KR101321476B1 - A high-temperature hydrolysis, sterilization and heat-recovery system for production of biogas and method thereof - Google Patents

Abstract

PURPOSE: A system for high-temperature hydrolysis, sterilization, and heat recovery to produce biogas is provided to improve production efficiency by a hydrolysis process in a high temperature and reduce energy and operating costs using a heat used in a heating process with heat transmission through a thermal cycling process. CONSTITUTION: A method for high-temperature hydrolysis, sterilization, and heat recovery to produce biogas comprises steps of: a step(S2) of performing hydrolysis and sterilization processes for organic waste; a step(S3) of digesting the hydrolyzed and sterilized organic waste anaerobically; a step(S1) of heating by supplying heat necessary for high-temperature hydrolysis and sterilization; and a step of delivering the heat included in the organic waste treated by the hydrolysis and sterilization processes to the organic waste which is not treated in the hydrolysis and sterilization processes. [Reference numerals] (AA,BB) Heat; (S1) Step of supplying heat; (S2) Step of performing hydrolysis and sterilization; (S3) Step of anaerobically digesting; (S41) Step of firstly delivering the heat; (S42) Step of secondly delivering the heat

Description

A high-temperature hydrolysis, sterilization and heat-recovery system for production of biogas and method

The present invention relates to a high-temperature hydrolysis, sterilization and heat recovery system and method used in a plant for producing biogas from organic waste, and more specifically, to a high temperature treatment of a hydrolysis process in a plant for biogas production. In order to increase the efficiency of production, and to heat energy in high temperature heating process, it is possible to reduce energy efficiency and operating cost by using heat transfer through the heat circulation process in the process, and especially to the organic waste after the anaerobic digestion unit. By heating the organic waste prior to being supplied to the hydrolysis and sterilization part with the included heat and warming it again with the high temperature heat contained in the organic waste immediately after passing through the hydrolysis and sterilization part, the energy efficiency is increased through the heat recovery in the process. Temperature suitable for each process of digestion, sterilization and anaerobic digestion Relates to high temperature hydrolysis and sterilization, and the heat recovery system and method for bio-gas production control is made.

Various organic wastes such as food waste, livestock manure and agricultural by-products are increasing year by year, but the recycling rate is low and relies heavily on landfilling, incineration and marine discharges. Understand the London Convention Since 2013, marine discharges have been banned, and there is a need for technologies that can effectively treat these organic wastes on land, and as a result, technologies for producing biogas from organic wastes have been in the spotlight. .

(Patent Literature)

Registered Patent No. 10-0787074 (December 21, 2007) "Biogas generation device of organic waste"

The above (patent document) relates to a technique for generating biogas from conventional organic wastes, and includes a mixing tank in which organic wastes and microorganisms are mixed, an anaerobic digestion tank, a microbial culture tank, and the like, and anaerobic digestion from organic wastes containing high concentration solids. The main focus is on shortening processes and increasing biogas production.

However, in the above conventional techniques, the technical idea to improve the productivity of biogas by increasing the efficiency of the hydrolysis process in producing biogas from organic waste or in the process of producing biogas from organic waste No technical idea is disclosed or implied with regard to increasing energy efficiency in Esau and thus reducing energy and operating costs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems,

An object of the present invention is to improve the efficiency of the production by the hydrolysis process to be processed in the plant for biogas production at high temperature, while using the heat transfer through the heat cycle process in the process heat required for high temperature heating process It is to provide a high temperature hydrolysis, sterilization and heat recovery system and method for biogas production to reduce energy efficiency and operating cost.

Another object of the present invention is to first heat the organic waste before being fed to the hydrolysis and sterilization with heat contained in the organic waste after the anaerobic digestion, and the high temperature contained in the organic waste immediately after the hydrolysis and sterilization. By reheating with heat, it provides a high temperature hydrolysis, sterilization and heat recovery system and method for biogas production, which increases energy efficiency through heat recovery in the process, as well as temperature control suitable for each process of hydrolysis, sterilization and anaerobic digestion. It is.

Another object of the present invention is a high-temperature hydrolysis and sterilization and heat recovery system and method for biogas production to improve heat transfer efficiency through heat transfer process that does not use a separate heat transfer medium between the waste in the process heat recovery process To provide.

Still another object of the present invention includes a process for further reducing the temperature when the organic waste immediately after the hydrolysis and sterilization step is lower than the reference temperature for the anaerobic digestion process through the second heat transfer process. It is to provide a high-temperature hydrolysis, sterilization and heat recovery system and method for biogas production to increase the efficiency of the process.

High temperature hydrolysis and sterilization and heat recovery system and method for biogas production to achieve the above object of the present invention includes the following configuration.

