System for decolorization of cellulose-containing material

Abstract

Disclosed herein is a system for decolorizing a cellulose-containing material, the system comprising: a purification stage for removing non-cellulosic components from the cellulose-containing material under alkaline process conditions; a subsequent first decolorization stage for decolorizing the cellulose-containing material under alkaline process conditions; and a second decoloring stage for decoloring the cellulose-containing material under alkaline process conditions; wherein the first and second decolorization stages comprise a decolorization stage using ozone and a decolorization stage using hydrogen peroxide; at least the purification stage and the second decolorization stage comprise washing means comprising at least one scrubber for washing the material treated in said stages; a purification stage, the first decolorization stage and the second decolorization stage each being connected to a subsequent stage by means of a process line for feeding the material treated and washed in said stage to the subsequent stage; and wherein each washing device is connected to the washing device of the previous stage by means of a filtrate line for supplying at least part of the washing filtrate of the at least one scrubber of said washing device to the previous stage for use as washing water.

Description

Technical Field

[0001] The present disclosure generally relates to a system for processing a material containing cellulose. In particular, but not exclusively, the present disclosure relates to a system for processing a material containing cellulose selected from the group consisting of chemical pulp, recycled textiles, agricultural fibers, non-wood fibers, cardboard, and textile waste, scraps, or clothing. In particular, but not exclusively, the present disclosure relates to a system for processing a textile material. In particular, but not exclusively, the present disclosure relates to a system for processing a material containing cellulose using an alkaline process in a chemical base to produce a purified and decolorized material. Background Art

[0002] This section provides useful background information, but does not constitute an admission that any of the techniques described herein represent the state of the art.

[0003] Circular economy thinking is now part of everyday life. It has become an industry standard approach. In the textile industry, circular economy is now emerging in the form of new processes and new companies.

[0004] Currently, there are two main chemical textile fiber processes used in industry, the conventional viscose process and the lyocell process. Both processes require purified cellulose raw material (called dissolving pulp) to work. Further processes are being developed to compete with current methods, such as the ionic liquid alkaline process, the cellulose carbamate process and the cellulose activation process using cold alkali dissolution.

[0005] Instead of using virgin wood-based dissolving pulp feedstock, recycled textiles, textile scraps, etc. can be purified to produce a pulp corresponding to dissolving pulp. Consumer textile waste and other used textile waste / scraps / garments are first processed in a mechanical separation process to discard non-cellulose components such as zippers and buttons. Plastic materials such as polyester and spandex are then removed, the cellulosic material is chemically decolorized, and ultimately, the result is a recycled textile-based pulp with similar properties to dissolving pulp.

[0006] In chemical pulping technology, typical decolorizing chemicals are chlorine dioxide (ClO2), oxygen (O2), hydrogen peroxide (H2O2) and ozone (O3). Usually, ClO2 and O3 work in acidic environments, while O2 and H2O2 work in alkaline environments. For example, it is known that the use of acidic conditions in the ozone stage has a positive effect on the removal of lignin and is used to protect cellulose (Sixta, H. et al., Pulp bleaching – Ozone delignification, Handbook of pulp, Sixta, H. ed., pp. 777-848, 2006).

[0007] In the fiber production line of a pulp mill, chemical pulp bleaching is usually performed using a system in which the acid and alkaline decolorization stages are arranged in sequence. A different sequence does not provide adequate bleaching results. After each decolorization stage, the pulp is washed. The wash filtrate is circulated in reverse in a countercurrent flow so that the acid filtrate is treated to the previous acid stage and the alkaline filtrate to the previous alkaline stage. If the acid and alkaline wash filtrate streams are mixed, this will lead to precipitation problems in the process equipment, resulting in process shutdowns, or foaming, resulting in serious operating problems. In chemical pulps, lignin and chromophore compounds are the components against which the decolorization chemicals act.

