Waste treatment system and method of converting waste to energy

Abstract

To provide a method and a system for converting waste to energy with low environmental pollution and power consumption.SOLUTION: A method includes the steps of: (a) preparing a base containing fats and oils and reacting it with a biocatalyst to generate a surfactant molecular liquid; (b) pretreating organic waste with the surfactant molecular liquid to generate a first organic liquid; (c) performing sonication of the first organic liquid to generate a second organic liquid; and (d) performing anaerobic biological treatment of the second organic liquid to convert it to methane. The biocatalyst has at least one lipase. The surfactant molecular liquid has at least one of monoglyceride and diglyceride. A waste treatment system for converting waste to energy is also provided.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a waste treatment system and a method for converting waste into energy.

Background Art

[0002] Current manufacturing contributes a significant amount of total production in the world economy but also generates large amounts of waste. With the growing prevalence of the circular economy, the industry and governments are increasingly emphasizing how to turn waste into resources and reduce carbon emissions.

[0003] The goal of environmental protection is a sustainable environment, but sludge from the manufacturing industry containing large amounts of organic waste is considered a recyclable resource, and how to effectively treat and utilize the waste sludge has become an important issue in the manufacturing industry at present. Among current sludge treatment technologies, the physical pretreatment method based on ultrasonic waves is excellent in reducing environmental pollution, but the power consumption aspect remains a major issue.

Summary of the Invention

Problems to be Solved by the Invention

[0004] As described above, existing waste sludge treatment technologies generally meet the originally expected uses but do not fully meet the requirements in all aspects. Therefore, developing an energy-saving waste sludge treatment method that shortens the treatment time or improves the treatment efficiency while maintaining the efficiency of ultrasonic treatment is an issue attracting attention in the related field.

Means for Solving the Problems

[0005] According to some embodiments of the present disclosure, there is provided a method for converting waste into energy, comprising: (a) preparing an oil and fat-containing base and reacting it with a biocatalyst to produce a surfactant molecular liquid; (b) pretreating organic waste with the surfactant molecular liquid to produce a first organic liquid; (c) subjecting the first organic liquid to ultrasonic treatment to produce a second organic liquid; and (d) subjecting the second organic liquid to anaerobic biological treatment to convert it into methane. The biocatalyst contains at least one lipase, the weight percentage of the biocatalyst to the oil and fat-containing base is 0.005 to 0.02:1, and the surfactant molecular liquid contains at least one of monoglyceride and diglyceride.

[0006] According to some embodiments of the present disclosure, there is also provided a waste treatment system including a surfactant molecular liquid generator, an ultrasonic generator, and an anaerobic biological reactor. The surfactant molecular liquid generator contains a biocatalyst, which is used to treat the oil and fat-containing base to produce a surfactant molecular liquid. The ultrasonic generator is connected to the surfactant molecular liquid generator and is used to treat the organic liquid produced by mixing the organic waste and the surfactant molecular liquid. The anaerobic biological reactor is connected to the ultrasonic generator and is used to treat the organic liquid to produce methane. The biocatalyst contains at least one lipase, the weight percentage (wt%) of the biocatalyst to the oil and fat-containing base is 0.005 to 0.02:1, and the surfactant molecular liquid contains at least one of monoglyceride and diglyceride.

[0007] The following embodiments will be described in detail with reference to the accompanying drawings.

Brief Description of the Drawings

[0008] By referring to the accompanying drawings and reading the following detailed description and examples, the present invention can be more fully understood.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0009] In the following description, the waste treatment system and the method for converting waste into energy of the present disclosure will be described in detail. In the following detailed description, it should be understood that, for the purpose of explanation, numerous specific details and embodiments are shown so that the present disclosure can be more fully understood. The specific elements and configurations described in the following detailed description are shown for the purpose of clarifying the present disclosure. It will be apparent that the exemplary embodiments shown herein are for illustrative purposes only and are not intended to limit the present disclosure.

[0010] The description of the exemplary embodiments is intended to be read in conjunction with the accompanying drawings, which are considered to be a part of the overall description. It should be understood that the figures are not drawn to scale. In fact, the sizes of the elements may be arbitrarily enlarged or reduced in order to clearly represent the features of the present disclosure.

[0011] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which the present disclosure belongs. In various cases, terms defined in commonly used dictionaries should be interpreted to have a meaning consistent with the related technology of the present disclosure, and the background or context of the present disclosure, and should not be interpreted in an idealized or overly formal manner unless so defined.

[0012] In response to the current needs of the industry for waste sludge reduction and the market needs for products and services related to related technologies, embodiments of the present disclosure use catalyst technology with biocatalysts together with ultrasonic sludge treatment technology and combine a resource energy conversion unit to generate biomass methane, thereby providing a method for converting waste into energy to establish a waste treatment system with high processing efficiency and energy savings. According to embodiments of the present disclosure, the method for converting waste into energy and the waste treatment system can increase the speed of converting organic waste into biomass methane for reuse, reduce the processing cost of organic waste, and increase the production of biomass green power. At the same time, the carbon reduction effect due to waste reduction and the energy conversion of waste resources can be realized.