High temperature hydrolysis and sterilization and heat recovery system for biogas production according to an embodiment of the present invention is a hydrolysis and sterilization unit for hydrolyzing and sterilizing organic waste; Anaerobic digestion unit for anaerobic digestion of hydrolyzed and sterilized organic waste through the hydrolysis and sterilization unit; A heat supply unit for supplying heat to a temperature required for high temperature hydrolysis and sterilization in the hydrolysis and sterilization unit and heating it; And a heat transfer unit which transfers heat contained in the organic waste after passing through the hydrolysis and sterilization unit and / or anaerobic digestion unit to the organic waste before being supplied to the hydrolysis and sterilization unit. It is characterized by improving the efficiency through overheat recovery.

According to another embodiment of the present invention, in the system according to the present invention, the heat transfer part primarily transfers heat contained in the organic waste after passing through the anaerobic digestion unit to the organic waste before being supplied to the hydrolysis and sterilization unit. And a secondary heat transfer unit for transferring the heat contained in the organic waste immediately after passing through the heat transfer and sterilization unit to the organic waste after passing through the primary heat transfer unit.

According to another embodiment of the present invention, in the system according to the present invention, the primary heat transfer unit separates the heat transfer medium from the organic waste before the organic waste is fed to the hydrolysis and sterilization unit after passing through the anaerobic digestion unit. It is not used, and the secondary heat transfer unit is characterized in that the organic waste immediately after passing through the hydrolysis and sterilization unit to pass the heat to the organic waste after the first heat transfer unit without using a separate heat transfer medium. .

According to still another embodiment of the present invention, in the system according to the present invention, the first heat transfer part and the second heat transfer part may be each of the first conduit through which the organic waste before being supplied to the hydrolysis and sterilization part, and the first conduit. It is characterized in that it is formed in a dual structure including a second passage in contact with the first passage and the organic waste passed through the anaerobic digestion and / or hydrolysis and sterilization portion to increase the direct heat transfer efficiency.

High temperature hydrolysis and sterilization and heat recovery method for biogas production according to an embodiment of the present invention comprises a hydrolysis and sterilization step of hydrolyzing and sterilizing organic waste; Anaerobic digestion step of anaerobic digestion of hydrolyzed and sterilized organic waste through the hydrolysis and sterilization step; A heat supply step of heating by supplying heat to a temperature required for high temperature hydrolysis and sterilization in the hydrolysis and sterilization step; And a heat transfer step of transferring the heat contained in the organic waste after the anaerobic digestion step and / or the hydrolysis and sterilization step to the organic waste before being supplied to the hydrolysis and sterilization step. It is characterized by increasing efficiency through improvement and heat recovery.

According to another embodiment of the present invention, in the method according to the present invention, the heat transfer step primarily transfers heat contained in the organic waste after the anaerobic digestion step to the organic waste before being supplied to the hydrolysis and sterilization stage. And a second heat transfer step of transferring heat contained in the organic waste immediately after the hydrolysis and sterilization step to the organic waste after the first heat transfer step. do.

According to another embodiment of the present invention, in the method according to the present invention, the primary heat transfer step is a separate heat transfer of heat to the organic waste before the organic waste is subjected to the hydrolysis and sterilization step after the anaerobic digestion step And transfer the heat to the organic waste immediately after the first heat transfer step without the use of a separate heat transfer medium. It is characterized by.

According to another embodiment of the present invention, the method according to the present invention is the case where the temperature of the organic waste immediately after the hydrolysis and sterilization step through the secondary heat transfer step to the anaerobic digestion step is higher than the reference value. It is characterized in that it further comprises a;

The present invention can obtain the following effects by the above-described embodiment, the constitution described below, the combination, and the use relationship.

The present invention improves the production efficiency by allowing the hydrolysis process to be processed in the plant for biogas production at a high temperature, while using the heat transfer through the heat circulation process in the heat of the heat required during the high temperature heating process energy efficiency It also has the effect of reducing operating costs.

The present invention primarily heats the organic waste before being supplied to the hydrolysis and sterilization unit with heat contained in the organic waste after passing through the anaerobic digestion unit, and is re-returned to the high temperature heat contained in the organic waste immediately after passing through the hydrolysis and sterilization unit. By heating, it is possible to increase the energy efficiency through heat recovery in the process, as well as to effect temperature control suitable for each process of hydrolysis, sterilization and anaerobic digestion.

The present invention has the effect of improving the heat transfer efficiency through the heat transfer process that does not use a separate heat transfer medium between the waste and waste in the process heat recovery.