[0008] Textile materials are usually made of pure cotton, polyester-cotton, cotton-containing elastic fibers or man-made cellulose fibers (such as viscose or lyocell) or a combination of the foregoing materials. Therefore, the basic raw material is relatively pure cellulose, which has been processed so that there is no residue of lignin, chromophore or other natural color-inducing components. However, colorants are usually added to textiles to provide the desired appearance, glossiness and other characteristics. Typical colorants are reactive black, reactive orange, direct blue, direct red and vat blue. Therefore, in the case of textiles, the decolorization effect is different from that of chemical pulps. The chemical properties of the colorant are completely different from those of lignin, so different procedures are required, such as alkaline ozone stages, to effectively decolorize and obtain the desired results. Trevizani, J. et al. showed that the use of alkaline conditions in ozone bleaching provides faster and more effective dye removal (Trevizani, JLB, Nagalli, A., Passig, FH, Carvalho, KQde, Schiavon, GJ, & Model, AN de L. (2018). Influence of pH andconcentration on the decolorization and degradation of BR red azo dye byozonization. Acta Scientiarum. Technology, 40(1)).

[0009] There are also prior patent disclosures on chemical pulp decolorization and purification of recycled textile materials.

[0010] Patent FI123299 describes a fiber line bleaching system for a chemical pulp plant with acidic and alkaline process stages. In the described system, wash filtrate is taken from several places in the system and countercurrent washing is not used completely. Wash water is added at the end and in the middle of the process, thereby increasing the use of fresh water. The acid-alkaline alternating system leads to the following situation: the previous stage with different pH values ​​affects the chemical consumption of the subsequent stage, increasing its consumption.

[0011] WO2020251463 discloses a process in which recycled textile material is treated with alkali and treated using other process chemical stages to produce a cellulosic material to be fed to a dissolution process. The stages used operate in alkaline and acidic pH regions that limit optimal wash filtrate circulation.

[0012] WO20180731177 discloses a process for recycling textiles to make materials such as dissolving pulp. The process has an alkaline stage after the bleaching stages O2 and O3, but the ozone stage is carried out in an acidic medium and the washing filtrate cannot be treated to the previous stage without known problems (such as precipitation or foaming, etc.).

[0013] WO2019140245 discloses a method in which recycled textiles are treated in a subcritical process with an acidic or alkaline pH, followed by a decolorization stage using a solvent. The process stages work at different pH values ​​with water-based and solvent-based systems. This makes it difficult to utilize a filtrate circulation system for the wash filtrate, thereby increasing water consumption and material volume. It should also be noted that the solvent medium limits the liquid flow connection.

[0014] WO2018104330 discloses a process in which dissolving pulp or recycled textiles are chemically treated to produce purified material. The process has an alkaline stage, an oxygen stage and an acidic ozone stage. The process stages operate at different pH ranges and there is no reverse flow of the wash filtrate to minimize water consumption.

[0015] Therefore, there is a need for a method that can efficiently use chemicals, water and other process facilities to produce purified cellulose-containing materials and significantly reduce environmental burden. In general, it is desirable to provide a simple, sustainable, efficient method to produce purified cellulose-containing materials and alleviate the problems of previously known solutions. Summary of the invention

[0016] The claims define the scope of protection. Any examples and technical descriptions of devices, products and / or methods in the specification and / or drawings that are not covered by the claims are not embodiments of the present invention, but are presented as background technology or examples to help understand the present invention.

[0017] According to a first example aspect, there is provided a system for decolorization of a material comprising cellulose, the system comprising:

[0018] a purification stage for removing non-cellulose components from the cellulose-containing material under alkaline process conditions; followed by

[0019] a first decolorization stage for decolorizing the cellulose containing material under alkaline process conditions; and

[0020] a second decolorization stage for decolorizing the cellulose-containing material under alkaline process conditions; wherein

[0021] The first decolorization stage and the second decolorization stage include a decolorization stage using ozone and a decolorization stage using hydrogen peroxide;

[0022] at least said purification stage and said second decolorization stage comprise washing means comprising at least one washer for washing the material treated in said stages;

[0023] The purification stage, the first decolorization stage and the second decolorization stage are each connected to a subsequent stage by a process line for supplying the material treated and washed in the stage to the subsequent stage; and wherein

[0024] Each washing device is connected to the washing device of the preceding stage by a filtrate line for supplying at least a part of the washing filtrate of at least one washer of said washing device to the preceding stage for use as washing water.

