JP2008297340A - Solid fuel essentially consisting of sewage sludge, and production device therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide solid fuel which consists essentially of sewage sludge, and whose peculiar odor characteristic of sewage sludge is suppressed, and also, commercial value as solid fuel is high. <P>SOLUTION: Sewage sludge is heated and dried in the presence of pyroligneous acid, so as to obtain solid fuel consisting essentially of sewage sludge, and in which peculiar odor characteristic of sewage sludge is suppressed, and also commercial value as solid fuel is high. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a solid fuel using sewage sludge as a main raw material and an apparatus for producing the same, and more specifically, a sewage sludge having a high commercial value as a solid fuel that suppresses a unique odor derived from sewage sludge as a main component. The present invention relates to a solid fuel and an apparatus for manufacturing the same.

Conventionally, most of the sewage sludge generated in sewage treatment plants has been disposed of by incineration or landfilling, but in recent years, technology that contributes to global warming countermeasures by effectively using the thermal energy of sewage sludge is required. .
However, sewage sludge contains odor components such as ammonia, hydrogen sulfide, trimethylamine, methyl mercaptan, etc., and the dry sludge obtained by drying sewage sludge has a strong odor, which adversely affects the work environment such as transportation and storage. It is difficult to use as fuel.

  Therefore, as a technique for suppressing the unique odor derived from sewage sludge and converting sewage sludge into fuel, for example, Patent Document 1 discloses that after drying sewage sludge to dry sludge, a part of the dried sludge is carbonized. A technique for obtaining a solid fuel by mixing activated sludge activated carbon and untreated dry sludge and adding quick lime or slaked lime as necessary is disclosed.

  Further, in Patent Document 2, an amount of iron-containing sludge necessary for substantially eliminating odors is mixed with sewage sludge, then quick lime is added to the mixture and mixed to generate heat, and the mixture is dried. Thus, a technique for obtaining a sewage sludge treatment material is disclosed.

  Furthermore, in Patent Document 3, sewage sludge dried to a moisture content of 0 to 50% is carbonized at 250 to 500 ° C., and then mixed with waste oil and waste oil residue to form a solid fuel by granulation. Technology is disclosed.

JP 11-323359 A JP 2001-47093 A JP 2006-152097 A

  However, the technique disclosed in Patent Document 1 requires a carbonization facility to carbonize part of the dried sludge, which increases the facility installation cost. Moreover, since the energy which sludge itself holds is used when carbonizing, the calorific value of the obtained solid fuel becomes low, and the value as a fuel falls.

  In addition, since the technique disclosed in Patent Document 2 adds iron, which is an inorganic component, in order to suppress malodors, the calorific value of the obtained sewage sludge solid fuel is lowered, and therefore the value as a fuel is lowered.

  Moreover, since the technique disclosed in Patent Document 3 uses the energy held by the sludge itself when carbonizing, the calorific value of the obtained solid fuel becomes low, and the value as a fuel decreases. Furthermore, since the drying, carbonization, and granulation processes are performed, the equipment installation cost increases.

  Accordingly, in view of the problems of the prior art, the present invention provides a solid fuel mainly composed of sewage sludge having a high commercial value as a solid fuel and a manufacturing apparatus thereof, which suppress a unique odor derived from sewage sludge. Objective.

In order to solve the above-mentioned problems, in the present invention, a solid fuel mainly composed of sewage sludge obtained by heating and drying sewage sludge, the sewage sludge is heated and dried in the presence of wood vinegar. It is characterized by being obtained by this.
According to the present invention, by heating and drying sewage sludge in the presence of wood vinegar, acid such as acetic acid contained in wood vinegar reacts with ammonia, which is the main component of the odor component of activated sludge and the base. Neutralizes and suppresses odor. In general, the odor component in sewage sludge has the highest ammonia concentration, and the effect of suppressing odor by reducing by neutralizing ammonia is great.
Further, for example, odor components other than bases such as hydrogen sulfide, trimethylamine, and methyl mercaptan are not neutralized by an acid such as acetic acid in the wood vinegar solution, but the odor is suppressed by the masking effect by the wood vinegar solution.
That is, since the base component in the odor component of the sewage sludge is suppressed by neutralization, and the components other than the base are suppressed by the masking effect, the odor is suppressed, so that the solid fuel is suppressed.
Moreover, since the wood vinegar is an organic component, the fuel value of the solid fuel is not lowered by adding the wood vinegar.

