WO2022196841A1

WO2022196841A1 - Apparatus and method for treating citrus peel waste

Info

Publication number: WO2022196841A1
Application number: PCT/KR2021/003314
Authority: WO
Inventors: 차명철; 최영수; 정국; 문세인
Original assignee: 주식회사 부강테크
Priority date: 2021-03-16
Filing date: 2021-03-17
Publication date: 2022-09-22
Also published as: KR102337503B1

Abstract

An apparatus and method for treating citrus peel waste are disclosed. According to an aspect of the present embodiment, provided is an apparatus for treating citrus peel waste, the apparatus comprising: a first thermohydrolysis tank that receives wastes containing citrus (fruit of a citrus plant) peel and thermally hydrolyzes same in a preset first environment; a condensation tank that receives the steam generated in the first thermohydrolysis tank and condenses same; an anaerobic digestion tank that receives and anaerobically digest the reactants of the first thermohydrolysis tank, except for the steam; a first dehydrator that receives and dehydrates the digestion liquid that has passed through the anaerobic digestion tank; a second thermohydrolysis tank that receives the dehydrated cake that has passed through the first dehydrator and thermally hydrolyzes same in a preset second environment; and a second dehydrator that receives and dehydrates the reactants of the first thermohydrolysis tank.

Description

Citrus peel waste treatment device and method

The present invention relates to an apparatus and method for producing biogas, minimizing waste generation and treating citrus peel waste.

The content described in this section merely provides background information for the present embodiment and does not constitute the prior art.

Citrus (citrus fruit) contains an inedible peel on the outside of most fruits. Currently, most citrus peels are used as fodder after drying or converted into compost after fermentation. However, the process of converting citrus peels into fodder or compost consumes significant processing costs, so processing citrus peels is a significant burden for processors using citrus (eg beverage manufacturers).

In addition, the production of citrus may vary from year to year due to various force majeure factors such as natural disasters or pests, and citruses to be discarded occur due to changes in people's demand or problems in the distribution process. Citrus to be disposed of is usually landfilled because it contains a lot of moisture and is more expensive to feed or compost. However, due to the large volume of citrus to be disposed of, the disposal cost increases, the capacity used in the landfill decreases, and environmental problems that generate excessive leachate occur.

Due to these problems, attempts to reduce the amount of citrus peels or citrus to be discarded, such as fruits containing citrus peels (hereinafter, collectively referred to as "citrus peel waste"), are biologically processed and finally disposed of. there has been However, as D-limonene, the main component of essential oil present in citrus peel waste, inhibits the biological treatment process, an effective treatment method has not been developed.

An embodiment of the present invention, by extracting the oil component in the citrus peel waste, it is an object to provide a citrus peel waste treatment apparatus and method that significantly reduces the cost and time consumed in the treatment process of the citrus peel waste.

According to one aspect of the present invention, a first thermal hydrolysis tank that receives waste containing citrus (citrus fruit, Citrus) peel and thermally hydrolyzes it in a predetermined first environment and the first thermal hydrolysis tank generated in the An anaerobic digestion tank for receiving and anaerobic digestion of the reactants of the first thermal hydrolysis tank except for the condensation tank for receiving and condensing steam and the first dehydrator for dehydration by receiving the digestion liquid that has passed through the anaerobic digestion tank and dehydration through the first dehydrator A citrus peel waste treatment apparatus comprising: a second thermal hydrolysis tank that receives the cake and thermally hydrolyzes it in a preset second environment; and a second dehydrator that receives and dehydrates the reactants of the first thermal hydrolysis tank to provide.

According to one aspect of the present invention, the steam flowing into the condensing tank is characterized in that it includes a predetermined component together with moisture.

According to one aspect of the present invention, the preset component is a component of an essential oil used as a raw material in cosmetics or detergents.

According to one aspect of the present invention, the anaerobic digester performs anaerobic digestion and generates biogas.

According to one aspect of the present invention, the biogas is characterized in that it contains methane.

