JP2013181150A - Method for utilizing feces and urine of pig - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for effectively utilizing feces and urine of pigs as fuel at low cost.SOLUTION: A method for utilizing feces and urine of pigs comprises selecting a composting process of feces and urine of pigs, and using the compost composted via the selected composting process as fuel. The compost can be utilized as an industrial furnace fuel or a fireplace fuel. The composting process may include a solid-liquid separation process of the feces and urine of pigs. The composting process may include a fermentation process in a hermetically sealed vertical composting device in a latter part of the solid-liquid separation process of the feces and urine of pigs. The selected compost has a moisture content of 40% or less, chlorine concentration of 3,500 ppm or less and a gross calorific value of 2,500 kcal/kg or greater.

Description

  The present invention relates to a method for using pig manure, and more particularly, to a method for effectively using pig manure as fuel.

  Conventionally, pig manure is generally used as fertilizer in a fermented state. There are various methods for composting pig manure, which can be broadly divided into a deposition method and a stirring method. In the former, there are compost types represented by compost and aeration compost. In the latter, a method in which an agitator runs on the upper part of an open fermenter, an open type in which a crane-type turning device runs, and the compost material is moved while stirring periodically, and a sealed cylindrical shape are used. There is a closed type in which materials are put into a fermenter and composted while the materials are stirred by rotation of the fermenter and internal stirring blades.

  On the other hand, in Patent Document 1, in order to effectively use the energy of livestock excrement such as swine excrement, the fermented and reduced livestock excrement is compressed and solidified, shaped into a fixed form and made into fermented compost pellets, A technique for utilizing the fermented compost pellet as a fertilizer or a solid fuel according to demand is disclosed. Further, in Patent Document 2, as a technique for actively using livestock excrement as fuel, the livestock excrement is immersed in oil at a constant temperature under reduced pressure conditions, and then oiled to obtain a solid, A method for converting livestock excreta into fuel using the solid material as a combustion aid is disclosed.

JP-A-9-142980 JP-A-10-121074

  By the way, conventionally, the reason why it is difficult to use livestock excrement such as pig manure as energy is that the water content and the chlorine content are high. For example, livestock excrement mixed with washing water and urine discharged from pig houses has a high water content of 85 to 95% and a high chlorine concentration of about 20000 ppm on a dry basis.

  Therefore, when livestock excrement having such a high water content is used as fuel, the heat energy generated during combustion is lost to the latent heat of vaporization of water, making it difficult to effectively use the energy. In addition, when livestock excreta with a high chlorine content are introduced into the combustion device, the combustion device is corroded by this chlorine component, or low melting point chlorine compounds are generated and troubles such as blockage in various places such as piping. There was a risk of occurrence.

  Moreover, even if it is composted, since the moisture content is as high as 40 to 60%, for example, when it is input as a fuel into an industrial furnace or the like, as described above, the thermal energy generated during combustion is included in the compost. There is a problem that it is difficult to effectively use energy as fuel because it is deprived of the latent heat of vaporization of moisture. Furthermore, there is a risk that troubles such as the chlorine component in the compost corrode the industrial furnace or the like may occur.

  As described above, as disclosed in Patent Documents 1 and 2 and the like, conventionally, livestock excrement such as manure is finally dechlorinated and dried and solidified and used as fuel. Yes. Therefore, the cost of facilities, work, etc. is required, and effective use of livestock excrement as an energy source tends to be delayed.

  Accordingly, the present invention has been made in view of the above-described problems in the prior art, and an object thereof is to provide a method for effectively using pig manure as a fuel at a low cost.

  As a result of repeated investigations and researches to achieve the above object, the present inventors have conducted solid-liquid separation of pig manure for composting, and the chlorine or / and chlorine compound contained in the manure Most of it is separated as a liquid, and the chlorine content of solids is significantly reduced, and when a closed vertical composting device is used in the composting fermentation process, it is efficiently fermented in a short period of time. Since drying is performed, a compost that maintains a high calorific value with low moisture content and a small decrease in organic matter can be obtained.Depending on the composting method, the moisture content and chlorine concentration are low, and the total calorific value is low. A high compost was obtained, and it was found that the compost can be used as a fuel as it is, and the present invention was completed.