[0025] The system may comprise a purification stage, followed by a first decolorization stage comprising a decolorization stage using ozone, and then a second decolorization stage comprising a decolorization stage using hydrogen peroxide.

[0026] The system may comprise a purification stage, followed by a first decolorization stage comprising a decolorization stage using hydrogen peroxide, and then a second decolorization stage comprising a decolorization stage using ozone.

[0027] The purification stage, the first decolorization stage and the second decolorization stage may each comprise a washing device comprising at least one washer for washing the material treated in said stage.

[0028] The entire system can be configured to operate under alkaline process conditions.

[0029] The cellulose-containing material may include a textile material.

[0030] The textile material may be selected from cotton, viscose and lyocell.

[0031] Each filtrate line may also be connected to a preceding process line for supplying at least a portion of the wash filtrate of at least one scrubber of the scrubber arrangement for dilution.

[0032] The filtrate line of each washing device can be connected to at least one other filtrate line for combining at least a part of the wash filtrate of at least one washer of the washing device for dilution and / or as wash water.

[0033] Substantially all of the wash filtrate of at least one washer of each washing apparatus may be used for dilution and / or as wash water.

[0034] Each process line before each of the purification stage, the first decolorization stage, and the second decolorization stage may contain a pump and a chemical mixer.

[0035] The chemical mixer may be configured to supply process chemicals.

[0036] The purification stage, the first decolorization stage and the second decolorization stage may each comprise at least one upflow or downflow reactor.

[0037] The at least one washer each may comprise a washer selected from the group consisting of a drum washer, a DD washer, a centrifuge, a disc filter, a drum filter, a filter press, a belt press, a twin-line press, a screw press, a wash press, and a belt washer.

[0038] The system may further comprise means for supplying the purified and decolorized textile material to further processing selected from drying, derivatization including carbamation or xanthation, and textile fiber manufacturing including a lyocell process or an ionic liquid process.

[0039] Various non-binding example aspects and implementations have been described above. The implementations above are only used to explain selected aspects or steps that can be used in different implementations. Some implementations may be presented only with reference to specific example aspects. It should be understood that the corresponding implementations may also be applied to other example aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Some exemplary embodiments will be described with reference to the accompanying drawings, in which:

[0041] Figure 1 shows a simplified schematic block diagram of a system according to an exemplary embodiment of the present invention;

[0042] Figure 2 A schematic block diagram showing a system according to an exemplary embodiment of the present invention; and

[0043] Figure 3 Another schematic block diagram of a system according to another exemplary embodiment of the present invention is shown. DETAILED DESCRIPTION

[0044] In the following description, the same reference numerals denote the same elements or steps.

[0045] Figure 1 A simplified schematic block diagram of a system according to an exemplary embodiment is shown.A system according to an exemplary embodiment of the present invention operates in an alkaline environment for producing purified cellulose-containing material, for example from textile materials including waste, scraps or garments. Figure 1 The starting material, ie the material comprising cellulose, is shown entering the system at 1 .

[0046] Figure 1Also shown is a purification stage 2, where non-cellulosic components (such as different types of plastics or other unwanted materials) are chemically removed from the starting material under alkaline process conditions. The alkaline treated material is washed with fresh water or wash filtrate from a subsequent process stage.

[0047] Figure 1 Also shown are a first decolorization stage 3 and a second decolorization stage 4 following the purification stage 2. Figure 1 In an exemplary embodiment of the first decolorization stage 3 comprises an ozone stage and the second decolorization stage 4 comprises a hydrogen peroxide stage. The ozone stage is configured to operate in an alkaline environment. In the ozone stage, the cellulose-containing material from the previous process stage is decolorized using ozone and then washed using fresh water or a wash filtrate from a subsequent process stage. Alternatively, in one embodiment, the cellulose-containing material is not washed after being ozonated.

