Method for extracting cellulose from brewer's waste

Abstract

To provide a method for extracting cellulose from beer lees capable of elevating purity of extraction of cellulose in beer lees and accurately controlling a polymerization degree of cellulose as required.SOLUTION: A method includes a pretreatment step of washing beer lees raw material with water to obtain a first treated product, an alkaline solution soaking step of soaking the first treated product obtained in the pretreatment step in an alkaline solution to obtain a cellulose mixture, and an acidic solution soaking step of soaking the cellulose mixture obtained in the alkaline solution soaking step in an acidic solution to obtain a cellulose refined product, and is characterized by further including, in at least one of the alkaline solution soaking step or in the acidic solution soaking step, a polymerization degree control step of obtaining an extraction parameter value which is a parameter for extraction of cellulose and controlling the extraction parameter value, thereby controlling a polymerization degree of cellulose.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to cellulose extraction, and particularly to a method for extracting cellulose from beer lees.

Background Art

[0002] Beer lees is the main by-product during beer production, which is the residue after fermenting raw barley and extracting soluble carbohydrates in the seeds. Since about 200 g of beer lees is generated per liter of beer brewed, approximately 40 million tons of beer lees are generated annually worldwide.

[0003] Since beer lees is mainly composed of cereal husks and seed coats, it contains abundant lignin, cellulose, hemicellulose, protein, lipids, and trace elements, and is sold as inexpensive animal feed. However, most beer lees are discarded as they are, which is not only environmentally unfriendly but also causes economic losses. Therefore, various proposals have been made for technologies to extract components contained in beer lees. For example, Patent Document 1 discloses a technology for recovering proteinaceous and fibrous substances from beer lees.

[0004] Particularly, although the cellulose abundantly contained in beer lees has a wide range of uses, it has not been effectively utilized. Examples of uses of cellulose include making fabrics by using it for scourse fibers, cellulose fiber fillers, cellulose threads, etc. Also, since cellulose is a main component of pulp, various types of paper such as newsprint, book paper, and wrapping paper can be manufactured. Furthermore, it can be used as a coating agent for pharmaceutical capsules to improve the stability and absorbability of drugs. Beer lees cellulose can be used as a filler for plant fibers and is used to make biodegradable plastics, cardboard boxes, paper bags, etc., which also helps to reduce environmental pollution. Beer lees cellulose is a multifunctional natural material widely used in fields such as food, construction, and agriculture.

Prior Art Documents

[0005] [Patent Document 1] Special Publication No. 2022-501004 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, there are problems with mass production, such as the fact that the raw materials for beer lees have not been sufficiently developed, and the complex composition of beer lees results in low extraction purity of cellulose contained in beer lees.

[0007] Therefore, the present invention has been made in view of the above-mentioned problems, and aims to provide a method for extracting cellulose from beer lees that can increase the purity of the cellulose extract from beer lees and accurately adjust the degree of polymerization of cellulose as needed. [Means for solving the problem]

[0008] To solve the above problems, the method for extracting cellulose from beer lees according to the present invention comprises a pretreatment step of washing the beer lees raw material with water to obtain a first treated product, an alkaline solution immersion step of immersing the first treated product obtained in the pretreatment step in an alkaline solution to obtain a cellulose mixture, and an acidic solution immersion step of immersing the cellulose mixture obtained in the alkaline solution immersion step in an acidic solution to obtain a cellulose purified product, and further comprises a degree of polymerization adjustment step of obtaining an extraction parameter value, which is a parameter for extracting cellulose, in at least one of the alkaline solution immersion step or the acidic solution immersion step, and adjusting the degree of polymerization of cellulose by adjusting the extraction parameter value.

[0009] In this step, the extraction parameter values ​​adjusted are preferably at least one of the following: solution concentration, solution volume, solid-liquid mass ratio, impregnation temperature (the temperature of the solution at the time of immersion), or impregnation time (the duration of immersion).

[0010] Furthermore, it is preferable that the alkaline solution in the alkaline solution immersion step is a sodium hydroxide solution, and the acidic solution in the acidic solution immersion step is a peracetic acid solution.

[0011] Furthermore, the peracetic acid concentration in the peracetic acid solution is preferably 1-5%, and the impregnation temperature in the peracetic acid solution is preferably 60°C-90°C.

[0012] The impregnation time in the peracetic acid solution may be 3 to 15 hours, and the solid-liquid mass ratio of the cellulose mixture to the peracetic acid solution may be 1 / 5 to 1 / 20.

[0013] Furthermore, it is preferable that the sodium hydroxide concentration in the sodium hydroxide solution is between 0.5 mol / L and 1.0 mol / L.

[0014] Furthermore, the temperature of the alkaline solution in the alkaline solution immersion step may be 80°C to 120°C, and the immersion time in the alkaline solution may be 3 hours to 15 hours.

