Waste treatment system and method for converting waste into energy

Abstract

The invention provides a method for converting waste into energy, comprising the following steps: (a) providing a grease-containing substrate, and reacting the grease-containing substrate with a biocatalyst to produce an interfacial active molecular liquid; (b) pretreating the organic waste with an interfacial active molecule liquid to produce a first organic liquid; (c) performing ultrasonic treatment on the first organic liquid to generate a second organic liquid; and (d) carrying out anaerobic biological treatment on the second organic liquid so as to convert the second organic liquid into methane. The biocatalyst includes at least one lipase, and the interfacial active molecule liquid includes at least one of monoglyceride and diglyceride. The invention also provides a waste treatment system for converting waste into energy.

Description

Technical Field

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

[0002] The current manufacturing industry contributes a considerable output value to the global economy but also generates a large amount of waste. With the circular economy becoming the mainstream, how to convert waste into resources and reduce carbon emissions has gradually attracted the attention of the industry and the government.

[0003] Under the environmental protection requirements of a sustainable environment, the manufacturing industry sludge containing a large amount of organic waste is regarded as a recyclable resource. How to effectively treat and utilize the waste sludge has become an important issue for the current manufacturing industry. In the current sludge treatment technology, the ultrasonic-based physical pretreatment method has advantages in reducing environmental pollution, but it is still a major challenge in terms of power consumption.

[0004] As mentioned above, although the existing waste sludge treatment technologies can generally meet their original intended uses, they still do not fully meet the requirements in all aspects. Therefore, the development of an energy-saving waste sludge treatment method that can maintain the ultrasonic treatment efficiency while shortening the treatment time or improving the treatment efficiency is still a topic of concern in the relevant fields. Summary of the Invention

[0005] According to some embodiments of the present invention, there is provided a method for converting waste into energy, comprising the following steps: (a) providing a grease-containing substrate and reacting it with a biocatalyst to produce an interfacial active molecular liquid; (b) pretreating the organic waste with the interfacial active 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 comprises at least one lipase, the weight percentage of the biocatalyst to the grease-containing substrate is 0.005-0.02:1, and the interfacial active molecular liquid comprises at least one of monoglyceride and diglyceride.

[0006] According to some embodiments of the present invention, a waste treatment system is also provided, which includes a surfactant molecule liquid generator, an ultrasonic generator, and an anaerobic bioreactor. The surfactant molecule liquid generator includes a biocatalyst, which is used to process the oil-containing substrate to generate a surfactant molecule liquid. The ultrasonic generator is connected to the surfactant molecule liquid generator and is used to process the organic liquid produced by mixing the organic waste and the surfactant molecule liquid. The anaerobic bioreactor is connected to the ultrasonic generator and is used to process the organic liquid to generate methane. The biocatalyst includes at least one lipase, and the weight percentage (wt%) of the biocatalyst to the oil-containing substrate is 0.005 - 0.02:1, and the surfactant molecule liquid includes at least one of monoglyceride and diglyceride.

[0007] To make the features or advantages of the present invention more obvious and understandable, several embodiments are specifically given below and are described in detail in conjunction with the accompanying drawings as follows. Brief Description of the Drawings

[0008] Figure 1 Showing a schematic diagram of a waste treatment system according to some embodiments of the present invention;

[0009] Figure 2 Showing a schematic diagram of the hydrolysis reaction of triglyceride catalyzed by lipase (EC 3.1.1.3);

[0010] Figure 3 Showing a flowchart of the steps of a method for converting waste into energy according to some embodiments of the present invention;

[0011] Figure 4 Showing the test results of the oil conversion rate of lipases from different strain sources and biocatalysts with different composition ratios according to some embodiments of the present invention. BSL is the group where the lipase comes from Bacillus subtilis, YLL is the group where the lipase comes from Yarrowia lipolytica, ANL is the group where the lipase comes from Aspergillus niger, BSL+YLL+ANL(1:1:1) is the group where the lipase comes from Bacillus subtilis, Yarrowia lipolytica, and Aspergillus niger, and the weight percentages of the lipases from Bacillus subtilis, Yarrowia lipolytica, and Aspergillus niger used are 1:1:1 respectively. BSL+YLL+ANL(1:2:3) is the group where the lipase comes from Bacillus subtilis, Yarrowia lipolytica, and Aspergillus niger, and the weight percentages of the lipases from Bacillus subtilis, Yarrowia lipolytica, and Aspergillus niger used are 1:2:3 respectively;

[0012] Figure 5 andFigure 6 Show the analysis results of the influence of the addition of the test interfacial active molecular liquid on the ultrasonic treatment of organic waste according to some embodiments of the present invention;

[0013] Figure 7 Show the analysis results of the influence of the addition of the interfacial active molecular liquid on the anaerobic biological treatment (methane production potential) of organic waste according to some embodiments of the present invention.

