KR20210037898A - Biofuel production system using organic waste and biofuel production method using same - Google Patents

Abstract

The present invention relates to a biofuel production system using organic waste and a biofuel production method using the same, wherein hydrogen is produced by acid fermentation of the organic waste and a fermentation broth in the acid fermentation tank is separated into solid and liquid components through a solid-liquid separator. The content of organic acid containing butyrate negative ions, which is a raw material of alcohol, in the liquid component is increased through an electrodialysis device to increase the alcohol production yield, and the solid component is methane-fermented in a biogas fermenter and then carbon dioxide is removed therefrom through a biogas refining unit to produce high-purity biogas.

Description

Biofuel production system using organic waste and biofuel production method using the same {BIOFUEL PRODUCTION SYSTEM USING ORGANIC WASTE AND BIOFUEL PRODUCTION METHOD USING SAME}

The present invention relates to a biofuel production system using organic waste and a biofuel production method using the same, and more particularly, to produce hydrogen by acid fermentation of organic waste, and the fermentation broth of the acid fermentation tank is solid through a solid-liquid separator. Separation into a component and a liquid component, but the liquid component increases the alcohol production yield by increasing the content of the organic acid containing the butyrate anion, the raw material of alcohol through an electrodialysis device, while the solid component is fermented with methane in a biogas fermentation tank. The present invention relates to a biofuel production system using organic waste that can produce high-purity biogas by removing carbon dioxide through a biogas purification unit, and a biofuel production method using the same.

Currently, organic wastes (sewage sludge, livestock manure, food waste, organic urban solid waste) generated in Korea are over 100 million tons per year. It is being processed.

However, due to the lack of landfill sites and the possibility of inflow of secondary pollutants into the water system, negative perceptions about the reclamation of organic wastes have already prevailed, and ocean dumping, which was the most representative treatment method due to economic and technical advantages, was also prohibited by the London Convention. .

In addition, the anaerobic digestion process is recognized as the most environmentally friendly treatment method due to the difficulty of securing a vendor due to excessive energy consumption due to air injection and the low quality of the final product produced.

However, the existing biogasification technology through anaerobic digestion is problematic due to high initial facility investment, low biogas production rate, and long residence time, and successful operation cases due to the introduction of foreign technology that does not match the characteristics of domestic organic waste. Is known to be extremely rare. In addition, when biogas is used as electric power, conversion efficiency is low, and when it is used as vehicle fuel and city gas, there is a problem that expensive refining costs are additionally incurred.

Meanwhile, an example of a method for treating organic waste according to the prior art is disclosed in Korean Patent Publication No. 2016-0132165 (published on November 17, 2016, hereinafter referred to as'Patent Document 1').

However, since Patent Document 1 can only treat small-scale woody organic waste, there is a problem that its utility may be degraded.

In addition, a biofuel simultaneous production system and its production method (Korean Patent Registration No. 1814482, hereinafter referred to as'Patent Document 2') applied to the applicant of the present application have been registered.

However, the biogas produced by Patent Document 2 contains carbon dioxide and has a problem that the purity of methane is low, and by supplying the liquid component directly from the solid-liquid separator to the alcohol fermentation tank, other impurities other than the organic acid contained in the liquid component are included. There was a problem that the production yield was low.

Korean Patent Publication No. 2016-0132165 Korean Patent Registration No. 1814482

The present invention was conceived in consideration of the above problems, and the first object of the present invention is to produce hydrogen by acid fermentation of organic waste, and the fermentation broth of the acid fermentation tank is converted into solid components and liquid components through a solid-liquid separator. Separation, but the liquid component is a biofuel production system using organic waste that improves the alcohol production yield by increasing the content of organic acid including butyrate anion, which is a raw material for alcohol production, through an electrodialysis device, and a biofuel production method using the same. It is to provide.

Further, a second object of the present invention is to produce high-purity biogas from which hydrogen sulfide, siloxane and carbon dioxide are removed through the biogas purification unit after methane fermentation of the solid components separated in the solid-liquid separator is fermented with methane in a biogas fermentor. It is to provide a biofuel production system using organic waste and a biofuel production method using the same.