The present invention includes the process of further reducing the temperature when the organic waste immediately after the hydrolysis and sterilization step is lower than the reference temperature for the anaerobic digestion process after the secondary heat transfer process. Has the effect of raising.

1 is a block diagram showing the structure of a high temperature hydrolysis and sterilization and heat recovery system according to an embodiment of the present invention
Figure 2 is a block diagram showing the structure of the high temperature hydrolysis and sterilization and heat recovery system according to another embodiment of the present invention
3 is a cross-sectional view showing an example of the heat transfer pipe structure of FIG.
Figure 4 is a flow chart showing a high temperature hydrolysis and sterilization and heat recovery method according to an embodiment of the present invention
Figure 5 is a flow chart showing a high temperature hydrolysis and sterilization and heat recovery method according to another embodiment of the present invention

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the high temperature hydrolysis and sterilization and heat recovery system and method for biogas production according to the present invention will be described in detail. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements, rather than excluding other elements, unless specifically stated otherwise.

1 to 3, the high temperature hydrolysis and sterilization and heat recovery system for biogas production according to an embodiment of the present invention is a hydrolysis and sterilization unit 10 for hydrolyzing and sterilizing organic waste; Anaerobic digestion unit 20 for anaerobic digestion of hydrolyzed and sterilized organic waste through the hydrolysis and sterilization unit 10; A heat supply unit 30 for heating and supplying heat to a temperature required for high temperature hydrolysis and sterilization in the hydrolysis and sterilization unit 10; And a heat transfer unit configured to transfer heat included in the organic waste after passing through the hydrolysis and sterilization unit 10 and / or the anaerobic digestion unit 20 to the organic waste before being supplied to the hydrolysis and sterilization unit 10 ( 40); may include.

The hydrolysis and sterilization unit 10 is configured to hydrolyze and sterilize the organic waste as a pretreatment process for producing biogas from the organic waste. Organic wastes such as food waste and livestock manure, which are raw materials for producing biogas, are subjected to a process of hydrolysis, acid fermentation, and methane fermentation after mixing for homogenization. In the present invention, the active hydrolysis at high temperature by performing a high-temperature hydrolysis process in which the hydrolysis reaction takes place at a high temperature, that is, about 70 ° C. (a temperature of about 70 ° C., which is higher than about 38 ° C.). Decomposition shortens the number of days of extinguishing (retention time) and increases biogas production, thereby improving the processing performance of organic waste and productivity of biogas.

That is, in the present invention, before the hydrolysis of the organic waste is performed (that is, before the organic waste is introduced into the hydrolysis and sterilization unit 10), the heat supply unit 30 and the heat transfer unit as described later. Through the configuration of the 40, the temperature of the organic waste is heated (warmed up), so that the organic waste in a high temperature (approximately 70 ° C or about) temperature is supplied to the hydrolysis and sterilization unit 10 so that active hydrolysis is performed at high temperature. This reduces the number of days of extinguishing in the entire process and increases biogas production. In particular, the hydrolysis and sterilization unit 10 for the microorganisms that may be unnecessary or hygienic problems in the future anaerobic digestion, such as pathogens and other microorganisms contained in the organic waste at a high temperature (approximately 70 ℃ temperature around) The sterilization process is performed, and the stability and hygiene of the anaerobic digestion process can be prevented through the preliminary removal of factors that would interfere with the advantages of the microbial species required for anaerobic digestion in acid fermentation and methane fermentation in the future anaerobic digestion unit 20. To improve. In addition, the high-temperature hydrolysis and sterilization process in the hydrolysis and sterilization part 10 according to the present invention also exhibits the effect of stabilizing the subsequent anaerobic digestion process. In other words, once the organic material is heated to a high temperature, hydrolysis of the organic material is accelerated to simplify the biochemical molecular structure, thereby lowering the freezing point and the freezing of the substrate which is easy to decompose. Degassing in the anaerobic digestion process at or around high temperature (approximately 50 ° C) or at high temperature (approximately 50 ° C), and the organic matter removal rate and biogas production are increased.

The heating (heating) process for the organic waste to allow high temperature hydrolysis and sterilization in the hydrolysis and sterilization unit 10 is made through a heat supply unit 30 and a heat transfer unit 40 to be described later. This will be described in detail for each configuration.