[0014] Wherein, reference numerals:

[0015] 10: Waste treatment system

[0016] 20: Method for converting waste into energy

[0017] 110: Interfacial active molecular liquid generator

[0018] 110c: Biological catalyst

[0019] 112: Interfacial active molecular liquid storage tank

[0020] 120: Ultrasonic generator

[0021] 130: Anaerobic bioreactor

[0022] MT: Methane

[0023] OG: First organic liquid

[0024] OG’: Second organic liquid

[0025] S1, S2, S3, S4: Steps

[0026] SC: Interfacial active molecular liquid

[0027] W1: Grease-containing matrix

[0028] W2: Organic waste Detailed implementation manners

[0029] The following will make a detailed description of the waste treatment system and the method for converting waste into energy according to the embodiments of the present invention. It should be understood that the following description provides many different embodiments or examples for implementing different aspects of some embodiments of the present invention. The specific elements and arrangements described below are only for simply and clearly describing some embodiments of the present invention. Of course, these are only for illustration and not for limiting the present invention.

[0030] Embodiments of the present invention can be combined with the attached Figure 1It is understood that the drawings of the present invention are also regarded as part of the description of the invention. It should be understood that the drawings of the present invention are not drawn to scale. In fact, the dimensions of the elements may be arbitrarily enlarged or reduced to clearly show the features of the present invention.

[0031] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. It can be understood that these terms, such as those defined in a commonly used dictionary, should be interpreted as having a meaning consistent with the relevant technology and the background or context of the present invention, and should not be interpreted in an idealized or overly formal manner, unless specifically defined in the embodiments of the present invention.

[0032] In view of the demand for waste sludge reduction faced by the current industry and the market demand for related technical products and services, embodiments of the present invention provide a method for converting waste into energy, which combines a biological catalyst technology and an ultrasonic sludge treatment technology, and incorporates a resource and energy conversion unit to generate biogas, thereby establishing a waste treatment system with high treatment efficiency and energy conservation. According to the embodiments of the present invention, the method for converting waste into energy and the waste treatment system can accelerate the conversion of organic waste into biogas for reuse, reduce the treatment cost of organic waste, increase the output of biogreen electricity, and at the same time achieve the carbon reduction effect of waste reduction and the energy conversion of waste resources.

[0033] Figure 1 FIG. shows a schematic diagram of a waste treatment system 10 according to some embodiments of the present invention. It should be understood that for the sake of clarity, some elements of the waste treatment system 10 are omitted in the drawings, and only some elements are schematically shown. According to an embodiment, additional features may be added to the waste treatment system 10 described below.

[0034] Please refer to Figure 1 , the waste treatment system 10 may include a surfactant liquid generator 110, an ultrasonic generator 120, and an anaerobic bioreactor 130. The ultrasonic generator 120 may be connected to the surfactant liquid generator 110, and the anaerobic bioreactor 130 may be connected to the ultrasonic generator 120. The ultrasonic generator 120 may be located downstream of the surfactant liquid generator 110, and the anaerobic bioreactor 130 may be located downstream of the ultrasonic generator 120. According to some embodiments, the aforementioned surfactant liquid generator 110, ultrasonic generator 120, and anaerobic bioreactor 130 may be connected by pipelines.

[0035] The surfactant molecule liquid generator 110 may include a biocatalyst 110c, which can be used to process the oil-containing substrate W1 to generate a surfactant molecule liquid SC. According to some embodiments, the oil-containing substrate W1 may be provided by a substrate providing unit (not shown), and the substrate providing unit may be connected to the surfactant molecule liquid generator 110.

[0036] According to some embodiments, the oil-containing substrate W1 may include medium-and-long chain triglycerides (MLCT) with a carbon number of C12-C20. For example, triglycerides with a carbon number of C12, C14, C16, C18, or C20, but not limited thereto. According to some embodiments, the oil-containing substrate W1 may include long-chain triglycerides with a carbon number of C16-C20. According to some embodiments, the oil-containing substrate W1 may include food industry wastewater, manufacturing wastewater, edible oils, feed oils, recycled oils of the foregoing oils, other suitable oils, or a combination of the foregoing, but not limited thereto.

[0037] The biocatalyst 110c may include at least one lipase. Furthermore, the lipase may be immobilized on a carrier, and the substrate of the carrier may include chitosan or other suitable carrier substrates, but not limited thereto. According to some embodiments, the lipase may include triglyceride lipase (EC 3.1.1.3), but not limited thereto. According to some embodiments, the lipase may be from at least one of Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis. According to some embodiments, the lipase is from Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis, and the weight percentages of the lipases from Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis may be 1-3:1-3:1-3. In particular, lipases from multiple strains can provide better broad-spectrum properties and improve the efficiency of lipase-catalyzed oil hydrolysis.

