A method for synergistically dissolving lignin and hemicellulose in plant cellulose, and application of waste liquid
Patent Information
- Application Number
- CN202611177274.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-08-05
- Publication Date
- 2026-10-16
AI Technical Summary
然而，传统碱处理过程中产生的强碱性废液不仅对环境造成较大负担，其后续处理亦增加了整体工艺的成本与复杂度
1.本发明通过物理粉碎、含氮源碱液预处理与生物酶解的三级协同作用，实现了植物纤维素中木质素与半纤维素的高效溶出，所得纤维素浆料的纤维素含量≥90.2%，杂质含量≤4.8%，纤维聚合度≥1100，得率≥82%；同时将分离废液经微生物发酵转化为生物有机肥原料，有效活菌数≥0.20亿/g，有机质含量≥40%，实现了废液的全量化资源利用，避免了传统工艺中废液排放造成的环境污染。
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Figure CN122916732A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of biomass applications, and in particular to a method for the synergistic dissolution of lignin and hemicellulose in plant cellulose and the application of waste liquid. Background Technology
[0002] Plant cellulose is one of the most abundant renewable organic resources in nature, widely found in crop straw, forestry waste, and herbaceous plants. It is mainly composed of three high-molecular polymers: cellulose, hemicellulose, and lignin. These three polymers interact through covalent bonds, hydrogen bonds, and van der Waals forces to form a complex supramolecular structure, giving plant cell walls high resistance to degradation. In the comprehensive utilization of plant cellulose, how to efficiently and gently selectively dissolve lignin and hemicellulose from the cellulose matrix while maintaining the structural integrity and degree of polymerization of cellulose fibers has always been a key research focus in this field. Existing technologies commonly employ lignin removal methods such as alkaline cooking, acid hydrolysis, and organic solvent treatment. While these methods can achieve lignin dissolution to some extent, they generally suffer from problems such as harsh reaction conditions, high chemical consumption, severe cellulose degradation, and high wastewater treatment costs.
[0003] To address the aforementioned issues, researchers have attempted to combine chemical pretreatment with enzymatic hydrolysis, aiming to disrupt the cross-linking structure between lignin and hemicellulose through pretreatment and improve the accessibility of subsequent enzymatic hydrolysis. For example, pretreatment of plant cellulose with a dilute alkaline solution can, to some extent, dissolve lignin and swell cellulose fibers, thereby improving enzymatic hydrolysis efficiency. However, the strongly alkaline wastewater generated during traditional alkaline treatment not only imposes a significant burden on the environment but also increases the overall cost and complexity of the process due to its subsequent treatment. Furthermore, if the residual alkaline solution in the pretreatment system is not effectively neutralized or controlled, it will directly affect the activity and stability of the enzyme preparation during subsequent enzymatic hydrolysis, thus limiting the efficiency of the two-step process integration. Therefore, developing an integrated process that can achieve the synergistic dissolution of lignin and hemicellulose under mild conditions while simultaneously considering the resource utilization of wastewater has significant theoretical and practical value. Summary of the Invention
[0004] The purpose of this invention is to provide a method for the synergistic dissolution of lignin and hemicellulose in plant cellulose and the application of waste liquid. The method achieves efficient dissolution of lignin and hemicellulose through a three-stage synergistic effect of physical crushing, nitrogen-containing alkaline solution pretreatment and biological enzymatic hydrolysis. The separated waste liquid is then converted into bio-organic fertilizer raw material through microbial fermentation, thereby realizing the graded extraction of plant cellulose components and the full-scale resource utilization of waste liquid.
[0005] To achieve the above-mentioned technical objectives and effects, this invention discloses a method for the synergistic dissolution of lignin and hemicellulose in plant cellulose, comprising at least: S1. Physical pretreatment: The plant cellulose material is crushed and filamentized to increase its specific surface area. S2, Pretreatment with nitrogen-containing alkaline solution: The material obtained in S1 is placed in an alkaline solution containing nitrogen source and treated for 40-60 minutes at an initial pH of 8.5-9.5 and a temperature of 70-85℃ to allow lignin and hemicellulose to dissolve, and the outlet pH of the reaction system is controlled to 6.5-7.5. S3, biological enzymatic hydrolysis: Add enzyme preparation to the reaction system obtained in S2, and enzymatically hydrolyze at 60-80℃ for 36-48 hours to further degrade the residual hemicellulose and lignin-carbohydrate complex; S4. Liquid-solid separation: The enzymatic hydrolysis product obtained in S3 is subjected to solid-liquid separation to obtain cellulose slurry.