The anaerobic digestion unit 20 anaerobic digestion of organic wastes hydrolyzed and sterilized through the hydrolysis and sterilization unit 10 (more specifically, microorganisms sequentially go through organic fermentation and methane fermentation process. Disassembly). When the hydrolyzed and sterilized organic waste is supplied to the anaerobic digestion unit 20 through the hydrolysis and sterilization unit 10, firstly, the sugars are further decomposed by the action of microorganisms such as organic acid producing bacteria and hydrogen, carbon dioxide and the like. In addition, acetic acid, propionic acid, butyric acid are produced, and propionic acid and butyric acid are further decomposed to produce hydrogen, carbon dioxide, and acetate, which are precursors of methane production ('acid fermentation' or 'acid production' process). Is called). Subsequently, methane and carbon dioxide are produced using acetic acid, hydrogen, and carbon dioxide as substrates by the action of microorganisms such as methane microorganisms (this is called 'methane fermentation' or 'methane production' process). The biogas through the anaerobic digestion unit 20 will be utilized as an energy source for various uses in the future. The anaerobic digestion process in the anaerobic digestion unit 20 varies depending on the digestion method, but is effective at about medium temperature (about 30 to 60 ° C.) or at high temperature (about 50 ° C. or less), so that the hydrolysis and sterilization part ( 10) The temperature of the organic waste at high temperature (approximately 70 ° C. or less) state must be artificially controlled, and in this case, the temperature must be reduced between the hydrolysis and sterilization unit 10 and the anaerobic digestion unit 20. Through the heat recovery process so that the thermal energy is transferred to the organic waste before being supplied to the hydrolysis and sterilization unit 10 (warning (warm temperature)) to enable energy efficiency throughout the process. Description of this will be described later.

The heat supply unit 30 supplies heat to a temperature required for high temperature hydrolysis and sterilization in the hydrolysis and sterilization unit 10 to heat the temperature of the organic waste supplied to the hydrolysis and sterilization unit 10. to be. As described above, the present invention is characterized in that the 'high temperature' hydrolysis and sterilization process in the hydrolysis and sterilization unit 10, the organic waste in such a high temperature (temperature of about 70 ℃) In order to artificially control the temperature of the organic waste supplied to the hydrolysis and sterilization unit 10 by supplying external heat through an external heat source such as the heat supply unit 30 (for example, a boiler) to warm the temperature of the organic waste. Let's go. However, the heating of the organic waste through the heat supply unit 30 uses an external heat source, which has a disadvantage in that energy consumption and its cost increase in proportion thereto. Therefore, in the present invention, before the heating of the organic waste through the heat supply unit 30 through the heat transfer unit 40 to be described later separately to recover the unnecessary waste in the process is supplied to the hydrolysis and sterilization unit 10 It can be used to warm up organic wastes, thereby improving energy efficiency and reducing costs in the process.

The heat transfer part 40 transfers the heat contained in the organic waste after passing through the hydrolysis and sterilization unit 10 and the anaerobic digestion unit 20 to the organic waste before being supplied to the hydrolysis and sterilization unit 10. It is configured to increase the energy efficiency through the heat recovery in the process. To this end, the heat transfer unit 40 specifically transfers heat contained in the organic waste after passing through the anaerobic digestion unit 20 to the organic waste before being supplied to the hydrolysis and sterilization unit 10. Secondary heat transfer unit for transferring heat contained in the organic waste immediately after passing through the heat transfer unit 410 and the hydrolysis and sterilization unit 10 to the organic waste after passing through the first heat transfer unit 410. 420 may be included.

The primary heat transfer unit 410 is configured to heat transfer primarily to the organic waste before being supplied to the hydrolysis and sterilization unit 10 after passing through the anaerobic digestion unit 20 to the hydrolysis and sterilization unit 10 to be. As described above, in the anaerobic digestion unit 20, the anaerobic digestion process is performed at medium temperature (approximately about 30 ° C. and mid- or late) or at high temperature (approximately 50 ° C. or less), and the organic waste discharged through the anaerobic digestion unit 20 is discharged. Since the temperature is maintained at about 30 ~ 60 ℃ outside the waste heat is recovered and the first transfer to the organic waste before being supplied to the hydrolysis and sterilization unit 10, the heat supply unit 30 as described above Through the hydrolysis and sterilization unit 10 it is possible to reduce the amount of heat to be supplied to the external heat to the temperature required for high temperature hydrolysis and sterilization it is possible to reduce the energy consumption. That is, the energy and operating costs are reduced by reducing the amount of energy to be supplied from the outside through the circulation transfer of energy in the process. The energy transfer process in the primary heat transfer unit 410 may use an indirect heat exchange method through a heat exchanger using a heat exchange medium such as process water, as shown in FIG. As described above, a heat exchange method for transferring heat contained in the organic waste after passing through the anaerobic digestion unit 20 to the organic waste before supplying the hydrolysis and sterilization unit 10 without using a separate heat transfer medium may be used. . That is, the organic waste after passing through the anaerobic digestion unit 20 for supplying waste heat from the heat exchange method using a medium such as heat exchange water, before being supplied to the hydrolysis and sterilization unit 10 for receiving waste heat. Heat transfer efficiency can be improved in a structure in which heat is transferred between the waste pipe and the heat passage therebetween.

