JP2018176119A - Methane fermentation method and system of garbage waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a methane fermentation method and system of garbage waste capable of separating inorganic solid material in a short time.SOLUTION: Garbage waste A is pulverized together with hot water or steam H to produce heated garbage slurry S of a predetermined temperature, the heated garbage slurry S is caused to stay in a separation tank 30 in a prescribed time, inorganic solid material C is precipitated and separated, and the heated garbage slurry S after separating the inorganic solid material C is projected into a bioreactor 3 to perform methane fermentation treatment. Preferably, an energy recovery device 9 for generating hot water or steam H by utilizing methane gas G obtained by methane fermentation of the bioreactor 3 is provided, and the hot water or steam H generated by the energy recovery device 9 is supplied to a garbage slurry forming device 10. Further preferably, the garbage slurry forming device 10 is used as a foreign matter fractionation device 10 which fractionates foreign matter B in the garbage waste A and pulverizes the garbage waste A after fractionation of the foreign matter B into a heated garbage slurry S of a predetermined temperature.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method and system for methane fermentation treatment of garbage waste, and more particularly to a method and system for methane fermentation treatment of garbage waste including inorganic solids such as eggshells, shells and bones.

  In the past, organic waste (hereinafter referred to as garbage) discharged from general households, restaurants, food stores, food factories, etc. was incinerated or landfilled, but recently from the viewpoint of the formation of a recycling society A recycling process (recycling process) for recovering energy by methane fermentation process is in progress (see Non-Patent Document 1). FIG. 5 shows an example of a conventional recycling system using a wet methane fermentation method. The system in the illustrated example is a pretreatment system 1 for pulverizing garbage waste A into garbage slurry S of particle size and concentration suitable for methane fermentation, and mixing garbage S with methane gas G and digestive fluid W by methanogens. It consists of a bioreactor 3 that decomposes, a secondary treatment facility 5 that further processes residual organic substances in the digested liquid W after decomposition, and an energy recovery facility 6 that recovers energy such as power and high-temperature water from methane gas G (See Patent Document 1).

  In the bioreactor 3 of FIG. 5, for example, a microbial carrier made of carbon fiber or polyester fiber is filled therein to hold methanogenic bacteria, and a garbage waste S diluted to a predetermined concentration is supplied in a downflow manner. Also, a circulation path is provided for extracting the garbage S in the tank from the lower part to the outside of the tank and returning it to the upper part for circulation, and the heating device 3a using high temperature water H from the energy recovery facility 9 is disposed on the circulation path. The organic waste slurry S in the tank is brought into contact with the microorganism carrier while being heated to a temperature suitable for the activity of the methanogens to be decomposed into methane gas G and digestive fluid W.

  The energy recovery facility 6 shown in FIG. 5 includes a purification facility 7 such as a desulfurization apparatus for purifying methane gas G generated by the bioreactor 3, a gas holder 8 for storing methane gas G after purification, and electric power and high temperature using the methane gas G. And an energy recovery device 9 for generating water H. An example of the energy recovery device 9 is a fuel cell, gas engine, gas turbine, micro gas turbine, etc., and the generated power and high temperature water H are used in the system, and surplus power and high temperature water H are supplied out of the system can do. The digestive juice W generated in the bioreactor 3 is separated into a filtrate and a fermentation residue by a dehydrator. The fermentation residue is subjected to fermentation treatment using an aerobic microorganism in the secondary treatment facility 5, and is used as compost and feed material. On the other hand, the filtrate separated by the dehydrator further purifies the residual organic matter in the filtrate and releases it.