[0006] In step S2, the nitrogen-containing alkaline solution has an alkaline source selected from soda ash or lime, and a nitrogen source selected from urea, ammonium salt, or organic nitrogen source or a combination thereof, with a nitrogen content of 8-12 g / L.
[0007] The enzyme preparation mentioned in step S3 is a complex enzyme preparation that includes at least cellulase and hemicellulase.
[0008] In step S3, the amount of enzyme preparation added accounts for 0.8-1.2% (w / v) of the total mass of the reaction system.
[0009] In step S4, the liquid-solid separation is carried out using at least one of a screw press, a plate and frame filter press, or a centrifuge.
[0010] This invention also discloses an application of plant cellulose extraction waste liquid, wherein the plant cellulose extraction waste liquid is the liquid phase obtained from liquid-solid separation in step S4 of the above method, and the waste liquid is inoculated with microbial agents for fermentation to prepare bio-organic fertilizer raw materials, comprising at least: S5. Preparation of Microbial Agents: Prepare microbial agents, wherein the microbial agents use Bacillus as the main functional bacteria, supplemented by enzyme-producing bacteria and actinomycetes, with an effective viable count ≥ 1 × 10⁻⁶. 8 CFU / mL; S6. Inoculation and fermentation: Inoculate the microbial agent obtained in S5 into the waste liquid at 5-10% of the waste liquid volume, and ferment it aerobicly or facultatively anaerobicly at 28-37℃ for 3-7 days. S7. Product Acquisition: Collect the fermentation products obtained in S6, which are the raw materials for bio-organic fertilizer.
[0011] In step S5, the enzyme bacteria are a complex of yeast and lactic acid bacteria.
[0012] The bio-organic fertilizer raw material has an effective live bacteria count of ≥0.20 billion / g and an organic matter content of ≥40%.
[0013] The present invention has the following beneficial effects: 1. This invention achieves efficient dissolution of lignin and hemicellulose from plant cellulose through a three-stage synergistic effect of physical crushing, nitrogen-containing alkaline solution pretreatment, and biological enzymatic hydrolysis. The resulting cellulose pulp has a cellulose content ≥90.2%, an impurity content ≤4.8%, a fiber polymerization degree ≥1100, and a yield ≥82%. Simultaneously, the separation waste liquid is transformed into bio-organic fertilizer raw material through microbial fermentation, with an effective viable bacteria count ≥0.20 billion / g and an organic matter content ≥40%, realizing the full-scale resource utilization of the waste liquid and avoiding environmental pollution caused by waste liquid discharge in traditional processes.
[0014] 2. Through rational design, this invention seamlessly integrates the pretreatment of nitrogen-containing alkaline solutions with the bio-enzymatic hydrolysis process via precise outlet pH control. This reduces the amount of acid-base neutralizing agent used and protects the activity of subsequent enzyme preparations. Simultaneously, the nitrogen source introduced during the pretreatment stage is reused in the waste liquid fermentation section, eliminating the cost of additional nitrogen replenishment. The overall process is simple, requires a small equipment footprint, reduces overall energy consumption by approximately 20-30%, and lowers the overall cost per ton of product by approximately 25%, demonstrating promising prospects for industrial application. Attached Figure Description
[0015] The accompanying drawings, which are provided to further illustrate the invention and constitute a part of this invention, are illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention.
[0016] in: Figure 1 This is a flowchart of Embodiment 1 of the present invention.
[0017] Figure 2 This is a flowchart of Embodiment 2 of the present invention. Detailed Implementation
[0018] To make the technical problems, solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention. Example 1
[0019] like Figure 1 As shown in the figure, this embodiment provides a method for the synergistic dissolution of lignin and hemicellulose in plant cellulose, and the specific steps are as follows.
[0020] S1. Physical pretreatment: Take plant cellulose materials, such as crop straw and forestry waste, and use a pulverizer and filamentizer to pulverize and filamentize them to increase the specific surface area of the material, destroy the original physical structure of plant fibers, cut the fiber bundles, and create micro-cracks on the fiber surface, which is conducive to the penetration of subsequent chemical agents and enzyme preparations.
[0021] S2. Pretreatment with Nitrogen-Containing Alkaline Solution: The material obtained in S1 is placed in an alkaline solution containing a nitrogen source. The alkaline source is either soda ash or lime, and the nitrogen source is one or a combination of urea, ammonium salts, or organic nitrogen sources. The nitrogen content of the system is controlled at 8-12 g / L. The initial pH of the reaction system is controlled at 8.5-9.5, the temperature at 70-85℃, and the treatment time is 40-60 minutes. Under these conditions, the ester bonds and some ether bonds in lignin undergo saponification and hydrolysis, and the hemicellulose side chain groups dissolve, achieving partial cleavage of the lignin-carbohydrate complex. After the reaction, the outlet pH of the system is controlled at 6.5-7.5. This pH setting ensures effective alkalinity removal while avoiding the inhibition of subsequent enzyme activity by strong alkali residue, and also reduces the amount of acid-base neutralizing agent required.
