Production method for dried livestock excrement

Abstract

To provide a production method for dried livestock excrement, the method capable of performing dehydration of livestock excrement (chicken excrement, cow excrement, hog excrement, etc.) with a minimum facility and being more simplified.SOLUTION: A production method for dried livestock excrement produces the dried livestock excrement by dehydrating and granulating a livestock excrement composition including livestock excrement and a granulating agent.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing dried livestock manure. [Background technology]

[0002] In recent years, in the agricultural and horticultural fields, due to the rising prices of uric acid, ammonium phosphate, potassium chloride, and other sources of the main components of fertilizers (nitrogen, phosphorus, and potassium), dried livestock manure containing nitrogen, phosphorus, potassium, etc. has been attracting attention as a raw material for fertilizer.

[0003] Dried livestock manure is obtained by subjecting livestock manure (chicken manure, cow manure, pig manure, etc.) to a drying process (which may include a fermentation process), but there is a problem in that the drying process generates an odor, limiting the places where it can be dried. Patent Document 1 discloses a method for producing dried livestock manure in which livestock manure, coffee grounds, and other additives are fermented under aerobic conditions in a fermentation device, and then dried in a drying device to suppress the generation of odor.

[0004] In addition, since dried livestock manure is a powdery substance, it scatters when applied to fields, making it difficult to spread evenly. Countermeasures against scattering include granulation and pelletization. Patent Document 2 discloses a method for granulating dried livestock manure using an extrusion granulator. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2021 / 006285 [Patent Document 2] International Publication No. 2019 / 038820 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the production method disclosed in Patent Document 1 requires separate fermentation and drying steps under aerobic conditions, which results in problems such as a long time required for producing dried livestock manure and the need for fermentation equipment in addition to drying equipment. In addition, problems may arise such as the need to secure a storage space for the fermented material obtained through the fermentation step, and the need for extra man-hours to transport the fermented material into the drying equipment.

[0007] The manufacturing method disclosed in Patent Document 2 has a problem in that dried chicken manure with an adjusted moisture content is granulated using an extrusion granulation device, which requires not only drying equipment but also granulation equipment. Furthermore, if a large amount of equipment is required, problems such as investment in equipment, maintenance techniques or maintenance costs, and limited space for installing the equipment may arise, so a simple method for granulating dried livestock manure is desired.

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a simpler method for producing dried livestock manure that can dry livestock manure (chicken manure, cow manure, pig manure, etc.) with minimal equipment. [Means for solving the problem]

[0009] As a result of extensive research into the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by a method for producing dried livestock manure that includes specific steps, and have thus completed the present invention. The present invention relates to the following [1] to

[12] . [1] A method for producing dried livestock manure, comprising drying and granulating a livestock manure composition containing livestock manure and a granulating agent to obtain dried livestock manure. [2] A blending step of blending livestock manure with a granulating agent to obtain a livestock manure composition; A drying step of drying the livestock feces composition; The method for producing dried livestock feces according to the above [1], [3] The livestock manure includes one or more selected from the group consisting of chicken manure, cow manure, and pig manure; The method for producing dried livestock manure described in [1] or [2] above. [4] The method for producing dried livestock manure described in [3] above, wherein the chicken manure is derived from layer chickens. [5] The method for producing dried livestock manure described in any one of [1] to [4] above, wherein the granulating agent is one or more selected from the group consisting of natural organic granulating agents, synthetic organic granulating agents, and inorganic granulating agents. [6] The method for producing dried livestock manure described in [5] above, wherein the granulating agent is blackstrap molasses. [7] The granulating agent is 1 to 20 parts by mass per 100 parts by mass of the livestock feces. The method for producing dried livestock feces according to any one of the above [1] to [6]. [8] The method for producing dried livestock feces according to any one of the above [1] to [7], wherein in the drying step, the livestock feces composition is dried using hot air at 30 to 120°C. [9] The method for producing dried livestock feces described in [8] above, wherein in the drying step, the livestock feces composition is dried while being stirred under sealed conditions.

[10] The method for producing dried livestock manure described in [9] above, wherein the drying step is carried out using a sealed vertical fermentation machine.