  Garbage waste A may contain not only organic matter but also foreign matter B such as plastic, metal pieces, wood pieces, etc. In the pretreatment system 1 of FIG. At the same time, the foreign object B is separated. 6 (A) and 6 (B) show a cross-sectional view and a longitudinal cross-sectional view of an example of the foreign matter sorting apparatus 10 for forming the garbage of the waste while separating the garbage waste A with the foreign matter B (Patent Document 2 and Patent Reference 3). The foreign matter sorting apparatus 10 of the illustrated example has a cylindrical body 11 having a peripheral wall 12 (consisting of an arc-shaped half lower portion 12 b and a non-arc half upper portion 12 a) whose cross section is partially arc-shaped, and a central axis of the cylinder 11 And a plurality of plate-like blades (rotor blades) 16 fixed to a rotary shaft 16a along the axis, and a plurality of through holes 14 are provided in the lower half 12b of the cylindrical body 11. Further, an air flow passage 19 extending in the longitudinal direction of the cylinder is formed between the upper half 12a of the cylinder 11 and the tip end edge of the rotary wing 16, and as shown by the white triangle arrow in the figure, The air flow taken in from the air intake port 19a at one end is guided by the air guide plate 19c of the air flow path 19 in the longitudinal direction of the cylinder and discharged from the exhaust port 19b at the other end. An intake 17 for garbage waste A is provided in the upper half 12 a of the cylinder 11 facing the upstream portion of the air flow, in a direction intersecting the central axis of the cylinder 11. Reference numerals 17a and 17b in the figure indicate feed hoppers for food waste A attached to the inlet 17 and a fixed amount supply crusher, and reference numeral 15 indicates a leg portion for supporting the cylinder 11.

  In the foreign matter sorting apparatus 10 of FIG. 6, the garbage waste A introduced from the inlet 17 is broken up by the rotor 16 driven by the drive device 16 b and separated from the organic matter and the foreign matter B. The separated foreign matter B falls from the outlet 18 on the air stream downstream side to the foreign matter hopper 24 by the air flow of the air flow path 19 and is transported to a required place via the transport pipe 25. In addition, the organic matter after foreign matter separation is finely crushed between the end edge of the rotary wing 16 and the lower half 12b of the cylindrical body 11, and becomes a garbage S and falls from the pores 14 to the garbage slurry hopper 20 Do. The organic waste slurry S dropped to the hopper 20 is fed to the screw type delivery device 22 by the screw conveyor 21 and is transported from the delivery device 22 to the slurry adjustment tank 2 (see FIG. 5) via the transport pipe 23.

  In addition, in the garbage S separated from the foreign matter B, inorganic solids C such as relatively small eggshells, shells, bones of vertebrates, and outer bones of crustaceans may remain. Such inorganic solid C is ionized under acidity when it is methane-fermented with the garbage S without being separated, and it becomes a precipitate under alkaline conditions after that, the piping is clogged, equipment wear, water tank deposition It causes various problems such as Therefore, the pretreatment system 1 of FIG. 5 is provided with a separation tank 30 for separating the inorganic solid matter C from the garbage S. FIG. 7 shows an example of a conventional separation tank 30. As shown in FIG. In the separation tank 30 of the illustrated example, the garbage slurry S mixed with the inorganic solid material C for a predetermined time in the inside 30c surrounded by the substantially conical bottom (pyramidal bottom) 30a and the trunk side surface 30b around it. It stores and has an outlet 33 with opening and closing gates 33b and 33c provided at the lower end of the conical bottom surface 30a, and a stirring means 31 and a circulation means 32 for stirring the garbage S in the interior 30c. (Refer patent document 4).

  After the outlet 33 is closed, the garbage slurry S mixed with the inorganic solid C is charged into the inside 30c of the separation tank 30 of FIG. The raw garbage slurry S that has been added gradually solubilizes when it is allowed to stay for a predetermined time while being stirred by the stirring means 31 and the circulating means 32, and the non-solubilized inorganic solid substance C is precipitated at the bottom of the separation tank The sediment 37) can be collected at the outlet 33 along the slope of the conical bottom surface 30a. In this state, the gates 33b and 33c of the discharge port 33 are opened to separate the inorganic solid C from the garbage S by utilizing the difference in solubilization time by pulling the accumulated inorganic solid C downward. Can. The solubilized food waste slurry S from which the inorganic solid C is separated is sequentially overflowed from the outlet 35 through the sorting member 36 and conveyed to the food waste slurry adjustment tank 2.