  That is, the present invention is a method for using pig manure, wherein the composting process of pig manure is selected, and the compost composted through the selected composting process is used as a fuel. .

  In the method for using pig manure, the composting step may include a solid-liquid separation step of pig manure.

  In addition, the composting process may include a fermentation process in a closed vertical composting apparatus after the solid-liquid separation process of the swine manure.

  Furthermore, the sorted compost can have a moisture content of 40% or less, a chlorine concentration of 3500 ppm or less, and a total calorific value of 2500 kcal / kg or more.

  According to the method for using pig manure according to the present invention described above, the composting process of the pig manure is selected, and the compost composted through the selected composting process is directly input to an industrial furnace or the like as fuel. Therefore, when using pig manure as a fuel, no new equipment and work are required, and the pig manure can be used effectively as a fuel at low cost. In addition, since the compost that has undergone this composting process has a low moisture content and chlorine concentration and a high total calorific value, there is no risk of adversely affecting the operation of the industrial furnace or the like even if it is directly supplied to the industrial furnace or the like as fuel. .

  Hereinafter, an embodiment of a method for using swine manure according to the present invention will be described in detail. In addition, this embodiment is specifically described in order to clarify the gist of the present invention, and does not limit the present invention unless otherwise specified.

  The method for using swine manure according to the present invention selects a composting process of swine manure, and uses the compost composted through the selected composting process as fuel.

  Here, when composting swine manure, as described in the background section above, it is roughly divided into a sedimentation method and a stirring method. There is a typical compost type, and the latter includes an open type using an open type composting device and a closed type using a closed type composting device. Prior to these various types of fermentation processes, solid-liquid separation of pig manure may be performed.

  In order to compost pig manure, if the initial moisture is about 60%, it can be sent to the fermentation process as it is. A mixture of manure and bedding when the structure of the pig house is a type in which bedding is spread on the floor, such as sawdust, which is a by-product of wood processing, and rice husks of the outermost skin of rice bran. In many cases, the initial moisture is about 60%, and the mixture can be used as it is. Moreover, when there is much water | moisture content, a bedding can be added and water | moisture content can be adjusted to the said value. In a barn with a piggery structure where the floor is a spider child and the manure mixture is collected from the lower part of the spider manure, manure is discharged from the livestock in a slurry form. Is difficult. Therefore, prior to the fermentation process, solid-liquid separation of manure is performed using a solid-liquid separator.

  In the present invention, it is preferable to select compost composted through the solid-liquid separation process of pig manure. As a result of investigation by the present inventors, when solid-liquid separation of pig manure was performed, about 80 to 90% of chlorine and / or chlorine compounds contained in the manure were separated as liquid components, This is because it has been found that the chlorine concentration on the dry basis of the solid content is significantly reduced to about 2000 to 3000 ppm.

  As the solid-liquid separator, a screw press, a roller press, a belt screen, a centrifugal dehydrator or the like is used. The screw press is a system that separates solid and liquid with a screw and a pressing plate, presses the raw material with a screw from the popper at one end of the cylinder, separates the liquid with a screen provided in the middle casing, and then separates the solid from the other end. It is a device that discharges. There are many types of roller presses, but as a relatively simple structure, the screen is drummed and rotated, on which the manure is poured and squeezed with a roller, the liquid flows into the drum screen, Since the solid content adheres to the outer peripheral surface of the drum screen, there is a type in which it is removed with a scraping plate as the drum rotates. The belt screen uses a woven cloth belt formed into a belt shape on a screen, and squeezes manure on the cloth belt by the pressure of a roller to perform solid-liquid separation. In the present invention, any of these solid-liquid separators may be used for solid-liquid separation of pig manure, but in the solid-liquid separation step, the chlorine concentration is about 3000 ppm or less on a dry basis. It is preferable to select those that can obtain a solid content of 2%.