[11] The method for producing dried livestock manure according to any one of the above [1] to

[10] , wherein the moisture content of the dried livestock manure is 15 to 50 mass %.

[12] The method for producing dried livestock feces according to any one of the above [1] to

[11] , wherein the proportion of the dried livestock feces having a particle size of 1.40 mm or less relative to the total weight of the dried livestock feces is 30 to 60 mass %. Effect of the Invention

[0010] According to the present invention, it is possible to provide a simpler method for producing dried livestock manure (chicken manure, cow manure, pig manure, etc.) that can dry livestock manure using a minimum amount of equipment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, one embodiment of the present invention will be described in detail, but the present invention is not limited to the following embodiment. In the numerical ranges described in this specification, the upper or lower limit of the numerical range may be replaced with the values ​​shown in the examples. In addition, the lower and upper limits of the numerical ranges may be arbitrarily combined with the lower and upper limits of other numerical ranges, respectively. Furthermore, when the exemplified and preferred embodiments are a collection of options, any number of options may be extracted from the collection, and the extracted options may be arbitrarily combined with the embodiments described elsewhere. The present invention also includes any combination of the features described in this specification.

[0012] The method for producing dried livestock feces of this embodiment is a method for producing dried livestock feces in which a livestock feces composition containing livestock feces and a granulating agent is dried and granulated to obtain dried livestock feces. The production method preferably includes a blending step of blending livestock dung and a granulating agent to obtain a livestock dung composition, and a drying step of drying the livestock dung composition. Hereinafter, each step included in the manufacturing method of this embodiment will be described in order.

[0013] <Blending process> The blending step that may be included in the manufacturing method of this embodiment is a step of blending livestock manure with a granulating agent to obtain a livestock manure composition before the drying step described below. Since the livestock manure composition contains a granulating agent by the blending step, granular dried livestock manure can be obtained by carrying out a drying step using a drying facility without going through a granulation step using a granulation facility. The production method of this embodiment can obtain granular dried livestock manure without using a granulation facility, and therefore can be said to be a simpler granulation method for dried livestock manure.

[0014] (animal feces) The livestock manure is not particularly limited, and examples thereof include raw manure (including urine) of livestock animals such as chicken manure, cow manure, and pig manure, fermented manure, etc. These may be used alone or in combination of two or more types. In addition, the livestock manure may contain materials used as bedding for livestock stables, such as sawdust, straw, wood chips, tatami mat waste, and rice husks; composted feces (including urine); and materials other than feces derived from livestock, such as hair, feathers, and down, so long as the effects of the present invention are not impaired.

[0015] ((Chicken manure)) The chicken droppings are not particularly limited, and examples thereof include raw droppings (including urine) such as chicken droppings from rearing chickens, chicken droppings from meat producers (Breuer), and chicken droppings from layers for laying eggs (layer), fermented droppings, etc. These may be used alone or in combination of two or more kinds.

[0016] (Granulating agent) The granulating agent is not particularly limited, but those that are usually used as fertilizer binders can be suitably used. Specific examples of the granulating agent include natural organic granulating agents such as blackstrap molasses, lignin sulfonate, starch, konjac powder, sodium alginate, and sodium humate; synthetic organic granulating agents such as carboxymethylcellulose (CMC), polyvinyl alcohol (PVA), and polyacrylamide (PAM); and inorganic granulating agents such as bentonite and gypsum. These may be used alone or in combination of two or more. Among these, from the viewpoint of biodegradability, natural organic granulating agents such as blackstrap molasses, lignin sulfonate, starch, konjac powder, sodium alginate, etc.; and synthetic organic granulating agents such as carboxymethyl cellulose (CMC), polyvinyl alcohol (PVA), polyacrylamide (PAM), etc. are preferred. Furthermore, from the viewpoint of suppressing odor during drying, blackstrap molasses having a fragrance is more preferred.

[0017] The amount of the granulating agent is preferably 1 to 20 parts by mass relative to 100 parts by mass of livestock manure. When the amount is 1 part by mass or more, the effect of granulation during the drying process can be expected. On the other hand, when the amount is 20 parts by mass or less, it is economical. From this viewpoint, it is more preferably 1 to 10 parts by mass, and even more preferably 5 to 10 parts by mass.