According to a feature for achieving the above object, the first invention relates to a biofuel production system using organic waste, a storage tank for storing organic waste for this purpose; And, supplying organic waste from the storage tank A pulverizer for receiving and pulverizing; And an acid fermentation tank for acid-fermenting organic waste supplied from the pulverizer to decompose into organic acids and simultaneously producing hydrogen; and for solid-liquid separation of the fermentation broth supplied from the acid fermentation tank into solid and liquid components. A solid-liquid separator; and a biogas fermentation tank for generating biogas by fermenting the solid components separated in the solid-liquid separator; And an alcohol fermentation tank for producing alcohol by receiving the liquid components separated from the solid-liquid separator, wherein the biogas fermentation tank separates carbon dioxide contained in the biogas and purifies it into high-purity biogas. The biogas purification unit includes at least two filter units for removing foreign substances contained in the biogas, hydrogen sulfide and an adsorption tower for removing siloxane, hydrogen sulfide and siloxane. It is characterized in that it comprises a compressor that compresses the removed biogas at a high pressure, and a purification unit that receives the compressed biogas and removes carbon dioxide.

In the second invention, in the first invention, impurities contained in the liquid component are removed between the solid-liquid separator and the alcohol fermentation tank, and an organic acid containing butyrate anion, a raw material for alcohol production, is supplied to the alcohol fermentation tank to produce alcohol. It characterized in that it further comprises an electrodialysis device capable of increasing the yield.

In the third invention, in the second invention, the refining unit has a linear body having a diameter relatively larger than that of the inlet and the outlet so that the internal pressure is increased, a polyimide hollow fiber membrane filled in the body, and a circumference of the body. It is formed in the direction and characterized by comprising a discharge hole for discharging carbon dioxide that has passed through the polyimide hollow fiber membrane.

The fourth invention relates to a biofuel production method using a biofuel production system using organic waste of the third invention, the step of storing organic waste in a storage tank for this purpose; (S10) and stored in the storage tank Crushing organic waste with a grinder; (S20) and acid fermentation step of acid-fermenting the organic waste supplied from the grinder in an acid fermentation tank to decompose it into organic acid and to produce hydrogen at the same time; (S30) and the acid fermentation tank Separating the fermentation broth supplied from the solid-liquid separator into solid components and liquid components in a solid-liquid separator; (S40), and the solid components separated in the solid-liquid separator are supplied to a biogas fermentation tank to produce biogas (S51), and the solid-liquid The liquid component separated in the separator is supplied to an alcohol fermentation tank to produce alcohol (butanol); it consists of (S52), wherein the step S51 filters foreign substances contained in the biogas, desulfurization treatment and carbon dioxide are separated and purified. A post-treatment step (S511) of obtaining high-purity biogas is further included, and the step S52 is a pretreatment step of separating an organic acid that is a product of alcohol by introducing the liquid component separated in the solid-liquid separator into an electrodialysis device (S521). ) Characterized in that it further comprises.

In the fifth invention, in the fourth invention, the step S511 includes removing foreign substances contained in the biogas through at least two filter units (S511a), and supplying the biogas that has passed through the filter unit to the adsorption tower. The step of removing hydrogen sulfide and siloxane contained in (S511b), the step of high-compressing the biogas from which hydrogen sulfide and siloxane are removed through the adsorption tower (S511c), and the biogas compressed through the compressor is polyimide hollow It is characterized in that consisting of a step (S511d) of obtaining high-purity biogas by supplying it to a purification unit having a fiber membrane.

According to the biofuel production system using organic waste of the present invention and the biofuel production method using the same, it is possible to produce high-quality alcohol by supplying to an alcohol fermentation tank in a state where an organic acid, a raw material for alcohol production, is separated through an electrodialysis device. There is an effect.

In addition, there is an effect of producing high-purity biogas from which hydrogen sulfide, siloxane, and carbon dioxide are removed through a biogas purification unit after methane fermentation in a biogas fermentation tank.

1 is a block diagram of a biofuel production system using organic waste according to the present invention,
2 is a detailed configuration diagram showing the biogas purification unit of FIG. 1;
3 is a flow chart of a biofuel production method using a biofuel production system using organic waste according to the present invention,
4 is a detailed flowchart of step S511 of FIG. 3;
5 and 6 are test reports of biogas produced using the biofuel production system using organic waste of the present invention,
7 and 8 are test reports of unpurified biogas.