According to one aspect of the present invention, in a method for a citrus peel waste treatment apparatus to treat waste containing citrus (citrus fruit, Citrus) peel, the waste containing the citrus peel is received and heat in a preset first environment The first thermal hydrolysis process of hydrolysis, the condensation process of receiving and condensing the steam generated in the first thermal hydrolysis process, and the anaerobic digestion process of receiving and anaerobic digestion of the reactants of the first thermal hydrolysis process except for the steam and a first dehydration process of receiving and dehydrating the digestion liquid that has undergone the anaerobic digestion process, a second thermal hydrolysis process of receiving the dehydrated cake that has undergone the first dehydration process and thermally hydrolyzing it in a preset second environment, and the first It provides a citrus peel waste treatment method comprising a second dehydration process of dehydration by receiving the reactants of the thermal hydrolysis process.

According to one aspect of the present invention, the anaerobic digestion process is characterized in that anaerobic digestion is performed to generate biogas.

As described above, according to one aspect of the present invention, by extracting the oil component in the citrus peel waste, there is an advantage in that the cost and time consumed in the processing of the citrus peel waste is significantly reduced.

In addition, according to one aspect of the present invention, there is an advantage in that a preset oil component can be separately extracted in the process of processing the citrus peel waste.

1 is a view showing the configuration of a citrus peel waste treatment apparatus according to a first embodiment of the present invention.

Figure 2 is a view showing the configuration of the citrus peel waste treatment apparatus according to the second embodiment of the present invention.

3 is a flowchart illustrating a method of extracting an oil component and processing citrus peel waste by the citrus peel waste treatment apparatus according to the first embodiment of the present invention.

4 is a flowchart illustrating a method for extracting oil components and processing citrus peel waste by the citrus peel waste treatment apparatus according to the second embodiment of the present invention.

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention. In describing each figure, like reference numerals have been used for like elements.

Terms such as first, second, A, and B may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component. and/or includes a combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being “connected” or “connected” to another component, it may be directly connected or connected to the other component, but it is understood that other components may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that no other element is present in the middle.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. It should be understood that terms such as “comprise” or “have” in the present application do not preclude the possibility of addition or existence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification in advance. .

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

In addition, each configuration, process, process or method included in each embodiment of the present invention may be shared within a range that does not technically contradict each other.

1, the citrus peel waste treatment apparatus 100 according to the first embodiment of the present invention includes a first thermal hydrolysis tank 110, a condensation tank 120, an anaerobic digestion tank 130, a first dehydrator ( 140), a second thermal hydrolysis tank 150, and a second dehydrator 160. Furthermore, the citrus peel waste treatment apparatus 100 may further include a dryer 170 .

The citrus peel waste treatment apparatus 100 anaerobically digests the citrus peel waste to obtain biogas therefrom and can significantly reduce the amount of waste to be landfilled or disposed of. Citrus peel waste treatment apparatus 100 uses a thermal hydrolysis method to improve the anaerobic digestibility of sewage sludge. The thermal hydrolysis method is a method of thermally hydrolyzing sludge as a pre-treatment of anaerobic digestion and then injecting the reactants into the anaerobic digestion tank. By thermal hydrolysis, the cell walls of microorganisms in the sludge are destroyed, allowing faster anaerobic digestion and production of more biogas in the same amount of time.

However, the main component of essential oil called D-limonene exists in the citrus peel waste. D-limonene is a component used as a raw material for cosmetics, nutritional supplements, or detergents, as it has antioxidant, anti-cancer or cleaning effects. However, since D-limonene inhibits the activity of microorganisms, when wastes containing these components are introduced into the anaerobic digester, there is a problem that the anaerobic digestion proceeds slowly. Accordingly, the citrus peel waste treatment apparatus 100 separates and extracts the D-limonene component in processing the citrus peel waste, thereby improving the treatment efficiency of the citrus peel waste and additionally obtains the main component of the essential oil.