[0013] Refer to FIG. 1. FIG. 1 shows an explanatory diagram of a waste treatment system 10 according to some embodiments of the present disclosure. For clarity of explanation, it should be understood that in the drawings, some components of the waste treatment system 10 are omitted and only some components are shown illustratively. According to one embodiment, additional features can also be added to the waste treatment system 10 described below.

[0014] Refer to FIG. 1. The waste treatment system 10 may include a surfactant molecule liquid generator 110, an ultrasonic generator 120, and an anaerobic bioreactor 130. The ultrasonic generator 120 may be connected to the surfactant molecule liquid generator 110, and the anaerobic bioreactor 130 may be connected to the ultrasonic generator 120. The ultrasonic generator 120 may be disposed downstream of the surfactant molecule liquid generator 110, and the anaerobic bioreactor 130 may be disposed downstream of the ultrasonic generator 120. According to some embodiments, the above-described surfactant molecule liquid generator 110, ultrasonic generator 120, and anaerobic bioreactor 130 may be connected via pipes.

[0015] The surfactant molecule liquid generator 110 may include a biocatalyst 110c, and the biocatalyst 110c can be used to process the oil-containing base W1 to generate the surfactant molecule liquid SC. According to some embodiments, the oil-containing base W1 may be supplied by a substrate supply unit (not shown), and the substrate supply unit may be connected to the surfactant molecule liquid generator 110.

[0016] According to some embodiments, the oil-containing base W1 may include, but is not limited to, medium-and-long chain triglycerides (MLCT) having 12 to 20 carbon atoms, such as triglycerides having 12, 14, 16, 18, or 20 carbon atoms. According to some embodiments, the oil-containing base W1 may include long-chain triglycerides having 16 to 20 carbon atoms. According to some embodiments, the oil-containing base W1 may include, but is not limited to, food industry wastewater, manufacturing wastewater, edible oil, feed oil, recycled oil of the aforementioned oils, other suitable oils, or combinations of the foregoing.

[0017] The biocatalyst 110c may contain at least one lipase. Further, the lipase may be immobilized on a carrier, and the carrier substrate may include, but is not limited to, chitosan or other suitable carrier substrates. According to some embodiments, the lipase may include, but is not limited to, triglyceride lipase (EC 3.1.1.3). According to some embodiments, the lipase may be derived from at least one of Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis. According to some embodiments, the lipase is derived from Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis, and the weight percentages of the lipases derived from Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis may be 1 to 3:1 to 3:1 to 3, respectively. Lipases derived from multiple strains can, inter alia, provide a preferably broad spectrum and can improve the efficiency of catalyzing the hydrolysis of fats and oils by the lipase.

[0018] The surfactant molecular liquid SC formed by the action of lipase on the oil-containing base W1 is a liquid having surfactant properties, and the surfactant molecular liquid SC may contain at least one of monoglyceride and diglyceride. For example, refer to FIG. 2. FIG. 2 shows an explanatory diagram explaining that lipase (EC 3.1.1.3) catalyzes the hydrolysis reaction of triglyceride. Lipase acts on the ester bond of the oil molecule and can hydrolyze triglyceride into diglyceride and fatty acid, then diglyceride into monoglyceride and fatty acid, and further monoglyceride into glycerin and fatty acid. Note that the monoglyceride and diglyceride in the surfactant molecular liquid SC have an emulsifier-like function. When subsequently acting on the organic waste W2, it can enhance the solubility and homogeneity of the organic waste W2, reduce the surface tension of the mixed liquid to be treated, and shorten the time required for subsequent ultrasonic treatment. It should be noted in this regard. Also, the free fatty acid molecules can be a precursor nutrient for anaerobic organisms to be converted into methane, and can increase the production amount of biomass methane in the subsequent treatment stage in the anaerobic bioreactor 130.

[0019] Furthermore, the weight percentage (wt%) of the biocatalyst to the oil-containing base W1 is 0.005 - 0.02:1, for example, 0.006:1, 0.007:1, 0.008:1, 0.009:1, 0.01:1, 0.011:1, 0.012:1, 0.013:1, 0.014:1, 0.015:1, 0.016:1, 0.017:1, 0.018:1 or 0.019:1, but is not limited thereto. In particular, if the ratio of the biocatalyst to the oil-containing base W1 is too low (for example, lower than 0.005:1), the time required for the action of lipase will be excessively long, and the treatment efficiency of the surfactant molecular liquid generator 110 may decrease. On the other hand, if the ratio of the biocatalyst to the oil-containing base W1 is too high (for example, higher than 0.02:1), the production cost will increase significantly.

[0020] According to some embodiments, the surfactant molecular liquid generator 110 can carry out the reaction under the conditions of a temperature of 25°C to 45°C and a pH of 6.5 to pH 7.5, and by allowing the oil and fat-containing base W1 to act on the biocatalyst 110c, the surfactant molecular liquid SC can be generated. According to some embodiments, the reaction temperature of the surfactant molecular liquid generator 110 is 25°C to 40°C, or 25°C to 35°C, and can be, for example, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C or 34°C, but is not limited thereto. According to some embodiments, the reaction pH of the surfactant molecular liquid generator 110 can be pH 6.6, pH 6.7, pH 6.8, pH 6.9, pH 7, pH 7.1, pH 7.2, pH 7.3 or pH 7.4, but is not limited thereto.