The following objects, other objects, features, and advantages of the present invention will be easily understood through the following preferred embodiments related to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms.

Rather, the embodiments introduced herein are provided so that the disclosed content may be thorough and complete and the spirit of the present invention may be sufficiently conveyed to those skilled in the art.

The embodiments described and illustrated herein also include complementary embodiments thereof.

In this specification, the singular form also includes the plural form unless specifically stated in the phrase. As used in the specification, "comprise" and/or "comprising" does not exclude the presence or addition of one or more other components.

Hereinafter, the present invention will be described in detail with reference to the drawings. In describing the specific embodiments below, various specific contents have been prepared to more specifically describe the invention and to aid in understanding. However, readers who have knowledge in this field to the extent that they can understand the present invention can recognize that it can be used without these various specific contents. In some cases, it should be mentioned in advance that parts that are commonly known in describing the invention and are not significantly related to the invention are not described in order to avoid confusion in describing the invention.

Hereinafter, a biofuel production system using organic waste according to the present invention will be described in detail together with the accompanying drawings.

1 is a configuration diagram of a biofuel production system using organic waste according to the present invention, and FIG. 2 is a detailed configuration diagram showing a biogas purification unit of FIG. 1.

1 and 2, the present invention produces hydrogen by acid fermentation of organic waste, and the fermentation broth of the acid fermentation tank is separated into a solid component and a liquid component through a solid-liquid separator, but the liquid component is electrodialysis. High purity biogas by removing carbon dioxide through the biogas purification unit after methane fermentation in the biogas fermentation tank for solid components by increasing the content of organic acids containing butyrate anions, the raw material of alcohol through the device. It relates to a biofuel production system using organic waste that enables the production of biofuel.

The biofuel production system using organic waste of the present invention includes a pulverizer 10, a storage tank 20, an acid fermentation tank 30, a solid-liquid separator 40, an electrodialysis device 50, and an alcohol fermentation tank. It consists of 60 and a biogas fermentation tank 70.

The pulverizer 10 serves to receive organic waste from the storage tank 20 and crush it finely so that the acid fermentation process can be effectively performed in the acid fermentation tank 30.

The acid fermentation tank 30 functions to ferment the organic waste supplied from the grinder 10 to decompose it into organic acids and to produce hydrogen at the same time.

To this end, the acid fermentation tank 30 agitates the organic waste organic waste to decompose it into a C2-C4 complex organic acid, and at the same time _{produces hydrogen (H 2} ), a clean energy source.

At this time, the acid fermentation tank 30 uses the acetic acid/butyl acid producing bacteria in the organic waste, and the alcohol conversion rate of acetic acid/butyl acid is higher than that of other organic acids in the state that no additional phagocytosis bacteria are injected into the acid fermentation tank 30. Minimizes the generation of lactic acid and propionic acid through physicochemical pretreatment in

The mass balance after the acid fermentation process is performed in the acid fermentation tank 30 according to the present invention is as shown in [Table 1] below based on a volume of 2 ㎥.

Item Conc(kg/㎥) Mass (kg) COD 90 180 VS 45 90 Volatile Fatty Acids (VFAs) 30 60 H2 (hydrogen) 60(%) 24(㎥)

Referring to [Table 1], it can be seen that 24 ㎥ of hydrogen per ton of organic waste is generated in the acid fermentation tank 30 according to the present invention.

And the solid-liquid separator 40 separates the fermentation broth of the acid fermentation tank 30 into a solid component and a liquid component.

The solid-liquid separator 40 maximizes the biogas production rate by applying a dry fire extinguishing technology instead of the existing wet fire extinguishing, and performs a process of separating the solid components contained in the fermentation broth through centrifugation.

The electrodialysis device 50 functions to remove impurities that interfere with alcohol production from the liquid component separated by the solid-liquid separator 40.

The electrodialysis device 50 functions to increase the alcohol production yield by supplying an organic acid containing a butyrate anion excluding various impurities included in the liquid component to the alcohol fermentation tank 60.