The first thermal hydrolysis tank 110 receives the citrus peel waste and performs thermal hydrolysis in a preset first environment. As mentioned above, citrus peel waste is a concept that includes all fruits including citrus peels, such as citrus peels and citrus to be discarded. The first thermal hydrolysis tank 110 receives the citrus peel waste and performs thermal hydrolysis. Citrus peel waste contains materials such as pectin, cellulose, or hemicellulose, which are easily biodegradable, as a main component, and contains a relatively small amount of lignin, which is difficult to biodegrade. . Through the thermal hydrolysis process, the main components in the citrus peel waste are hydrolyzed into glucose or fructose. Hydrolysis occurs in the main component in the citrus peel waste, anaerobic digestion can proceed more quickly in an anaerobic digester to be described later, the size of the anaerobic digester can be reduced, and a greater amount of biogas can be produced during the same time.

The first thermal hydrolysis tank 110 performs thermal hydrolysis of the received citrus peel waste in a first preset environment. Here, the preset first environment may be an environment in which a temperature of 170 to 180° C. and a pressure of 7 to 10 bar are applied for 10 to 30 minutes. The first thermal hydrolysis tank 110 thermally hydrolyzes the citrus peel waste under a first preset environment. Accordingly, cellulose or hemicellulose constituting the main component of citrus peel waste is hydrolyzed to glucose, fructose, or Hydroxy Methyl Furfural (HMF). On the other hand, D-limonene contained in the citrus peel waste has a boiling point of 176 ℃. Accordingly, D-limonene evaporates together with moisture in the preset first environment. The first thermal hydrolysis tank 110 transfers the reactants after thermal hydrolysis to the anaerobic digester 130 , and the generated steam is transferred to the condensation tank 120 .

The condensing tank 120 receives steam from the first thermal hydrolysis tank 110 and condenses it. The condensation tank 120 receives steam generated by thermal hydrolysis in the first environment preset in the first thermal hydrolysis tank 110 . The vapor flowing into the condensing tank 120 contains not only moisture, but also D-limonene component that evaporates in a preset first environment. The condensing tank 120 provides a pressure (eg, atmospheric pressure) lower than the preset first environment. The vapor introduced into the condensing tank 120 providing a relatively lower pressure and temperature than the first thermal hydrolysis tank 110 is condensed (liquefied) in the condensing tank 120 . The main component (D-limonene) of the essential oil contained in the citrus peel waste from the condensing tank 120 may be recovered along with moisture. As the D-limonene component is separated into the condensing tank 120 , anaerobic digestion of the reactants after thermal hydrolysis in the anaerobic digestion tank 130 to be described later can be smoothly performed.

The anaerobic digester 130 receives the thermal hydrolysis reaction product from which the steam is separated and performs anaerobic digestion. The thermal hydrolysis reactants introduced into the anaerobic digester 130 are anaerobically digested by microorganisms in the anaerobic digester 130 . As described above, through the thermal hydrolysis process, all of the main components of the citrus peel waste are hydrolyzed to polysaccharide or monosaccharide sugar, which can be food for microorganisms. Since the citrus peel wastes are introduced as they are already completely decomposed as food for microorganisms, anaerobic digestion can be smoothly performed in the anaerobic digester 130 . Anaerobic digestion is performed in the anaerobic digester 130 , and the generated biogas is discharged to the outside. Methane is contained in biogas and can be used as a fuel to generate electricity and the like.