To this end, the structure of the pipe in which the primary heat transfer part 410 is located, in which heat transfer is performed, is shown in FIG. 3, in which the organic waste before being supplied to the hydrolysis and sterilization part 10 passes (① direction). It may be formed in a dual structure including a conduit 610 and a second conduit 620 in contact with the first conduit 610 and the organic waste passing through the anaerobic digestion unit 20 (② direction). That is, in the state where the organic waste before being supplied to the hydrolysis and sterilization unit 10 passes the first pipe line 610 (1 direction), the organic waste that has passed through the anaerobic digestion unit 20 is the first pipe ( Passing the second pipe 620 in contact with (610) (direction ②), the organic waste before the waste heat of the organic waste passed through the anaerobic digestion unit 20 is directly supplied to the hydrolysis and sterilization unit 10 The heat transfer between the two to increase the heat transfer efficiency.

The secondary heat transfer unit 420 is a heat transfer to transfer the heat contained in the organic waste immediately after passing through the hydrolysis and sterilization unit 10 to the organic waste after passing through the primary heat transfer unit 410 secondary It is a configuration made. As described above, the hydrolysis and sterilization unit 10 is a high temperature hydrolysis process in which the hydrolysis reaction takes place at a temperature of about 70 ℃, the organic waste discharged through the hydrolysis and sterilization unit 10 Since it maintains a temperature of about 70 ℃ and recovers this waste heat and delivers it to the organic waste before being supplied to the hydrolysis and sterilization unit 10, through the heat supply unit 30 as described above Since it is possible to reduce the amount of external heat to the temperature required for high temperature hydrolysis and sterilization in the hydrolysis and sterilization unit 10 to reduce the energy consumption (in particular, such a secondary heat transfer unit ( Heat transfer process in 420, the anaerobic digestion process in the anaerobic digestion unit 20 (approximately medium temperature (approximately about 30 ℃ mid and late) or high temperature (about 50 ℃) It is able to demonstrate the effect of artificially adjusting the temperature of the organic waste according to the outside))). That is, the temperature reduction process between the hydrolysis and sterilization unit 10 and the anaerobic digestion unit 20 is performed in parallel while reducing the amount of energy to be supplied from the outside through the circulation transfer of energy in the process. Will reduce the cost. The energy transfer process in the secondary heat transfer unit 420 may also utilize an indirect heat exchange method through a heat exchanger using a heat exchange medium, such as process water, as shown in FIG. 1, in particular, in the present invention. As described above, a heat exchange method for transferring heat contained in the organic waste after passing through the hydrolysis and sterilization unit 10 to the organic waste before being supplied to the hydrolysis and sterilization unit 10 without using a separate heat transfer medium is utilized. Can be. That is, the secondary heat transfer unit 420 also escapes from an indirect heat exchange method using a medium such as heat exchange water as in the primary heat transfer unit 410, and heat transfer is performed through a structure in which heat transfer is performed without using a separate heat transfer medium. Efficiency can be increased.

To this end, the structure of the pipe in which the second heat transfer part 420 is located, in which heat transfer is performed, is also shown in FIG. 3, in which the organic waste before being supplied to the hydrolysis and sterilization part 10 passes (1 direction). It can be formed in a dual structure including a conduit 610 and a second conduit 620 in contact with the first duct 610 and the organic waste passed through the hydrolysis and sterilization unit 10 (② direction). have. Structure and function thereof is the same principle as in the primary heat transfer unit 410 described above, so a detailed description thereof will be omitted.

On the other hand, as shown in Figure 2, between the hydrolysis and sterilization unit 10 and the anaerobic digestion unit 20 may further include an emergency cooler (50). As described above, the anaerobic digestion process in the anaerobic digestion unit 20 is effective at medium temperature (about 30 ~ 60 ℃) or high temperature (about 50 ℃), the hydrolysis and sterilization part 10 The temperature of the organic waste in the high temperature (approximately 70 ° C temperature around) state must be artificially controlled, and the hydrolysis and sterilization unit 10 by heat transfer through the secondary heat transfer unit 420 described above. The process of reducing the temperature of the organic waste is carried out between the anaerobic digestion unit 20 and, in some cases, when the temperature of the organic waste flowing into the anaerobic digestion unit 20 is higher than a reference value. Additionally, the emergency cooler 50 may be operated to reduce the temperature of the organic waste flowing into the anaerobic digestion unit 20.