[0021] Also, according to some embodiments, the waste treatment system 10 may further include a surfactant molecular liquid storage tank 112. The surfactant molecular liquid storage tank 112 is connected to the surfactant molecular liquid generator 110 and can be used to temporarily store the surfactant molecular liquid SC, and the surfactant molecular liquid storage tank 112 may further be connected to an ultrasonic generator 120 so that the surfactant molecular liquid SC can be sent to the ultrasonic generator 120.

[0022] Specifically, before sending it to the ultrasonic generator 120, the surfactant molecular liquid SC can be mixed with the organic waste W2. By performing pretreatment on the organic waste W2 with the surfactant molecular liquid SC, the first organic liquid OG can be generated, and the treated first organic liquid OG can be decomposed into a homogeneous organic liquid having relatively small molecules, such as organic sludge.

[0023] According to some embodiments, the organic waste W2 may be supplied by a waste supply unit (not shown), and the waste supply unit may be connected to the ultrasonic generator 120. Specifically, after the pipe of the waste supply unit is connected to the pipe of the surfactant molecular liquid generator 110, they are both connected to the ultrasonic generator 120.

[0024] According to some embodiments, the organic waste W2 may include, but is not limited to, manufacturing waste, petrochemical waste, agricultural waste, livestock waste, food waste, other suitable organic waste, or combinations thereof.

[0025] As described above, the surfactant molecular liquid SC generated after the oil-containing base W1 is treated by the surfactant molecular liquid generator 110 contains at least one of monoglyceride and diglyceride. Monoglyceride and diglyceride have an emulsifier-like function, can enhance the solubility and homogeneity of the organic waste W2, reduce the surface tension of the mixed liquid to be treated, and can shorten the time required for subsequent ultrasonic treatment.

[0026] According to some embodiments, in the homogeneous first organic liquid OG, the volume percentage (v / v%) of the surfactant molecular liquid SC to the organic waste W2 may be 0.005 - 0.05:1, for example, 0.01:1, 0.015:1, 0.02:1, 0.025:1, 0.03:1, 0.035:1, 0.04:1, or 0.045:1, but is not limited thereto. It should be noted that when the ratio of the surfactant molecular liquid SC to the organic waste W2 is within the above range, the treatment efficiency of the surfactant molecular liquid SC for the organic waste W2 can be effectively increased.

[0027] According to some embodiments, the pretreatment performed on the organic waste W2 with the surfactant molecular liquid SC is to carry out a continuous reaction under the conditions of a temperature of 20°C to 60°C and a pH of 5 to pH8. According to some embodiments, the reaction temperature of the above-mentioned pretreatment may be 30°C to 50°C, or 30°C to 40°C, for example, 22°C, 24°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C, 42°C, 45°C, 48°C, 52°C, 55°C, or 58°C, but is not limited thereto. According to some embodiments, the reaction pH of the above-mentioned pretreatment may be pH6.5 to pH7.5, for example, pH6.6, pH6.7, pH6.8, pH6.9, pH7, pH7.1, pH7.2, pH7.3, or pH7.4, but is not limited thereto.

[0028] Further, the ultrasonic generator 120 is used to process the first organic liquid OG produced by mixing the organic waste W2 and the surfactant liquid SC to produce a second organic liquid OG'. The ultrasonic generator 120 can apply ultrasonic energy to the first organic liquid OG to hydrolyze the organic matter and improve the efficiency of the biological anaerobic treatment performed in the subsequent anaerobic bioreactor 130. Specifically, the impact force generated by the cavitation effect provided by the ultrasonic waves destroys the structure of the first organic liquid OG (for example, the cell wall of microorganisms in the organic sludge), thereby increasing the concentration of the dissolved organic matter in the first organic liquid OG. As a result, the subsequent anaerobic microorganisms can digest more easily, and thus the time required for the biological anaerobic treatment is shortened.

[0029] According to some embodiments, the output power of the ultrasonic treatment may be from 300 watts to 1200 watts, such as 400 watts, 500 watts, 600 watts, 700 watts, 800 watts, 900 watts, 1000 watts or 1100 watts, but is not limited thereto. According to some embodiments, the frequency of the ultrasonic treatment may be from 20 kilohertz (kHz) to 100 kHz, such as 30 kHz, 40 kHz, 50 kHz, 60 kHz, 70 kHz, 80 kHz or 90 kHz, but is not limited thereto.

[0030] The anaerobic bioreactor 130 can be used to process the second organic liquid OG' to generate methane MT. The methane MT can be provided to a subsequent biogas power generation facility and converted into electrical energy. Specifically, the anaerobic biological treatment can decompose and convert small-molecule organic matter through the biochemical metabolism of microorganisms to generate biogas, such as methane and the like. According to some embodiments, the anaerobic bioreactor 130 may include hydrolytic bacteria, acid-forming bacteria, methanogens, other suitable bacterial species or combinations thereof, but is not limited thereto.