Foundation for New Energy Foundation "Biomass Technology Handbook-Know-how for Introduction and Commercialization-Chapter 3 Methane Fermentation" Ohm Co., Ltd., October 25, 2008, pp. 206-447

JP 2000-167523 A JP 2002-177888 A JP 2004-154624 A JP, 2011-167604, A

  By providing the pretreatment system 1 including the foreign matter sorting apparatus 10 of FIG. 6 and the separation tank 30 of FIG. 7 described above, the methane fermentation treatment of the garbage waste A in the recycling system of FIG. Can be continued. However, the conventional pretreatment system 1 has a problem that it takes time to separate the inorganic solid C. That is, in the method of settling and separating the inorganic solid material C from the garbage S by using the difference in solubilization time, although it differs somewhat depending on the type of garbage waste A, it takes about 8 hours to solubilize the garbage S The volume of the separation tank 30 for retaining the food waste slurry S is required only for that time. For this reason, when the amount of garbage waste A received increases, the separation tank 30 becomes large, and a large installation space is required for the pretreatment system 1, and the initial introduction cost and maintenance cost of the system also increase. . In order to promote the recycling system of garbage waste A as shown in FIG. 5, it is effective to make the apparatus compact, and to make the separation tank 30 compact, inorganic solids C from garbage slurry S are used. It is desirable to develop a technology that can settle and separate in a short time.

  Therefore, an object of the present invention is to provide a method and a system for methane fermentation treatment of garbage that can settle inorganic solids in a short time.

  Referring to the embodiment of FIG. 1, the method for methane fermentation treatment of garbage according to the present invention comprises heating garbage waste at a predetermined temperature by crushing garbage waste A while warming it with warm water or steam H. Let S be the heated garbage slurry S retained in the separation tank 30 for a predetermined time to precipitate and separate the inorganic solid C, and charge the heated garbage slurry S after separation of the inorganic solid C into the bioreactor 3 It is produced by methane fermentation.

  Further, referring to the embodiment of FIG. 1, the methane fermentation treatment system for garbage waste according to the present invention is crushed while heating the garbage waste A with warm water or steam H to perform heating at a predetermined temperature. Garbage slurry forming device 10 as waste slurry S, separation tank 30 for settling and separating inorganic solid material C by keeping warm raw garbage slurry S for a predetermined time, and heated garbage waste after separation of inorganic solid material C It comprises the bioreactor 3 which inputs S and performs methane fermentation processing.

  Preferably, an energy recovery device 9 for producing hot water or steam H using methane gas G obtained by the methane fermentation treatment of the bioreactor 3 is provided, and the hot water or steam H produced by the energy recovery device 9 is a garbage refuse Supply device 10. More preferably, the foreign matter is used to separate the foreign matter B in the raw waste waste A and to divide the raw waste waste A after the separation of the foreign matter B into the heated waste slurry S at a predetermined temperature, more preferably. It is set as the separation device 10 (see FIG. 6).

  In the foreign matter sorting device 10, the temperature sensor 41 for measuring the temperature of the heated garbage slurry S outputted from the sorting device 10 and the difference between the measured temperature of the temperature sensor 41 and a predetermined temperature A controller 40 may be included to adjust the temperature or the amount of water to be supplied. In a preferred embodiment, the predetermined temperature of the heated garbage slurry S supplied to the sorting apparatus 10 can be set to 20 to 35 ° C., and the residence time of the heated garbage slurry S in the separation tank 30 can be set to 2 to 6 hours. .

  In the method and system for methane fermentation treatment of garbage according to the present invention according to the present invention, the garbage waste A is pulverized while heated with warm water or steam H to be a heated garbage slurry S having a predetermined temperature, and heated Garbage slurry S is allowed to stay in separation tank 30 for a predetermined time to precipitate and separate inorganic solid C, and after heating inorganic waste C to be separated, charged biomass slurry S is fed to bioreactor 3 for methane fermentation treatment. , Produces the following advantageous effects.