[0015] Furthermore, it is preferable to include a washing step in which the cellulose mixture obtained in the alkaline solution immersion step is washed to neutralize it, and in the acidic solution immersion step, the cellulose mixture washed to neutralize in the washing step is immersed in an acidic solution, and further, it is preferable to include a final washing step in which the purified cellulose obtained in the acidic solution immersion step is washed to neutralize it and obtained as a cellulose extract. [Effects of the Invention]

[0016] According to the cellulose extraction method from beer lees of the present invention, impurities in the beer lees can be removed as much as possible by treating them in the order of alkaline solution followed by acidic solution, thereby improving the purity of the extracted cellulose. Furthermore, by adjusting the immersion concentration, immersion temperature, and immersion time of the acidic or alkaline solution, the degree of polymerization of the cellulose can be accurately controlled to the required set range. In addition, the operating procedure can be simplified, the range of applications for cellulose can be increased, and the accuracy of controlling the degree of polymerization of cellulose can be improved. Moreover, the extracted cellulose may not reach the required degree of polymerization during the application process, thus reducing the yield rate of the product and saving production costs. [Brief explanation of the drawing]

[0017] [Figure 1] This flowchart shows the procedure for extracting cellulose from beer lees. [Modes for carrying out the invention]

[0018] The method for extracting cellulose from beer lees according to the present invention will be described in detail below.

[0019] Beer lees are a major by-product of the beer industry and consist of cellulose, hemicellulose, ligsol, insoluble protein, fat, ash, and a small amount of undegraded starch. The method for extracting cellulose from beer lees according to an embodiment of the present invention is a method for increasing the extraction purity of cellulose in beer lees and for accurately adjusting the degree of polymerization of cellulose as needed.

[0020] Figure 1 is a flowchart showing the procedure for extracting cellulose from beer lees. First, as a pretreatment, the beer lees raw material is washed in a container of water and dried to obtain the first processed product (Step S1).

[0021] Take an appropriate amount of beer lees and put it into a container containing an appropriate amount of room-temperature deionized water, and wash it at least three times. At this time, the deionized water can remove impurities such as ash, soluble amino acids, and some starch in the beer lees. Then, filter and dry the washed beer lees to obtain a solid substance. This is the first processed product of the beer lees. In order to increase the drying speed and prevent further fermentation and mold growth of the beer lees, the washed beer lees are dried in an oven or reaction kettle at 40°C to 90°C until the beer lees reach a certain weight. This is to avoid wasting resources due to the use of excessive alkaline solution.

[0022] Next, immerse the first processed product in a container containing an alkaline solution for alkali treatment (step S2). When immersing in the alkaline solution, adjust the extraction parameters (step S3), filter and then dry to obtain a cellulose mixture.

[0023] In the first processed product of the beer lees, cellulose, a large amount of lignosol, fat, and a small amount of protein remain. By adding sodium hydroxide, sodium sulfite, potassium hydroxide, or other alkaline solutions to this first processed product, the impurities of cellulose can be removed. As the alkaline solution used here, a sodium hydroxide solution is preferred. This is because the purchase cost is relatively low, it can remove the impurities in the first processed product, and it is advantageous in increasing the purity of the cellulose contained in the beer lees.

[0024] Through a large number of tests by the inventors, it was found that parameters such as the concentration value, immersion time, and immersion temperature of the alkaline solution affect the impurity removal effect of cellulose. Therefore, by adjusting any one of the above parameters or a plurality of parameters selected from them, an optimal impurity removal effect can be achieved. Also, the three parameters for adjusting the alkaline solution are regarded as the second parameter group, and the value of the cellulose polymerization degree obtained by adjusting the second parameter group also changes accordingly. The range of the change amount is smaller than the change amount of the cellulose polymerization degree when adjusting the first parameter group.

[0025] Therefore, the extraction parameter values ​​in step S3 include at least one of the concentration value of the alkaline solution, the impregnation temperature value, and the impregnation time. The extraction parameter values ​​may also include the concentration, immersion time, immersion temperature, and solid-liquid mass ratio of the brewer's lees in the alkaline solution.

[0026] Alkaline solution may remain on the surface of the cellulose mixture after filtration. If the brewer's lees are immersed in the alkaline solution for too long, the structure of the brewer's lees cellulose will break down, affecting the extraction of the degree of polymerization of the cellulose. Furthermore, the remaining alkaline solution will also affect the overall concentration of the solution used in the subsequent acid treatment, making it difficult to accurately control the concentration during the acid treatment and thus affecting the purity and degree of polymerization of the brewer's lees cellulose.

[0027] To avoid the presence of residual alkaline solution in the cellulose mixture, that is, to avoid a prolonged immersion time in the residual alkaline solution in the cellulose and a decrease in the degree of polymerization of the cellulose, the cellulose mixture after alkaline solution treatment is washed with deionized water at room temperature to neutralize it (pH=7), filtered, and then dried to produce a mixture of cellulose and ligsol.

[0028] Next, the cellulose mixture is immersed in a container of acidic solution to perform acid treatment (Step S4). The extraction parameters are adjusted before immersion in the acidic solution (Step S5).

[0029] The dried cellulose mixture is added to a container containing an acidic solution. In this case, the acidic solution can be used not only as an acidic reagent, but also to remove impurities such as lignin and organic matter from the cellulose mixture by immersion in the acidic solution, and to bleach the cellulose mixture.

[0030] Acidic solutions, such as perchloracetic acid and hypochlorous acid, are acidic reagents that possess bleaching properties. Hypochlorous acid is unstable, easily decomposes, is inconvenient to store, and has weak bleaching properties; therefore, increasing the concentration of hypochlorous acid can be used to remove off-flavors. Additionally, impregnation with other strong acids can destroy or decompose the cellulose structure in the beer lees. For this reason, a 1-5% peracetic acid solution is prepared by mixing a 20% peracetic acid solution with deionized water in a fixed ratio, which reduces costs, meets the purity requirements for extracting cellulose from beer lees, and does not easily result in high concentrations.