[0038] The surfactant molecule liquid SC generated by the action of lipase on the oil-containing substrate W1 refers to a liquid with surfactant properties, and the surfactant molecule liquid SC may include at least one of monoglyceride and diglyceride. For example, please refer to Figure 2 , Figure 2Schematic diagram showing the hydrolysis reaction of triglycerides catalyzed by lipase (EC 3.1.1.3). Lipase acts on the ester bond of oil molecules, which can hydrolyze triglycerides into diglycerides and fatty acids, and can subsequently hydrolyze diglycerides into monoglycerides and fatty acids, and can further hydrolyze monoglycerides into glycerol and fatty acids. It should be noted that monoglycerides and diglycerides in the surfactant molecule liquid SC have an emulsifier-like function. When continuously acting on the organic waste W2, they can increase 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, free fatty acid molecules can be used as precursor nutrients for anaerobic bioconversion into methane, which can increase the production of biogas methane in the subsequent treatment stage of the anaerobic bioreactor 130.

[0039] Furthermore, the weight percentage (wt%) of the biocatalyst to the oil-containing substrate W1 can be 0.005 to 0.02:1. For example, it can be 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 not limited thereto. In particular, if the ratio of the biocatalyst to the oil-containing substrate W1 is too low (for example, less than 0.005:1), the time required for the action of lipase may be too long, reducing the processing efficiency of the surfactant molecule liquid generator 110; conversely, if the ratio of the biocatalyst to the oil-containing substrate W1 is too high (for example, higher than 0.02:1), the production cost will be greatly increased.

[0040] According to some embodiments, the surfactant molecule liquid generator 110 reacts under the conditions of a temperature of 25°C to 45°C and a pH value of pH 6.5 to pH 7.5, so that the oil-containing substrate W1 reacts with the biocatalyst 110c to produce the surfactant molecule liquid SC. According to some embodiments, the reaction temperature of the surfactant molecule liquid generator 110 is 25°C to 40°C, or 25°C to 35°C. For example, it can be 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, or 34°C, but not limited thereto. According to some embodiments, the reaction pH value of the surfactant molecule 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 not limited thereto.

[0041] Furthermore, according to some embodiments, the waste treatment system 10 may further include a surfactant liquid storage tank 112. The surfactant liquid storage tank 112 may be connected to the surfactant liquid generator 110 for temporarily storing the surfactant liquid SC. Moreover, the surfactant liquid storage tank 112 may be further connected to the ultrasonic generator 120 to deliver the surfactant liquid SC to the ultrasonic generator 120.

[0042] Specifically, before being delivered to the ultrasonic generator 120, the surfactant liquid SC may be mixed with the organic waste W2. The surfactant liquid SC may pre-treat the organic waste W2 to produce a first organic liquid OG. The treated first organic liquid OG may be decomposed into a homogeneous organic liquid with smaller molecules, such as organic sludge.

[0043] According to some embodiments, the organic waste W2 may be provided by a waste supply unit (not shown). The waste supply unit may be connected to the ultrasonic generator 120. Specifically, after the pipeline of the waste supply unit is connected to the pipeline of the surfactant liquid generator 110, they may be connected together to the ultrasonic generator 120.

[0044] According to some embodiments, the organic waste W2 may include manufacturing waste, petrochemical waste, agricultural waste, livestock waste, food waste, other suitable organic wastes, or a combination of the foregoing, but is not limited thereto.

[0045] As mentioned above, the surfactant liquid SC produced after the oil-containing matrix W1 is processed by the surfactant liquid generator 110 includes at least one of monoglyceride and diglyceride. Monoglyceride and diglyceride have an emulsifier-like function, which can increase 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.

[0046] According to some embodiments, in the homogeneous first organic liquid OG, the volume percentage (v / v%) of the surfactant liquid SC to the organic waste W2 may be 0.005 - 0.05:1. For example, it may be 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 liquid SC to the organic waste W2 is within the foregoing range, the treatment efficiency of the surfactant liquid SC for the organic waste W2 can be effectively improved.

[0047] According to some embodiments, the pretreatment of the surfactant molecule liquid SC on the organic waste W2 is carried out by a continuous reaction under the conditions of a temperature of 20°C to 60°C and a pH value of pH 5 to pH 8. According to some embodiments, the reaction temperature of the aforementioned pretreatment can be 30°C to 50°C, or 30°C to 40°C. For example, it can be 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 not limited thereto. According to some embodiments, the reaction pH value of the aforementioned pretreatment can be pH 6.5 to pH 7.5. For example, it 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 not limited thereto.

[0048] Furthermore, the ultrasonic generator 120 is used to process the first organic liquid OG generated by mixing the organic waste W2 and the surfactant molecule liquid SC to generate a second organic liquid OG'. The ultrasonic generator 120 can apply ultrasonic energy to the first organic liquid OG to hydrolyze organic matter and improve the efficiency of subsequent biological anaerobic treatment in the anaerobic bioreactor 130. Specifically, the impact force generated by the cavitation effect provided by the ultrasonic wave can destroy the structure of the first organic liquid OG (for example, the cell wall of microorganisms in the organic sludge), increase the concentration of dissolved organic matter in the first organic liquid OG, make it easier for subsequent anaerobic microorganisms to digest, and thus shorten the time required for biological anaerobic treatment.