[0031] According to some embodiments, the anaerobic biological treatment performed in the anaerobic bioreactor 130 proceeds under conditions of a temperature of 25°C to 45°C and a pH of 6.8 to pH 7.2. According to some embodiments, the reaction temperature of the aforementioned anaerobic biological treatment may be from 30°C to 40°C, such as 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C, 40°C, 41°C, 42°C, 43°C or 44°C, but is not limited thereto. According to some embodiments, the reaction pH of the aforementioned anaerobic biological treatment may be pH 6.9, pH 7 or pH 7.1, but is not limited thereto.

[0032] The present disclosure also provides a method 20 for converting waste into energy. FIG. 3 shows a step flow diagram of a method 20 for converting waste into energy according to some embodiments of the present disclosure. According to some embodiments, the method 20 for converting waste into energy includes a step of treating organic waste using the aforementioned waste treatment system 10, but the present disclosure is not limited thereto. It should be understood that according to some embodiments, additional steps can be added, or some steps can be replaced or omitted, before, during and / or after the progress of the method 20 for converting waste into energy described below.

[0033] As shown in FIG. 3, the method 20 for converting waste into energy may include a step S1 of preparing an oil and fat-containing base W1 and reacting it with a biocatalyst 110c to produce a surfactant ionic liquid SC.

[0034] According to some embodiments, the oil and fat-containing base W1 may contain medium- and long-chain triglycerides having 12 to 20 carbon atoms, for example, triglycerides having 12, 14, 16, 18 or 20 carbon atoms, but is not limited thereto. According to some embodiments, the oil and fat-containing base W1 may contain long-chain triglycerides having 16 to 20 carbon atoms. According to some embodiments, the oil and fat-containing base W1 may include, but is not limited to, food industry wastewater, manufacturing industry wastewater, edible oil, feed oil, recycled oil of the aforementioned oils, other suitable oils or combinations of the aforementioned.

[0035] The biocatalyst 110c may contain at least one lipase. Further, the lipase may be immobilized on a carrier, and the carrier substrate may include, but is not limited to, chitosan or other suitable carrier substrates. According to some embodiments, the lipase may include, but is not limited to, triglyceride lipase (EC 3.1.1.3). According to some embodiments, the lipase may be derived from at least one of Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis. According to some embodiments, the lipase is derived from Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis, and the weight percentages of the lipases derived from Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis are 1-3:1-3:1-3, for example, 1:1:1, 1:1:2, 1:1.5:2, 1:1.8:2.5, 1:2:3, 1:2.5:3, 1:3:2, 1:3:1.5, 2:1:2, 2:1:2.5, 2:1:3, 2:2:1, 2:2.5:1.8, 2:3:1, 3:1:2, 3:1.8:1.5, 3:2:1, 3:2.5:1, 3:3:1, or 3:3:2, but are not limited thereto. Lipases derived from multiple strains can, inter alia, provide a more preferred broad spectrum and improve the efficiency of catalyzing the hydrolysis of fats and oils by the lipase. Further, the lipases derived from the specific strains described above have good compatibility with the substrate and particularly have good catalytic performance for medium- and long-chain triglycerides having 12 to 20 carbon atoms.

[0036] The surfactant molecular liquid SC produced by the action of lipase on the oil-containing base W1 may contain at least one of monoglyceride and diglyceride. The monoglyceride and diglyceride in the surfactant molecular liquid SC have an emulsifier-like function. When they continue to act on the organic waste W2, they can enhance the solubility and homogeneity of the organic waste W2, reduce the surface tension of the mixed liquid to be treated, and shorten the time required for subsequent ultrasonic treatment. Furthermore, the released fatty acid molecules can be a precursor nutrient for converting anaerobic organisms into methane, and can increase the production amount of biomass methane.

[0037] Furthermore, the weight percentage (wt%) of the biocatalyst to the oil-containing base W1 is 0.005 - 0.02:1, for example, 0.006:1, 0.007:1, 0.008:1, 0.009:1, 0.01:1, 0.011:1, 0.012:1, 0.013:1, 0.014:1, 0.015:1, 0.016:1, 0.017:1, 0.018:1 or 0.019:1, but is not limited thereto. In particular, if the ratio of the biocatalyst to the oil-containing base W1 is too low (for example, lower than 0.005:1), the time required for the action of lipase will be excessively long, and the treatment efficiency may decrease. On the other hand, if the ratio of the biocatalyst to the oil-containing base W1 is too high (for example, higher than 0.02:1), the production cost will increase significantly.

[0038] According to some embodiments, step S1 involves reacting for 1 to 9 hours under the conditions of a temperature of 25°C to 45°C and a pH of 6.5 to 7.5. According to some embodiments, the reaction temperature in step S1 may be 25°C to 40°C or 25°C to 35°C, for example, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C, 40°C, 41°C, 42°C, 43°C or 44°C, but is not limited thereto. According to some embodiments, the reaction pH in step S1 may be pH6.6, pH6.7, pH6.8, pH6.9, pH7, pH7.1, pH7.2, pH7.3 or pH7.4, but is not limited thereto. According to some embodiments, the reaction time in step S1 may be 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, 6.5 hours, 7 hours, 7.5 hours, 8 hours or 8.5 hours, but is not limited thereto.

