydrated red algae immersed in an extraction solvent for a certain time to extract the agar gel, the extracted gel and residue The present invention provides a method for producing red algae pulp by bleaching in multiple stages and collecting and fibrillating the same.

In order to achieve the above object, the present invention comprises the steps of (a) immersing red algae in an acidic solution for a predetermined time, followed by washing with water and dehydrating; (b) extracting the gel by immersing the dehydrated red alga in an extraction solvent for a predetermined time; (c) bleaching the extracted gel and residue in multiple stages; (d) collecting and fiberizing the bleached red algae to provide a method for producing red algae pulp.

In the present invention, the red algae may be any one or more selected from the group consisting of Locust spruce, Dolphin spree, gambling and Noodle sprouts, but includes all red algae with minimal fiber, It is also possible to use carrageenan or agar obtained.

In the present invention, the multi-stage bleaching process of step (c) comprises: i) O ₃ (ozone) bleaching; ii) Element Chlorine Free (ECF) or Total Chlorine Free (TCF) bleaching; And iii) H ₂ O ₂ (hydrogen peroxide) bleaching step, and further comprising the step of adding a reducing agent in step iii), O ₃ (ozone) of step i) Bleaching may be characterized in that it is repeated until the whiteness of the red algae is 50 or more.

In the present invention, the ECF (Element Chlorine Free) or TCF (Total Chlorine Free) bleaching of step ii) may be repeated until the whiteness of the red alga is 60 or more, and iii) H ₂ O ₂ (Hydrogen Peroxide) Bleaching may be characterized by repeating until the whiteness of the red algae is 70 or more.

The present invention also provides a red algae pulp produced by the above method, and uses the red algae pulp as a raw material.

Hereinafter, the present invention will be described in detail.

1. Raw material of the present invention: red algae

Red algae inhabit relatively deeper water than other algae, and are relatively small in size, with more than 4000 species. Red algae have a wider range of habitat than green algae and brown algae, and grow from shallow depths to deep water rays.

On the other hand, agar is a product that is processed through the process of freezing, thawing, drying by extracting the complex polysaccharide, which is a cell wall component of red algae with hot water. Red algae, which are widely used as raw materials of agar, include wood starfish, ox radish, buckwheat, stalks, thorn radish, silk grass, scabbard, stone starfish, stone and Jinuaari. Agar is largely composed of agarose and agalopectin 7: 3. These ingredients become the active ingredient of agar. Agarose, a neutral polysaccharide, has a property of increasing gel strength due to its strong gelling property, and agalopectin, an acidic polysaccharide, has a property of improving viscoelasticity instead of weak gel. Representative properties of agar include coagulation, viscoelasticity and water retention. Because agar has the opposite properties of coagulation and viscoelasticity, it can be used as a stabilizer, extender, forming agent, thickening agent, drying inhibitor, or physical property maintaining agent by controlling two physical properties.

In addition, the agar solution shows stronger gelling properties than any other gel forming agent. Agar solution forms a gel at 32-43 ℃, once formed gel does not melt below 80-85 ℃, it is characterized by little change in the original gel properties even after repeated gelling and dissolution. Transparent gels are easy to color, and the addition of sugar, glucose, glycerin, etc. increases the refractive index and makes it glossy.

The raw material according to the present invention may be any one or more selected from the group consisting of Locust spruce tree, Dolphin spree, gambling tree and Noodle sprout tree, but includes all red algae in which minimal fiber exists, and also carrageenan obtained from red algae It is also possible to use agar or the like.

Usually, agar extracted from hot water from wormwood or stalks has a stronger strength than carrageenan extracted from hot water from Kotoni or Spino island, and agar components extracted from hot water from stalks are superior to agar extracted from hot water. Carrageenan, which is included in red algae such as kotoni and spino island, exhibits the same properties in that it contains fibers that can be made into pulp as compared to gel components contained in red algae such as wood starfish and stalks. Therefore, in the present invention, agar components contained in red algae, such as carrageenan, wood starfish and stalks, included in red algae, such as kotoni and spino island, will be collectively referred to as 'gel'.

2. Preparation of Pulp

2-1 Extraction of Red Algae

Red algae are immersed in an acid solution of pH 2-3 for a certain time, washed with water, and dehydrated. At this time, through the process of immersing the red algae in an acidic aqueous solution for a predetermined time, impurities are removed, the skin of the red algae is softened.

When the washed and dehydrated red alga is immersed in the extraction solvent of the present invention, the gel contained in the red alga is extracted with the extraction solvent. At this time, the extraction solution may be used water, ethyl alcohol, methyl alcohol, acetone and ketones, depending on the nature of the pulp can be used oxidizing water, acidic chemicals and oxidizing or reducing water, basic chemicals and reducing agents. However, since the melting point of the gel is about 60 ℃, the temperature of the extraction solvent is preferably heated to 60 ℃ or more.

2-2 Bleaching Process After Extraction Process

After elution of the gel extract, bleaching is performed in multiple steps. First, a bleaching treatment is performed using ozone. After ozone treatment, the gel extracts dissolved are compressed and removed by pressurization at a pH of 2-10 kg / cm ² , and the ozone treatment is repeated. Ozone treatment is repeated until the color of red alga is over 50 based on whiteness.

After ozone treatment, go through ECF (Element Chlorine Free) process using bleaching with chlorine dioxide or repeat TBC (Total Chlorine Free) bleaching process by further strengthening ozone bleaching process until whiteness is over 60 do.