[0048] The hydrogen peroxide stage is configured to operate in an alkaline environment. The cellulose-containing material from the previous process stage is decolorized using hydrogen peroxide and then washed using fresh water, wash filtrate from one or more subsequent process stages, or one or more other suitable liquid streams from a subsequent process system (e.g., a pulp drying process, a textile fiber manufacturing process, or a cellulose carbamate process).

[0049] Although Figure 1 The exemplary embodiment of shows that the ozone stage 3 precedes the hydrogen peroxide stage 4, but in another exemplary embodiment of the invention, the order of these stages can be reversed. Thus, in another exemplary embodiment, the first decolorization stage 3 comprises a hydrogen peroxide stage, while the second decolorization stage 4 comprises an ozone stage.

[0050] Figure 1 Also shown is a product 5 leaving the system according to an exemplary embodiment of the invention. The product 5 is a purified and decolorized cellulose containing material which can be sent to further treatment, such as drying, a derivatization stage or to a further system or plant, such as a textile manufacturing process, a cellulose carbamate process, a viscose process or a lyocell process.

[0051] Figure 2 A schematic block diagram of a system according to an exemplary embodiment of the present invention is shown. Hereinafter, the stages and elements included in the system according to an exemplary embodiment are explained and described in accordance with the process that the system and its various components are configured to perform. It will be understood by those skilled in the art that all individual equipment, devices, etc. (e.g., pumps, heaters, and mixers) of the system are not described in detail below because they are of the type commonly used in the industry.

[0052] exist Figure 2In a system, according to an exemplary embodiment, a material 101 containing cellulose, an alkali 102 and hot water 103 are respectively fed into a process line 201 through at least one inlet. In one embodiment, the process line 201 comprises a pump, one or more steam mixers and a chemical mixer. The type of alkali used is not limited to any specific type. In an exemplary embodiment, NaOH is used. Hot water is used when dilution is required. In an exemplary embodiment, the system comprises filtrate lines 205, 209, 210 for feeding the wash filtrate of the subsequent washing stage explained below to the process line 201 separately or in the form of a mixture for dilution purposes and / or minimizing the use of hot water, and / or slightly reducing the consumption of alkali 102 depending on the alkalinity level in the first filtrate line.

[0053] In process line 201, the cellulose-containing material is heated and mixed using a suitable heater and then pumped to a purification stage 301. The purification stage is configured to remove non-cellulose components, such as plastics, lignin or other undesirable materials. The purification stage comprises at least one upward flow or downward flow purification reactor commonly used in chemical pulp plant fiber lines. In purification stage 301, mother liquor 104 is separated and directed to further processing, such as to be used in a chemical pulp plant, and / or purified and recovered for reuse. In one embodiment, a portion of the mother liquor is configured to be supplied to process line 201 for dilution.

[0054] After the purification reactor, the treated cellulose-containing material is configured to be transferred to a washing device 303 of the purification stage through a process line 204. The washing device 303 comprises at least one washer for washing the previously treated material. The at least one washer comprises a device suitable for washing fibrous materials, such as a drum washer, a DD washer, a centrifuge, a disc filter, a drum filter, a filter press, a belt press, a twin-line press, a screw press, a washing press or a belt washer.

[0055] The washing device 303 is configured to use hot water 105 and / or washing filtrates 209, 210 from subsequent stages, either alone or in a mixture. In another embodiment, the washing filtrates 209, 210 from the subsequent washing devices are configured to be used as diluents after the washing device 303, after which the cellulose-containing material enters the process line 206. Since only alkaline conditions are used in the system according to the present invention, substantially all of the washing filtrates can be processed to the previous process stage without worrying about precipitation and foaming problems that occur when washing filtrates with different pH levels are mixed. The washing filtrate from the washing device 303 is configured to be directed to further processing 106 and / or directed to the purification stage 301 as a diluent 205. In one embodiment in which several washers are included in the washing device 303, each washer in one embodiment includes a connection similar to the connection described above, i.e., the washing filtrate is configured to be directed to the previous stage to be used as washing water or diluent.