(B) By heating the garbage slurry S and keeping it in the separation tank 30, solubilization of the garbage slurry S is promoted, the viscosity of the garbage slurry S is reduced early, and the inorganic solid C is shortened. Sedimentation can be separated in time.
(B) By shortening the residence time of the garbage S to be separated from the inorganic solid C, the separation tank 30 can be made compact.
(3) The pH of the garbage S can rise by heating, and solubilization of not only the garbage S but also the inorganic solid C can be promoted, but by shortening the residence time in the separation tank 30, the inorganic solid The inorganic solid C can be separated from the garbage S before the solubilization of the substance C progresses significantly.

(D) The hot water or steam H required for heating the garbage S can be supplied from the energy recovery device 9 using methane gas G, and the energy of the separation tank 30 is generated using the energy generated in the methane fermentation system. It can be made compact.
(E) Also, by introducing hot water or steam H simultaneously with the garbage waste A into the conventional foreign matter sorting apparatus 10, the waste A is pulverized while being separated from the foreign matter B to be a heated garbage slurry S It is possible to make the separation tank 30 compact while utilizing the apparatus of the conventional methane fermentation system.

Hereinafter, modes and examples for carrying out the present invention will be described with reference to the attached drawings.
These are explanatory drawings of one Example of the methane fermentation processing system of this invention. These are experimental results which show the relationship between the temperature and viscosity of the heated garbage slurry S. These are experimental results showing the relationship between the temperature and pH of the heated garbage S. These are experimental results which show the relationship between the temperature of the heated garbage S and the concentration of dissolved calcium. These are explanatory drawings of an example of the conventional methane fermentation processing system. These are explanatory drawings of an example of the foreign material classification device used with the pretreatment system of methane fermentation. These are explanatory drawings of an example of the separation tank of the inorganic solid substance used with the pretreatment system of methane fermentation.

  FIG. 1 shows a block diagram of an embodiment in which the present invention is applied to the conventional wet methane fermentation processing system (recycling system) described above with reference to FIG. Similar to the system shown in FIG. 5, the system of the illustrated example is a pretreatment system 1 for pulverizing garbage waste A into garbage slurry S and a bio that decomposes the garbage slurry S into methane gas G and digested liquid W. And a reactor 3. The illustrated bioreactor 3 is similar to a conventional bioreactor. However, the pretreatment system 1 of the illustrated example has the garbage scraping device 10 for pulverizing the garbage waste A while heating it with warm water or steam H, and the garbage waste A is not a normal temperature but a predetermined temperature It can be crushed into a heated garbage slurry S at a temperature.

  Further, the pretreatment system of FIG. 1 has a separation tank 30 for retaining the heated garbage S at a predetermined temperature to separate the inorganic solid material C. By heating the garbage slurry S and keeping it in the separation tank 30, the solubilization of the garbage slurry S is promoted and the viscosity is reduced early, as compared with the case where the garbage slurry S is kept at normal temperature as shown in FIG. , The inorganic solid C can be precipitated and separated from the garbage S in a short time. Moreover, since the inorganic solid material C can be precipitated and separated in a short time, the residence time of the garbage S in the separation tank 30 can be shortened, and hence the separation tank 30 can be made compact.

  For example, as shown in FIG. 6, the garbage separating apparatus 10 of the illustrated example can be a foreign matter sorting apparatus 10 provided with a plurality of water supply nozzles 28. The foreign matter sorting apparatus 10 of FIG. 6 is provided with a plurality of water supply nozzles 28 in the cylindrical body 11 and the garbage refuse hopper 20 in order to adjust and dilute the moisture of the garbage waste A taken in from the inlet 17. In the embodiment of FIG. 1, when the garbage waste A is introduced from the inlet 17 of the foreign matter sorting apparatus 10, the hot water or the steam H is supplied from the water supply nozzle 28 of the cylindrical body 11, and the garbage 16 is discarded by the rotary wing 16. By grinding the substance A with warm water or steam H, the foreign matter B in the waste A is separated, and at the same time the garbage slurry S falling from the pores 14 of the cylinder 11 to the garbage slurry hopper 20 is heated to a predetermined temperature can do.

