JP5188716B2 - Method for producing solid fuel - Google Patents

Description

The present invention relates to a method for producing a solid fuel using biomass and oil mud, and more particularly, to a method for producing a solid fuel using biomass and oil mud with improved adhesion to pipes.

  Silicon wafers are useful as members for semiconductor devices, solar cells and the like, and their demand is increasing year by year. Such a silicon wafer is manufactured by cutting into a wafer form from a crystal of high-purity silicon, but in recent years, cutting with a wire saw is becoming mainstream from the viewpoint of the performance of a cutting machine.

In the cutting with this wire saw, a wire saw oil containing silicon carbide abrasive grains having an average particle diameter of 10 to 50 μm and mineral oil or an aqueous solution is usually used as a cutting medium. The wire saw oil cannot be used because its cutting ability is reduced due to wear of abrasive grains, an increase in silicon scraping, etc. due to repeated use.
And now, most of the waste wire saw oil that can no longer be used is incinerated and treated as industrial waste.

Here, since the above-mentioned waste wire saw oil has high energy, it is expected to be effectively used as fuel without being incinerated as industrial waste.
However, so-called oil mud such as waste wire saw oil has high viscosity, has no fluidity at room temperature, or has solid content that settles and settles. The handling property during transportation is poor, and handling as a fuel is difficult as it is.

  Therefore, in recent years, in Europe, oil sludge such as crude oil sludge is not used alone as a fuel, but it is proposed that the oil mud and biomass such as sawdust are mixed to form a solid fuel and used as an alternative fuel in a cement kiln. In Japan, similar solid fuel production methods have been proposed (for example, Patent Documents 1, 2, and 3).

JP-A-54-39401 JP 2002-323213 A JP 2006-169376 A

However, even in the case of solid fuel that is a mixture of oil mud and sawdust, waste tatami, etc., solid fuel gradually adheres to the pipeline when it is pumped through a pipeline to a cement kiln and used as fuel. However, there was a case where the pipeline was blocked.
In particular, when the waste wire saw oil used for cutting out the silicon wafer is used, the tendency is particularly remarkable, and improvement of adhesion to the pipe line has been strongly desired.

  Here, it is clear that the cause of the adhesion of the solid fuel is the presence of viscous oil mud, so it is conceivable to reduce the mixing ratio of oil mud to biomass. The consumption of oil mud is reduced, which is not preferable from the viewpoint of promoting the use of oil mud as waste. Also, a solid fuel with a reduced oil mud mixing ratio is not preferable as a fuel because its calorific value is reduced.

The present invention has been made in view of the problems of the background art described above, and its object is to change the mixing ratio of oil mud to biomass so much in a method for producing solid fuel using biomass and oil mud. And a method for producing a solid fuel that hardly adheres to a pipe.

As a result of intensive studies to solve the above problems, the present inventors have surprisingly found that by adding a powder having a predetermined particle size, it is possible to significantly improve the adhesion of solid fuel to a pipe line. Completed the invention.
That is, the present invention is a method for producing a solid fuel as described in [1] to [ 2 ] below.
[1] 50 to 100 parts by mass of waste wire saw oil, 5 to 50 parts by mass of powder composed of at least one of waste white clay, meat and bone meal, and fly ash having an average particle size of 2 mm or less are mixed with 100 parts by mass of biomass. A method for producing a solid fuel.
[2] The method for producing a solid fuel according to [1], wherein the biomass is at least one of waste crushed material, wood chips, wood flour, sawdust, and paper waste.

According to the above-described method for producing a solid fuel according to the present invention, the reason is not clear, but the presence of powder having a predetermined particle size can greatly reduce adhesion to the pipeline during pumping and block the pipeline. It is possible to provide a solid fuel capable of preventing the occurrence of the problem.
For this reason, waste wire saw oil , which has been difficult to use for solid fuel due to its high adhesion, can be used, and the use of waste oil mud can be promoted.