Hereinafter, the high temperature hydrolysis and sterilization and heat recovery method for biogas production using the high temperature hydrolysis and sterilization and heat recovery system for biogas production according to the present invention will be described with reference to FIGS. 4 and 5.

4, the high temperature hydrolysis and sterilization and heat recovery method for biogas production according to an embodiment of the present invention is a hydrolysis and sterilization step (S2) for hydrolyzing and sterilizing organic waste; Anaerobic digestion step (S3) for anaerobic digestion of the hydrolyzed and sterilized organic waste through the hydrolysis and sterilization step (S2); A heat supply step (S1) of supplying heat to a temperature required for high temperature hydrolysis and sterilization in the hydrolysis and sterilization step (S2) and heating; And a heat transfer step of transferring heat contained in the organic waste after the hydrolysis and sterilization step (S2) and / or anaerobic digestion step (S3) to the organic waste before being supplied to the hydrolysis and sterilization step (S2). S4); may include.

The heat supply step (S1) is configured to heat the temperature of the organic waste supplied to the hydrolysis and sterilization step (S2) by supplying heat to the temperature required for high temperature hydrolysis and sterilization in the hydrolysis and sterilization step (S2) to be. As described above, the present invention is characterized in that the 'high temperature' hydrolysis and sterilization process in the hydrolysis and sterilization step (S2), the organic waste of such a high temperature (approximately 70 ℃ temperature) state In order to artificially control the temperature, the external heat is supplied through an external heat source in the heat supply step S1 to warm the temperature of the organic waste supplied to the hydrolysis and sterilization step S2.

The hydrolysis and sterilization step (S2) is a process for hydrolyzing and sterilizing organic wastes as a pretreatment process for producing biogas from organic wastes. Particularly, in the hydrolysis process in which organic matter is decomposed, the present invention undergoes a high temperature hydrolysis process in which the hydrolysis reaction is performed at a high temperature, that is, about 70 ° C. or so, and thus, the number of days of extinguishing by active hydrolysis at high temperature (retention time ) And shorter biogas production, which can improve the processing performance of organic waste and the productivity of biogas. In addition, in the hydrolysis and sterilization step (S2) for the microorganisms that may be unnecessary or hygienic problems in the future anaerobic digestion, such as pathogens and other microorganisms contained in the organic waste at a high temperature (about 70 ℃ temperature) The sterilization process is performed, and the stability and hygiene of the anaerobic digestion process can be prevented through the preliminary removal of factors that would interfere with the advantages of the microbial species required for anaerobic digestion in acid fermentation and methane fermentation in the future anaerobic digestion unit 20. To improve. In addition, the high temperature hydrolysis and sterilization process in the hydrolysis and sterilization step (S2) according to the present invention will also exhibit the effect of enabling the stabilization of the subsequent anaerobic digestion process. In other words, once the organic material is heated to a high temperature, hydrolysis of the organic material is accelerated to simplify the biochemical molecular structure, so that the freezing point is lowered and the coagulating substrate is not easily cooled, so that the solidification is not easy. Foaming is suppressed in the anaerobic digestion process at high temperature (approximately around 50 ° C.), and the organic matter removal rate and biogas production are increased.

The anaerobic digestion step (S3) is a process of anaerobic digestion of the hydrolyzed and sterilized organic waste through the hydrolysis and sterilization step (S2). When the hydrolyzed and sterilized organic waste is subjected to the anaerobic digestion step (S3) through the hydrolysis and sterilization step (S2), first, the sugars are further decomposed by the action of microorganisms such as organic acid producing bacteria, together with hydrogen and carbon dioxide. Acetic acid, propionic acid, butyric acid, etc. are produced, and propionic acid and butyric acid are further decomposed to produce hydrogen, carbon dioxide, acetate, etc., which are precursors of methane production. Subsequently, methane and carbon dioxide are generated using acetic acid, hydrogen, carbon dioxide, and the like by the action of microorganisms such as methane microorganisms. The anaerobic digestion process in the anaerobic digestion step (S3) is generally performed at medium temperature (about 30 ° C. mid- or late) or at high temperature (about 50 ° C. mid- / out), so that the high temperature (about 2 ° C.) undergoes the hydrolysis and sterilization step (S 2). The temperature of the organic waste of the temperature (about 70 ℃) state must be artificially adjusted, which will be described later.

The heat transfer step (S4) is an organic waste before supplying heat contained in the organic waste after the hydrolysis and sterilization step (S2) and / or anaerobic digestion step (S3) to the hydrolysis and sterilization step (S2). In the process of delivering to, more specifically, the first heat transfer that primarily transfers heat contained in the organic waste after the anaerobic digestion step (S3) to the organic waste before being supplied to the hydrolysis and sterilization step (S2). Second heat transfer step of transferring the heat contained in the organic waste immediately after the step (S41) and the hydrolysis and sterilization step (S2) to the organic waste after the first heat transfer step (S41) ( S42) may be included.