[0056] After the washing device 303 of the purification stage, the washed material is transferred to the process line 206, and the alkali 107 and ozone 108 are configured to be supplied to the process line 206 through at least one inlet, respectively. In one embodiment, the alkali content of the washed material is sufficient to maintain the desired pH level in the ozone stage, so there is no need to add alkali 107. The process line 206 contains a pump and a chemical mixer, and the material containing cellulose is configured to be mixed before it is pumped to the ozone stage 304.

[0057] In one embodiment, the ozone stage 304 is operated with a pH level of about greater than 7.0 to 11, preferably about 8.0-9.0, and in one embodiment, has a residence time of about 0.01 seconds-300.0 seconds, preferably about 0.1 seconds-120.0 seconds at a pressure of about 5.0 bar-12.0 bar, preferably about 8.0 bar-10 bar. The ozone stage 304 uses an ozone dosage of about 0.5 kg / BDt-6.0 kg / BDt, preferably about 2.0 kg / BDt-4.0 kg / BDt, and an operating temperature of about 40°C-90°C, preferably about 50°C-70°C. The alkaline ozone stage 304 is configured to decolorize the material containing cellulose and prevent the viscosity of the cellulosic material from decreasing. As a result, the chemical oxygen demand (COD) is reduced, i.e., the organic waste burden on the environment is reduced. The system according to the present invention is configured to maintain a specific viscosity level that is conducive to the further use of the cellulosic material. The ozone stage 304 comprises at least one reactor of the type used in fiber lines of chemical pulp plants. In one embodiment, at the end of the ozone stage 304, the wash filtrate 208 of the subsequent washing unit 305 is used as diluent.

[0058] The system according to an exemplary embodiment of the present invention is configured to supply the ozonated cellulose-containing material to a subsequent washing device 305 of the ozone stage via process line 207. The washing device 305 comprises at least one washer for washing the previously treated material. The at least one washer comprises a device suitable for washing fibrous materials, such as a drum washer, a DD washer, a centrifuge, a disc filter, a drum filter, a filter press, a belt press, a twin-line press, a screw press, a washing press or a belt washer.

[0059] The washing device 305 is configured to use hot water 109 and / or wash filtrate 210 from a subsequent stage. In another embodiment, the wash filtrate 210 from a subsequent washing device is configured to be used as a diluent after the washing device 305 before the cellulose-containing material enters the process line 211. The wash filtrate from the washing device 305 is configured to be directed to further processing 110 and / or the ozone stage 304 as a diluent 208. In one embodiment comprising several washers in the washing device 305, each washer in one embodiment comprises connections similar to those described above, i.e., the wash filtrate is configured to be directed to a previous stage to be used as wash water or diluent.

[0060] After the washing device 305, the material containing cellulose is supplied to the process line 211. The process line 211 comprises a pump and a chemical mixer, into which the alkali 111 and the hydrogen peroxide 112 are configured to be supplied respectively through at least one inlet, after which the material containing cellulose is mixed and pumped to the hydrogen peroxide stage 306. The hydrogen peroxide stage 306 is configured to decolorize the material containing cellulose to a desired level. The hydrogen peroxide stage 306 comprises at least one upflow or downflow reactor used in a fiber line of a chemical pulp plant. In one embodiment, the hydrogen peroxide stage is operated using the following conditions: pH is about greater than 7.0 to 11.0, preferably about 8.0-10.0, at atmospheric pressure, a temperature of about 60°C-100°C, preferably about 70°C-90°C, and in one embodiment, a residence time of about 30-120 minutes, preferably about 60 minutes-90 minutes. In one embodiment, at the end of the hydrogen peroxide stage 306, the wash filtrate 213 of the subsequent washing device 307 is used as a diluent.