As a final step of the bleaching process, bleaching with hydrogen peroxide is carried out. When bleaching with hydrogen peroxide, a reducing agent may be added to prepare pulp having a whiteness of 70 or more.

3. Papermaking Process

In general, "paper" refers to a cellulose fiber in the form of a sheet so that it can be used for printing, writing, packaging, etc., and manufacturing paper suitable for the purpose by various treatments is called "paper". The paper making process, or paper making process, varies slightly depending on the purpose of the paper, which is the final product.

3-1 Confession

If the pulp produced in the pulp mill is made of paper without any processing, the paper is hard to use for general purposes such as weak strength, rough surface and excessive air permeability. This is because the fibers of natural pulp are rigid and have a low surface area, which causes the fibers to hardly bond.

Therefore, the fibers must be mechanically treated in water to make them suitable for papermaking. This process is called beating. Breaking of the fiber is called free beating, and when fibrillation occurs mainly, it is called wet beating. By beating, the fiber outer layer is removed, internal fibrillation occurs, the fiber length is cut, microfibers are formed, and partial dissolution of the chemical composition occurs. The beating makes the fiber flexible and increases the bonds between the fibers, so that as the altitude rises, the paper has a dense structure.

3-2 Sizing

It is a process of imparting resistance to ink or water to paper, and the chemical used at this time is called sizing agent. There are two types of sizing, surface sizing and internal sizing.

3-3 charge

Minerals such as clay or calcium carbonate are incorporated into pulp during papermaking. Increase paper opacity, printability and basis weight.

3-4 Screening and Selection

Before sending the paper to the paper machine, it is a process to remove the contaminants mixed in the paper so that the properties of the paper are made constant.

3-5 grassland

After forming a web on a wire from a pulp, a sizing agent, a filler, various additives, and the like, a paper is pressed, dehydrated, and dried to make paper. According to the method of forming the paper on the wire, the paper machine is divided into a long mesh, a circular mesh, and a twin mesh.

3-6 processing

Processing is a step of performing various processing such as coating, modification, absorption, lamination, etc., using the produced paper as a base paper. In the papermaking method according to the present invention, because the red algae rather than wood pulp is used as a raw material, the beating process is not essential, but it is preferable to go through the beating process when using the aid. If you use high-purity agar products, you do not have to perform confession separately.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are only for illustrating the present invention, it will be apparent to those skilled in the art that the scope of the present invention is not to be construed as being limited by these examples.

Example 1 Preparation of Pulp Using Gelium Chylenes

A stringer with a suitable thickness of the shell produced pulp as shown in FIG. 1. The red alga was immersed in a hydrochloric acid solution at pH 2.5 for 1 hour, washed with water and then dehydrated. The washed and dehydrated red algae were immersed in reducing water at a temperature of 110 ° C. for 2 hours to elute the gel extract. In addition, the extract was subjected to bleaching treatment in multiple stages. First, bleaching was performed using ozone, followed by bleaching using chlorine dioxide, and finally, bleaching was performed using hydrogen peroxide to increase the whiteness to 80 or more. A small amount of hydrosulfite, a reducing agent, was added to hydrogen peroxide to prevent further whiteness and discoloration of red algae pulp.

As described above in detail the specific parts of the present invention, for those of ordinary skill in the art, these specific descriptions are only preferred embodiments, which are not intended to limit the scope of the present invention. Will be obvious. Therefore, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

According to the method for preparing pulp according to the present invention, the main raw material is to use red algae rather than wood, so that pulp and paper can be produced at low cost, and compared with the process for producing wood pulp for lignin removal and bleaching. The use of chemicals is significantly reduced, which is environmentally friendly, and has the advantage of producing pulp with high whiteness using red algae.

Claims (9)

Process for preparing red algae pulp comprising the following steps: (a) immersing red algae in an acidic solution for a period of time, followed by washing with water and dehydrating; (b) extracting the gel and collecting the residue by immersing the dehydrated red alga in an extraction solvent for a predetermined time; (c) bleaching the residue in several steps with different bleaches; (d) collecting the bleached red algae and fibrosis to make red algae pulp. The method of claim 1, wherein the red algae is any one or more selected from the group consisting of Locust spruce tree, Dolphin spree, Gambling tree and Noodle sprouts tree. [Claim 2] The method of claim 1, wherein the various bleaching process using different bleaching agents of step (c) comprises the following bleaching processes: i) O ₃ (ozone) bleaching; ii) Element Chlorine Free (ECF) or Total Chlorine Free (TCF) bleaching; And iii) H ₂ O ₂ (hydrogen peroxide) bleaching. The method of claim 3, wherein the red alga pulp is characterized in that the addition of the reducing agent in step iii). The method for preparing red algae pulp according to claim 3, wherein the O ₃ (ozone) bleaching in step i) is repeated until the whiteness of the red alga is 50 or more. The method of claim 3, wherein bleaching the ECF (Element Chlorine Free) or TCF (Total Chlorine Free) of step ii) is repeated until the whiteness of the red alga is 60 or more. The method according to claim 3, wherein the iii) H ₂ O ₂ (hydrogen peroxide) bleaching is repeated until the whiteness of the red alga is 70 or more. Red algae pulp prepared by the method of any one of claims 1 to 7. A process for producing paper, comprising processing the red algae pulp of claim 8.

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