  In FIG. 6, hot water or steam H may be supplied from the water supply nozzle 28 of the garbage slurry hopper 20 instead of or in addition to the water supply nozzle 28 of the cylindrical body 11. By supplying hot water or steam H to the garbage refuse hopper 20, the garbage slurry S after falling from the pores 14 of the cylindrical body 11 can be heated to a predetermined temperature to be a heated garbage slurry S . Or, as shown by the alternate long and short dash line in FIG. It is also possible to use the heat exchanger 42 provided in the foreign matter sorting apparatus 10 or the separation tank 30 as the organic waste slurry forming device 10. For example, the heat exchanger 42 is disposed in the flow path (for example, the transport pipe 23 of FIG. 6) of the garbage S from the foreign matter sorting apparatus 10 to the separation tank 30 and hot water or steam H is supplied to the heat exchanger 42 By heating the organic waste slurry S, the organic waste waste A is made to be a heated organic waste slurry S having a predetermined temperature.

  The hot water or steam H supplied to the raw material slurry slurrying apparatus 10 can be heated using the methane gas G obtained by the methane fermentation treatment of the bioreactor 3. In the illustrated example of FIG. 1, an energy recovery device 9 for producing hot water or steam H using methane gas G is provided, and a part of the hot water or steam H produced by the energy recovery device 9 is supplied to the bioreactor 3 A portion of the waste water is supplied to the garbage recycling device 10. By heating the garbage S by using the methane gas G generated in the methane fermentation system, the present invention can be implemented without additionally supplying energy from the outside of the system. Also, by supplying warm water or steam H generated by the energy recovery device 9 to the garbage recycling device 10 to heat the garbage slurry S, bio from the energy recovery device 9 as compared with the conventional example of FIG. It can also be expected to reduce the hot water or steam H supplied to the reactor 3, and the separation tank 30 can be made compact by effectively utilizing the energy generated by the energy recovery device 9.

  Preferably, the predetermined temperature of the heated garbage slurry S generated by the garbage slurry forming apparatus 10 is 20 to 35 ° C., and more preferably 25 to 30 ° C. The viscosity of the food waste slurry S is about half of the initial value in about 1/2 time in the case of normal temperature by setting the temperature of the food waste slurry S to 20 ° C. or more although it differs somewhat depending on the type of the food waste waste A The present inventors were able to confirm experimentally that the inorganic solid C settles and separates in a short time. On the other hand, when the temperature of the garbage S becomes 35 ° C. or higher, the solubilization of not only the garbage S but also the inorganic solid C is promoted in a short time. By setting the heated garbage slurry S to 20 to 35 ° C., it is possible to separate the inorganic solids C from the garbage slurry S before the solubilization of the inorganic solids C greatly progresses. Moreover, it becomes possible to separate the inorganic solid C from the slurry S while suppressing the solubilization of the inorganic solid C by setting the heated garbage slurry S to 25 to 30 ° C.

  More preferably, in order to control the temperature of the heated garbage slurry S generated by the garbage slurrying apparatus 10, as shown in FIG. The controller 40 to adjust and the temperature sensor 41 to measure the temperature of the heated garbage S are included. For example, when the foreign matter sorting apparatus 10 is a garbage separating apparatus 10, a temperature sensor 41 is attached to a flow path (for example, the transport pipe 23 of FIG. 6) of the garbage slurry S from the foreign matter sorting apparatus 10 to the separation tank 30; A flow rate adjusting valve V1 is attached to a supply line of warm water or steam H from the energy recovery device 9 to the foreign matter separating device 10, and the temperature sensor 41 and the adjusting valve V1 are connected to the control device 40.