[0018] The method of mixing the granulating agent and the livestock manure (order of addition, mixing method, etc.) is not particularly limited, so long as the livestock manure and granulating agent are mixed at the time of drying. For example, the granulating agent may be added to the livestock manure in advance and then stirred to mix uniformly, or the livestock manure may be stirred while the granulating agent is added all at once or in several portions and mixed, or the livestock manure may be stirred while the granulating agent is added all at once or in several portions and mixed, and this mixing may take place either before or during drying. Among these, from the viewpoint of granulating dried livestock manure, it is preferable to use a closed vertical fermenter that can also be used in the drying process.

[0019] (Livestock feces composition) The livestock manure composition is not particularly limited as long as it contains at least livestock manure and a granulating agent, and may contain additives other than livestock manure and a granulating agent as long as the effects of the present invention are not hindered. For example, animal residues such as animal or fish skin, meat, bones, internal organs, rump, egg shells, shells, and feathers, which are sources of nitrogen and phosphoric acid; vegetable waste, used tea leaves, fruit peels, soybean dregs, coffee grounds, sake lees, oil lees, fermentation lees, brewing lees, medicinal herb lees, candy lees, seaweed lees, and beer lees; and the like. These may be used alone or in combination of two or more.

[0020] The content of the livestock feces in the livestock feces composition is preferably 70 to 99% by mass, more preferably 70% by mass or more from the viewpoint of drying, and more preferably 99% by mass or less from the viewpoint of granulation. The total content of the livestock manure and the granulating agent in the livestock manure composition is preferably 80 to 100% by mass, preferably 80% by mass or more from the viewpoint of drying, and preferably 100% by mass or less from the viewpoint of granulation.

[0021] The method for mixing the livestock feces and the livestock feces composition containing the granulating agent is not particularly limited, and examples thereof include mechanical mixing methods using a stirrer, kneader, closed vertical fermenter (which allows drying while stirring), etc.; manual mixing methods; etc. Among these, from the viewpoint of efficient production of granulated dried livestock feces, it is preferable to use a closed vertical fermenter that can also be used in the drying process.

[0022] <Drying process> The drying step that may be included in the production method of this embodiment is a step of drying the livestock dung composition obtained in the blending step to obtain granulated dried livestock dung without going through a granulation step using a granulation facility. Note that, in the drying step, it is also possible to carry out a fermentation treatment simultaneously with the drying treatment of the livestock dung. In the drying step that may be included in the manufacturing method of this embodiment, the generation of odor that occurs when the livestock manure is dried can be suppressed. Although the principle behind this is unclear, it is presumed that the odor is suppressed by covering the surface of the livestock manure during drying with the granulating agent.

[0023] (Drying method) The drying method in the drying step that may be included in the production method of this embodiment is not particularly limited and may be appropriately determined depending on the moisture content and other factors contained in the livestock manure composition, and examples of the drying method include natural drying, heat drying, hot air drying, vacuum drying, ultrasonic drying, microwave drying, etc. These may be used alone or in combination of two or more. Among these, hot air drying is preferred from the viewpoint of granulation effect.

[0024] (Drying temperature and duration) The drying temperature in the case of hot air drying is not particularly limited, but is preferably 30 to 120°C, more preferably 35 to 90°C, and further preferably 40 to 70°C, from the viewpoint of the granulation effect. Furthermore, the drying time in the case of hot air drying is not particularly limited, but from the viewpoint of the granulation effect, it is preferably 2 to 12 days, more preferably 3 to 10 days, and even more preferably 4 to 8 days.

[0025] (drying equipment) In the drying process that may be included in the manufacturing method of this embodiment, a sealed vertical fermenter having a sealing function and a stirring function is used, but is not limited thereto. The drying device used for hot air drying is not particularly limited and may be either a batch type or a continuous type, but it is preferable that the drying device is capable of stirring the livestock manure composition during drying and distributing the granulating agent evenly, and it is also preferable that the drying device is sealable in order to prevent the diffusion of odors.