[0039] Also, according to some embodiments, step S1 further includes adjusting the oil and fat content of the oil and fat-containing base W1 to 30 wt% to 50 wt%, for example, it can be adjusted to 35 wt%, 40 wt% or 45 wt%, but is not limited thereto. It should be noted that if the oil and fat content in the oil and fat-containing base W1 is too high (for example, higher than 50 wt%), lipase may not act effectively, and the effect of fat hydrolysis may deteriorate.

[0040] Furthermore, the method 20 for converting waste into energy may include step S2 of pretreating the organic waste W2 with the surfactant ionic liquid SC to produce the first organic liquid OG.

[0041] According to some embodiments, the organic waste W2 may include, but is not limited to, manufacturing waste, petrochemical industry waste, agricultural waste, livestock industry waste, food waste, other suitable organic waste or combinations of the foregoing.

[0042] As described above, the surfactant molecular liquid SC contains at least one of monoglyceride and diglyceride. Since monoglyceride and diglyceride have an emulsifier-like function, they can enhance the solubility and homogeneity of the organic waste W2, reduce the surface tension of the mixture to be treated, and shorten the time required for subsequent ultrasonic treatment.

[0043] According to some embodiments, in step S2, the volume percentage (v / v%) of the surfactant molecular liquid SC to the organic waste W2 may be 0.005 to 0.05:1, such as 0.01:1, 0.015:1, 0.02:1, 0.025:1, 0.03:1, 0.035:1, 0.04:1 or 0.045:1, but is not limited thereto. It should be noted that when the ratio of the surfactant molecular liquid SC to the organic waste W2 is within the above range, the treatment efficiency of the surfactant molecular liquid SC for the organic waste W2 can be effectively increased.

[0044] According to some embodiments, step S2 proceeds with a continuous reaction under the conditions of a temperature of 20°C to 60°C and a pH of 5 to pH8. According to some embodiments, the reaction temperature in step S2 is 30°C to 50°C, or 30°C to 40°C, such as 22°C, 24°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C, 42°C, 45°C, 48°C, 52°C, 55°C or 58°C, but is not limited thereto. According to some embodiments, the reaction pH in step S2 may be pH6.5 to pH7.5, such as pH6.6, pH6.7, pH6.8, pH6.9, pH7, pH7.1, pH7.2, pH7.3 or pH7.4, but is not limited thereto.

[0045] Furthermore, the method 20 for converting waste into energy may include step S3 of performing ultrasonic treatment on the first organic liquid OG to produce a second organic liquid OG'.

[0046] According to some embodiments, the output power of the ultrasonic treatment may be from 300 watts to 1200 watts, such as 400 watts, 500 watts, 600 watts, 700 watts, 800 watts, 900 watts, 1000 watts or 1100 watts, but is not limited thereto. According to some embodiments, the frequency of the ultrasonic treatment may be from 20 kHz to 100 kHz, such as 30 kHz, 40 kHz, 50 kHz, 60 kHz, 70 kHz, 80 kHz or 90 kHz, but is not limited thereto.

[0047] Furthermore, the method 20 for converting waste into energy may further include a step S4 of performing anaerobic biological treatment on the second organic liquid OG' to convert it into methane MT.

[0048] According to some embodiments, step S4 may include performing anaerobic biological treatment using hydrolytic bacteria, acid-producing bacteria, methane-producing bacteria, other suitable bacterial species or combinations thereof, but is not limited thereto. According to some embodiments, step S4 is performed under conditions of a temperature of 25°C to 45°C and a pH of 6.8 to pH 7.2. According to some embodiments, the reaction temperature of step S4 may be from 30°C to 40°C, such as 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C, 40°C, 41°C, 42°C, 43°C or 44°C, but is not limited thereto. According to some embodiments, the reaction pH of step S4 may be pH 6.9, pH 7 or pH 7.1, but is not limited thereto.

[0049] In order to make the above and other objects, features and advantages of the present disclosure more complete and easier to understand, a number of examples are presented below and described in detail as follows, but they are not intended to limit the scope of the present disclosure.

[0050] Example 1 - Preparation of Biocatalyst

[0051] Chitosan was dissolved in 1% acetic acid to prepare a 2% chitosan solution. The chitosan solution was added dropwise into a 10% sodium hydroxide solution using a syringe and coagulated in the solution to form chitosan gel beads. After standing at room temperature for 60 minutes for hardening, it was repeatedly washed with deionized water until it became neutral. Subsequently, a cross-linking fixation treatment was performed on the above-mentioned 2% chitosan-containing gel beads and a lipase solution (EC 3.1.1.3, derived from Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis, with a composition ratio of the three being 1:1:1) with a concentration of 500 U / g with respect to the carrier. After taking it out and washing it 180 minutes later, chitosan gel beads containing immobilized lipase were completed. When the obtained immobilized enzyme was compared with the free enzyme, the enzyme activity retention rate reached 72.6%, and the retention rate also reached 88.2% after conducting 10 batches of oil hydrolysis reaction tests. As can be seen from this, the biocatalyst prepared according to the examples of the present disclosure has good enzyme activity and stability and can be applied to waste treatment systems.