The first dehydrator 140 receives the digestion liquid that has passed through the anaerobic digestion tank 130 and dehydrates it. The first dehydrator 140 dehydrates the digestion liquid between the anaerobic digestion tank 130 and the second thermal hydrolysis tank 150 in the process. About 15 to 20% of the moisture in the digestive juice is dehydrated by the first dehydrator 140 , and the dehydrated cake having a moisture content of 80 to 85% is carried out to the second thermal hydrolysis tank 150 . As such, by being primarily dehydrated in the first dehydrator 140 , the total volume of the digestion liquid to be thermally hydrolyzed may be reduced. The reduction in the volume of the digestion liquid to be thermally hydrolyzed can prevent the size of the second thermal hydrolysis tank 150 from becoming excessively large. If the digestion liquid directly flows into the second thermal hydrolysis tank 150 without dehydration of the first dehydrator 140 , the second thermal hydrolysis tank 150 becomes too large to thermally hydrolyze the entire digestion liquid or the entire digestion liquid There is a possibility that it will take too long to thermally hydrolyze. To prevent this, the first dehydrator 140 primarily receives the digested liquid that has passed through the anaerobic digester 130 and dehydrates it to reduce the volume of the digested liquid. The dehydrated cake that has passed through the first dehydrator 140 is introduced into the second thermal hydrolysis tank 150, and the dewatered filtrate is transferred to the outside such as a wastewater treatment plant for treatment.

The second thermal hydrolysis tank 150 receives the dehydrated cake passed through the first dehydrator 140 and thermally hydrolyzes it in a preset second environment. The second thermal hydrolysis tank 150 thermally hydrolyzes the dehydrated cake in a preset second environment. The preset second environment may be an environment in which a temperature of 180 to 200° C. and a pressure of 10 to 16 bar are applied for 10 to 30 minutes. As the dehydrated cake is thermally hydrolyzed in such an environment, the cell wall of the sludge present in the dehydrated cake is destroyed, moisture inside the cell is lost, and the dewatering efficiency can be further improved. That is, in order to maximize the dehydration efficiency of the second dehydrator 160 to be described later, the second thermal hydrolysis tank 150 receives the dehydrated cake and thermally hydrolyzes it.

The second dehydrator 160 receives the reactant thermally hydrolyzed in the second thermal hydrolysis tank 150 and dehydrates it. The second dehydrator 160 also dehydrates the introduced reactants like the first dehydrator 140 . At this time, since the incoming dehydration cake passes through the second thermal hydrolysis tank 150 and the cell walls of microorganisms in the sludge are destroyed and the moisture inside the cells is lost, considerable dehydration efficiency can be secured in the second dehydrator 160. have. Through the second dehydrator 160, the moisture content of the dewatering cake may be reduced to 45% or less, and the sludge reduction rate accordingly becomes 80% or more. By going through the above process, the citrus peel waste can be reduced in volume by 80% or more, and the moisture content is 45% or less, so there is no problem in being buried. Along with this, it is possible to additionally extract D-limonene, which is a main component of the essential oil. The dehydration filtrate generated from the second dehydrator 160 is transferred to the outside, such as a wastewater treatment plant, and treated, like the first dehydrator 140 .

The second dehydrator 160 may be implemented as a filter press, but is not limited thereto.

Citrus peel waste treatment apparatus 100 may further include a dryer 170 . The dryer 170 receives the dehydrated cake that has passed through the second dehydrator 160 and dries it. The dehydrated cake that has passed through the dryer 170 may have a moisture content of less than 15%. As such, when the moisture content is reduced to less than 15%, the dehydrated cake can be recycled as fuel for power plants and the like. The citrus peel waste treatment apparatus 100 may process the citrus peel waste to be more smoothly processed, as well as to be further recycled.

Referring to FIG. 2 , the citrus peel waste treatment apparatus 200 according to the second embodiment of the present invention further includes a thickening tank 210 in the configuration of the citrus peel waste treatment apparatus 100 .

The concentration tank 210 receives the reactant of the first thermal hydrolysis tank 110 and separates the carbon source in the reactant.

A general wastewater treatment process undergoes a nitrification process (oxidation of NH ₄ ⁺ to NO ₃ ^- ) and a denitrification process (denitrification of NO ₃ ^- into N ₂ gas) to remove nitrogen introduced in the form of ammonia. The nitrification process is carried out by nitrifying microorganisms in a reaction tank in an environment where air is supplied, and most organic substances contained in sewage and wastewater are decomposed and removed by the nitrifying microorganisms. On the other hand, the denitrification process is carried out by denitrification microorganisms in a reaction tank in an anoxic environment. Since all organic matter was removed during the nitrification process, a carbon source had to be artificially supplied from the outside for the growth of denitrification microorganisms. The supply of carbon sources from the outside has been a cause of increasing the operating cost of the wastewater treatment process.