[0031] The combination of one or more parameters in the immersion parameters of the acidic solution—immersion concentration, immersion time, and immersion temperature—affects the purity and degree of polymerization of cellulose in beer lees. After immersion in the acidic solution, the beer lees with the acidic solution are filtered. The acidic solution can remove almost all impurities from the cellulose mixture of beer lees, resulting in a purified cellulose product. Furthermore, the degree of polymerization of cellulose in beer lees can be better controlled, as the parameters of the acidic solution itself significantly influence the degree of polymerization of cellulose, including residual lignin, semicellulose, and fat.

[0032] Therefore, the extraction parameter values ​​in step S5 include at least one of the concentration value of the acidic solution, the impregnation temperature value, and the impregnation time. The extraction parameter values ​​may also include the concentration, immersion time, immersion temperature, and solid-liquid mass ratio of the brewer's lees in the acidic solution.

[0033] At this time, an acidic solution may remain on the surface of the filtered cellulose. If the cellulose is immersed in the acidic solution for too long, the cellulose structure will be destroyed. Therefore, it is preferable to wash the cellulose with deionized water at room temperature.

[0034] Finally, the purified cellulose is dried to obtain the final cellulose extract, and the process is complete. To extract as much cellulose as possible from the brewer's lees, the entire lees is immersed in an acidic solution and an alkaline solution during the treatment process. This effectively removes all impurities from the lees, minimizing the amount of acidic and alkaline solutions used, reducing waste, and lowering manufacturing costs.

[0035] In this embodiment, the cellulose extraction process involves passing the brewer's lees through an alkaline solution followed by immersion in an acidic solution. In another embodiment, the cellulose extraction process may involve passing the brewer's lees through an acidic solution followed by immersion in an alkaline solution. The combined action of the acidic and alkaline solutions removes all impurities from the brewer's lees, improving the purity of the cellulose. Furthermore, by adjusting the extraction parameter values ​​of the acidic solution and / or the alkaline solution during the acidic and alkaline solution treatments, the degree of polymerization of the extracted cellulose can be controlled within a predetermined range as needed. In other words, the degree of polymerization of cellulose can be controlled to a predetermined value as needed, and the cellulose obtained at this time can all be applied to industries corresponding to the predetermined value.

[0036] In this embodiment, a sodium hydroxide solution is used, and the immersion parameters for the sodium hydroxide solution are set so that the solid-to-liquid mass ratio of the sodium hydroxide solution is 1 / 5 to 1 / 15 for concentrations of 0.5 mol / L to 1.0 mol / L. The immersion treatment time at 80°C to 120°C is 3 to 15 hours. To maintain a constant immersion temperature, for example, the mixture may be placed in an oven or reaction vessel at 80°C to 120°C. This makes it possible to remove all semicellulose and small amounts of protein impurities from the brewer's lees.

[0037] Furthermore, in this embodiment, peracetic acid solution (peroxoacetic acid solution) is used as the acidic solution in which the brewer's lees are immersed. The immersion parameters for the peracetic acid solution are as follows.

[0038] Using a 1-5% peracetic acid solution results in a solid-liquid mass ratio of brewer's lees to peracetic acid solution of 1 / 5 to 1 / 20. By confirming that the peracetic acid solution is not brewer's lees, waste of the peracetic acid solution can be prevented. The effect of acid immersion can be achieved with the minimum amount of peracetic acid solution, removing all lignin and any remaining impurities from the cellulose mixture.

[0039] To enhance the impurity removal effect of brewer's lees, it is necessary to use peracetic acid at an immersion temperature of 60°C to 90°C and an immersion treatment time of 3 to 15 hours. Furthermore, to maintain the temperature within the set range, the acid treatment can be carried out in an oven or reaction vessel at 60°C to 90°C. This ensures that the acidic solution is optimally effective in removing lignin and other impurities, maintaining the purity of cellulose in the cellulose refined from the brewer's lees and controlling the degree of polymerization of the resulting cellulose.

[0040] In summary, the method for extracting brewer's lees cellulose with controllable degree of polymerization using brewer's lees raw materials, as described in this embodiment, can extract brewer's lees cellulose with increased purity using the cellulose extraction method described above. Furthermore, it can ensure the purity of the extracted cellulose and prevent the reduction of cellulose due to excessive impurities in the cellulose. As a result of numerous experiments, the effect of removing impurities from brewer's lees after per-alkali treatment and acid treatment is clear, and the purity of cellulose can reach 90%.

[0041] Furthermore, the brewer's lees are treated by immersing them in a sodium hydroxide solution and a peroxoacetic acid solution, respectively. Various parameters such as the concentration of the sodium hydroxide and acetic acid solutions, immersion time, immersion temperature, and solid-liquid mass ratio can be adjusted. Additionally, the cellulose extracted by combining these parameters will have different degrees of polymerization, allowing for on-demand production of cellulose with the desired degree of polymerization.

[0042] The cellulose polymer obtained in this embodiment can be precisely controlled within a set range. For example, by adjusting the parameter values ​​of the acidic and alkaline solutions, the degree of polymerization of cellulose can be controlled within the range of 375 to 836.