[0052] Example 2 - Preparation of Surfactant Ionic Liquid

[0053] Food factory wastewater containing medium- and long-chain triglycerides was used as the oil-containing base, and its oil content was adjusted to the range of 30 - 50 wt%. The above-mentioned oil-containing base was used as the substrate raw material for preparing the surfactant ionic liquid. Subsequently, the oil-containing base was reacted with the biocatalyst prepared in Example 1. The weight percentage (wt%) of the biocatalyst to the oil-containing base was 0.005 - 0.02:1. The conversion reaction was a batch process that proceeded for 1 - 3 hours under the conditions of a temperature of 25°C to 45°C and a pH of 6.5 to pH 7.5, and a surfactant ionic liquid containing monoglyceride, diglyceride, and free fatty acid molecules was generated by the catalytic action.

[0054] Example 3 - Oil Conversion Rate Test of Biocatalysts with Lipases Having Different Source Strains and Compositions

[0055] The food factory wastewater from the same source as in Example 2 was based on oil and fat content, and it was diluted until the oil and fat content reached 50 wt%, and the above-mentioned oil and fat-containing base was used as the substrate raw material for this reaction test. Furthermore, five groups of biocatalysts with the origin strains and compositions shown in Table 1 below were prepared.

[0056]

Table 1

[0057] The test was divided into five groups. 100 g of the above-mentioned oil and fat-containing base was taken for each group as the substrate for the reaction test, and 2 g of the biocatalysts with five different compositions described above were added respectively. Under the conditions of a temperature of 30 °C and a pH of 7.0, the reaction was allowed to proceed with uniform stirring. After the reaction time reached 3 hours, 6 hours, and 9 hours respectively, 1 ml of the reaction solution was taken for oil and fat decomposition rate analysis to obtain the oil and fat conversion rate data of the biocatalysts with the five different compositions described above. The results are as shown in Figure 4. BSL is Group 1 derived from Bacillus subtilis of lipase, YLL is Group 2 derived from Yarrowia lipolytica of lipase, ANL is Group 3 derived from Aspergillus niger of lipase, BSL + YLL + ANL(1:1:1) is Group 4 derived from Bacillus subtilis, Yarrowia lipolytica and Aspergillus niger (weight percentage 1:1:1) of lipase, and BSL + YLL + ANL(1:2:3) is Group 5 derived from Bacillus subtilis, Yarrowia lipolytica and Aspergillus niger (weight percentage 1:2:3) of lipase.

[0058] As shown in Figure 4, the oil conversion rates of BSL derived from a single strain after reaction times of 3 hours, 6 hours, and 9 hours were 12%, 14%, and 15% respectively; the oil conversion rates of YLL derived from a single strain after reaction times of 3 hours, 6 hours, and 9 hours were 21%, 24%, and 26% respectively; the oil conversion rates of ANL derived from a single strain after reaction times of 3 hours, 6 hours, and 9 hours were 25%, 32%, and 37% respectively; the oil conversion rates of BSL+YLL+ANL(1:1:1) derived from multiple strains after reaction times of 3 hours, 6 hours, and 9 hours were 38%, 46%, and 50% respectively; the oil conversion rates of BSL+YLL+ANL(1:2:3) derived from multiple strains after reaction times of 3 hours, 6 hours, and 9 hours were 49%, 52%, and 53% respectively.

[0059] As can be seen from the above results, both the biocatalysts with lipases derived from single strains and those derived from multiple strains can catalyze oil conversion. However, the biocatalysts with lipases derived from multiple strains have a better conversion catalytic effect, and especially show an excellent effect when the proportion of Aspergillus niger is high (BSL+YLL+ANL(1:2:3)).

[0060] Example 4 - Oil conversion rate test of biocatalysts using various oils as substrate raw materials

[0061] Two types of oils with different carbon chain lengths, olive oil (belonging to long-chain triglycerides (LCT)) and coconut oil (belonging to medium-chain triglycerides (MCT)), were each used as substrates in this reaction test, and the same biocatalyst of BSL+YLL+ANL(1:1:1) derived from multiple strains as described in Example 3 was added respectively to prepare surfactant ionic liquids. After the reaction, the conversion rates of these two types of oil types with different chain lengths were analyzed.

[0062] The test was divided into two groups. 100 g of each of the water samples containing 50 wt% olive oil and 50 wt% coconut oil described above were taken respectively as the substrates for this reaction test, and 2 g of the biocatalyst BSL+YLL+ANL (1:1:1) derived from multiple strains as described in Example 3 was added to each. Under the conditions of a temperature of 30°C and a pH of 7.0, the reaction was allowed to proceed with uniform stirring. After 3 hours, 1 ml of the reaction solution was taken and the oil hydrolysis rate was analyzed to obtain the oil conversion rate data when the above two different types of oils were used as substrates.

[0063] As a result, it was shown that the oil conversion rate of the water sample containing olive oil (LCT) was about 51%, and the oil conversion rate of the water sample containing coconut oil (MCT) was about 23%. As can be seen from the above results, both long-chain fatty acid type oils and medium-chain fatty acid type oils can be used as substrates for biocatalysts derived from multiple strains.