Hereinafter, the above-described method for producing a solid fuel according to the present invention will be described in detail.

〔biomass〕
Examples of biomass used in the present invention include crushed tatami (used waste tatami), wood chips (for example, crushed construction waste timber), wood flour, sawdust, and paper waste. Biomass is a general term for biologically derived organic resources (excluding fossil fuels) that can be used as fuel.

The waste tatami used as the material of the crushed tatami mat may be any material as long as it contains at least a part of plant material. Specifically, not only the main tatami mat that uses rice straw as a tatami floor material, but also polystyrene. Foam plates (plate-shaped molded bodies formed by adding a foaming agent to a polystyrene resin composition and expanding) and insulation boards (for example, in the wet method, wood is crushed in water, and adhesives are added. Also included are building material tatami mats, which are made from a soft fiberboard that has been dried after being made, and tatami flooring materials, and paddy sand tatami mats, which are made from rice straw and polystyrene foam plates.
The above-mentioned wood chip refers to a crushed or crushed product of wood having a maximum particle size (mesh size with a sieve residue within 5% by mass) exceeding 5 mm and 10 mm or less.
The above-mentioned wood powder refers to a pulverized product of wood having a maximum particle size (a mesh size with a sieve residue within 5% by mass) of 5 mm or less.
The sawdust usually has a particle size distribution of about 0.5 to 5 mm. As said paper waste, a shredder cutting thing etc. are mentioned, for example.

It is preferable that the average particle size of the biomass (aperture size such that the sieve residue is within 50% by mass) is 0.5 mm or more. When the average particle size is less than 0.5 mm, the entire particle system is miniaturized, so that fluidity and dispersibility are lowered, and it is difficult to obtain effects such as improvement of oil mud handling properties.
Further, the maximum particle size of the biomass (a mesh size in which the remainder of the sieve is within 5% by mass) is 10 mm or less, preferably 5 mm or less, more preferably 3 mm or less. When the maximum particle size exceeds 10 mm, for example, when used in a burner of a cement kiln, it is difficult to form a flame (frame), and combustion continues even after the fuel has landed. There is a risk of causing. If the maximum particle size is 5 mm or less, the proportion of particles that land and burn is reduced, and the proportion of solid fuel used can be increased, which is preferable.

[Oil mud]
The oil mud used in the present invention includes waste wire saw oil, oil sludge (for example, heavy oil sludge, crude oil sludge, etc.), waste oil regeneration residue (residue that remains after waste oil is regenerated using a distillation facility, etc.), waste cutting oil, waste grinding oil , Waste polishing oil, waste paint, waste ink, waste solvent, grease, waste vegetable oil, waste edible oil, degreasing organic sludge and other oily substances, or a mixture of two or more of these. Among them, waste wire saw oil used for cutting a silicon wafer is used in the present invention .
This is because, due to the increasing demand for silicon wafers that are useful as components for semiconductor devices and solar cells, a large amount of waste wire saw oil has been generated in recent years. This is because, when the waste wire saw oil is used as the solid combustion oil mud, the adhesion to the pipe line is particularly high, and the improvement is strongly desired.
Hereinafter, the waste wire saw oil may be simply referred to as “oil mud”.

〔powder〕
The powder used in the present invention is a powder having an average particle diameter of 2 mm or less. Even if a powder having an average particle size exceeding 2 mm is added, the effect of increasing the specific surface area, the bearing function, etc. are hardly exhibited, so that the effect of reducing the adhesion of solid fuel is not sufficiently observed. From this viewpoint, a powder having an average particle size of 1000 μm or less is more preferable.
The average particle diameter of the powder is determined by a laser diffraction scattering method (microtrack method).