[0049] According to some embodiments, the output power of the ultrasonic treatment can be 300 watts to 1200 watts. For example, it can be 400 watts, 500 watts, 600 watts, 700 watts, 800 watts, 900 watts, 1000 watts or 1100 watts, but not limited thereto. According to some embodiments, the frequency of the ultrasonic treatment can be 20 kilohertz (kHz) to 100 kHz. For example, it can be 30 kHz, 40 kHz, 50 kHz, 60 kHz, 70 kHz, 80 kHz or 90 kHz, but not limited thereto.

[0050] The anaerobic bioreactor 130 can be used to treat the second organic liquid OG' to generate methane MT, and the methane MT can be provided to a subsequent biogas power generation facility for conversion into electrical energy. Specifically, anaerobic biological treatment can decompose and transform small-molecule organic substances through the biochemical metabolism of microorganisms to produce biogas, such as methane. According to some embodiments, the anaerobic bioreactor 130 may contain hydrolytic bacteria, acid-forming bacteria, methanogens, other suitable bacterial species, or a combination of the foregoing, but is not limited thereto.

[0051] According to some embodiments, the anaerobic biological treatment carried out in the anaerobic bioreactor 130 is carried out under the conditions of a temperature of 25°C to 45°C and a pH value of 6.8 to 7.2. According to some embodiments, the reaction temperature of the foregoing anaerobic biological treatment may be 30°C to 40°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 value of the foregoing anaerobic biological treatment may be pH 6.9, pH 7, or pH 7.1, but is not limited thereto.

[0052] In addition, the present invention also provides a method 20 for converting waste into energy. Figure 3 Shown is a flowchart of the steps of the method 20 for converting waste into energy according to some embodiments of the present invention. According to some embodiments, the method 20 for converting waste into energy includes using the foregoing waste treatment system 10 to treat organic waste, but the present invention is not limited thereto. It should be understood that according to some embodiments, additional steps may be added before, during, and / or after the following-described method 20 for converting waste into energy, or some steps may be replaced or omitted.

[0053] As Figure 3 shown, the method 20 for converting waste into energy may include step S1: providing an oil-containing substrate W1 and reacting it with the biocatalyst 110c to produce an interfacial active molecular liquid SC.

[0054] According to some embodiments, the oil-containing substrate W1 may include medium- and long-chain triglycerides with a carbon number of C12-C20. For example, it may be a triglyceride with a carbon number of C12, C14, C16, C18, or C20, but is not limited thereto. According to some embodiments, the oil-containing substrate W1 may include long-chain triglycerides with a carbon number of C16-C20. According to some embodiments, the oil-containing substrate W1 may include food industry wastewater, manufacturing industry wastewater, edible oils, feed oils, recycled oils of the foregoing oils, other suitable oils, or a combination of the foregoing, but is not limited thereto.

[0055] The biocatalyst 110c may include at least one lipase. Furthermore, the lipase may be immobilized on a carrier, and the substrate of the carrier may include chitosan or other suitable carrier substrates, but is not limited thereto. According to some embodiments, the lipase may include triglyceride lipase (EC 3.1.1.3), but is not limited thereto. According to some embodiments, the lipase may be from at least one of Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis. According to some embodiments, the lipase is from Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis, and the weight percentages of the lipases from Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis may be 1-3:1-3:1-3. For example, they may be 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 is not limited thereto. In particular, lipases from multiple strains can provide better broad-spectrum effects and can improve the efficiency of lipase-catalyzed oil hydrolysis. Furthermore, the lipases from the aforementioned specific strains have good substrate pairing properties, especially good catalytic performance for medium and long-chain triglycerides with carbon numbers C12-C20.

[0056] The surfactant molecular liquid SC produced by the action of lipase on the oil-containing matrix W1 may include at least one of monoglyceride and diglyceride. The monoglyceride and diglyceride in the surfactant molecular liquid SC have an emulsifier-like function. When continuously acting on the organic waste W2, they can increase 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, free fatty acid molecules can be used as precursor nutrients for anaerobic bioconversion to methane, increasing the production of biogas methane.

[0057] Furthermore, the weight percentage (wt%) of the biocatalyst to the oil-containing substrate W1 can be 0.005 to 0.02:1. For example, it can be 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 not limited thereto. In particular, if the proportion of the biocatalyst relative to the oil-containing substrate W1 is too low (e.g., lower than 0.005:1), the action time of lipase may be too long, resulting in poor treatment efficiency. On the contrary, if the proportion of the biocatalyst relative to the oil-containing substrate W1 is too high (e.g., higher than 0.02:1), the production cost will be significantly increased.