[0061] The system according to an exemplary embodiment of the present invention is configured to feed the cellulose-containing material treated with hydrogen oxide to a subsequent washing device 307 via a process line 214. The washing device 307 comprises at least one washer for washing the previously treated material. The at least one washer comprises a device suitable for washing fibrous materials, such as a drum washer, a DD washer, a centrifuge, a disc filter, a drum filter, a filter press, a belt press, a twin-line press, a screw press, a washing press or a belt washer. The washing device 307 is configured to use hot water 113 and / or liquid 114 from a subsequent process stage (e.g., a dryer, a cellulose derivatization stage) or from a textile fiber manufacturing process (e.g., viscose or lyocell).

[0062] The wash filtrate from the washing device 307 is configured to be directed to further processing 116 and / or to the previous stage 304 as diluent 213, or to the previous stage through process line 210. In one embodiment comprising several washers in the washing device 307, each washer in one embodiment comprises connections similar to those described above, i.e., the wash filtrate is configured to be directed to the previous stage for use as wash water or diluent.

[0063] Finally, the system according to the invention is configured to feed the purified and decolorized cellulose-containing material 215 to a subsequent process stage or system. Examples of subsequent process stages include drying processes, cellulose modification stages (e.g., carbamation) and textile fiber manufacturing processes (e.g., viscose or lyocell processes).

[0064] Figure 3 Another schematic block diagram of a system according to another exemplary embodiment of the present invention is shown.

[0065] exist Figure 3 In the exemplary embodiment shown, the system does not include a washing unit after the ozone stage 304. Therefore, the treated cellulose-containing material is fed to the second decolorization stage 306 via the process line 207 after the ozone stage 304. In such an embodiment, the number of process units is minimized and the amount of wash water and waste water is further reduced. Figure 3 In an embodiment, the system comprises the above reference Figure 2 Similar components and functions are described, except that components related to the washing device 305 are omitted.

[0066] In another exemplary embodiment of the present invention, different from the above reference Figure 2 and 3As described, the first decolorization stage 304 comprises a hydrogen peroxide stage, and the second decolorization stage 306 comprises an ozone stage. In such an embodiment, the system comprises the same as described above with reference to Figure 2 and 3 Similar components and functions as described, except that the order of the decolorization stages is reversed and therefore the chemicals are also fed thereto.

[0067] Without limiting the scope of the claims in any way, some technical effects of the system according to an exemplary embodiment of the present invention are explained below.

[0068] According to Figure 1-3 The system of the exemplary embodiment of the present invention shown in is configured to minimize fresh water consumption, thereby improving process efficiency by using an alkaline environment in all of the purification stage and the first and second decolorization stages and by utilizing various liquid streams in dilution and washing. Figure 1-3 The system of the exemplary embodiment of the present invention shown in is further configured to significantly minimize the amount of process system effluent compared to other existing processes, thereby having a lower environmental impact. In addition, according to the exemplary embodiment of the present invention, due to liquid circulation, the alkalinity of the entire process system can be utilized, so the alkali consumption will also be reduced.

[0069] Therefore, a technical effect of an exemplary embodiment of the present invention is to eliminate the disadvantages of the prior art and improve the purification process of cellulose-containing materials. A further technical effect of an exemplary embodiment of the present invention is to reduce the consumption of water and chemicals and to reduce the amount of effluent.

[0070] Various embodiments have been described.It should be understood that the words include, comprise and contain herein are used as open-ended expressions and are not intended to be exclusive.

[0071] The above description has provided a comprehensive and detailed description of the best mode currently contemplated by the inventor for carrying out the present invention through non-limiting specific embodiments and embodiments. However, it should be clear to those skilled in the art that the present invention is not limited to the details of the embodiments described above, but can be implemented using equivalent means or in different embodiments without departing from the characteristics of the present invention.