[0043] More specifically, it is possible to manufacture cellulose with different degrees of polymerization required for light industries such as the textile, paper, and medical industries, thereby guaranteeing the quality of the manufactured products. For example, when applied to industries that use cellulose to spin yarn, the degree of polymerization of cellulose extracted from brewer's lees can be controlled to within the range required for yarn spinning. Similarly, when cellulose is used in the paper industry, the degree of polymerization of cellulose can be controlled to the degree required for papermaking. Furthermore, the degree of polymerization of cellulose can be controlled to within the range required for advanced medical industries. This reduces the loss of cellulose extracted from brewer's lees. Moreover, this extraction method is simple, and by diluting the acid and alkaline solutions after extraction and neutralizing the waste, it does not cause environmental pollution.

[0044] The following describes embodiments of the present invention.

[0045] The above procedure involves immersing washed beer lees in a sodium hydroxide solution of a predetermined concentration and performing alkaline treatment under predetermined conditions for immersion time, immersion temperature, and solid-liquid mass ratio to obtain a cellulose mixture. The obtained cellulose mixture is then sequentially immersed in a peracetic acid solution of a predetermined concentration, with each immersion parameter selected. Acid treatment is performed with pre-set immersion time, immersion temperature, and solid-liquid mass ratio to obtain a cellulose purified product. This removes all impurities from the beer lees. In this case, the purity of the extracted cellulose reaches 90%, and the degree of polymerization of the cellulose is obtained through the interaction of the immersion parameters of the peracetic acid solution and the sodium hydroxide solution. By increasing the purity of the cellulose extracted from beer lees and, if necessary, setting the degree of polymerization of the extracted cellulose to a constant value, the efficiency of the extracted cellulose can be ensured. An example in which the extraction parameters of the acidic and alkaline solutions are adjusted as follows will be given to illustrate the procedure.

[0046] (Example 1) 40g of beer lees was immersed in a 1mol / L sodium hydroxide solution with a solid-liquid mass ratio of 1 / 15. After immersion, the mixture was filtered and dried. The immersed beer lees were then immersed in 1% peracetic acid at 80°C for 15 hours, and the solid-liquid mass ratio was adjusted to 1 / 20, with a cellulose degree of polymerization value of 644.62, for extraction. The cellulose extracted in this way is suitable for the manufacture of printing paper, spinning, flexible membranes, shopping bags, and other applications.

[0047] (Example 2) 40g of beer lees raw material was immersed in a 0.5 mol / L sodium hydroxide solution at 80°C for 5 hours, then the solid-liquid mass ratio was adjusted to 1 / 15. After further mixing, it was immersed in a 3% concentration peracetic acid solution at 60°C for 6 hours, again with a solid-liquid mass ratio of 1 / 15. Under these conditions, the impurity removal effect from the beer lees was adjusted to 39%, and the degree of polymerization of the cellulose was adjusted to 735.75 for extraction. The cellulose extracted in this way is suitable for preparing very high-strength membranes such as high-strength monofilaments, duplex filaments, ultrafine fibers, and surgical sutures, and can be used in the medical industry.

[0048] (Example 3) Example 3 differs from Example 1 in that it adjusts the specific immersion parameter values ​​for the acetic acid solution and the specific immersion parameter values ​​for the sodium hydroxide solution.

[0049] 40g of beer lees raw material was immersed in a 0.5 mol / L sodium hydroxide solution at 80°C for 5 hours. Then, the solid-liquid mass ratio was adjusted to 1 / 15, and 4% peracetic acid was added. After immersion for another 5 hours at 80°C, the solid-liquid mass ratio was adjusted to 1 / 20, achieving a 40% removal effect from the beer lees and a cellulose polymerization degree of 613.71 before extraction. The cellulose extracted in this way is suitable for the manufacture of printing paper, spinning, cosel fibers, flexible membranes, shopping bags, and other products.

[0050] (Example 4) Example 4 involves changing the immersion concentration and immersion time of the acetic acid solution, as well as the immersion concentration and immersion time of the sodium hydroxide solution.

[0051] 40g of brewer's lees raw material was immersed in a 0.5 mol / L sodium hydroxide solution at 80°C for 5 hours. Then, the solid-liquid mass ratio was adjusted to 1 / 15, the impurity removal effect from the brewer's lees was 42%, and the degree of polymerization of cellulose was adjusted to 462.12 before extraction. The cellulose extracted in this way is suitable for making soft cotton towels, cosmetic cotton, toilet paper, short fibers of spun scouse, flexible membranes, and shopping bags.

[0052] (Example 5) Example 5 involves changing the immersion time of the acetic acid solution, as well as the concentration and immersion time of the sodium hydroxide solution.

[0053] 40g of brewer's lees raw material was immersed in a 0.75 mol / L sodium hydroxide solution at 80°C for 10 hours, then 1% peracetic acid was added and the mixture was immersed again at 80°C for 10 hours. Finally, the solid-liquid mass ratio was adjusted to 1 / 10 and the degree of polymerization of cellulose to 669.66 before extraction.

[0054] (Example 6) Example 6 involves varying the immersion concentration, immersion time, and immersion temperature of the acetic acid solution, and also varying the immersion time of the sodium hydroxide solution.

[0055] 40g of beer lees raw material was immersed in a 0.5 mol / L sodium hydroxide solution at 80°C for 5 hours, with a solid-liquid mass ratio of 1 / 15. Further immersion in a 3% peracetic acid solution at 90°C for 6 hours, followed by a solid-liquid mass ratio of 1 / 5. The impurity removal rate from the beer lees was adjusted to 45%, and the degree of polymerization of cellulose was adjusted to 375.01 before extraction. The cellulose extracted in this way is suitable for the manufacture of products requiring high strength and low cellulose content, such as disposable tableware, biodegradable food packaging, toilet paper, and cotton tissues.