Therefore, the alcohol fermentation tank 60 receives a liquid component including an organic acid, which is a raw material of alcohol, through the electrodialysis device 50, and increases the production yield of alcohol by separately inoculating a strain that produces alcohol. You will be able to produce alcohol.

Meanwhile, the biogas fermentation tank 70 functions to produce biogas by fermenting the solid components separated by the solid-liquid separator 40.

The biogas fermentation tank 70 produces biogas by performing dry anaerobic digestion under high pressure conditions.

The components of the biogas thus produced are 70.9% of methane and 24.6% of carbon dioxide, as shown in the test reports of FIGS. 7 and 8, and are connected to the biogas purification unit 80 in order to purify the biogas with high purity.

The biogas purification unit 80 removes hydrogen sulfide and siloxane contained in the biogas, and separates carbon dioxide and purifies it into high-purity biogas.

The biogas purification unit 80 includes a filter unit 81, an adsorption tower 82, a compressor 83, and a purification unit 84.

The filter unit 81 is provided in a plurality of two or more, and removes foreign substances contained in the biogas in multiple stages.

In addition, the adsorption tower 82 receives the biogas passing through the filter unit 81 and adsorbs and removes hydrogen sulfide and siloxane to improve the quality of the biogas.

The compressor 83 is compressed at high pressure through the biogas from which hydrogen sulfide and siloxane have been removed, so that the purification unit 84 facilitates the removal of carbon dioxide.

The purification unit 84 functions to obtain high-purity biogas by removing carbon dioxide contained in the biogas.

This refining part passes through a linear body 841, a polyimide hollow fiber membrane 842 filled in the body 841, and a polyimide hollow fiber membrane 842 formed in the circumferential direction of the body 841 It is configured to include a discharge hole (841c) for discharging one carbon dioxide.

The body 841 of the refining unit 84 increases the internal pressure due to the difference in the inner diameter of the inlet 841a and the outlet 841b, thereby forming carbon dioxide as a polyimide hollow fiber membrane 842 filled in the body 841. Are separated.

As for the components of the biogas produced in this way, it was found that the carbon dioxide was removed as shown in the test reports of FIGS. 5 and 6 and thus had a high purity of 86% or more.

Hereinafter, a biofuel production method using a biofuel production system using organic waste according to the present invention will be described together with the accompanying drawings.

3 is a flowchart of a biofuel production method using a biofuel production system using organic waste according to the present invention, and FIG. 4 is a detailed flowchart of step S511 of FIG. 3.

As shown in Fig. 3, first, organic waste is stored in a storage tank (S10).

In addition, the organic waste stored in the storage tank is finely pulverized with a grinder so that the acid fermentation process can be effectively performed in an acid fermentation tank (S20).

And the organic waste pulverized in the pulverizer is acid-fermented in an acid fermentation tank to decompose into organic acids and produce hydrogen at the same time. (S30)

And the fermentation broth supplied from the acid fermentation tank is put into a solid-liquid separator and separated into a solid component and a liquid component (S40).

And the liquid component separated in the solid-liquid separator is supplied to the alcohol fermentation tank to produce alcohol (butanol) (S52), and the solid component separated in the solid-liquid separator is supplied to the biogas fermentation tank to produce biogas (S51).

In this case, prior to the step S52, a process of separating the organic acid as a raw material of alcohol by introducing the liquid component separated in the solid-liquid separator into the electrodialysis device must be preceded (S521).

And after step S51, as shown in FIG. 5, a purification step is performed, and first, foreign substances contained in the biogas are removed through the filter unit (S521a).

In addition, the biogas passing through the filter unit adsorbs and removes hydrogen sulfide and siloxane through an adsorption tower, thereby improving the quality of the biogas (S521b).

In addition, the biogas from which hydrogen sulfide and siloxane have been removed is compressed at high pressure through the compressor 83, so that the purification unit facilitates the removal of carbon dioxide (S521c).

Finally, biogas compressed through a compressor is supplied to a purification unit having a polyimide hollow fiber membrane to obtain biogas having a purity of 86% or more from which carbon dioxide has been removed (S521d).