Examples of the powder used in the present invention include waste clay, meat and bone powder, fly ash, waste toner, waste plastic powder, heavy oil ash, pulverized coal, activated carbon powder, paper powder, and organic distillation residue powder. Any one or more of waste clay, meat-and-bone meal, and fly ash are used in the present invention. This is the waste clay and MBM, recently, with the advent of effective utilization methods is strongly demanded, because it has a high calorific value. Since fly ash is spherical, it has fluidity, and since it is porous, it acts to absorb oil, and because it is highly wear-resistant, before solid fuel attached to the pipe grows. This is because a cleaning effect can be expected.

The waste clay is white clay used for decolorization and removal of impurities in the oil refining process, and contains many oil components, and is a powder having an average particle size of about 300 μm. In the present invention, it is possible to use waste clay containing oil as it is, and it is also possible to use heat-treated and removed oil.
The above meat-and-bone meal is obtained by heat-treating bones and internal organs remaining after removing meat from livestock, removing fat, compressing and drying, and then pulverizing. However, it is considered to be the cause of Mad Cow Disease (BSE) infection, and in recent years, detoxification treatment by incineration is being sought.
The fly ash is a fine ash particle collected from a flue gas of a pulverized coal combustion boiler by a dust collector, and is usually a spherical shape of about several μm to several tens of μm.

[Combination ratio]
The blending ratio of the above materials is 50 to 100 parts by mass of oil mud and 5 to 50 parts by mass of powder with respect to 100 parts by mass of biomass.
This is not preferable if the blended amount of oil mud is less than 50 parts by mass from the viewpoint of promoting utilization of waste oil mud and the amount of heat generated from the obtained solid fuel. Conversely, if the blended amount of oil mud exceeds 100 parts by mass, a large amount of oil remains on the surface of the resulting solid fuel particles, and even if powder is mixed, it is difficult to improve its adhesion. . From this viewpoint, the blending ratio of the oil mud is preferably 50 to 100 parts by mass and particularly preferably 60 to 70 parts by mass with respect to 100 parts by mass of the biomass.
On the other hand, when the blending amount of the powder is less than 5 parts by mass, the effect of improving the adhesion of the obtained solid fuel is not remarkably recognized. On the other hand, if powder exceeding 50 parts by mass is blended, the ash content increases and the fuel quality is lowered. From this viewpoint, the blending ratio of the powder is preferably 5 to 50 parts by mass, particularly preferably 10 to 20 parts by mass.

〔mixture〕
The above materials may be mixed by putting each material in one mixer and mixing them at the same time. First, oil mud and powder are mixed, and the mixture of oil mud and powder is mixed with biomass. Alternatively, the biomass and the oil mud may be mixed first, and the powder may be mixed with the mixture of the biomass and the oil mud. Furthermore, the biomass and the powder are first mixed, Oil mud may be mixed with the powder mixture. That is, the mixing may be performed in any order, but from the viewpoint of exerting the bearing effect of the powder, it is preferable to mix the powder into the mixture after mixing the biomass and the oil mud.

By the mixing operation of the biomass, the oil mud, and the powder, the solid fuel obtained has greatly improved adhesion to the pipeline.
The reason for this is not clear, but it is thought that the addition of powder increased the specific surface area and improved the ability to absorb oil mud, and the added powder fulfilled the bearing function and improved releasability. It is done. Furthermore, it is considered that the bulk density of the solid fuel is increased by mixing the powder, and the action of stripping off deposits is generated.

If there is a concern about volatilization of combustible gas during the above mixing operation, air may be introduced into the mixer, and the combustible gas that volatilizes from the mixture may be diluted to a concentration that does not cause an explosion or fire. preferable.
This is because when waste wire saw oil is used as oil mud, when the waste wire saw oil and biomass are mixed, hydrogen is generated from the waste wire saw oil, and sparks generated in the rotating part of the mixer are ignited by the hydrogen. There is a risk of explosion. Therefore, it is preferable to perform the mixing operation while introducing air into the mixer and diluting the generated hydrogen concentration to a concentration at which explosion does not occur, that is, lower than the explosion lower limit concentration of 4%.