[0058] According to some embodiments, step S1 is carried out under the conditions of a temperature of 25°C to 45°C and a pH value of 6.5 to 7.5 for 1 hour to 9 hours. According to some embodiments, the reaction temperature of step S1 can be 25°C to 40°C or 25°C to 35°C. For example, it can be 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 not limited thereto. According to some embodiments, the reaction pH value of step S1 can be pH6.6, pH6.7, pH 6.8, pH 6.9, pH 7, pH 7.1, pH 7.2, pH 7.3, or pH 7.4, but not limited thereto. According to some embodiments, the reaction time of step S1 can 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 not limited thereto.

[0059] In addition, according to some embodiments, step S1 further includes adjusting the oil content of the oil-containing substrate W1 to 30wt% to 50wt%. For example, it can be adjusted to 35wt%, 40wt%, or 45wt%, but not limited thereto. It should be noted that if the oil content in the oil-containing substrate W1 is too high (e.g., higher than 50wt%), lipase may not act effectively, resulting in poor fat hydrolysis effect.

[0060] Furthermore, the method 20 for converting waste into energy may include step S2: pretreating the organic waste W2 with the surfactant ionic liquid SC to produce the first organic liquid OG.

[0061] According to some embodiments, the organic waste W2 may include manufacturing waste, petrochemical waste, agricultural waste, livestock waste, food waste, other suitable organic waste, or a combination of the foregoing, but is not limited thereto.

[0062] As mentioned above, the surfactant molecular liquid SC includes at least one of monoglyceride and diglyceride. Since monoglyceride and diglyceride have an emulsifier-like function, the solubility and homogeneity of the organic waste W2 can be increased, the surface tension of the mixed liquid to be treated can be reduced, and the time required for subsequent ultrasonic treatment can be shortened.

[0063] 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. For example, it may be 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 foregoing range, the treatment efficiency of the surfactant molecular liquid SC for the organic waste W2 can be effectively improved.

[0064] According to some embodiments, step S2 is carried out under continuous reaction conditions of a temperature of 20°C to 60°C and a pH value of pH 5 to pH 8. According to some embodiments, the reaction temperature of step S2 may be 30°C to 50°C, or 30°C to 40°C. For example, it may be 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 value of step S2 may be pH 6.5 to pH 7.5. For example, it may 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.

[0065] Furthermore, the method 20 for converting waste into energy may include step S3: subjecting the first organic liquid OG to ultrasonic treatment to produce a second organic liquid OG'.

[0066] According to some embodiments, the output power of the ultrasonic treatment may be from 300 watts to 1200 watts. For example, it may be 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. For example, it may be 30 kHz, 40 kHz, 50 kHz, 60 kHz, 70 kHz, 80 kHz, or 90 kHz, but is not limited thereto.

[0067] Furthermore, the method 20 of converting waste into energy may include step S4: anaerobically biotreating the second organic liquid OG' to generate methane MT.

[0068] According to some embodiments, step S4 includes performing anaerobic biotreatment using hydrolytic bacteria, acid-forming bacteria, methanogenic bacteria, other suitable strains, or a combination of the foregoing, 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. For example, it may be 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.

[0069] To make the above and other objects, features, and advantages of the present invention more apparent and understandable, several embodiments, comparative examples, and test examples are hereinafter specifically described in detail. However, they are not intended to limit the content of the present invention.

[0070] Example 1 - Preparation of Biocatalyst

[0071] Dissolve chitosan with 1% acetic acid to prepare a 2% chitosan solution. Use a syringe to dropwise add the chitosan solution into 10% sodium hydroxide solution, and chitosan gel microspheres are formed by coagulation in the solution. Place them at room temperature to harden for 60 minutes, and then repeatedly rinse with deionized water until neutral. Next, cross-link and immobilize the gel microspheres containing 2% chitosan and a lipase solution with a relative carrier concentration of 500 U / g (EC 3.1.1.3, from Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis, and the composition ratio of the three is 1:1:1). After 180 minutes, take them out and wash them clean to complete the chitosan gel microspheres containing immobilized lipase. Compared with the free enzyme, the enzyme activity retention rate of the obtained immobilized enzyme can reach 72.6%, and the retention rate can still reach 88.2% after 10 batches of oil hydrolysis reaction tests. It can be seen from this that the biocatalyst prepared in the embodiment of the present invention has good enzyme activity and stability and can be applied to the waste treatment system.

[0072] Example 2 - Preparation of Surfactant Ionic Liquid

[0073] Use the wastewater from a food factory containing medium and long-chain triglycerides as the oil-containing substrate, and adjust its oil content to the range of 30 - 50 wt%. Use the aforementioned oil-containing substrate as the substrate raw material for preparing the surfactant ionic liquid. Then, react the oil-containing substrate with the biocatalyst prepared in Example 1. The weight percentage (wt%) of the biocatalyst to the oil-containing substrate is 0.005 - 0.02:1. The conversion reaction 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 - 3 hours of batch treatment to catalytically produce a surfactant ionic liquid containing monoglyceride, diglyceride, and free fatty acid molecules.