[0026] ((Closed vertical fermentation machine)) The sealed vertical fermenter is one of the devices that uses a sealed stirring system, has a stirring function and a hot air blowing function, is sealable, and can be installed in a space-saving manner. Specific examples of sealed vertical fermentation machines include, but are not limited to, a drying device having a vertical cylindrical reaction tank (the part where drying and fermentation take place) that is sealed and covered with insulation, a stirring blade that can stir the livestock dung composition containing livestock dung and a granulating agent that is added from the top of the reaction tank, and an air hole that can blow warm air while stirring.

[0027] (dried animal feces) The dried livestock manure obtained by the production method of this embodiment can be obtained by drying the livestock manure composition. Furthermore, the dried livestock manure obtained by the manufacturing method of this embodiment can be granulated without going through a granulation step.

[0028] The moisture content of the dried livestock manure obtained by the manufacturing method of this embodiment is not particularly limited, but is preferably 15 to 50% by mass, more preferably 20 to 40% by mass, and even more preferably 25 to 35% by mass. If the moisture content is 15% by mass or more, the granulation effect is commensurate with the drying labor (time, energy used for hot air, etc.), which is economical. On the other hand, if the moisture content is 50% by mass or less, the dried livestock manure is prevented from becoming a slurry due to the high moisture content, and granulation can be efficiently performed.

[0029] The particle size of the dried livestock feces obtained by the manufacturing method of this embodiment is not particularly limited, but from the viewpoint of preventing scattering during spraying, the ratio (mass%) of dried livestock feces having a particle size of 1.40 mm or less is preferably 60 mass% or less, more preferably 30 to 60 mass%, even more preferably 30 to 55 mass%, and particularly preferably 30 to 50 mass%. If the ratio (mass%) of dried livestock feces having a particle size of 1.40 mm or less is 30 mass% or more, a granulation effect commensurate with optimization of drying conditions (optimization of blending conditions such as time and temperature) and optimization of blending of livestock feces composition (optimization of blending ratio, mixing conditions, consideration of other additives, etc.) can be obtained, which is economical. On the other hand, if the ratio (mass%) of dried livestock feces having a particle size of 1.40 mm or less is 60 mass% or less, scattering during spraying can be prevented. EXAMPLES

[0030] The present invention will be described in detail below with reference to examples. The following examples are provided to facilitate understanding of the present invention, and are not intended to limit the present invention. Various modifications and improvements are possible without departing from the gist of the present invention.

[0031] <Measurement of moisture content of dried livestock manure> After drying, approximately 10 g of each dried feces sample was evaporated using a moisture content meter (Kurita Water Industries Ltd.'s "Kurigansui"), and the moisture content was calculated from the weight change before and after drying. The measurement was performed under conditions where the temperature of the heating wire of the moisture content meter was 140°C.

[0032] <Calculation of the percentage of dry livestock manure with a particle size of less than 1.40 mm> 1000cc of each sample of dried livestock feces was sieved using a sieve with 1.40mm mesh to separate dried livestock feces with a particle size of less than 1.40mm from the rest. The weight of the 1000cc was measured before sieving, and the weight of the separated dried livestock feces with a particle size of less than 1.40mm was measured and the proportion was calculated.

[0033] <Production of dried livestock manure> Example 1 100 parts by mass of chicken droppings (layer) as livestock droppings and 10 parts by mass of blackstrap molasses as a granulating agent were charged into a closed vertical fermenter to obtain a livestock droppings composition, which was then mixed by stirring. The mixture was dried at 70° C. for 6 days with stirring to obtain a dried livestock feces composition.

[0034] Example 2 Dried livestock manure was produced under the same conditions as in Example 1, except that the amount of blackstrap molasses was changed to 5 parts by mass.

[0035] Example 3 100 parts by mass of chicken manure (layer) as livestock manure, 5 parts by mass of blackstrap molasses as a granulating agent, and 5 parts by mass of coffee grounds were charged into a closed vertical fermenter to obtain a livestock manure composition, which was then stirred and mixed. Drying was carried out under the same conditions as in Example 1 to obtain dried livestock manure.