Moreover, it is preferable to use a mixer that is not simply provided with stirring blades but also has a structure that rotates the mixing container itself. This is because a highly viscous material such as oil mud and a low bulk density material such as biomass can be mixed well, and the combustible gas that has volatilized by the rotation of the container flows and flows into a part of the container. This is because it does not accumulate and can be easily and reliably diluted by the introduced air.
Examples of the mixer having such a structure that also rotates the container itself include an intensive mixer manufactured by Eirich.

[How to use solid fuel]
By the above mixing operation, a solid fuel made of a mixture of biomass, waste wire saw oil and powder is obtained. Since this solid fuel has low adhesion to the pipeline, it can be suitably used as a fuel by pumping the solid fuel into the firing furnace via the pipeline.
Here, examples of the firing furnace include a cement kiln for producing a clinker and a kiln for firing quick lime and lightweight aggregate.

Embodiment
Next, with reference to the drawings, an embodiment of a production facility for realizing the method for producing a solid fuel according to the present invention and a facility for using the produced solid fuel will be described.
FIG. 1 is a diagram conceptually illustrating a solid fuel production facility and a cement kiln using the solid fuel.

  As shown in the figure, first, one batch of waste tatami mat A weighed by a predetermined method is put into the crusher 1, and the proportion of crushed material having a length of 5 cm or less is reduced to 80% by mass or more. It is crushed. And the crushed material of the obtained waste tatami A is conveyed by the conveyor 2, and is stored by the hopper 3. FIG.

One batch of waste tatami A crushed material (approx. 200 kg) stored in the hopper 3 is fed into a mixer (Eirich mixer manufactured by Eirich) together with one batch of oil mud (waste wire saw oil approx. 200 kg) X. First, the mixture is stirred and mixed for a predetermined time (about 1 minute). Subsequently, powder (about 20 kg) P is added from the charging port of the mixer 4, and the mixture is stirred and mixed for a predetermined time (about 2 minutes). During this time, a predetermined amount (up to about 20 m ³ / min) of air is introduced into the mixer 4, and the mixing operation is performed while diluting the combustible gas (hydrogen) generated from the mixture to a concentration that does not cause an explosion. Is called.

  By the above mixing operation, a solid fuel Y made of a mixture of waste tatami A crushed material, waste wire saw oil X and powder P is obtained. The solid fuel Y discharged from the mixer 4 is crushed by a pulverizer 5 installed downstream thereof, conveyed upward by a conveyor 6, foreign matters are removed by a drum magnetic separator 7, and the particle size of the solid fuel Y is reduced by a trommel 8. It is arranged and stored in the storage tank 9.

A predetermined amount (up to about 30 m ³ / min) of air is introduced into the storage tank 9, and storage is performed while diluting the combustible gas (hydrogen) generated from the solid fuel Y to a concentration that does not cause an explosion. . The solid fuel Y stored in such a state is measured by the meter 10 and is pneumatically fed toward the burner 12 instead of or in combination with the pulverized coal that is the main fuel of the cement kiln 11. The fuel is injected into the cement kiln 11 from the fuel injection port of the burner 12.

  The solid fuel Y introduced into the cement kiln 11 is completely burned in a short time before landing on the furnace bottom by the flame from the burner 12, and the combustion residue of the solid fuel Y becomes a part of the components of the clinker. . On the other hand, the foreign matter or the like in the solid fuel Y removed by the drum magnetic separator 7 and the trommel 8 is input from the kiln bottom of the cement kiln 11 and used as fuel, and the residue becomes a part of the clinker component. .

As mentioned above, although one embodiment of the manufacturing equipment which realizes the manufacturing method of the solid fuel according to the present invention and the equipment for using the manufactured solid fuel has been described, the present invention is limited to the embodiment described above. It is not a thing.
In particular, the mixing position and mixing order of the powder are not limited to those in the above embodiment. For example, another mixer is installed in front of the mixer 4, and the waste tatami A is crushed by the mixer. Goods and powder P or waste wire saw oil X and powder P may be mixed in advance.