Further, the woody biomass is added to and mixed with the sewage sludge, and the mixture of the sewage sludge and the woody biomass is obtained by heating and drying the sewage sludge at a temperature at which the wood vinegar is extracted from the woody biomass. It is characterized by that.
Examples of woody biomass include forest land residue, thinned wood, pharmaceutical waste, waste wood, waste paper, and the like, but other woody biomass can be used. Moreover, as heat drying temperature, it is preferable to set it as 300-400 degreeC from which wood vinegar liquid generate | occur | produces most from wood type biomass.

  According to the present invention, in addition to being able to neutralize the base component in the odor component of the sewage sludge and to suppress the odor due to the masking effect of components other than the base, extraction of wood vinegar from woody biomass and Since the sewage sludge can be heated and dried at the same time, there is no need for equipment for extracting the wood vinegar liquid, and the equipment installation cost can be kept low.

The sewage sludge may be obtained by adding a wood vinegar solution to the sewage sludge and mixing the mixture, and heating and drying the sewage sludge.
Depending on the components in the sewage sludge, the pyroligneous acid may have self-heating at a temperature (for example, 300 to 400 ° C.) at which the wood vinegar liquid is extracted from the woody biomass.
According to the present invention, since it is not necessary to heat the heating and drying temperature to a temperature at which the wood vinegar is extracted from the woody biomass, sewage sludge having self-heating properties is used at the temperature at which the wood vinegar is extracted from the woody biomass. Even so, a solid fuel using sewage sludge as a main raw material can be obtained.
In addition, a wood vinegar liquid may be obtained by providing the wood vinegar liquid manufacturing apparatus which extracts a wood vinegar liquid from woody biomass, and a commercially available wood vinegar liquid may be used.

In addition, it is characterized in that it is obtained by contacting a solid fuel mainly composed of sewage sludge with terpene-containing steam generated from woody biomass.
According to the present invention, when brought into contact with terpenes (C ₅ H ₈ ) _n , the effect of suppressing odor is further enhanced by neutralization and masking effect of ammonia by terpenes.

Moreover, it has a drier for heating and drying the sewage sludge and a supply means for supplying the sewage sludge to the drier, and the drier is mainly composed of sewage sludge that is dried by heating and drying the sewage sludge. A solid fuel production apparatus comprising a mixing means for mixing the sewage sludge with the woody biomass, the supply means supplying the dryer with a mixture of the sewage sludge and the woody biomass obtained by the mixing means; The dryer is characterized in that the mixture of the sewage sludge and the woody biomass is at a temperature at which the wood vinegar is extracted from the woody biomass and the sewage sludge is heated and dried.
This makes it possible to neutralize and reduce the base components in the odor component of sewage sludge with acids such as acetic acid in the wood vinegar solution, and to reduce the odor components other than the base by suppressing the odor by the masking effect of the wood vinegar solution. A solid fuel having a main component can be produced. Furthermore, the extraction of the wood vinegar from the woody biomass and the heat drying of the sewage sludge can be performed at the same time, so there is no need for equipment for extracting the wood vinegar and the equipment installation cost can be kept low.

Moreover, it has a drier for heating and drying the sewage sludge and a supply means for supplying the sewage sludge to the drier, and the drier is mainly composed of sewage sludge that is dried by heating and drying the sewage sludge. In the solid fuel production apparatus, the solid fuel production apparatus includes a mixing unit that mixes the sewage sludge with the wood vinegar solution, the supply unit supplies the dryer with a mixture of the sewage sludge and the wood vinegar solution obtained by the mixing unit, and the dryer The mixture of the sewage sludge and the wood vinegar is dried by heating.
Depending on the components in the sewage sludge, it may have self-heating properties at a temperature (for example, 300 to 400 ° C.) at which the wood vinegar is extracted from the woody biomass. According to the present invention, since the solid fuel can be produced without heating the drying temperature to the temperature at which the wood vinegar liquid is extracted from the woody biomass, self heating is performed at the temperature at which the wood vinegar liquid is extracted from the woody biomass. Even if it is a sewage sludge which has the property, the solid fuel which made the sewage sludge the main raw material can be manufactured.
In addition, a wood vinegar liquid may be obtained by providing the wood vinegar liquid manufacturing apparatus which extracts a wood vinegar liquid from woody biomass, and a commercially available wood vinegar liquid may be used.