[0056] (Example 7) Example 7 involves varying the immersion concentration and immersion time of the peracetic acid solution, and also varying the immersion time of the sodium hydroxide solution.

[0057] 40g of beer lees raw material was immersed in a 1 mol / L sodium hydroxide solution at 80°C for 10 hours, resulting in a solid-liquid mass ratio of 1 / 15. Further immersion was performed at 80°C for 5 hours using 3% peracetic acid, resulting in a solid-liquid mass ratio of 1 / 5. At this point, the degree of polymerization of cellulose in the beer lees was adjusted to 809.43, and then extracted. The cellulose extracted in this way is suitable for the manufacture of high-strength monofilaments, duplex filaments, ultrafine fibers, surgical sutures, high-strength membranes, and disposable cups. For such applications, it is necessary to guarantee relatively high strength, i.e., the structural integrity of the cellulose itself, and the extracted cellulose satisfies this requirement.

[0058] (Example 8) Example 8 involves varying the immersion time of the acetic acid solution, as well as the immersion concentration and immersion time of the sodium hydroxide solution.

[0059] 40g of beer lees raw material was immersed in a 0.5 mol / L sodium hydroxide solution at 80°C for 15 hours, resulting in a solid-liquid mass ratio of 1 / 5. Further immersion was then performed at 80°C for another 15 hours using 3% peracetic acid, resulting in a solid-liquid mass ratio of 1 / 20. At this point, the degree of polymerization of cellulose in the beer lees was adjusted to 559.23, and the cellulose was extracted. The cellulose extracted in this way is suitable for preparing short fibers, toilet paper, short or long fibers of cosne, filtration membranes, etc.

[0060] (Example 9) Example 9 involves varying the immersion time of the acetic acid solution, as well as the immersion concentration and immersion time of the sodium hydroxide solution.

[0061] 40g of brewer's lees raw material was immersed in a 0.5 mol / L sodium hydroxide solution at 80°C for 5 hours, with a solid-liquid mass ratio of 1 / 5. Then, 2% peracetic acid was added and the mixture was immersed again at 80°C for 5 hours. Afterward, the solid-liquid mass ratio was adjusted to 1 / 5, the impurity removal rate from the brewer's lees was 34%, and the degree of polymerization of cellulose in the brewer's lees was adjusted to 708.19 before extraction. The cellulose extracted in this way is suitable for preparing high-strength single threads, double threads, surgical sutures, and very high-strength membranes. It can also be used in the medical industry; the plastic can be used to reinforce materials or as a sealing material, and it can also be used as a friction-resistant heat insulating material.

[0062] (Example 10) Example 10 is the same as Example 9, but with the only changes being the immersion concentration and immersion time of the peracetic acid solution.

[0063] 40g of beer lees raw material was immersed in a 0.5 mol / L sodium hydroxide solution at 80°C for 5 hours, with a solid-liquid mass ratio of 1 / 5. Then, 3% peracetic acid was added and the mixture was immersed again at 80°C for 5 hours. Afterward, the solid-liquid mass ratio was adjusted to 1 / 20, the impurity removal rate from the beer lees was 37%, and the degree of polymerization of cellulose in the beer lees was adjusted to 836.69 before extraction. The cellulose extracted in this way is suitable for the production of high-strength monofilaments, duplex filaments, and high-strength membranes for surgical sutures, and can be used in the medical industry.

[0064] Table 1 shows the detailed parameter values ​​for the acidic and alkaline solutions in Examples 1 to 10 described above. The acidic solution is a peracetic acid solution.

[0065] [Table 1]

[0066] Furthermore, comparing Example 2 and Example 6 shown in Table 1, it can be seen that by changing only the immersion temperature of the peracetic acid solution and leaving the other parameters the same, it is possible to increase the purity of cellulose while maintaining the effect of removing impurities other than cellulose.

[0067] The weight loss rate of brewer's lees after impregnation increased from 39% to 45%, and corresponding to the positive correlation between the concentration and temperature of the peracetic acid solution, the degree of polymerization of cellulose decreased from 735.75 to 375.01. Since increasing both the impregnation concentration and temperature of the acetic acid solution simultaneously tends to decrease the degree of polymerization of cellulose, combining the impregnation concentration and temperature of the acetic acid solution results in a significant decrease in the degree of polymerization, with the simultaneous increase in both factors being inversely proportional. Simultaneous increases or decreases in the impregnation concentration and temperature of the acetic acid solution have a significant impact on the degree of polymerization of cellulose.

[0068] Furthermore, comparing Examples 9, 3, and 4 shown in Table 1, the weight loss rate of the brewer's lees raw material gradually increases as the impregnation concentration of the acetic acid solution increases, while other conditions remain constant. In this case, the weight loss rates are 34%, 40%, and 42%, respectively. Since the degree of polymerization of cellulose is adjusted to 708.19, 613.71, and 462.12, it can be seen that the magnitude of the degree of polymerization value of cellulose is inversely proportional to a single parameter, the concentration of the peracetic acid solution, and the degree of polymerization value can be adjusted quickly. If the amount of peracetic acid added increases even slightly, the degree of polymerization of cellulose may not be obtainable, and by adjusting the concentration of the peracetic acid solution alone, the increase or decrease in the degree of polymerization value becomes large, making it difficult to accurately adjust the degree of polymerization value of cellulose, thus the adjustment of the degree of polymerization of cellulose is not optimized.