〔３〕粉体
粉体として、肉骨粉、廃白土、フライアッシュの３種類を用いた。
肉骨粉は、分級することにより、平均粒径１００μｍ程度（規定内のなかで小粒群）、平均粒径２０００μｍ程度（規定内で中粒群）、平均粒径２２００μｍ程度（規定より大粒群）の３種類を用意した。廃白土は、平均粒径３００μｍ程度であった。フライアッシュは、平均粒径２０μｍ程度であった。 1. Materials used [1] Biomass A crushed tatami mat was used. The crushed tatami mat was prepared by the following method.
The tatami mat is crushed using a uniaxial crusher (rooster opening: 15 mm), and the balance of the sieve having an average particle size of 0.5 mm or more and an opening size of 10 mm is 5% by mass or less. A crushed material of this tatami mat was prepared.
[2] Oil mud Waste wire saw oil having the composition shown in Table 1 was used.

[3] Powder As the powder, three kinds of meat-and-bone meal, waste white clay, and fly ash were used.
By classifying the meat-and-bone meal, the average particle size is about 100 μm (small particle group within the specification), the average particle size is about 2000 μm (medium particle group within the specification), and the average particle size is about 2200 μm (large particle group from the specification). Three types were prepared. Waste white clay had an average particle size of about 300 μm. The fly ash had an average particle size of about 20 μm.

2. Production of solid fuel The biomass, oil mud and powder were mixed at various blending ratios shown in Table 2 to produce a solid fuel.
The mixing was performed by first mixing the biomass and the oil mud for 1 minute using a small Eirich mixer (20 L), and adding the powder to the resulting mixture and mixing for 2 minutes.

3. Amount of solid fuel deposited The amount of solid fuel deposited was measured for each of the produced solid fuels.
For the measurement of the amount of adhesion, 100 g of a sample was put into a stainless steel cylindrical container (capacity: 1.7 L) having a diameter of 120 mm and a length of 150 mm, and the cylindrical container was rotated at a rotation speed of 46 rpm for 20 minutes around the axis. And measuring the weight of the sample adhering to the inner wall of the container.
The sample was collected immediately after production from the solid fuel after production (after mixing).
The measurement results of the adhesion amount are also shown in Table 2.

4). Summary The solid fuel obtained by the method for producing a solid fuel according to the present invention in which biomass, waste wire saw oil, and powder having a predetermined particle size (2 mm or less) are mixed is markedly reduced from the above examples. I found out. Moreover, although it depends on the blending ratio of biomass and waste wire saw oil , the blending ratio of the powder is 5 to 50 parts by mass (the upper limit is approximately when the optimum blending ratio of biomass and waste wire saw oil is used). In consideration of fuel quality such as an increase in ash other than adhesion), it was found to be suitable.
The effect shown in this embodiment is naturally considered to be effective even when scaled up to an actual machine, and the method for producing a solid fuel according to the present invention greatly reduces adhesion to the pipe line during pumping. It has been found that a solid fuel capable of preventing the blockage of the pipe line can be provided .

It is the figure which showed notionally the manufacturing equipment which implement | achieves the manufacturing method of the solid fuel which concerns on this invention, and the cement kiln which uses the manufactured solid fuel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crusher 2 Conveyor 3 Hopper 4 Mixer 5 Crusher 6 Conveyor 7 Drum magnetic separator 8 Trommel 9 Storage tank 10 Meter 11 Cement kiln 12 Burner A Waste tatami X Oil mud P Powder Y Solid fuel

Claims (2)

Mixing 50 to 100 parts by mass of waste wire saw oil, 5 to 50 parts by mass of powder consisting of at least one of waste clay, meat-and-bone meal and fly ash having an average particle size of 2 mm or less with respect to 100 parts by mass of biomass. A method for producing a solid fuel. 2. The method for producing a solid fuel according to claim 1, wherein the biomass is at least one of waste crushed material, wood chips, wood flour, sawdust, and paper waste.

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