Means for heating the woody biomass to generate terpene-containing steam; and means for contacting the terpene-containing steam with solid fuel mainly composed of sewage sludge obtained by heating and drying with the dryer. It is characterized by having.
Thus, by contacting with terpenes (C ₅ H _{8) n,} neutralization of ammonia due terpenes, the effect of suppressing further odor by the masking effect increases.

The means for generating the terpene-containing steam heats the woody biomass using waste heat obtained by heating and drying sewage sludge with the dryer.
As a result, waste heat from the dryer can be used effectively, and the running cost of the apparatus can be kept low.

  As described above, according to the present invention, it is possible to provide a solid fuel mainly composed of sewage sludge having a high commercial value as a solid fuel and a manufacturing apparatus thereof, which can suppress a unique odor derived from sewage sludge.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.

The block diagram of the solid fuel manufacturing apparatus which uses the sewage sludge based on the present Example 1 as a main raw material in FIG. 1 is shown. The solid fuel device mainly using sewage sludge according to the present embodiment was mixed by the biaxial screw conveyor 3 that conveys sewage sludge and wood chips that are woody biomass while mixing, and the biaxial screw conveyor 3. Screw conveyor 4 that quantitatively feeds the mixture of sewage sludge and wood chips to the dryer, dryer 5, and bark and leaves that are woody biomass to heat terpene (C ₅ H ₈ ) _n- containing steam It mainly comprises a heater 7 to be generated, and a deodorizing device 6 for bringing the dried sludge obtained by the dryer ₅ into contact with the terpene (C ₅ H ₈ ) _n -containing vapor.

Next, the flow of the solid fuel production apparatus using sewage sludge as the main raw material according to the first embodiment will be described together with the specific configuration of each apparatus based on FIG.
The sewage sludge is supplied to the twin screw conveyor 3 by the supply facility 2. On the other hand, wood chips are also supplied to the twin screw conveyor 3. In this embodiment, wood chips are supplied to the twin screw conveyor 3, but other woody biomass may be supplied instead of the wood chips. Sewage sludge and wood chips are conveyed while being mixed by the twin screw conveyor 3, and quantitatively charged into the dryer 5 by the screw conveyor 4.

The dryer 5 is an externally heated rotary kiln that heats the inside of the furnace by indirect heating. The dryer 5 is a device in which a heating jacket is provided around the furnace, and high temperature gas is circulated from the boiler 8 to the heating jacket to heat sewage sludge and wood chips in the dryer 5.
In the dryer 5, the sewage sludge is heated and dried at a temperature at which the wood vinegar is extracted from the wood chips. The temperature at which the wood vinegar liquid is extracted is preferably 300 to 400 ° C. at which the wood vinegar liquid is extracted most from the wood chips.
Thus, the wood vinegar liquid is extracted from the wood chip by heating and drying at the temperature at which the wood vinegar liquid is extracted by the dryer 5, and the acid such as acetic acid in the wood vinegar liquid is the main component of the odor component of the sewage sludge. It reacts with ammonia, which is a base, to neutralize and suppress odor. Further, odor components other than the base (for example, hydrogen sulfide, trimethylamine, methyl mercaptan, etc.) do not neutralize with acids such as acetic acid in the wood vinegar solution, but the odor is suppressed by the masking effect by the wood vinegar solution.