The first heat transfer step (S41) is a process in which heat transfer is performed to transfer heat contained in the organic waste after the anaerobic digestion step (S3) to the organic waste before being supplied to the hydrolysis and sterilization step (S2). to be. As described above, in the anaerobic digestion step (S3), the anaerobic digestion process is performed at medium temperature (approximately about 30 ° C./mid) or at high temperature (approximately about 50 ° C./mid), and the organic matter is discharged through the anaerobic digestion step (S3). Since the waste is maintained at a temperature of approximately 30 ~ 60 ℃ to recover the waste heat such as the first delivery to the organic waste before being supplied to the hydrolysis and sterilization step (S2), the heat supply step (S1) as described above ) Through the hydrolysis and sterilization step (S2) it is possible to reduce the amount of heat to be supplied to the external heat to the temperature required for high temperature hydrolysis and sterilization it is possible to reduce the energy consumption. That is, the energy and operating costs are reduced by reducing the amount of energy to be supplied from the outside through the circulation transfer of energy in the process. The energy transfer process in the first heat transfer step (S41) may utilize an indirect heat exchange method through a heat exchanger using a heat exchange medium such as process water, in particular, in the present invention, the organic matter after the anaerobic digestion step (S3). Heat transfer efficiency may be improved through a heat exchange method in which heat contained in the waste is transferred to the organic waste before being supplied to the hydrolysis and sterilization unit price (S2) without using a separate heat transfer medium.

The second heat transfer step (S42) is a heat transfer to transfer heat contained in the organic waste immediately after the hydrolysis and sterilization step (S2) to the organic waste after the first heat transfer step (S41) to the secondary It is a configuration made. As described above, in the hydrolysis and sterilization step (S2) is a high-temperature hydrolysis process in which the hydrolysis reaction is performed at a temperature of about 70 ℃, the organic waste discharged through the hydrolysis and sterilization step (S2) Since it maintains a temperature of about 70 ℃ and recovers this waste heat and delivers it to the organic waste before being supplied to the hydrolysis and sterilization step (S2), the heat supply step (S1) as described above In the hydrolysis and sterilization step (S2) it is possible to reduce the amount to supply the external heat to the temperature required for high temperature hydrolysis and sterilization to reduce the energy consumption (in particular, such a secondary heat transfer step (S42) The heat transfer process in) is the temperature of the anaerobic digestion process in the anaerobic digestion step (S3) (approximately medium temperature (approximately about 30 ℃ mid- or late half) or high temperature ( It is possible to artificially control the temperature of organic wastes in accordance with the mid-to-50 ° C). That is, the temperature reduction process between the hydrolysis and sterilization step (S2) and the anaerobic digestion step (S3) is carried out in parallel while reducing the amount of energy to be supplied from the outside through the circulation transfer of energy in the process. Will reduce the cost. The energy transfer process in the second heat transfer step (S42) may also utilize an indirect heat exchange method through a heat exchanger such as process water, in particular, in the present invention, included in the organic waste after the hydrolysis and sterilization step (S2). Through the heat exchange method for transferring the heat to the organic waste before being supplied to the hydrolysis and sterilization step (S2) it can be possible to increase the heat transfer efficiency.

On the other hand, referring to Figure 5, the high temperature hydrolysis and sterilization and heat recovery method for biogas production according to another embodiment of the present invention the organic heat immediately after the hydrolysis and sterilization step (S2) is the second heat transfer Emergency temperature reduction step (S5) to reduce the temperature when the temperature input to the anaerobic digestion step (S3) through the step (S42) is higher than the reference value; may further include.

In the emergency temperature reduction step (S5), the temperature at which the organic waste immediately after the hydrolysis and sterilization step (S2) is introduced into the anaerobic digestion step (S3) through the secondary heat transfer step (S42) is higher than a reference value. It is a process of temperature reduction. As described above, the anaerobic digestion process in the anaerobic digestion step (S3) is effective at medium temperature (about 30 ℃ mid- or late half) or high temperature (about 50 ℃ middle or around), so the hydrolysis and sterilization step (S2) The temperature of the organic waste at high temperature (approximately 70 ° C. or less) state must be artificially controlled, and hydrolysis and sterilization step (S2) by heat transfer through the second heat transfer step (S42) described above. And a step of reducing the temperature of the organic waste between the anaerobic digestion step (S3), in which case the temperature of the organic waste flowing into the anaerobic digestion step (S3) is higher than the reference value. In addition, by operating the emergency cooler 50 through the emergency temperature reduction step (S5) to reduce the temperature of the organic waste flowing into the anaerobic digestion step (S3) It can allow.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Should be interpreted as belonging to the scope.