[0064] Example 5 - Organic Waste Decomposition Test

[0065] Taking the waste solid sludge from the petrochemical industry as organic waste, the organic waste was mixed with the surfactant ionic liquid prepared in Example 2 above to form a homogeneous organic liquid. After ultrasonic treatment of the organic liquid, the chemical oxygen demand (COD) (i.e., the concentration of dissolved organic matter, unit: mg / L) of the ultrasonically pretreated reaction hydrolyzate was measured, and the effect of ultrasonic pretreatment was judged based on this data.

[0066] When the measurement was carried out after mixing 250 ml of organic sludge with 250 ml of pure water and 250 ml of the surfactant ionic liquid respectively, the concentration of suspended solids (SS) in the organic sludge was 10256 mg / L, and the concentration of volatile suspended solids (VSS) was 7423 mg / L. Subsequently, ultrasonic treatment was carried out sequentially for 2.5 minutes, 5 minutes, 7.5 minutes, and 10 minutes with an ultrasonic wave of a frequency of 20 kHz and an output of 500 watts. The results are as shown in Figure 5.

[0067] Figure 5 shows the results of the analysis of the concentration of dissolved organic matter in experimental samples that have undergone no pretreatment (organic sludge with pure water added, but no ultrasonic treatment), no addition of surfactant ionic liquid (organic sludge with pure water added, ultrasonic treatment performed), and addition of surfactant ionic liquid (organic sludge with surfactant ionic liquid added, ultrasonic treatment performed), with ultrasonic treatment applied for 2.5 minutes, 5 minutes, 7.5 minutes, and 10 minutes respectively.

[0068] As shown in Figure 5, for the sample with no pretreatment, the concentration of dissolved organic matter is maintained at 208 mg / L. For the sample without the addition of the surfactant ionic liquid, the concentrations of dissolved organic matter after 2.5 minutes, 5 minutes, 7.5 minutes, and 10 minutes of ultrasonic treatment are successively 1755 mg / L, 2508 mg / L, 3106 mg / L, and 3512 mg / L. For the sample with the addition of the surfactant ionic liquid, the concentrations of dissolved organic matter after 2.5 minutes, 5 minutes, 7.5 minutes, and 10 minutes of ultrasonic treatment are successively 3226 mg / L, 3806 mg / L, 3921 mg / L, and 4008 mg / L.

[0069] Compared with the concentration of dissolved organic matter of 3512 mg / L after 10 minutes of ultrasonic treatment of the sample without the addition of the surfactant ionic liquid, the concentration of dissolved organic matter after 10 minutes of ultrasonic treatment of the sample with the addition of the surfactant ionic liquid increased to 4008 mg / L, and the decomposition effect of the organic waste improved by about 14%.

[0070] Next, please refer to Figure 6. Figure 6 is a line graph converted from the experimental results of Figure 5. As shown in Figure 6, the concentration of dissolved organic matter after 5 minutes of ultrasonic treatment of the sample with the addition of the surfactant ionic liquid reached 3806 mg / L (power consumption 42 W), already exceeding 3512 mg / L (power consumption 83 W) which was reached after 10 minutes of ultrasonic treatment of the sample without the addition of the surfactant ionic liquid.

[0071] As can be seen from the above results, compared with the ultrasonic sludge treatment method without using a biocatalyst (without adding a surfactant molecular liquid), the treatment method using a catalyst with a biocatalyst (adding a surfactant molecular liquid) together with the ultrasonic sludge treatment technology only requires half the power consumption (reduced from 83 W to 42 W), increases the concentration of dissolved organic matter in the object to be treated to 3512 mg / L, and can effectively increase the treatment efficiency by 50% or more.

[0072] Example 6 - Methanogenic ability test

[0073] The test was divided into two groups, and for each group, three identical 600 ml reaction flasks were prepared. In the reaction flasks of the two groups, 350 ml of the organic hydrolyzed sludge substrate that had been ultrasonically treated for 5 minutes of the (1) surfactant molecular liquid - free and (2) surfactant molecular liquid - added liquids obtained in the above - mentioned Example 5, which were fully mixed, and 150 ml of seed sludge (the seed sludge was taken from the tank of the anaerobic biological treatment unit in the wastewater treatment plant of a food factory and contained common anaerobic bacterial species such as hydrolytic bacteria, oxidizing bacteria, and methanogenic bacteria) were respectively put in. Under the conditions of a temperature of 35°C and a pH of 7.0, they were continuously reacted by shaking and stirring for 21 days or more to conduct a batch anaerobic digestion experiment. A gas collection hole was provided above the lid of the reaction flask, and the gas generated by the decomposition of the organic hydrolyzed sludge was collected daily by the water displacement method, and the cumulative gas generation amount of each test sample was recorded. The results are as shown in Figure 7.

[0074] As shown in Figure 7, the reaction was almost completed on the 11th day of anaerobic biological treatment. The cumulative gas generation amount of the surfactant molecular liquid - free organic waste hydrolyzed sludge was 99 ml, and the cumulative gas generation amount of the surfactant molecular liquid - added organic waste hydrolyzed sludge was 121 ml. Judging from this, compared with the surfactant molecular liquid - free sample, the methane generation amount of the surfactant molecular liquid - added sample increased by about 22%, and the effect of converting waste into energy was effectively enhanced.