[0069] Comparing Example 7 and Example 10, it can be seen that when only the immersion concentration of the sodium hydroxide solution is adjusted and the immersion time of the sodium hydroxide solution is shortened, a degree of polymerization value can be obtained even if other conditions remain the same, and the degree of polymerization shows an upward trend from 809.43 to 836.69. Since the degree of polymerization of 836.69 obtained by this method is the upper limit for obtaining a degree of polymerization, it is clear that when adjusting only the immersion concentration and immersion time of the sodium hydroxide solution without changing the immersion conditions of the peracetic acid solution, a higher precision is required for adjusting the degree of polymerization of cellulose, thus increasing the demands on the cellulose extraction process. Experimental failures due to operational errors can be avoided, and it leads to increased manpower, time, economic costs, and even manufacturing costs, so it can be said that simply changing the immersion concentration and immersion time of the sodium hydroxide solution is not an effective way to adjust the degree of polymerization of cellulose.

[0070] Referring to Examples 8 and 9 shown in Table 1, the immersion concentration of the peracetic acid solution can be reduced from 3% to 2%, and the immersion time of the peracetic acid solution and sodium hydroxide solution can be shortened from 15 hours to 5 hours, thereby increasing the degree of polymerization of cellulose from 559.23 to 708.19. When the ratio of the impregnation time of the acidic solution to the alkaline solution is shortened, the concentration of peracetic acid decreases, and the combination parameters of the degree of polymerization of cellulose and the impregnation concentration and impregnation time become inversely proportional, so the degree of polymerization can be adjusted to the set value as needed.

[0071] Referring to Table 1, which combines Examples 1 and 7, as the acetic acid concentration increased from 1% to 3%, the immersion time in the acetic acid solution was shortened from 15 hours to 5 hours, the immersion time in the sodium hydroxide solution was shortened from 15 hours to 10 hours, and the degree of polymerization of cellulose was shortened from 644.62 to 809.43. Since the degree of polymerization of cellulose clearly increases as the concentration of the acetic acid solution increases and the immersion time decreases, the combination of acetic acid solution concentration and immersion time has a large effect on the degree of polymerization of cellulose, while the immersion time in the sodium hydroxide solution has a small effect on the degree of polymerization of cellulose.

[0072] Referring to Table 1 for Examples 4 and 10, in the immersion of beer lees, as the concentration of the peracetic acid solution decreased, the immersion time in peracetic acid also decreased, and a tendency for the degree of polymerization of cellulose to increase significantly was observed, assuming other conditions remained the same. The weight loss rate of beer lees after impregnation decreased from 42% to 37%, and a negative correlation was observed between raising or lowering the parameters combining peracetic acid concentration and impregnation time and the degree of polymerization of cellulose.

[0073] Referring to Table 1 for Examples 6 and 10, it can be seen that while the immersion temperature and immersion time of acetic acid were changed, the remaining parameters remained unchanged. As the immersion time shortened and the immersion temperature decreased, the weight loss rate of the brewer's lees also tended to decrease from 45% to 37%, indicating a tendency for the degree of cellulose polymerization to increase. At this time, the degree of polymerization of cellulose increased inversely from 375.01 to 836.69, matching the common parameters of acetic acid immersion temperature and immersion time, enabling a rapid conversion of cellulose from the manufacture of disposable tableware. It can also be used in the manufacture of high-strength single threads, double threads, and very high-strength surgical suture membranes. In this case, strict requirements are placed on the tester, so to avoid runaway phenomena in the degree of polymerization of cellulose due to operational errors, the immersion temperature and immersion time of peracetic acid are effective as single adjustments for controlling the degree of polymerization of cellulose.

[0074] The inventors discovered that in Examples 1 and 8, as the concentration of the peracetic acid solution increased, the degree of polymerization of cellulose tended to decrease from 644.62 to 559.23, corresponding to the decrease in the concentration of the sodium hydroxide solution. Since the degree of polymerization of cellulose decreases as the concentration of sodium hydroxide decreases, it is considered that the effect of the sodium hydroxide concentration on the degree of polymerization of cellulose becomes smaller.

[0075] The higher the concentration of the peracetic acid solution in the brewer's lees, the longer the immersion time, and the higher the immersion temperature, the easier it is for the cellulose in the brewer's lees to be immersed, ensuring the removal of impurities from the brewer's lees while avoiding cellulose destruction. The higher the concentration of the alkaline solution, the higher the immersion temperature, and the longer the immersion time, the greater the effect of removing impurities from the brewer's lees. Furthermore, by limiting the degree of polymerization of the cellulose within a set range according to user needs, the utilization rate of brewer's lees cellulose can be increased, preventing situations where the extracted cellulose cannot be used to manufacture products that require it, thereby reducing manufacturing costs and improving economic efficiency.

[0076] In summary, in this embodiment, after sequentially immersing the brewer's lees in a sodium hydroxide solution and an acetic acid solution, and ensuring the removal of impurities from the brewer's lees, the required degree of polymerization of cellulose for the product can be obtained by adjusting various parameters such as the immersion concentration, immersion temperature, and immersion time of the acetic acid solution or sodium hydroxide solution.

[0077] From a comparison of Examples 1 to 10 above, it was found that the effect of the acetic acid solution impregnation concentration on the degree of polymerization of cellulose was relatively significant. However, when only the acetic acid solution impregnation concentration was changed, it showed a positive ratio to the excessive removal effect, and the ratio of acetic acid concentration to the degree of polymerization of cellulose was inverse, indicating that it is difficult to accurately adjust the degree of polymerization of cellulose.