  The control device 40 of FIG. 1 stores in advance the set temperature of the heated garbage S generated by the garbage slurrying apparatus 10, and adjusts the adjustment valve V1 based on the difference between the measured temperature of the temperature sensor 41 and the set temperature. The temperature or the amount of water of the hot water or steam H supplied to the food waste slurrying device 10 is adjusted by adjusting the opening degree of If necessary, connect the water (cold water) supply line to the hot water or steam H supply line, attach the flow adjustment valve V2 to the water supply line, and adjust the opening degree of the adjustment valve V1 and V2 by the controller 40 By doing this, the temperature or the amount of water of the hot water or the steam H to be supplied to the garbage separating apparatus 10 may be adjusted.

  The separation tank 30 of the illustrated example is the same as the conventional separation tank 30 shown in FIG. 5, but since the inorganic solid material C can be separated by sedimentation in a short time, it is compact can do. Specifically, by setting the temperature of the organic waste slurry S to 20 ° C. or higher, the time required to complete the settling of the inorganic solid C can be shortened to about 1/2 to 3/4 as compared with the case of normal temperature. It could be confirmed experimentally. Therefore, it is possible to precipitate and separate the inorganic solid matter C from the garbage S by using a compact separation tank 30 having a volume of about 1/2 to 3/4 as compared with the conventional case.

[Experimental Example 1]
In order to confirm that the settling time of the inorganic solid C can be shortened by heating the organic waste slurry S, the organic waste slurry S at normal temperature discharged from the conventional foreign matter sorting apparatus 10 shown in FIG. 4 samples of A to D were prepared, and experiments were conducted to measure changes in temperature, viscosity, pH, and calcium concentration (Ca ²⁺ concentration) of inorganic solid C over 24 hours for each sample. . The samples B and D were immersed in the constant temperature water bath for 8 hours immediately after the start of the experiment, and then the water bath was taken out and the experiment was continued for 24 hours at room temperature. The returned food waste slurry from the food waste slurry adjustment tank 2 added to the sample C and the sample D simulates the food waste slurry S remaining in the separation tank 30 from the previous day.

Sample A: Garbage slurry S at normal temperature
Sample B: Garbage slurry S immersed and heated in a 30 to 40 ° C. constant temperature water bath for 8 hours
Sample C: Garbage slurry S at normal temperature added by returning the returned slurry from the slurry adjustment tank 2 (see the arrow from the tank 2 to the separation tank 30 in FIG. 1)
Sample D: Garbage slurry S that was added by returning the garbage scrap from the garbage slurry adjustment tank 2 (see FIG. 1) and further immersed in a 30 to 40 ° C. constant temperature water bath for 8 hours and heated

  First, FIG. 2 shows the experimental results of measuring the temperature change and the viscosity change of each sample A to D over 24 hours. Graphs a to d in FIG. 2 represent the viscosity changes of the samples A to D, graph e represents the temperature changes of the samples A and C, and graph f represents the temperature changes of the samples B and D. The graph a in FIG. 2 requires about 4 hours for the viscosity of the sample A at normal temperature to be less than half the initial value, while the graph b has the viscosity of the sample B heated to about 20 ° C. It shows that it takes about 2 hours to become less than half. According to this experimental result, by heating the temperature of the garbage S to 20 ° C. or higher, the time for the viscosity to fall to half or less of the initial value can be shortened to about half compared to the case of normal temperature. Can be confirmed.

  Also, graph c in FIG. 2 requires about 2 hours for the viscosity of sample C at normal temperature to which return garbage slurry is added to be less than or equal to half of the initial value, and graph d heats up by adding return garbage slurry It shows that it takes about 2 hours for the viscosity of sample D to be less than half of the initial value. From this experimental result, acid fermentation has already progressed considerably in the raw garbage slurry S of the raw garbage slurry adjustment tank 2 (raw garbage slurry S left from the previous day), and the microbe group contributing to the acid generation is predominant By returning and adding the organic waste slurry S of the organic waste slurry adjustment tank 2, it can be estimated that the viscosity decreases in a short time even at normal temperature.

