Low-emission degumming method of nettle

Abstract

The invention provides a low-emission degumming method for nettle, and belongs to the technical field of nettle degumming, the low-emission degumming method for nettle comprises the following steps: S1, nettle is put into a kneading machine, and the structure of nettle fiber bundles is destroyed through a rotation and extrusion mode to preliminarily loosen colloid; s2, the kneaded nettle fibers are soaked in a tank containing a proper amount of water, an ultrasonic generator is adopted to generate high-frequency vibration, the frequency range is preferably 20 kHz to 100 kHz, so that a colloid structure is effectively damaged, the fibers are not damaged, and a heat exchanger is used for collecting heat in the degumming process; by using the scheme, energy consumption and pollutant emission in the degumming process are remarkably reduced, and meanwhile, the quality of fibers is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of nettle degumming, and particularly relates to a low-emission degumming method for nettle. Background Art

[0002] The degumming process in nettle processing is a key process that involves removing non-cellulose components from the fibers extracted from the nettle phloem to improve the textile properties of the fibers. This process is mainly divided into two methods: chemical degumming and biological degumming; in chemical degumming, the traditional practice is to use sodium hydroxide for cooking to remove the colloid. Although this method is effective, it produces a large amount of wastewater and causes serious pollution to the environment. Therefore, researchers have begun to turn to more environmentally friendly biological degumming technology. Biodegumming uses enzymes secreted by microorganisms to degrade nettle colloids. The key enzymes include pectin lyase and hemicellulase. These enzymes can effectively degrade pectin and hemicellulose in the fiber, thereby achieving the purpose of degumming; biodegumming technology has the advantages of energy saving, emission reduction, and consumption reduction. Compared with traditional chemical degumming methods, it is more environmentally friendly and efficient. For example, a research team from the Chinese Academy of Agricultural Sciences has developed a method for biodegumming using efficient strains. This method not only reduces the consumption of resources and energy, but also simplifies the production process and improves product quality;

[0003] In the prior art, nettle fiber degumming methods use chemical agents or hot water boiling to remove the colloid in the fiber. These methods are not only energy-intensive, but also produce a large amount of wastewater and waste gas, causing serious pollution to the environment. Summary of the invention

[0004] The purpose of the present invention is to provide a low-emission degumming method for nettles, aiming to solve the problem that the nettle fiber degumming method in the prior art uses chemical agents or hot water boiling to remove the colloid in the fiber. These methods not only consume a lot of energy, but also generate a large amount of wastewater and waste gas, causing serious pollution to the environment.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A low-emission degumming method for nettles comprises the following steps:

[0007] S1. Put the nettle into a kneading machine, and destroy the structure of the nettle fiber bundle by rotating and squeezing, so that the colloid is initially loosened;

[0008] S2, immersing the kneaded nettle fiber in a tank containing an appropriate amount of water, using an ultrasonic generator to generate high-frequency vibration, the frequency range is preferably between 20kHz and 100kHz, so as to effectively destroy the colloid structure without damaging the fiber, using a heat exchanger to collect heat during the degumming process, and the heat is used to preheat the washing water step, and the tank is equipped with a temperature control system to keep the water temperature in an appropriate range to improve the ultrasonic treatment effect;

[0009] S3, adding nettle fiber to a reaction container, and adding cellulase into the container, controlling the temperature in the reaction tank according to the optimal activity temperature of the selected enzyme, adjusting the pH value of the reaction solution to the optimal activity range of the enzyme, and setting a reasonable reaction time according to the enzyme activity and colloid content;

[0010] S4, washing the nettle fibers with circulating water;

[0011] S5. After washing, the nettle fiber is dried using low-temperature hot air.

[0012] As a preferred solution of the present invention, in step S1, the rotation speed of the kneading machine is 100 to 500 revolutions per minute, the extrusion pressure is 0.5 MPa to 2.0 MPa, and the kneading time is 10 to 30 minutes.

[0013] As a preferred solution of the present invention, in step S2, the high-frequency vibration frequency generated by the ultrasonic generator is preferably 30kHz to 80kHz, and the water temperature in the tank is maintained at 35°C to 45°C to improve the ultrasonic treatment effect; and during the ultrasonic treatment process, the duration is preferably 30 minutes to 120 minutes.

[0014] As a preferred solution of the present invention, in step S2, the heat collected by the heat exchanger can be used to preheat the washing water, and the preheated water temperature is increased to 30°C to 50°C to reduce the energy consumption required for heating the washing water; in addition, the heat collected by the heat exchanger can also be used to preheat the reaction container in step S3, so that the temperature inside the reaction container is maintained at 45°C to 60°C.

[0015] As a preferred solution of the present invention, in step S3, the optimal activity temperature of the selected cellulase is 45° C. to 55° C., the pH value is 5.5 to 6.5; and the reaction time is 12 hours to 24 hours.