[0078] Furthermore, adjusting only the concentration of the sodium hydroxide solution will affect the degree of polymerization of cellulose. The concentration of the alkaline solution and the degree of polymerization of cellulose are inversely proportional, and the degree of polymerization changes near the boundary value, making it difficult to precisely adjust the degree of polymerization.

[0079] Therefore, while ensuring the decontamination effect of brewer's lees, we discovered that by combining the immersion conditions of the peracetic acid solution and the sodium hydroxide solution, any combination of immersion concentration, immersion temperature, and immersion time is possible.

[0080] Furthermore, the method of this embodiment can guarantee that the degree of polymerization of the cellulose extracted is lower. For example, the degree of polymerization value for extracting cellulose can be precisely adjusted over a wide range of 375 to 830, and then adjusted to the degree of polymerization value required for the product as needed.

[0081] This invention provides a complete structure and performance profile for cellulose extracted from beer lees, enabling the creation of products with varying strengths—high, low, and tough—depending on product requirements. This expands the range of applications for beer lees cellulose and provides the conditions necessary for industrial production.

[0082] Further comparative tests were conducted to verify that the combination of impregnation parameters for acidic and alkaline solutions in this invention significantly affects the extraction purity and degree of polymerization of cellulose. Specific comparative test data are shown in Table 2.

[0083] [Table 2]

[0084] Comparative Example 1 differs from Example 1 in that the cellulose mixture was immersed in an alkaline solution and then in an acidic solution. The acidic solution was nitric acid and the alkaline solution was sodium hydroxide. The concentration of the nitric acid solution was 1%, the immersion time was 5 hours, the immersion temperature was 80°C, and the solid-liquid mass ratio of beer lees to nitric acid solution was 1 / 20. However, under these conditions, cellulose could not be extracted from the beer lees.

[0085] As is well known, nitric acid is a strong acid. During the immersion process of beer lees, the structure of the cellulose itself in the lees is destroyed, making the cellulose-based yarn prone to breakage or hydrolysis, and significantly reducing the purity of the cellulose. Even if the extraction purity is not reduced, the destruction of cellulose results in relatively poor toughness, and the extracted cellulose cannot be applied to industrial fields depending on demand, thus reducing the range of cellulose uses and lowering the utilization rate of beer lees. Furthermore, because nitric acid is highly corrosive, there are safety hazards during the process, and strict restrictions on the skills of workers in handling it lead to increased labor costs. The cellulose mixture obtained by sequentially immersing beer lees in sodium hydroxide solution and strong acid solutions such as nitric acid, and hydrolyzing most of the beer lees with peracetic acid, contains a large amount of impurities, so the obtained cellulose cannot be used to spin yarn or to produce high-toughness medical industrial products.

[0086] Comparative Example 2 differs from Example 1 in that the immersion parameter values ​​for each immersion parameter in the acidic solution exceed the upper limits for each immersion parameter in the present invention. Furthermore, the alkaline solution is a sodium hydroxide solution, and the immersion parameter values ​​for each immersion parameter in the alkaline solution also exceed the upper limits for each parameter in the present invention.

[0087] Comparative Example 2 involved immersing 40g of beer lees raw material in a 2mol / L sodium hydroxide solution at 140°C for 20 hours, followed by immersion in a 20% peracetic acid solution at 100°C for another 20 hours, resulting in a solid-liquid mass ratio of 1 / 20. At this time, most of the cellulose in the beer lees was hydrolyzed by the peracetic acid, and the resulting cellulose mixture contained a large amount of impurities. Therefore, a cellulose raw material for beer lees that could be used for yarn or other processing could not be obtained.

[0088] Thus, in Comparative Example 2, the same acidic and alkaline solutions as in the present invention are used, but because the impregnation parameters of the acidic and alkaline solutions are outside the set range, the structure of cellulose in the beer lees is damaged, and the purity of the cellulose extraction tends to decrease. In other words, the utilization rate of the extracted cellulose decreases, resulting in the waste of a large amount of cellulose, which increases production costs and further reduces quality.

[0089] Comparative Example 3 involved setting the immersion parameters of the acidic solution higher than the upper limits of the parameter values ​​of the present invention, while the alkaline solution was prepared under the same conditions as in Example 2, for example, by immersing 40g of beer lees in a 0.5 mol / L sodium hydroxide solution at 80°C for 5 hours. In Comparative Example 3, 10% peracetic acid was used and the solution was immersed at 100°C for 20 hours. The concentration of the acidic solution was higher than 5% of the maximum value of the acidic solution of the present invention, and the immersion time exceeded the maximum time of 5 hours, thus falling under the category of an experiment involving a complete excess amount. As a result, no significant increase in the removal rate was observed. On the contrary, hydrolysis of the beer lees cellulose occurred, causing rupture of the sugar chains of the beer lees cellulose, making it impossible to accurately obtain the purity and degree of polymerization of the cellulose itself.

[0090] Comparative Example 4 was compared to Example 2, specifically in which the concentration, immersion temperature, and immersion time of the peracetic acid solution were within the set range, while the concentration, immersion time, and solid-liquid mass ratio of the sodium hydroxide solution were higher than the upper limit of the set values. When 40g of beer lees was immersed in 2mol / L sodium hydroxide solution at 140°C for 20 hours with a solid-liquid mass ratio of 1 / 20, and then immersed in 3% peracetic acid solution at 80°C for 5 hours with a solid-liquid mass ratio of 1 / 20, the decontamination effect of the beer lees was 41%, and the degree of polymerization of cellulose was 701.28.