  Various facilities or apparatuses are used in the fermentation process as described above. Among them, the compost house, which is roughly divided into sedimentation methods, is a facility that uses a turning device such as an excavator loader to aerobically decompose and ripen the livestock excrement deposited on the pile only by turning it over. The treatment period is as long as 2-3 months. The ventilation type composting house is a facility that not only turns over but also forcibly ventilates using an aeration device such as a blower to aerobically decompose and ripen livestock excrement and compost. When this ventilated compost is used, the treatment period is shorter than that of the compost house, but still requires a treatment period of about 1 to 2 months.

  On the other hand, the open-type composting device, which is roughly divided into agitation methods and performs open-type fermentation, is a device that promotes composting by aerobically decomposing and ripening livestock excrement mainly by turning over by mixing or transferring. And a fermenter whose upper surface is opened, and a turning-over device that stirs, mixes and transfers the compost raw material in the fermenter. The processing period by this open type composting apparatus is about 15 to 25 days.

  In addition, there are two types of closed-type composting apparatuses that are roughly divided into stirring methods and perform closed-type fermentation. The sealed vertical composting apparatus is a cylindrical fermentation tank covered with heat insulating material placed vertically, and the fermentation tank is usually divided into two upper and lower tanks, and compost raw materials are put into the upper tank, Fermentation decomposition is promoted by mixing and stirring the fermentation material left in advance and the attached stirring device. The upper and lower tanks are equipped with rotating stirring blades. The hot air exchanged with the electric heater or the exhaust gas from the small holes attached to the stirring blades or the hot air by the compressed air of the high-pressure blower is ventilated for fermentation and drying. Promoting. In addition, a kerosene burner is attached to the lower tank, and the kerosene burner is burned as necessary to dry the material in the tank. The compost raw material that has been stirred and composted is taken out from the lower part of the fermenter. Generally, the processing period using this sealed vertical composting apparatus is as short as about 1 to 2 weeks.

  On the other hand, the closed horizontal composting apparatus is also called a rotary kiln type, and is a cylindrical fermenter covered with a heat insulating material, which is inclined and laid down. Stirring is performed by rotation of the fermenter itself and a fixed stirring blade inside. On the contrary, there is a type in which the fermenter is fixed and the internal stirring blades rotate. Although the fermentation period can be changed by changing the inclination, usually, the charged material moves to the discharge port over 5 to 7 days while being rotated and stirred, and in the meantime, it is composted in contact with air.

  In addition, when performing closed type fermentation, sawdust and rice husk may be used to adjust the water content of the input, but these secondary materials are expected to reduce chlorine and increase heat, so mix them. Is preferred. These are often valuable and rarely used by farmers more than necessary.

  In the present invention, compost composted through a fermentation process using a closed composting apparatus is selected from among the fermentation processes using the various facilities or apparatuses described above. As a result of investigations by the present inventors, the closed composting apparatus efficiently fermented and dried the compost raw material in a short period of time, so that the moisture content is as low as about 30 to 40%, and the organic matter This is because it has been found that compost having a high calorific value with a total calorific value of about 3000 kcal / kg or more can be obtained because of a small decrease. As described above, there are a vertical type and a horizontal type in this closed type composting apparatus, and any type of closed type composting apparatus that has been fermented may be selected. In general, the horizontal apparatus is complicated, and as an example of introduction of a farmer, there are many sealed vertical composting apparatuses.

  As described above, the compost obtained by selecting the composting process has a moisture content of about 40%. As organic matter decreases due to fermentation, the chlorine concentration apparently rises slightly, but the chlorine concentration is as low as about 3500 ppm or less, and the total calorific value is about 2500 kcal / kg or more, which is a relatively high calorific value in compost. It will be what. The compost preferably has a moisture content of 35% or less, a chlorine concentration of 3000 ppm or less, and a total calorific value of 3000 kcal / kg or more, more preferably a moisture content of 30% or less and a chlorine concentration of 2500 ppm or less. The total calorific value is 3500 kcal / kg or more.

  The compost having the above properties can be used as various fuels as follows. In addition, in the use shown below, the said compost can be used as a fuel, alone or mixed with other fuels.

1. Fuel for industrial furnaces It can be used as fuel for industrial furnaces such as firing furnaces, heating furnaces, preheating furnaces and drying furnaces.