[0016] As a preferred solution of the present invention, in step S4, the water temperature used in the circulating water washing system is 20°C to 35°C, the number of cycles in the water washing process is 3 to 5 times, and the time for each cycle is 10 to 20 minutes.

[0017] As a preferred solution of the present invention, in step S5, the low-temperature hot air temperature used is 60° C. to 80° C., and the hot air drying time is 1 hour to 2 hours.

[0018] As a preferred solution of the present invention, in step S2, a stirring device is further provided in the ultrasonic treatment tank, and the stirring speed is 50 to 150 revolutions per minute.

[0019] As a preferred solution of the present invention, in step S3, a pH adjustment system is also provided in the reaction container, and the pH value is accurately controlled within the optimal activity range of the enzyme by adding acid and alkali solutions to ensure efficient enzymatic hydrolysis. At the same time, a stirring device is also provided in the reaction container, and the stirring speed is 30 to 100 revolutions per minute.

[0020] As a preferred solution of the present invention, in step S4, the circulating water washing system is also equipped with a high-efficiency filtering device with a filtering accuracy of 5μm to 20μm to ensure that suspended particles in the washing water are effectively removed, and the washing water can be recycled after purification, reducing the consumption of water resources; at the same time, during the washing water circulation process, an online pH value monitoring and adjustment system is also provided to ensure that the pH value of the washing water is maintained between 6.0 and 7.5.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. In this scheme, a reasonable reaction time is set according to the enzyme activity and the colloid content; the nettle fiber is washed with circulating water; after washing, the nettle fiber is dried with low-temperature hot air; by using this scheme, the energy consumption and pollutant emissions in the degumming process are significantly reduced, and the quality of the fiber is improved.

[0023] 2. In this scheme, the optimal activity temperature of the selected cellulase is 45°C to 55°C, and the pH value is 5.5 to 6.5; the reaction time is 12 hours to 24 hours to ensure that the colloid is fully decomposed while maintaining the integrity and strength of the fiber.

[0024] 3. In this solution, the water temperature used in the circulating water washing system is 20℃ to 35℃, the number of cycles during the washing process is 3 to 5 times, and the time for each cycle is 10 minutes to 20 minutes, so as to ensure that the colloid residual on the fiber surface is completely removed while minimizing the consumption of water resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0026] Figure 1 It is a flowchart of the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Example 1

[0029] See also Figure 1 , the present invention provides the following technical solutions:

[0030] A low-emission degumming method for nettles comprises the following steps:

[0031] S1. Put the nettle into a kneading machine, and destroy the structure of the nettle fiber bundle by rotating and squeezing, so that the colloid is initially loosened;

[0032] S2, immersing the kneaded nettle fiber in a tank containing an appropriate amount of water, using an ultrasonic generator to generate high-frequency vibration, the frequency range is preferably between 20kHz and 100kHz, so as to effectively destroy the colloid structure without damaging the fiber, using a heat exchanger to collect heat during the degumming process, and the heat is used to preheat the washing water step, and the tank is equipped with a temperature control system to keep the water temperature in an appropriate range to improve the ultrasonic treatment effect;

[0033] S3, adding nettle fiber to a reaction container, and adding cellulase into the container, controlling the temperature in the reaction tank according to the optimal activity temperature of the selected enzyme, adjusting the pH value of the reaction solution to the optimal activity range of the enzyme, and setting a reasonable reaction time according to the enzyme activity and colloid content;

[0034] S4, washing the nettle fibers with circulating water;

[0035] S5. After washing, the nettle fiber is dried using low-temperature hot air.

[0036] In a specific embodiment of the present invention,.

[0037] For details, please refer to Figure 1 In step S1, the rotation speed of the kneading machine is 100 to 500 revolutions per minute, the extrusion pressure is 0.5 MPa to 2.0 MPa, and the kneading time is 10 to 30 minutes.

[0038] In this embodiment: in step S1, the rotation speed of the kneading machine is 100 to 500 revolutions per minute, the extrusion pressure is 0.5 MPa to 2.0 MPa, and the kneading time is 10 to 30 minutes to ensure that the structure of the nettle fiber bundle is fully destroyed without damaging the fiber itself.

[0039] For details, please refer to Figure 1 In step S2, the high-frequency vibration frequency generated by the ultrasonic generator is preferably 30kHz to 80kHz, and the water temperature in the tank is maintained at 35°C to 45°C to improve the ultrasonic treatment effect; and during the ultrasonic treatment process, the duration is preferably 30 minutes to 120 minutes.

[0040] In this embodiment: in step S2, the high-frequency vibration frequency generated by the ultrasonic generator is preferably 30kHz to 80kHz, and the water temperature in the tank is maintained at 35°C to 45°C to improve the ultrasonic treatment effect; and during the ultrasonic treatment process, the duration is preferably 30 minutes to 120 minutes to ensure that the colloid is effectively destroyed.