[0091] Therefore, under the specified conditions for acetic acid solution concentration, immersion temperature, and immersion time, the sodium hydroxide solution concentration, immersion time, and immersion temperature are higher than the upper limits, but the effect is small. To further verify that the combination of parameters for the acidic and alkaline solutions of the present invention significantly affects the extraction purity and degree of polymerization of cellulose, several more experiments were conducted. The specific experimental data are shown in Table 3 below.

[0092] [Table 3]

[0093] As shown in Table 3, in Experimental Examples 3 to 5, when the acetic acid concentration and immersion temperature were kept constant and the concentration of the sodium hydroxide solution was increased, the degree of polymerization of cellulose was 726.14 when the immersion time of the acidic solution and the immersion time of the alkaline solution were the same. When the immersion time of the acidic solution was shortened and the immersion time of the alkaline solution was lengthened, the degree of polymerization of cellulose increased slightly to 727.69. On the other hand, when the immersion time of the acidic solution was lengthened and the immersion time of the alkaline solution was shortened, the degree of polymerization of cellulose decreased to 598.06.

[0094] Furthermore, referring to Experimental Examples 1, 2, and 5, when the acetic acid concentration, sodium hydroxide concentration, and acetic acid immersion time increased, while other values ​​remained constant, the degree of polymerization of cellulose decreased. When the acetic acid immersion time increased from 5 hours to 10 hours, the degree of polymerization of cellulose decreased only slightly, but when the peracetic acid immersion time increased from 10 hours to 15 hours, the degree of polymerization of cellulose decreased sharply. At this point, it can be considered that the peracetic acid immersion time had reached its upper limit.

[0095] Furthermore, referring to Experimental Examples 2 and 4, it can be seen that when the peracetic acid concentration was increased, the immersion time in the peracetic acid solution was shortened, and the immersion time in the alkaline solution was lengthened, while other conditions were kept the same, the degree of polymerization of cellulose increased slightly.

[0096] The cellulose extraction method from beer lees according to the present invention has been described above based on embodiments. However, the present invention is not limited thereto, and various design modifications are possible as long as they achieve the objectives of the present invention and do not depart from the gist of the invention, and all of these are also included within the scope of the present invention. [Industrial applicability]

[0097] The method for extracting cellulose from beer lees according to the present invention is suitable as a method for extracting cellulose from beer lees.

Claims

1. A pre-treatment step in which the beer lees raw material is washed with water to obtain the first processed product, An alkaline solution immersion step is performed in which the first treated material obtained in the pretreatment step is immersed in an alkaline solution to obtain a cellulose mixture, The process includes an acidic solution immersion step in which the cellulose mixture obtained in the alkaline solution immersion step is immersed in an acidic solution to obtain a purified cellulose product, Furthermore, the process includes an adjustment step in which an extraction parameter value, which is a parameter for extracting cellulose, is obtained in at least one of the alkaline solution immersion step or the acidic solution immersion step, and the extraction parameter value is adjusted. The extraction parameter values ​​adjusted in the adjustment step are at least one of the following: solution concentration, solution volume, solid-liquid mass ratio, impregnation temperature (the temperature of the solution during immersion), or impregnation time (the duration of immersion). In the alkaline solution immersion step, the alkaline solution is a sodium hydroxide solution. The acidic solution used in the acidic solution immersion step is peracetic acid solution. A method for extracting cellulose from brewer's lees, characterized by the following features.

2. The peracetic acid concentration in a peracetic acid solution is 1-5%. The method for extracting cellulose from beer lees according to claim 1, characterized by the feature described above.

3. The impregnation temperature in the peracetic acid solution is 60°C to 90°C. The method for extracting cellulose from beer lees according to claim 1, characterized by the feature described above.

4. The impregnation time in the peracetic acid solution is 3 to 15 hours. The method for extracting cellulose from beer lees according to claim 1, characterized by the feature described above.

5. The solid-liquid mass ratio of the cellulose mixture to the peracetic acid solution is between 1 / 5 and 1 / 20. The method for extracting cellulose from beer lees according to claim 1, characterized by the feature described above.

6. The sodium hydroxide concentration in the sodium hydroxide solution is between 0.5 mol / L and 1.0 mol / L. The method for extracting cellulose from beer lees according to claim 1, characterized by the feature described above.

7. The temperature of the sodium hydroxide solution in the alkaline solution immersion step is 80°C to 120°C, and the immersion time in the sodium hydroxide solution is 3 hours to 15 hours. The method for extracting cellulose from beer lees according to claim 1, characterized by the feature described above.

8. Furthermore, the process includes a washing step in which the cellulose mixture obtained in the alkaline solution immersion step is washed to neutralize it. In the acidic solution immersion step, the cellulose mixture, which has been washed to a neutral state in the washing step, is immersed in an acidic solution. The method for extracting cellulose from beer lees according to claim 1, characterized by the feature described above.

9. Furthermore, the process includes a final washing step in which the cellulose purified product obtained in the acidic solution immersion step is washed to neutralize it and obtain a cellulose extract. A method for extracting cellulose from beer lees according to claim 1 or 8, characterized by the features described above.

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