[0022] S3. Enzymatic hydrolysis: Add an enzyme preparation, which is a complex enzyme preparation including at least cellulase and hemicellulase, to the reaction system obtained in S2. The amount added is 0.8-1.2% (w / v) of the total mass of the reaction system. Hydrolyze at 60-80℃ for 36-48 hours. During the hydrolysis process, the complex enzyme preparation further degrades residual hemicellulose and lignin-carbohydrate complexes that were not completely removed by the alkali solution, while simultaneously hydrolyzing the microfibrils on the cellulose surface, releasing soluble sugars, and improving the purity and reactivity of cellulose. Since the pH at the S2 outlet is already controlled within the range of 6.5-7.5, this system can directly carry out enzymatic hydrolysis without additional pH adjustment, achieving a seamless connection between the two steps.
[0023] S4. Liquid-solid separation: The enzymatic hydrolysis product obtained in S3 is subjected to solid-liquid separation using at least one of a screw press, plate and frame filter press, or centrifuge to obtain cellulose slurry. The obtained cellulose slurry has a cellulose content ≥90.2%, an impurity content ≤4.8%, a degree of polymerization ≥1100, and a yield ≥82%.
[0024] To further verify the synergistic dissolution method proposed in this embodiment, the product obtained from the above experimental steps was tested accordingly, and the specific results are as follows:
[0025] The cellulose pulp prepared using the synergistic dissolution method described in this embodiment has a cellulose content of over 90.2%, a significant improvement over traditional chemimechanical pulping. The impurity content is controlled below 4.8%, far lower than the over 8% of traditional processes, indicating thorough removal of lignin and hemicellulose. The degree of fiber polymerization remains above 1100, higher than the typical below 900 of the strong alkali method, demonstrating that this method effectively protects the molecular chain structure of cellulose fibers while dissolving lignin and hemicellulose, avoiding excessive degradation. The cellulose yield reaches over 82%, nearly double that of traditional sulfate pulping, significantly improving raw material utilization.
[0026] The above results indicate that this embodiment achieves efficient dissolution of lignin and hemicellulose through a three-stage synergistic effect of physical pulverization, nitrogen-containing alkaline solution pretreatment, and biological enzymatic hydrolysis, while maintaining the structural integrity of cellulose fibers under mild conditions. Example 2
[0027] This embodiment further processes and utilizes the waste liquid obtained in the steps of Example 1, converting it into raw materials for bio-organic fertilizer. For example... Figure 2 As shown, the specific steps are as follows.
[0028] S5. Preparation of Microbial Agents: A microbial agent is prepared, wherein Bacillus is the main functional bacteria, supplemented with enzyme-producing bacteria and actinomycetes. The enzyme-producing bacteria are a complex of yeast and lactic acid bacteria. The effective viable count of the agent is not less than 1 × 10⁻⁶. 8 CFU / mL. The various bacterial species in this agent work synergistically to utilize the organic carbon source in the waste liquid and the residual nitrogen source from the pretreatment section for metabolic growth, gradually converting macromolecular organic matter into functional components such as bacterial proteins, humic substances, and polysaccharides.
[0029] S6. Inoculation and Fermentation: Inoculate the microbial agent obtained in S5 into the waste liquid obtained in Example 1 at 5-10% of the waste liquid volume, and carry out aerobic or facultative anaerobic fermentation at 28-37℃ for 3-7 days. During the fermentation process, the microorganisms rapidly proliferate using the nutrients in the waste liquid, while simultaneously converting the organic pollutants in the waste liquid into stable humic substances, thus achieving the harmless treatment and resource transformation of the waste liquid.
[0030] S7. Product Acquisition: The fermentation product obtained in S6 is collected, which is the raw material for bio-organic fertilizer. Testing shows that the effective viable bacteria count of this bio-organic fertilizer raw material is ≥0.20 billion / g, and the organic matter content is ≥40%, all of which meet the standards for bio-organic fertilizer. This product can be directly applied to farmland as liquid organic fertilizer, or it can be processed into solid organic fertilizer products through conventional post-processing steps such as concentration, drying, and granulation to suit different agricultural application scenarios.