The reactant of the first thermal hydrolysis tank 110 corresponds to a mixture of liquid and solid. As described above, polysaccharides or monosaccharides such as glucose or fructose produced by hydrolysis are contained in the liquid. Sugar is a substance that can be ingested by microorganisms and is a component that can be used as a carbon source. The concentration tank 210 receives the reactant from the first thermal hydrolysis tank 110 and separates the solid-liquid. In the case of solid-liquid separation, it is separated into supernatant and precipitate. As described above, the supernatant contains hydrolyzed polysaccharides or monosaccharides. The enrichment tank 210 may supply supernatant water to the outside as a carbon source, and may deliver the precipitate to the anaerobic digestion tank 130 for anaerobic digestion.

The first thermal hydrolysis tank 110 thermally hydrolyzes the citrus peel waste in a preset first environment (S310). The steam generated by thermal hydrolysis flows into the concentration tank 120, and the component (D-limonene) of the essential oil in the steam is extracted.

The anaerobic digester 130 anaerobically digests the reactants except for steam (S320). The reactant from which the vapor is separated is introduced into the anaerobic digester 130 and is anaerobically digested in the anaerobic digester 130 . Biogas is produced by anaerobic digestion.

The first dehydrator 140 primarily dehydrates the digestive juice (S330). In order to reduce the volume of the digestion liquid to be hydrolyzed in the thermal hydrolysis process to be described later, the first dehydrator 140 primarily dehydrates the digestion liquid.

The second thermal hydrolysis tank 150 thermally hydrolyzes the dehydrated cake in a preset second environment after dehydration (S340). The second thermal hydrolysis tank 150 further thermally hydrolyzes the dehydrated cake to minimize the moisture content of the dehydrated cake after dehydration by a dehydration process to be described later and to minimize the volume of waste after treatment.

The second dehydrator 160 dehydrates the reactants secondarily (S350). Additionally, drying may be performed on the dehydrated cake after dehydration by the dryer 170 .

The first thermal hydrolysis tank 110 thermally hydrolyzes the citrus peel waste in a preset first environment (S410).

The concentration tank 210 receives the reactants except steam, separates the solid-liquid, and discharges the supernatant (S420), and the concentration tank 210 receives the reactants except the steam and separates the solid-liquid. Accordingly, the reactant is separated into a precipitate and supernatant, and the supernatant is discharged to the outside as a carbon source.

The anaerobic digester 130 receives the solid-liquid separated sediment and performs anaerobic digestion (S430). The sediment among the solid-liquid separated reactants flows into the anaerobic digester 130 and is anaerobically digested in the anaerobic digester 130 . Biogas is produced by anaerobic digestion.

The first dehydrator 140 primarily dehydrates the digestive juice (S440).

The second thermal hydrolysis tank 150 thermally hydrolyzes the dehydrated cake in a preset second environment after dehydration (S450).

The second dehydrator 160 dehydrates the reactants secondarily (S460).

Although it is described that each process is sequentially executed in FIGS. 3 and 4 , this is merely illustrative of the technical idea of an embodiment of the present invention. In other words, a person of ordinary skill in the art to which an embodiment of the present invention pertains may change the order described in each drawing within a range that does not depart from the essential characteristics of an embodiment of the present invention, or perform one or more of each process. Since various modifications and variations may be applied by executing in parallel, FIGS. 3 and 4 are not limited to a time-series order.

Meanwhile, the processes illustrated in FIG. 3 or 4 may be implemented as computer-readable codes on a computer-readable recording medium. The computer-readable recording medium includes all types of recording devices in which data readable by a computer system is stored. That is, the computer-readable recording medium includes a magnetic storage medium (eg, a ROM, a floppy disk, a hard disk, etc.) and an optical readable medium (eg, a CD-ROM, a DVD, etc.). In addition, the computer-readable recording medium is distributed in a network-connected computer system so that the computer-readable code can be stored and executed in a distributed manner.