[0072] In addition, some features of the foregoing exemplary embodiments may be utilized without corresponding use of other features. Therefore, the above description should be regarded only as an illustration of the principles of the present invention, rather than limiting the present invention. Therefore, the scope of the present invention is limited only by the claims.

Claims

1. A system for decolorizing a material containing cellulose, the system comprising: a purification stage for removing non-cellulose components from the cellulose-containing material under alkaline process conditions; followed by a first decolorization stage for decolorizing the cellulose-containing material under alkaline process conditions; as well as a second decolorization stage for decolorizing the cellulose-containing material under alkaline process conditions; in The first decolorization stage and the second decolorization stage include a decolorization stage using ozone and a decolorization stage using hydrogen peroxide; at least said purification stage and said second decolorization stage comprise washing means comprising at least one washer for washing the material treated in said stages; The purification stage, the first decolorization stage and the second decolorization stage are each connected to a subsequent stage by a process line for supplying the material treated and washed in the stage to the subsequent stage; and in Each washing device is connected to the washing device of the preceding stage by a filtrate line for supplying at least a part of the washing filtrate of at least one washer of said washing device to the preceding stage for use as washing water.

2. A system for the decolorization of a material comprising cellulose according to claim 1, wherein the system comprises a purification stage, followed by a first decolorization stage comprising a decolorization stage using ozone, and then a second decolorization stage comprising a decolorization stage using hydrogen peroxide.

3. A system for the decolorization of a material comprising cellulose according to claim 1, wherein the system comprises a purification stage, followed by a first decolorization stage comprising a decolorization stage using hydrogen peroxide, and then a second decolorization stage comprising a decolorization stage using ozone.

4. A system for the decolorization of a material containing cellulose according to any one of the preceding claims, wherein the purification stage, the first decolorization stage and the second decolorization stage each comprise a washing device comprising at least one washer for washing the material treated in said stage.

5. A system for decolorization of cellulose-containing material according to any one of the preceding claims, wherein the entire system is configured to operate under alkaline process conditions.

6. A system for decolorizing a cellulose-containing material according to any one of the preceding claims, wherein the cellulose-containing material comprises a textile material.

7. System for decolorization of materials containing cellulose according to claim 6, wherein the textile material is selected from the group consisting of cotton, viscose and lyocell.

8. System for decolorization of material containing cellulose according to any of the preceding claims, wherein each filtrate line is further connected to a preceding process line for supplying at least a portion of the wash filtrate of at least one washer of the washer device for dilution.

9. A system for decolorizing material containing cellulose according to any of the preceding claims, wherein the filtrate line of each washing device is connected to at least one other filtrate line for combining at least a portion of the wash filtrate of at least one washer of the washing device for dilution and / or use as wash water.

10. System for the decolorization of cellulose containing material according to any of the preceding claims, wherein substantially all of the wash filtrate of at least one washer of each washing apparatus is used for dilution and / or as wash water.

11. A system for decolorizing a material containing cellulose according to any one of the preceding claims, wherein: Each process line before each of the purification stage, the first decolorization stage, and the second decolorization stage contains a pump and a chemical mixer.

12. The system for decolorization of cellulose containing material according to claim 9, wherein the chemical mixer is configured for supplying process chemicals.

13. A system for decolorization of a cellulose-containing material according to any one of the preceding claims, wherein the purification stage, the first decolorization stage and the second decolorization stage each comprise at least one upflow or downflow reactor.

14. A system for decolorizing a material containing cellulose according to any one of the preceding claims, wherein at least one washer each comprises a washer selected from the group consisting of a drum washer, a DD washer, a centrifuge, a disc filter, a drum filter, a filter press, a belt press, a twin-line press, a screw press, a washing press and a belt washer.

15. A system for decolorizing a material comprising cellulose according to any one of the preceding claims, wherein the system further comprises means for supplying the purified and decolorized textile material to further treatment selected from drying, derivatization including carbamation or xanthation, and textile fiber manufacturing including a lyocell process or an ionic liquid process.

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