[0074] Example 3 - Oil Conversion Rate Test of Biocatalysts with Lipases from Different Strain Sources and Compositions

[0075] Take the wastewater from a food factory with the same source as in Example 2 as the oil-containing substrate, and dilute it to an oil content of 50 wt%. Use the aforementioned oil-containing substrate as the substrate raw material for this reaction test. Furthermore, establish 5 groups of biocatalysts with the strain sources and compositions shown in Table 1 below.

[0076] Table 1

[0077]

[0078]

[0079] The experiment was divided into 5 groups. 100 g of the aforementioned oil-containing matrix was taken as the substrate for the reaction test, and 2 g of the aforementioned 5 kinds of biocatalysts with different compositions were added respectively. Under the conditions of a temperature of 30°C and a pH of 7.0, the reaction was carried out with uniform stirring. 1 ml of the reaction solution was taken out after the reaction time reached 3 hours, 6 hours, and 9 hours respectively for the analysis of the oil decomposition rate, so as to obtain the oil conversion rate data of the above 5 kinds of biocatalysts with different compositions. The results are as Figure 4 shown. Among them, BSL is Group 1 where the lipase is from Bacillus subtilis, YLL is Group 2 where the lipase is from Yarrowia lipolytica, ANL is Group 3 where the lipase is from Aspergillus niger, BSL + YLL + ANL (1:1:1) is Group 4 where the lipase is from Bacillus subtilis, Yarrowia lipolytica and Aspergillus niger (weight percentage is 1:1:1), and BSL + YLL + ANL (1:2:3) is Group 5 where the lipase is from Bacillus subtilis, Yarrowia lipolytica and Aspergillus niger (weight percentage is 1:2:3).

[0080] As Figure 4 shown, the oil conversion rates of BSL from a single strain source at 3 hours, 6 hours, and 9 hours of reaction time were 12%, 14%, and 15% respectively; the oil conversion rates of YLL from a single strain source at 3 hours, 6 hours, and 9 hours of reaction time were 21%, 24%, and 26% respectively; the oil conversion rates of ANL from a single strain source at 3 hours, 6 hours, and 9 hours of reaction time were 25%, 32%, and 37% respectively; the oil conversion rates of BSL + YLL + ANL (1:1:1) from multiple strain sources at 3 hours, 6 hours, and 9 hours of reaction time were 38%, 46%, and 50% respectively; the oil conversion rates of BSL + YLL + ANL (1:2:3) from multiple strain sources at 3 hours, 6 hours, and 9 hours of reaction time were 49%, 52%, and 53% respectively.

[0081] From the above results, it can be seen that biocatalysts with lipases from single strain sources and multiple strain sources can both catalyze the conversion of oil, and biocatalysts with lipases from multiple strain sources have better catalytic conversion efficiency, and the effect is better when the proportion of Aspergillus niger is high (BSL + YLL + ANL (1:2:3)).

[0082] Example 4 - Experiment on the oil conversion rate of biocatalysts using different types of oils as substrate raw materials

[0083] Olive oil (belonging to long-chain triglycerides, LCT) and coconut oil (belonging to medium-chain triglycerides, MCT), two types of oils with different carbon chain lengths, were respectively used as the substrates for this reaction experiment. And the biocatalyst of BSL+YLL+ANL (1:1:1) from various strain sources described in Example 3 was added respectively to prepare the surfactant liquid. After the reaction, the conversion rates of these two types of oil with different chain lengths were analyzed.

[0084] The experiment was divided into 2 groups. 100 g of the water samples containing 50 wt% olive oil and 50 wt% coconut oil described above were respectively taken as the substrates for this reaction experiment. 2 g of the biocatalyst of BSL+YLL+ANL (1:1:1) from various strain sources described in Example 3 was added respectively. Under the conditions of a temperature of 30 °C and a pH of 7.0, after uniformly stirring and reacting for 3 hours, 1 ml of the reaction solution was taken out for the analysis of the oil decomposition rate to obtain the oil conversion rate data when the above two different types of oils were used as the substrate raw materials.

[0085] The results showed 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%. From the above results, it can be seen that both long-chain carbon oils and medium-chain carbon oils can be used as the substrate raw materials for biocatalysts from various strain sources.

[0086] Example 5 - Organic waste decomposition experiment

[0087] Taking the waste solid sludge from the petrochemical industry as the organic waste, the organic waste was mixed with the surfactant liquid prepared in Example 2 above to form a homogeneous organic liquid. The organic liquid was subjected to ultrasonic treatment, and then the chemical oxygen demand (COD) (i.e., the concentration of dissolved organic matter, unit: mg / L) of the reaction hydrolyzate after ultrasonic treatment was measured to determine the effect of ultrasonic pretreatment.