[0036] Example 4 Dried livestock manure was produced under the same conditions as in Example 1, except that 10 parts by mass of carboxymethyl cellulose (CMC) was used instead of 10 parts by mass of blackstrap molasses.

[0037] Example 5 Dried livestock manure was produced under the same conditions as in Example 1, except that 100 parts by mass of cow manure was used instead of 100 parts by mass of chicken manure.

[0038] Example 6 Dried livestock manure was produced under the same conditions as in Example 1, except that the amount of blackstrap molasses was 1 part by mass.

[0039] Example 7 Dried livestock feces was produced under the same conditions as in Example 1, except that the drying temperature was changed from 70°C to 50°C.

[0040] Comparative Example 1 Dried livestock feces was produced under the same conditions as in Example 1, except that no granulating agent was used.

[0041] Comparative Example 2 100 parts by mass of chicken manure (layer) as livestock manure and 5 parts by mass of coffee grounds were put into a closed vertical fermenter to obtain a livestock manure composition, which was then stirred and mixed. Drying was carried out under the same conditions as in Example 1 to obtain dried livestock manure.

[0042] The moisture content and particle size of the dried livestock feces obtained in each example were measured and evaluated by the methods described above. The results are shown in Table 1.

[0043] [Table 1]

[0044] It can be seen from Table 1 that the proportion of dried livestock feces with particle sizes of 1.40 mm or less is low in the dried livestock feces of Examples 1 to 7 obtained by the production method of this embodiment. The results of Examples 2 and 3 show that the excellent effect of the present invention (reducing the proportion of dried livestock manure with a particle size of 1.40 mm or less) is enhanced by adding coffee grounds to the livestock manure composition as an additive other than the livestock manure and granulating agent. The results of Examples 1 and 4 show that when carboxymethylcellulose (CMC) is used as a granulating agent other than blackstrap molasses, the excellent effect of the present invention (reduction in the proportion of dried livestock manure with a particle size of 1.40 mm or less) is achieved. From the results of Examples 1 and 5, it can be seen that the excellent effect of the present invention (reduction in the proportion of dry livestock manure with a particle size of 1.40 mm or less) can be achieved even when cow manure is used as livestock manure other than chicken manure.

Claims

1. A method for producing dried livestock feces, comprising drying and granulating a livestock feces composition containing livestock feces and a granulating agent to obtain dried livestock feces.

2. A blending step of blending livestock feces with a granulating agent to obtain a livestock feces composition; A drying step of drying the livestock feces composition; The method for producing dried livestock feces according to claim 1, comprising:

3. The method for producing dried livestock manure according to claim 1 or 2, wherein the livestock manure comprises at least one selected from the group consisting of chicken manure, cow manure, and pig manure.

4. The method for producing dried livestock feces according to claim 3, wherein the chicken manure is derived from layer chickens.

5. 3. The method for producing dried livestock manure according to claim 1 or 2, wherein the granulating agent is one or more selected from the group consisting of natural organic granulating agents, synthetic organic granulating agents, and inorganic granulating agents.

6. The method for producing dried livestock manure according to claim 5, wherein the granulating agent is blackstrap molasses.

7. The method for producing dried livestock feces according to claim 1 or 2, wherein the granulating agent is used in an amount of 1 to 20 parts by mass per 100 parts by mass of the livestock feces.

8. The method for producing dried livestock feces according to claim 1 or 2, wherein in the drying step, the livestock feces composition is dried using hot air at 30 to 120°C.

9. The method for producing dried livestock feces according to claim 8, wherein in the drying step, the livestock feces composition is dried while being stirred under a sealed condition.

10. The method for producing dried livestock manure according to claim 9, wherein the drying step is carried out by a closed vertical fermentation machine.

11. The method for producing dried livestock feces according to claim 1 or 2, wherein the moisture content of the dried livestock feces is 15 to 50 mass %.

12. The method for producing dried livestock feces according to claim 1 or 2, wherein the proportion of the dried livestock feces having a particle size of 1.40 mm or less to the total weight of the dried livestock feces is 30 to 60 mass %.

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