[0075] To summarize, the method for converting waste into energy provided by the embodiments of the present disclosure uses a catalyst technology with a biocatalyst together with an ultrasonic sludge treatment technology, and combines a resource energy conversion unit to generate biomethane. As a result, a waste treatment system with high processing efficiency and energy savings is established. The method for converting waste into energy and the waste treatment system according to the embodiments of the present disclosure can increase the speed of converting organic waste into biomethane for reuse, reduce the processing cost of organic waste, and increase the production of biomass green power. At the same time, the carbon reduction effect due to waste reduction and the energy conversion of waste resources can be realized.

[0076] Although some embodiments of the present disclosure and their advantages have been described as above, it should be understood that substitutions and changes can be made to these without departing from the spirit and scope of the present disclosure as defined by the appended claims. In addition, each claim constitutes an independent embodiment, and the scope of the patent of the present disclosure includes combinations of these claims and embodiments. The protection scope of the present disclosure is defined by the definition of the appended claims.

Description of Reference Numerals

[0077] 110… Surfactant Molecular Liquid Generator 110c… Biocatalyst 112… Surfactant Molecular Liquid Storage Tank 120… Ultrasonic Generator 130… Anaerobic Bioreactor W1… Oil and Fat Containing Base W2… Organic Waste OG… First Organic Liquid OG’… Second Organic Liquid MT… Methane SC… Surfactant Molecular Liquid

Claims

1. A method for converting waste into energy, comprising: (a) preparing an oil-containing base and reacting it with a biocatalyst to produce a surfactant ionic liquid; (b) pretreating organic waste with the surfactant ionic liquid to produce a first organic liquid; (c) subjecting the first organic liquid to ultrasonic treatment to produce a second organic liquid; (d) subjecting the second organic liquid to anaerobic biological treatment to convert it into methane; wherein the biocatalyst contains at least one lipase, the weight percentage (wt%) of the biocatalyst to the oil-containing base is 0.005 to 0.02:1, and the surfactant ionic liquid contains at least one of monoglyceride and diglyceride. A method for converting waste into energy.

2. The oil-containing base includes food industry wastewater, manufacturing industry wastewater, edible oil, feed oil, recycled oil of the above-mentioned oil, or a combination of the foregoing, and the organic waste includes manufacturing waste, petrochemical waste, agricultural waste, livestock waste, food waste, or a combination of the foregoing. The method for converting waste into energy according to Claim 1.

3. The method for converting waste into energy according to Claim 1, wherein the oil-containing base contains triglycerides having 12 to 20 carbon atoms (medium-and-long chain triglyceride, MLCT).

4. The method for converting waste into energy according to Claim 1, wherein step (a) further includes adjusting the oil content of the oil-containing base from 30 wt% to 50 wt%.

5. The method for converting waste into energy according to Claim 1, wherein step (a) is carried out under the conditions of a temperature of 25°C to 45°C and a pH of 6.5 to 7.5 for 1 hour to 9 hours.

6. The method for converting waste into energy according to Claim 1, wherein the lipase contains triglyceride lipase (EC 3.1.1.3).

7. The method for converting waste into energy according to Claim 6, wherein the lipase is derived from at least one of Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis.

8. The method for converting waste into energy according to claim 7, wherein the lipase is derived from Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis, and the weight percentages of the lipases derived from Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis are 1-3:1-3:1-3.

9. The method for converting waste into energy according to claim 1, wherein in step (b), the volume percentage of the surfactant ionic liquid to the organic waste is 0.005-0.05:

1.

10. The method for converting waste into energy according to claim 1, wherein in step (c), the output power of the ultrasonic treatment is 300 watts to 1200 watts, and the frequency is 20 kHz to 100 kHz.

11. A surfactant ionic liquid generator containing a biocatalyst used to treat an oil-containing base to produce a surfactant ionic liquid, An ultrasonic generator connected to the surfactant ionic liquid generator and used to treat the organic liquid formed by mixing the organic waste and the surfactant ionic liquid, An anaerobic bioreactor connected to the ultrasonic generator and used to treat the organic liquid to produce methane, A waste treatment system comprising: The waste treatment system, wherein the biocatalyst contains at least one lipase, the weight percentage (wt%) of the biocatalyst to the oil-containing base is 0.005-0.02:1, and the surfactant ionic liquid contains at least one of monoglyceride and diglyceride.

12. The waste treatment system according to claim 11, wherein the oil-containing base contains triglycerides having 12 to 20 carbon atoms, and the lipase contains triglyceride lipase (EC 3.1.1.3).

13. The waste treatment system according to claim 12, wherein the lipase is derived from at least one of Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis.

14. The waste treatment system according to claim 13, wherein the lipase is derived from Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis, and the weight percentages of the lipases derived from Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis are 1 to 3:1 to 3:1 to 3, respectively.

15. The waste treatment system according to claim 11, wherein the lipase is immobilized on a carrier, and the base material of the carrier contains chitosan.

Images