The above description is merely illustrative of the technical idea of this embodiment, and various modifications and variations will be possible without departing from the essential characteristics of the present embodiment by those of ordinary skill in the art to which this embodiment belongs. Accordingly, the present embodiments are intended to explain rather than limit the technical spirit of the present embodiment, and the scope of the technical spirit of the present embodiment is not limited by these embodiments. The protection scope of this embodiment should be interpreted by the claims below, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present embodiment.

This patent is the result of research conducted with the support of the Environmental Industry and Technology Institute with funding from the Korean government (Ministry of Environment) in 2020 (task number: 2020003170009, task name: biogas production/sludge reduction and commercialization of the optimal return water treatment system).

CROSS-REFERENCE TO RELATED APPLICATION

*This patent application claims priority under section 119(a) of the U.S. Patent Act (35 U.S.C § 119(a)) with respect to Patent Application No. 10-2021-0033808 filed in Korea on March 16, 2021. All contents thereof are incorporated into this patent application by reference. In addition, if this patent application claims priority for countries other than the United States for the same reason as above, all contents thereof are incorporated into this patent application by reference.

Claims

a first thermal hydrolysis tank for receiving waste containing citrus (citrus fruit, Citrus) peel and thermally hydrolyzing it in a first preset environment;

a condensing tank receiving and condensing the steam generated in the first thermal hydrolysis tank;

An anaerobic digestion tank for anaerobic digestion by receiving the reactants of the first thermal hydrolysis tank, except for steam;

a first dehydrator for dehydrating by receiving the digestion liquid that has passed through the anaerobic digester;

a second thermal hydrolysis tank that receives the dehydrated cake that has passed through the first dehydrator and thermally hydrolyzes it in a preset second environment; and

A second dehydrator for dehydrating by receiving the reactants of the first thermal hydrolysis tank

Citrus peel waste treatment device comprising a.
According to claim 1,

The steam flowing into the condensing tank,

Citrus peel waste treatment device, characterized in that it comprises a predetermined component together with moisture.
3. The method of claim 2,

The preset component is

Citrus peel waste treatment device, characterized in that it is a component of essential oil used as a raw material in cosmetics or detergents.
According to claim 1,

The anaerobic digester,

Citrus peel waste treatment device, characterized in that anaerobic digestion and generating biogas.
5. The method of claim 4,

The biogas is

Citrus peel waste treatment device comprising methane.
A method for the citrus peel waste treatment device to treat waste containing citrus (citrus fruit, Citrus) peel,

A first thermal hydrolysis process of receiving the waste containing the citrus peel and thermally hydrolyzing it in a preset first environment;

a condensation process of receiving and condensing the steam generated in the first thermal hydrolysis process;

Anaerobic digestion process of receiving the reactants of the first thermal hydrolysis process and performing anaerobic digestion, except for steam;

a first dehydration process in which the digested liquid that has undergone the anaerobic digestion process is introduced and dehydrated;

a second thermal hydrolysis process of receiving the dehydrated cake that has undergone the first dehydration process and thermally hydrolyzing it in a preset second environment; and

A second dehydration process in which the reactants of the first thermal hydrolysis process are introduced and dehydrated

Citrus peel waste treatment method comprising a.
7. The method of claim 6,

The steam flowing into the condensing tank,

Citrus peel waste treatment method, characterized in that it comprises a predetermined component with moisture.
8. The method of claim 7,

The preset component is

Citrus peel waste treatment method, characterized in that it is a component of essential oil used as a raw material in cosmetics or detergents.
7. The method of claim 6,

The anaerobic digestion process is

Citrus peel waste treatment method, characterized in that anaerobic digestion and generating biogas.
10. The method of claim 9,

The biogas is

Citrus peel waste treatment method comprising methane.