[0088] After 250 ml of organic sludge was mixed with 250 ml of pure water and 250 ml of the surfactant liquid respectively, the concentration of suspended solids (SS) in the organic sludge was measured to be 10256 mg / L, and the concentration of volatile solids (VSS) was 7423 mg / L. Then, ultrasonic waves with a frequency of 20 kHz and a power of 500 watts were used to treat it sequentially for 2.5 minutes, 5 minutes, 7.5 minutes, and 10 minutes. The results are as Figure 5 shown.

[0089] Figure 5Analysis results of the dissolved organic matter concentration of experimental samples without any pretreatment (organic sludge added with pure water, but without ultrasonic treatment), without adding surfactant liquid (organic sludge added with pure water, with ultrasonic treatment), and adding surfactant liquid (organic sludge added with surfactant liquid, with ultrasonic treatment) after ultrasonic treatment for 2.5 minutes, 5 minutes, 7.5 minutes, and 10 minutes respectively.

[0090] As Figure 5 shown, for the samples without any pretreatment, the concentration of dissolved organic matter remained at 208 mg / L; for the samples without adding surfactant liquid, the concentrations of dissolved organic matter after ultrasonic treatment for 2.5 minutes, 5 minutes, 7.5 minutes, and 10 minutes were 1755 mg / L, 2508 mg / L, 3106 mg / L, and 3512 mg / L in sequence; for the samples adding surfactant liquid, the concentrations of dissolved organic matter after ultrasonic treatment for 2.5 minutes, 5 minutes, 7.5 minutes, and 10 minutes were 3226 mg / L, 3806 mg / L, 3921 mg / L, and 4008 mg / L in sequence.

[0091] Compared with the concentration of dissolved organic matter of 3512 mg / L after ultrasonic treatment for 10 minutes for the samples without adding surfactant liquid, the concentration of dissolved organic matter of the samples adding surfactant liquid after ultrasonic treatment for 10 minutes increased to 4008 mg / L, and the decomposition effect of organic waste increased by about 14%.

[0092] Next, please refer to Figure 6 , Figure 6 which is the conversion of the Figure 5 experimental results into a line chart. As Figure 6 shown, the concentration of dissolved organic matter of the samples adding surfactant liquid reached 3806 mg / L (energy consumption of 42 W) after ultrasonic treatment for 5 minutes, which has exceeded 3512 mg / L (energy consumption of 83 W) reached after ultrasonic treatment for 10 minutes for the samples without adding surfactant liquid.

[0093] From the above results, it can be seen that compared with the ultrasonic sludge treatment method without using a biological catalyst (without adding surfactant liquid), the treatment method of using a biological catalyst (adding surfactant liquid) to catalyze and cooperate with the ultrasonic sludge treatment technology only requires half of the energy consumption (from 83 W to 42 W), and can increase the concentration of dissolved organic matter of the object to be treated to 3512 mg / L, effectively increasing the treatment efficiency by more than 50%.

[0094] Example 6 - Methane production potential test

[0095] The experiment was divided into two groups. Three identical 600 ml reaction flasks were prepared for each group. The two groups of reaction flasks were respectively filled with 350 ml of organic hydrolyzed sludge matrix and 150 ml of inoculated sludge (the inoculated sludge was taken from the anaerobic biological treatment unit of the wastewater treatment plant in a food factory, and contained general anaerobic bacteria such as hydrolytic bacteria, acidifying bacteria and methanogenic bacteria) that had been ultrasonically treated for 5 minutes after fully mixing the (1) liquid without surfactant molecules and (2) liquid with surfactant molecules obtained in Example 5 above. And the reaction was continuously carried out with shaking and stirring for more than 21 days under the conditions of a temperature of 35 °C and a pH of 7.0 to conduct a batch anaerobic digestion experiment. A gas collection hole was provided above the bottle cap of the reaction flask. The gas generated by the decomposition of the organic hydrolyzed sludge was collected by the water displacement method every day, and the cumulative gas production of each test sample was recorded. The results are as Figure 7 shown.

[0096] As Figure 7 shown, when the anaerobic biological treatment reached the 11th day, the reaction was roughly completed. The cumulative gas production of the organic waste hydrolyzed sludge without surfactant molecules was 99 ml, and the cumulative gas production of the organic waste hydrolyzed sludge with surfactant molecules was 121 ml. It is estimated from this that compared with the sample without surfactant molecules, the methane production of the sample with surfactant molecules increased by about 22%, effectively improving the efficiency of converting waste into energy.

[0097] To sum up, according to the embodiments of the present invention, the method for converting waste into energy is provided, which uses biological catalyst technology to cooperate with ultrasonic sludge treatment technology, and combines a resource and energy unit to generate biogas. Thereby, a waste treatment system with high treatment efficiency and energy saving is established. According to the embodiments of the present invention, the method for converting waste into energy and the waste treatment system can accelerate the conversion of organic waste into biogas for reuse, reduce the treatment cost of organic waste, increase the output of biogenic green electricity, and at the same time achieve the carbon reduction effect of waste reduction and the energy conversion of waste resources.