  Moreover, the experimental result which measured the temperature change and pH change over 24 hours of each sample AD is shown in FIG. Graphs a to d in FIG. 3 represent pH changes of samples A to D, graph e represents temperature changes of samples A and C, and graph f represents temperature changes of samples B and D. Graphs a and c in FIG. 3 indicate that the pH of the samples A and C at ordinary temperature decreased relatively slowly (acidification), and graphs b and d indicate that the pH of the heated samples B and D is It shows that it has decreased relatively strongly (acidification), and in particular, it shows that the pH drops sharply when the temperature of the samples B and D becomes 25 ° C. or higher.

  The graphs a and c in FIG. 3 indicate that the pH of the samples A and C after 24 hours passed at normal temperature became about 3.8, and the graphs b and d represent 24 hours of the heated samples B and D. It indicates that the pH after aging has become about 3.6, indicating that the heated sample is more acidified. According to the experimental results, acid fermentation proceeds with time for all the raw garbage slurry S, but acid fermentation is promoted by heating, particularly acid fermentation which is heated to 25 ° C. or more is greatly promoted. Can be confirmed. Moreover, since the acid fermentation is greatly promoted, it can be estimated that the viscosity of the garbage slurry S is efficiently lowered by heating the temperature of the garbage slurry S to 25 ° C. or higher.

Furthermore, the experimental result which measured the temperature change and calcium concentration (Ca ^<2+ > concentration) change over 24 hours of each sample AD is shown in FIG. Graphs a to d in FIG. 4 represent pH changes of the samples A to D, graph e represents temperature changes of the samples A and C, and graph f represents temperature changes of the samples B and D. Graphs a and c in FIG. 3 indicate that the calcium concentration of samples A and C at room temperature increased relatively slowly, and graphs b and d indicate that the calcium concentrations of heated samples B and D are relatively It shows that the calcium concentration increases sharply, especially when the temperature of the samples B and D becomes 30 ° C. or more (warming time is about 6 hours).

  The experimental results in FIG. 4 indicate that heating of the garbage S promotes the solubilization of the inorganic solid C, particularly when the temperature of the garbage S becomes 30 ° C. or higher. It shows that solubilization is greatly promoted. From this experimental result, it can be confirmed that the inorganic solid C can be separated from the garbage S while the solubilization of the inorganic solid C is effectively suppressed by suppressing the temperature of the heated garbage S to 30 ° C. or lower. . Further, it can be seen from the experimental results of FIG. 2 described above that the temperature of the garbage slurry S is set to 25 ° C. or more in order to efficiently reduce the viscosity of the garbage slurry S, so the inorganic solid C can be solubilized In order to separate the inorganic solid matter C from the garbage S while effectively suppressing the problem, the temperature of the garbage S is set to 20 to 35 ° C., preferably 25 to 30 ° C., and the garbage slurry S in the separation tank 30 is It can be confirmed that setting the residence time of 2 to 6 hours is effective.

  As confirmed from the above experimental results, since the present invention heats the garbage S and keeps it in the separation tank 30, it promotes the solubilization of the garbage S and reduces the viscosity of the garbage S As a result, the inorganic solid C can be sedimented and separated in a short time, and the separation tank 30 can be made compact. Moreover, solubilization of not only the garbage S but also the inorganic solid C is promoted by heating, but the temperature of the garbage S is set to 20 to 35 ° C., preferably 25 to 30 ° C. By setting the residence time of the waste slurry S to 2 to 6 hours, it is possible to separate the inorganic solid C from the garbage S while suppressing the solubilization of the inorganic solid C.

  Thus, it is possible to achieve the object of the present invention, "a method and system for methane fermentation treatment of garbage, capable of settling and separating inorganic solids in a short time".