[0031] To further verify the effectiveness of the waste liquid resource utilization method proposed in this embodiment, the bio-organic fertilizer raw materials obtained in the above steps were tested accordingly, and the specific results are as follows:
[0032] The bio-organic fertilizer raw material prepared using the method described in this embodiment has an organic matter content of 45.6%, which is higher than the ≥40% qualification line specified in the industry standard NY 884-2012, indicating that the organic matter in the waste liquid is effectively converted into stable humic substances after microbial fermentation. The effective viable bacteria count is ≥0.20 billion / g, meeting the standard requirements, indicating that the microbial agent maintains good survival and reproduction capabilities during the fermentation process. In terms of hygiene indicators, the fecal coliform count is 90-95 CFU / g, lower than the standard upper limit of 100 CFU / g; the ascarid egg mortality rate is 98%, higher than the standard requirement of ≥95%, indicating that the fermentation process has a good killing effect on pathogenic microorganisms. In terms of heavy metal content, the five indicators of arsenic, cadmium, lead, chromium, and mercury all meet the standard limits, and the product is safe and reliable.
[0033] The above results show that this embodiment successfully transformed high-concentration organic waste liquid, which is difficult to treat in traditional processes, into bio-organic fertilizer raw materials that meet national standards by inoculating the waste liquid generated in Example 1 with a specific microbial agent for fermentation, thus realizing the full-scale resource utilization of waste liquid.
[0034] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.
Claims
1. A method for the synergistic dissolution of lignin and hemicellulose in plant cellulose, characterized in that, At least including: S1. Physical pretreatment: The plant cellulose material is crushed and filamentized to increase its specific surface area. S2, Pretreatment with nitrogen-containing alkaline solution: The material obtained in S1 is placed in an alkaline solution containing nitrogen source and treated for 40-60 minutes at an initial pH of 8.5-9.5 and a temperature of 70-85℃ to allow lignin and hemicellulose to dissolve, and the outlet pH of the reaction system is controlled to 6.5-7.
5. S3, biological enzymatic hydrolysis: Add enzyme preparation to the reaction system obtained in S2, and enzymatically hydrolyze at 60-80℃ for 36-48 hours to further degrade the residual hemicellulose and lignin-carbohydrate complex; S4. Liquid-solid separation: The enzymatic hydrolysis product obtained in S3 is subjected to solid-liquid separation to obtain cellulose slurry.
2. The method for the synergistic dissolution of lignin and hemicellulose in plant cellulose as described in claim 1, characterized in that, The nitrogen-containing alkaline solution mentioned in step S2 has an alkaline source selected from soda ash or lime, and a nitrogen source selected from urea, ammonium salt or organic nitrogen source or a combination thereof, with a nitrogen content of 8-12 g / L.
3. A method for the synergistic dissolution of lignin and hemicellulose in plant cellulose as described in claim 1 or 2, characterized in that, The enzyme preparation mentioned in step S3 is a complex enzyme preparation that includes at least cellulase and hemicellulase.
4. The method for the synergistic dissolution of lignin and hemicellulose in plant cellulose as described in claim 3, characterized in that, The amount of enzyme preparation added in step S3 accounts for 0.8-1.2% (w / v) of the total mass of the reaction system.
5. The method for the synergistic dissolution of lignin and hemicellulose in plant cellulose as described in claim 4, characterized in that, The liquid-solid separation described in step S4 is carried out using at least one of a screw press, a plate and frame filter press, or a centrifuge.
6. An application of plant cellulose extraction waste liquid, characterized in that, The plant cellulose extraction waste liquid is the liquid phase obtained from the liquid-solid separation in step S4 of the method according to any one of claims 1-5. The waste liquid is inoculated with microbial agents for fermentation to prepare bio-organic fertilizer raw materials, comprising at least: S5. Preparation of Microbial Agents: Prepare microbial agents, wherein the microbial agents use Bacillus as the main functional bacteria, supplemented by enzyme-producing bacteria and actinomycetes, with an effective viable count ≥ 1 × 10⁻⁶. 8 CFU / mL; S6. Inoculation and fermentation: Inoculate the microbial agent obtained in S5 into the waste liquid at 5-10% of the waste liquid volume, and ferment it aerobicly or facultatively anaerobicly at 28-37℃ for 3-7 days. S7. Product Acquisition: Collect the fermentation products obtained in S6, which are the raw materials for bio-organic fertilizer.
7. The application of a plant cellulose extraction waste liquid as described in claim 6, characterized in that, The enzyme bacteria mentioned in step S5 are a complex flora of yeast and lactic acid bacteria.
8. The application of the plant cellulose extraction waste liquid as described in claim 6, characterized in that, The bio-organic fertilizer raw material has an effective live bacteria count of ≥0.20 billion / g and an organic matter content of ≥40%.