[0098] Although the embodiments of the present invention and their advantages have been disclosed above, it should be understood that any person with common general knowledge in the technical field can make changes, substitutions and modifications without departing from the spirit and scope of the present invention. Furthermore, each claim constitutes an individual embodiment, and the protection scope of the present invention also includes the combination of each claim and embodiment. The protection scope of the present invention shall be subject to the scope defined by the appended claims.

Claims

1. A method for converting waste into energy, comprising the following steps: (a) providing a lipid matrix and reacting it with a biocatalyst to produce a surface active molecular liquid; (b) pre-treating an organic waste with the surface-active molecular liquid to produce a first organic liquid; (c) performing an ultrasonic treatment on the first organic liquid to produce a second organic liquid; and (d) subjecting the second organic liquid to an anaerobic biological treatment to convert it into methane, The biocatalyst includes at least one lipase, the weight percentage (wt%) of the biocatalyst to the oil-containing matrix is ​​0.005-0.02:1, and the surface active molecular liquid includes at least one of monoglyceride and diglyceride.

2. The method for converting waste into energy according to claim 1, wherein the oil-containing matrix comprises food industry wastewater, manufacturing industry wastewater, edible oil, feed oil, recycled oil of the aforementioned oils, or a combination thereof.

3. The method for converting waste into energy according to claim 1, wherein the oil-containing matrix comprises triglycerides (medium-and-long chain triglycerides, MLCT) with carbon numbers of C12-C20.

4. The method for converting waste into energy according to claim 1, wherein step (a) further comprises adjusting the fat content of the fat-containing matrix to 30 wt% to 50 wt%.

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

6. The method of converting waste into energy according to claim 1, wherein the lipase comprises 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 from Aspergillus niger, Yarrowia lipolytica and Bacillus subtilis, and the weight percentage of the lipases from Aspergillus niger, Yarrowia lipolytica and Bacillus sphaericus respectively is 1-3:1-3:1-3.

9. The method for converting waste into energy according to claim 1, wherein the lipase is immobilized on a support, and the substrate of the support comprises chitosan.

10. The method for converting waste into energy according to claim 1, wherein the organic waste comprises manufacturing waste, petrochemical waste, agricultural waste, livestock waste, food waste or a combination thereof. 11 . The method for converting waste into energy according to claim 1 , wherein in step (b), the volume percentage of the surface active molecule liquid to the organic waste is 0.005-0.05:

1.

12. The method for converting waste into energy according to claim 1, wherein step (b) is a continuous reaction carried out at a temperature of 20°C to 60°C and a pH of 5 to 8.

13. The method of 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.

14. A waste treatment system comprising: A surface active molecule liquid generator, comprising a biocatalyst, for treating a lipid-containing matrix to produce a surface active molecule liquid; an ultrasonic generator connected to the surface active molecule liquid generator for treating an organic liquid generated by mixing an organic waste with the surface active molecule liquid; and an anaerobic bioreactor connected to the ultrasonic generator for treating the organic liquid to generate methane, The biocatalyst includes at least one lipase, the weight percentage (wt%) of the biocatalyst to the oil-containing matrix is ​​0.005-0.02:1, and the surface active molecular liquid includes at least one of monoglyceride and diglyceride.

15. The waste treatment system of claim 14, wherein the lipid-containing matrix comprises triglycerides with carbon numbers of C12-C20. 16 . The waste treatment system according to claim 14 , wherein the surfactant molecule liquid generator performs the reaction at a temperature of 25° C. to 45° C. and a pH of 6.5 to 7.

5.

17. The waste treatment system of claim 14, wherein the lipase comprises a triglyceride lipase (EC 3.1.1.3).

18. The waste treatment system according to claim 17, wherein the lipase is derived from at least one of Aspergillus niger, Yarrowia lipolytica, and Bacillus subtilis. 19 . The waste treatment system according to claim 18 , wherein the lipase is from Aspergillus niger, Yarrowia lipolytica and Bacillus subtilis, and the weight percentage of the lipases from Aspergillus niger, Yarrowia lipolytica and Bacillus subtilis respectively is 1-3:1-3:1-3.

20. The waste treatment system according to claim 14, wherein the lipase is immobilized on a support, and a substrate of the support comprises chitosan.

21. The waste treatment system according to claim 14, wherein the surface active molecular liquid pre-treats the organic waste to produce the organic liquid, and the pre-treatment is a continuous reaction at a temperature of 20°C to 60°C and a pH of 5 to 8.

22. The waste treatment system of claim 14, wherein the output power of the ultrasonic treatment is 300 watts to 1200 watts, and the frequency is 20 kHz to 100 kHz.

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