DESCRIPTION OF SYMBOLS 1 ... Pretreatment facility 2 ... Garbage slurry adjustment tank 2a ... Garbage slurry pump 3 ... Bioreactor 3a ... Heating device 5 ... Secondary treatment facility 6 ... Energy recovery facility 7 ... Methane purification equipment (desulfurization device)
8: Gas holder 9: Energy recovery device 10: Garbage slurrying device (foreign matter sorting device)
11 ... cylinder 12a ... peripheral wall (half upper part)
12b ... peripheral wall (half lower part) 14 ... pore 15 ... leg part 16 ... rotor blade (plate-like blade)
16a: rotation shaft 16b: drive device 17: intake 17a: supply hopper 17b: fixed amount supply crusher 18: discharge port 19: air flow path 19a: intake port 19b: exhaust port 19c: air guide plate 20: garbage refuse hopper 21 ... screw conveyor 22 ... screw type delivery device 23 ... transport pipe 24 ... foreign material hopper 25 ... transport pipe 28 ... water supply nozzle 30 ... separation tank 30 a ... conical bottom surface 30 b ... body side surface 30 c ... inside 31 ... stirring means 31 a ... stirring Vane 32: circulation means 32a: collection port 32b: discharge port 33: discharge port 33a: discharge flow path 33b, 33c: gate 33d: liquid supply means 33e: pump 33f: injection port 34: inlet port 35: outlet port 36: sorting Member 37: Sediment 40: Control device 41: Temperature sensor 42: Heat exchanger A: Garbage organic matter B: Foreign matter C: Inorganic solid matter S The organics G ... Biogas W ... digestive juices H ... hot water or steam (hot water)

Claims (10)

Garbage waste is crushed while heated with warm water or steam to form a heated garbage slurry at a predetermined temperature, and the heated garbage slurry is retained in a separation tank for a predetermined time to separate and separate inorganic solids, The methane fermentation processing method of the garbage waste which inputs the biomass waste matter after heating the garbage waste after inorganic solid matter isolation | separation, and carries out the methane fermentation process. The method for methane fermentation treatment of garbage according to claim 1, wherein the hot water or steam is heated by methane gas obtained by methane fermentation treatment of the bioreactor. The method according to claim 1 or 2, wherein the garbage waste is introduced into the foreign matter sorting apparatus together with the hot water or steam to separate foreign matter in the waste and heating the garbage waste after the foreign matter sorting to a predetermined temperature The methane fermentation processing method of the garbage waste formed by crushing to garbage garbage. 4. The method according to claim 3, wherein the temperature or amount of hot water or steam supplied to the separating device is adjusted so that the heated refuse slurry discharged from the separating device reaches a predetermined temperature. Fermentation process method. The method according to any one of claims 1 to 4, wherein the predetermined temperature of the heated garbage is 20 to 35 ° C, and the residence time of the heated garbage slurry in the separation tank is 2 to 6 hours. Methane fermentation treatment method of waste. Garbage slurry making device which crushes garbage waste while heating it with warm water or steam and makes it a heated garbage slurry of a predetermined temperature, let the above-mentioned heated garbage slurry stay for a predetermined time and settle inorganic solids by settling The methane fermentation processing system of the garbage waste provided with the separation tank which carries out, and the bioreactor which inputs the heated garbage slurry after the said inorganic solid matter separation, and carries out methane fermentation processing. 7. The system according to claim 6, further comprising: an energy recovery device for producing hot water or steam using methane gas obtained by methane fermentation treatment of the bioreactor, wherein the hot water or steam produced by the energy recovery device is a garbage refuse Methane fermentation treatment system for garbage waste that is supplied to the plant. The system according to claim 6 or 7, wherein the garbage separating device separates the foreign matter in the garbage waste and crushes the garbage waste after the foreign matter separation into a heated garbage slurry having a predetermined temperature A methane fermentation treatment system for garbage waste that becomes a foreign matter separation device. 9. The system according to claim 8, wherein said foreign matter sorting device includes a temperature sensor for measuring the temperature of the heated garbage slurry outputted from said sorting device, and a sorting device based on the difference between the measured temperature of said temperature sensor and a predetermined temperature. And a control device for adjusting temperature or amount of hot water or steam supplied to the system. The system according to any one of claims 6 to 9, wherein the predetermined temperature of the heated garbage is 20 to 35 ° C, and the residence time of the heated garbage slurry in the separation tank is 2 to 6 hours. Methane fermentation processing system.