[0041] For details, please refer to Figure 1 In step S2, the heat collected by the heat exchanger can be used to preheat the washing water, and the preheated water temperature is increased to 30°C to 50°C to reduce the energy consumption required for heating the washing water; in addition, the heat collected by the heat exchanger can also be used to preheat the reaction container in step S3, so that the temperature inside the reaction container is maintained at 45°C to 60°C.

[0042] In this embodiment: in step S2, the heat collected by the heat exchanger can be used to preheat the washing water, and the preheated water temperature is increased to 30°C to 50°C to reduce the energy consumption required for heating the washing water; in addition, the heat collected by the heat exchanger can also be used to preheat the reaction container in step S3, so that the temperature in the reaction container is maintained at 45°C to 60°C to increase the activity of the enzyme.

[0043] For details, please refer to Figure 1 In step S3, the optimal activity temperature of the selected cellulase is 45°C to 55°C, the pH value is 5.5 to 6.5; and the reaction time is 12 hours to 24 hours.

[0044] In this embodiment: in step S3, the optimal activity temperature of the selected cellulase is 45°C to 55°C, and the pH value is 5.5 to 6.5; the reaction time is 12 hours to 24 hours to ensure that the colloid is fully decomposed while maintaining the integrity and strength of the fiber.

[0045] For details, please refer to Figure 1 In step S4, the water temperature used in the circulating water washing system is 20°C to 35°C, the number of cycles in the water washing process is 3 to 5 times, and the time for each cycle is 10 minutes to 20 minutes.

[0046] In this embodiment: in step S4, the water temperature used in the circulating water washing system is 20°C to 35°C, the number of cycles in the water washing process is 3 to 5 times, and the time for each cycle is 10 to 20 minutes, so as to ensure that the colloid residual on the fiber surface is completely removed while minimizing the consumption of water resources.

[0047] For details, please refer to Figure 1 In step S5, the low-temperature hot air temperature used is 60°C to 80°C, and the hot air drying time is 1 hour to 2 hours.

[0048] In this embodiment: in step S5, the low-temperature hot air temperature used is 60°C to 80°C, and the hot air drying time is 1 hour to 2 hours to ensure that the moisture in the fiber is completely removed and prevent the fiber strength from decreasing due to high temperature.

[0049] For details, please refer to Figure 1 In step S2, a stirring device is also provided in the ultrasonic treatment tank, and the stirring speed is 50 to 150 revolutions per minute.

[0050] In this embodiment: in step S2, a stirring device is also provided in the ultrasonic treatment tank, and the stirring speed is 50 to 150 revolutions per minute to promote uniform dispersion of the colloid during the ultrasonic treatment process and enhance the treatment effect.

[0051] For details, please refer to Figure 1 In step S3, a pH adjustment system is also provided in the reaction container, and the pH value is accurately controlled within the optimal activity range of the enzyme by adding acid and alkali solutions to ensure efficient enzymatic hydrolysis. At the same time, a stirring device is also provided in the reaction container, and the stirring speed is 30 to 100 revolutions per minute.

[0052] In this embodiment: In step S3, a pH adjustment system is also provided in the reaction container, and the pH value is accurately controlled within the optimal activity range of the enzyme by adding acid and alkali solutions to ensure efficient enzymatic hydrolysis. At the same time, a stirring device is also provided in the reaction container, and the stirring speed is 30 to 100 revolutions per minute to ensure sufficient contact between the enzyme and the fiber, thereby improving the efficiency of colloid decomposition.

[0053] For details, please refer to Figure 1 In step S4, the circulating water washing system is also equipped with a high-efficiency filtering device with a filtering accuracy of 5μm to 20μm to ensure that the suspended particles in the washing water are effectively removed. The washing water can be recycled after purification, reducing the consumption of water resources; at the same time, during the washing water circulation process, an online pH value monitoring and adjustment system is also provided to ensure that the pH value of the washing water is maintained between 6.0 and 7.5.

[0054] In this embodiment: In step S4, the circulating water washing system is also equipped with a high-efficiency filtering device with a filtering accuracy of 5μm to 20μm to ensure that suspended particles in the washing water are effectively removed, and the washing water can be recycled after purification, reducing the consumption of water resources; at the same time, during the washing water circulation process, an online pH value monitoring and adjustment system is also provided to ensure that the pH value of the washing water is maintained between 6.0 and 7.5 to protect the fiber from damage.