10: hydrolysis and sterilization 20: anaerobic digestion
30: heat supply part 40: heat transfer part
410: primary heat transfer unit 420: secondary heat transfer unit
50: emergency cooler
610: pipeline 1 620: pipeline 2

Claims (8)

Hydrolysis and sterilization for hydrolyzing and sterilizing organic wastes;
Anaerobic digestion unit for anaerobic digestion of hydrolyzed and sterilized organic waste through the hydrolysis and sterilization unit;
A heat supply unit for supplying heat to a temperature required for high temperature hydrolysis and sterilization in the hydrolysis and sterilization unit and heating it; And
Heat transfer unit for transferring the heat contained in the organic waste after the hydrolysis and sterilization unit to the organic waste before being supplied to the hydrolysis and sterilization unit; including, to improve productivity through high temperature treatment and increase the efficiency through heat recovery High temperature hydrolysis and sterilization and heat recovery system for the production of biogas. The method of claim 1,
The heat transfer unit primarily transfers heat contained in the organic waste after passing through the anaerobic digestion unit to the organic waste before being supplied to the hydrolysis and sterilization unit, and organic waste immediately after passing through the hydrolysis and sterilization unit. High temperature hydrolysis and sterilization and heat recovery system for biogas production, characterized in that it comprises a secondary heat transfer unit for transferring the heat contained in the secondary organic waste after passing through the primary heat transfer unit. 3. The method of claim 2,
The primary heat transfer unit transfers heat without using a separate heat transfer medium while passing through the pipeline through which the organic waste after passing through the anaerobic digestion unit is supplied to the hydrolysis and sterilization unit.
The second heat transfer part is also characterized in that the organic waste immediately after passing through the hydrolysis and sterilization portion, the organic waste after passing through the first heat transfer portion through the passage passing through the heat without using a separate heat transfer medium, characterized in that the bio High temperature hydrolysis and sterilization and heat recovery systems for gas production. The method of claim 3, wherein
The first heat transfer part and the second heat transfer part are respectively connected to the first pipe through which the organic waste before being supplied to the hydrolysis and sterilization part, and the organic pipes which have passed through the anaerobic digestion part or the hydrolysis and sterilization part in contact with the first pipe. High temperature hydrolysis and sterilization and heat recovery system for biogas production, characterized in that the dual structure including the second passage through the waste to increase the heat transfer efficiency. Hydrolysis and sterilization step of hydrolyzing and sterilizing organic waste;
Anaerobic digestion step of anaerobic digestion of hydrolyzed and sterilized organic waste through the hydrolysis and sterilization step;
A heat supply step of heating by supplying heat to a temperature required for high temperature hydrolysis and sterilization in the hydrolysis and sterilization step; And
Heat transfer step of transferring the heat contained in the organic waste after the hydrolysis and sterilization step to the organic waste before being supplied to the hydrolysis and sterilization step; including, through the high temperature treatment to improve productivity and efficiency through heat recovery High temperature hydrolysis and sterilization and heat recovery methods for biogas production, characterized in that the increase. The method of claim 5, wherein
The heat transfer step includes a first heat transfer step of firstly transferring heat contained in the organic waste after the anaerobic digestion step to the organic waste before being supplied to the hydrolysis and sterilization step, and immediately after the hydrolysis and sterilization step. The high temperature hydrolysis and sterilization and heat recovery method for biogas production, characterized in that it comprises a secondary heat transfer step of transferring the heat contained in the organic waste of the organic wastes after the first heat transfer step in the secondary. The method according to claim 6,
The first heat transfer step is to pass the heat without using a separate heat transfer medium while passing through the pipeline through which the organic waste after the anaerobic digestion step is fed to the hydrolysis and sterilization step,
The second heat transfer step is also characterized in that the organic waste immediately after the hydrolysis and sterilization step is passed through the pipeline through which the organic waste after the first heat transfer step passes heat without using a separate heat transfer medium. High temperature hydrolysis, sterilization and heat recovery methods for biogas production. The method of claim 6, wherein the high temperature hydrolysis and sterilization and heat recovery methods for producing biogas
Biodegradation step further comprising the step of reducing the temperature when the organic waste immediately after the hydrolysis and sterilization step is higher than the standard input temperature through the secondary heat transfer step to the anaerobic digestion step; High temperature hydrolysis, sterilization and heat recovery methods for gas production.

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