Since the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiment of the present invention and do not represent all the technical spirit of the present invention, various equivalents that can replace them at the time of the present application It should be understood that there may be variations and variations.

10: grinder
20: storage tank
30: acid fermentation tank
40: solid-liquid separator
50: electrodialysis device
60: alcohol fermentation tank
70: biogas fermentation tank
80: biogas purification unit 81: filter unit 82: adsorption tower
83: compressor 84: purification unit
841: body 841a: inlet
841b: outlet 841c: discharge hole
842: Polyimide hollow fiber membrane

Claims (5)

A storage tank 20 for storing organic waste;
A crusher 10 for receiving and pulverizing organic waste from the storage tank 20;
An acid fermentation tank 30 for producing hydrogen at the same time by acid-fermenting the organic waste supplied from the pulverizer 10 to decompose it into organic acids;
A solid-liquid separator 40 for separating the fermentation broth supplied from the acid fermentation tank 30 into a solid component and a liquid component;
A biogas fermentation tank 70 for generating biogas by fermenting the solid components separated in the solid-liquid separator; And
Containing an alcohol fermentation tank 60 for producing alcohol by receiving the liquid components separated by the solid-liquid separator 40,
The biogas fermentation tank 70 is connected to a biogas purification unit 80 that separates carbon dioxide contained in the biogas and purifies it into high-purity biogas,
The biogas purification unit 80 includes at least two filter units 81 for removing foreign substances contained in the biogas, and hydrogen sulfide and siloxane contained in the biogas that has passed through the filter unit 81. Organic waste comprising an adsorption tower 82, a compressor 83 for compressing the biogas from which hydrogen sulfide and siloxane are removed at high pressure, and a purification unit 84 for removing carbon dioxide by receiving the compressed biogas. Biofuel production system utilizing the.
The method of claim 1
Between the solid-liquid separator 40 and the alcohol fermentation tank 60, impurities contained in the liquid component are removed, and an organic acid containing butyrate anion, which is a raw material for alcohol generation, is supplied to the alcohol fermentation tank to increase the alcohol production yield. Biofuel production system using organic waste, characterized in that it further comprises an electrodialysis device (50).
The method of claim 1,
The refining unit 84 includes a linear body 841 having a relatively larger diameter than the inlet 841a and the outlet 841b so that the internal pressure is increased, and a polyimide hollow fiber membrane filled in the body 841 Biofuel using organic waste, characterized in that it comprises a discharge hole (841c) formed in the circumferential direction of the body (841) to discharge carbon dioxide that has passed through the polyimide hollow fiber membrane (842) Production system.
In the biofuel production method using the biofuel production system using organic waste of claim 3,
Storing organic waste in a storage tank; (S10)
Crushing the organic waste stored in the storage tank with a crusher; (S20)
Acid fermentation step of acid-fermenting the organic waste supplied from the grinder in an acid fermentation tank to decompose it into organic acid and to produce hydrogen at the same time; (S30)
Separating the fermentation broth supplied from the acid fermentation tank into solid components and liquid components in a solid-liquid separator; (S40)
The solid component separated in the solid-liquid separator is supplied to a biogas fermentation tank to produce biogas (S51), and the liquid component separated in the solid-liquid separator is supplied to an alcohol fermentation tank to produce alcohol (butanol); (S52) Is made of,
The step S51 further includes a post-treatment step (S511) of filtering foreign substances contained in the biogas, desulfurization treatment, and separating and purifying carbon dioxide to obtain high-purity biogas,
The step S52 further comprises a pretreatment step (S521) of separating an organic acid, which is a product of alcohol, by introducing the liquid component separated in the solid-liquid separator into an electrodialysis device.
The step S511 is
Removing foreign substances contained in the biogas through at least two or more filter units (S511a),
Supplying the biogas that has passed through the filter unit to the adsorption tower to remove hydrogen sulfide and siloxane contained in the biogas (S511b),
High-pressure compression of the biogas from which hydrogen sulfide and siloxane have been removed through the adsorption tower (S511c),
Biofuel production production method comprising the step of obtaining high-purity biogas by supplying the biogas compressed through a compressor to a purification unit having a polyimide hollow fiber membrane (S511d).

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