[0055] The working principle and use process of the present invention are as follows: when the present scheme is used, firstly, nettle is put into a kneading machine, and the structure of the nettle fiber bundle is destroyed by rotation and extrusion to preliminarily loosen the colloid; the kneaded nettle fiber is immersed in a tank containing an appropriate amount of water, and an ultrasonic generator is used to generate high-frequency vibration, and the frequency range is preferably between 20kHz and 100kHz, so as to effectively destroy the colloid structure without damaging the fiber; a heat exchanger is used to collect heat during the degumming process, and the heat is used for the step of preheating washing water; a temperature control system is provided in the tank to keep the water temperature within a suitable range to improve the ultrasonic treatment effect; the nettle fiber is added into a reaction container, and cellulase is added into the container; according to the optimal activity temperature of the selected enzyme, the temperature in the reaction tank is controlled, the pH value of the reaction solution is adjusted to the optimal activity range of the enzyme, and a reasonable reaction time is set according to the enzyme activity and the colloid content; the nettle fiber is subjected to circulating water washing; after water washing, the nettle fiber is dried by low-temperature hot air; by using the present scheme, the energy consumption and pollutant emission in the degumming process are significantly reduced, and the quality of the fiber is improved at the same time.

[0056] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A low-emission degumming method for nettles, characterized in that: The steps include: S1. Put the nettle into a kneading machine, and destroy the structure of the nettle fiber bundle by rotating and squeezing, so that the colloid is initially loosened; S2, immersing the kneaded nettle fiber in a tank containing an appropriate amount of water, using an ultrasonic generator to generate high-frequency vibration, the frequency range is preferably between 20kHz and 100kHz, so as to effectively destroy the colloid structure without damaging the fiber, using a heat exchanger to collect heat during the degumming process, and the heat is used to preheat the washing water step, and the tank is equipped with a temperature control system to keep the water temperature in an appropriate range to improve the ultrasonic treatment effect; S3, adding nettle fiber to a reaction container, and adding cellulase into the container, controlling the temperature in the reaction tank according to the optimal activity temperature of the selected enzyme, adjusting the pH value of the reaction solution to the optimal activity range of the enzyme, and setting a reasonable reaction time according to the enzyme activity and colloid content; S4, washing the nettle fibers with circulating water; S5. After washing, the nettle fiber is dried using low-temperature hot air.

2. A low-emission degumming method for nettle according to claim 1, characterized in that: In step S1, the rotation speed of the kneading machine is 100 to 500 revolutions per minute, the extrusion pressure is 0.5 MPa to 2.0 MPa, and the kneading time is 10 to 30 minutes.

3. A low-emission degumming method for nettle according to claim 2, characterized in that: In step S2, the high-frequency vibration frequency generated by the ultrasonic generator is preferably 30kHz to 80kHz, and the water temperature in the tank is maintained at 35°C to 45°C to improve the ultrasonic treatment effect; and during the ultrasonic treatment process, the duration is preferably 30 minutes to 120 minutes.

4. A low-emission degumming method for nettle according to claim 3, characterized in that: In step S2, the heat collected by the heat exchanger can be used to preheat the washing water, and the preheated water temperature is raised to 30°C to 50°C to reduce the energy consumption required for heating the washing water; in addition, the heat collected by the heat exchanger can also be used to preheat the reaction container in step S3, so that the temperature inside the reaction container is maintained at 45°C to 60°C.

5. A low-emission degumming method for nettles according to claim 4, characterized in that: In step S3, the optimal activity temperature of the selected cellulase is 45° C. to 55° C., the pH value is 5.5 to 6.5, and the reaction time is 12 hours to 24 hours.

6. A low-emission degumming method for nettles according to claim 5, characterized in that: In step S4, the water temperature used in the circulating water washing system is 20°C to 35°C, the number of cycles in the water washing process is 3 to 5 times, and the time for each cycle is 10 to 20 minutes.

7. A low-emission degumming method for nettles according to claim 6, characterized in that: In step S5, the low-temperature hot air temperature used is 60° C. to 80° C., and the hot air drying time is 1 hour to 2 hours.

8. A low-emission degumming method for nettles according to claim 7, characterized in that: In step S2, a stirring device is further provided in the ultrasonic treatment tank, and the stirring speed is 50 to 150 revolutions per minute.

9. A low-emission degumming method for nettles according to claim 8, characterized in that: In step S3, a pH adjustment system is provided in the reaction vessel, which accurately controls the pH value within the optimal activity range of the enzyme by adding acid and alkali solutions to ensure efficient enzymatic hydrolysis. At the same time, a stirring device is provided in the reaction vessel, and the stirring speed is 30 to 100 revolutions per minute.

10. A low-emission degumming method for nettles according to claim 9, characterized in that: In step S4, the circulating water washing system is also equipped with a high-efficiency filtering device with a filtering accuracy of 5μm to 20μm to ensure that suspended particles in the washing water are effectively removed. The washing water can be recycled after purification, reducing the consumption of water resources; at the same time, during the washing water circulation process, an online pH value monitoring and adjustment system is also provided to ensure that the pH value of the washing water is maintained between 6.0 and 7.5.

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