1.1. Firing furnace fuel It can be used as a fuel for a firing furnace for firing ceramics, cement, activated carbon and the like. In particular, when used as a fuel for an external heat kiln, the burned material does not contain ash after compost is burned, and therefore, it is suitable for use as compost in which a large amount of ash is generated after combustion.

1.2. Heating furnace fuel As a furnace fuel for heating an object (solid, liquid, gas) to a predetermined temperature, it can be used for rolling, forging, heat treatment, melting, distillation, degassing, purification, and the like. In this case as well, by indirectly heating using an external heat kiln or the like, the compost in which a large amount of ash is generated after combustion can be used more effectively as fuel.

1.3. Preheating furnace fuel It can utilize as a fuel of the furnace which preheats a process target object in the front | former stage of the said baking furnace or a heating furnace.

1.4. Drying furnace fuel It can be used as a fuel to dry sludge, waste liquid, painted products, wood, etc. with high water content.

2. Fuel for fireplaces It can be used as a fuel for boilers that generate steam used for heating or heating stoves and rooms.

3. Others In smelting furnaces that perform metal refining, melting, alloy production, etc., high temperatures of about 1500 ° C. are required, so it is difficult to use compost having a combustion temperature of 1000 ° C. or less alone as fuel. . Therefore, it can be used as a fuel for a smelting furnace together with another fuel having a high calorific value.

  In addition, when compost having the above properties is used as a fuel, odor and moisture become problems. Therefore, when it is used as a fuel for a fireplace, an odor countermeasure or the like is separately required. However, when combusted at a high temperature, the odor component from the compost is decomposed by the combustion, so that there is no problem with the odor of the combustion exhaust gas.

  In the present invention, the compost obtained by selecting the composting step is transported to the vicinity of an industrial furnace or the like by a vehicle, preferably a sealed vehicle with a canopy, and the transported compost is directly fed into an industrial furnace or the like as fuel. To do. Here, “as is” means “without active drying using energy or active solidification or granulation using a granulating apparatus or the like. It does not exclude operations such as standing before being put into an industrial furnace, natural drying by transportation, fluidization by stirring, mixing with other raw materials, and the like.

  As described above, according to the method for using swine manure according to the present invention, the composting process of the swine manure is selected, and the compost composted through the selected composting process is used as an industrial fuel as it is. Since it is put into a furnace or the like, no new equipment or work is required when using pig manure as fuel, and pig manure can be used effectively at low cost. In addition, when using swine manure as fuel, compost composted through a selected composting process is selected, so compost with low moisture content and chlorine concentration and high total calorific value is used. Therefore, there is no possibility of adversely affecting the operation of the industrial furnace or the like even if it is directly supplied to the industrial furnace or the like as fuel.

[Test example]
Hereinafter, although the investigation result and test example which discovered this invention are described, this invention is not limited by these investigation result and test example at all.

1. Investigation of compost derived from swine manure We investigated the difference in properties of compost derived from swine manure based on the difference in composting process. The survey results are shown in Table 1.

  The moisture content of compost is measured by JIS M 8812 “Coal and cokes-industrial analysis method”, the chlorine concentration is measured by Eshka method, and the total calorific value is measured by JIS M 8814 “Coal and coke”. It was carried out by the “method of measuring the total calorific value with a bomb calorimeter and the method of calculating the true calorific value” In addition, the evaluation as a fuel is based on the test results when various past wastes are adjusted and used as fuel for industrial furnaces, etc. The thing was evaluated as “×”.

Claims (4)

  A method for using swine manure, wherein a composting process for swine manure is selected, and the compost composted through the selected composting process is used as fuel.   The method for using swine manure according to claim 1, wherein the composting step includes a solid-liquid separation step of swine manure.   The method for using swine manure according to claim 2, wherein the composting step includes a fermentation step in a closed vertical composting apparatus after the solid-liquid separation step of the swine manure.   The use of swine manure according to claim 1, 2 or 3, wherein the sorted compost has a moisture content of 40% or less, a chlorine concentration of 3500ppm or less, and a total calorific value of 2500 kcal / kg or more. Method.