The dried sludge with reduced odor obtained by drying at 300 to 400 ° C. from which wood vinegar is extracted from the wood chips by the dryer 5 is led to the deodorizing device 6 and terpenes generated by the heater 7 described later. (C ₅ H ₈ ) Contact with _n- containing vapor. The deodorizing device 6 is a device that makes the terpene-containing vapor contact from below through a plurality of through holes provided in the inclined surface 61 while passing the dried sludge on the inclined surface 61 provided in the device.
Such a dried sludge deodorizing apparatus 6 is brought into contact with the terpenes (C ₅ H _{8) n-containing} vapor, neutralization of ammonia by terpenes, and further suppressing the odor by the masking effect.
Thus, the dried sludge that has come into contact with the terpene-containing vapor in the deodorizer 6 is a solid fuel product mainly composed of sewage sludge.
Incidentally, terpenes after contact with dry sludge (C ₅ H _{8) n-containing} vapor is processed by the exhaust gas treatment apparatus 54 to be described later.

  Moreover, after the hot gas supplied from the boiler 8 to the heating jacket of the dryer 5 is used to heat and dry the mixture of the sewage sludge and the drying gas in the dryer 5, a part of the high-temperature gas becomes boiler. 8 is returned to the heater 7.

The heater 7 contains a steam generating chamber 72 that contains and heats woody biomass such as bark and leaves, and surrounds the steam generating chamber 72 and distributes the drain supplied from the dryer 5 to steam. The heating chamber 71 mainly transfers heat into the generation chamber 72. Woody biomass such as bark and leaves housed in the steam generation chamber 72 is heated by heat transfer from the heating chamber 71 to generate terpene (C ₅ H ₈ ) _n- containing steam. The generated terpenes (C ₅ H ₈ ) _n- containing vapor is supplied to the deodorizing device 6 described above.

Further, woody biomass such as bark and leaves after generating terpene (C ₅ H ₈ ) _n- containing steam is accommodated in the steam generation chamber 72 constituting the heating chamber 7 together with the sewage sludge. By putting it on the conveyor 3, it can be used as an alternative to at least a part of the wood chips. Therefore, the woody biomass such as bark and leaves stored in the heating chamber 7 generates steam containing terpenes (C ₅ H ₈ ) _{n in} the heating chamber 7 and then the wood vinegar liquid is extracted by a dryer. The wood chip consumption can be reduced and the cost can be reduced.

Further, the exhaust gas generated in the dryer 5 is introduced into the bag filter 51 and removed, and then cooled and oil-water separated by the cooler 52 and the oil-water separator 53 and introduced into the exhaust gas treatment device 54 from the cooler 52. Is done. The exhaust gas processing apparatus 54 processes the exhaust gas into clean gas. A part of the exhaust gas treated by the exhaust gas treatment device 54 is returned to the dryer 5 by the fan 55 and released to the atmosphere.
In this way, by treating the exhaust gas generated in the dryer 5 with the exhaust gas processing device 54 into a clean gas, the exhaust gas can be released into the atmosphere.

  In Example 1, it is necessary to heat to the temperature (300-400 degreeC) by which the wood vinegar liquid is extracted with the dryer 5. FIG. Depending on the components in the sewage sludge, it may have a self-heating property at this temperature, and this embodiment 2 is used when producing a solid fuel from such sewage sludge.

FIG. 2 shows a configuration diagram of a solid fuel production apparatus using sewage sludge as a main raw material according to the first embodiment, and the same components as those in FIG. 1 are denoted by the same reference numerals. That is, the solid fuel device mainly using sewage sludge according to the present embodiment is mixed with the biaxial screw conveyor 3 that conveys the sewage sludge and wood chips that are woody biomass while mixing, and the biaxial screw conveyor 3 Containing a terpene (C ₅ H ₈ ) _n by heating the bark and leaves, which are woody biomass, by the screw conveyor 4 that quantitatively feeds the mixture of the sewage sludge and wood chips to the dryer It mainly comprises a heater 7 for generating steam and a deodorizing device 6 for bringing the dried sludge obtained by the dryer ₅ into contact with the terpene (C ₅ H ₈ ) _n -containing steam.

Next, the flow of the solid fuel production apparatus using sewage sludge as the main raw material according to the second embodiment will be described together with the specific configuration of each apparatus based on FIG.
First, a wood vinegar solution is produced by the wood vinegar solution production apparatus 1.

The pyroligneous acid produced by the pyroligneous acid production apparatus 1 is supplied to a twin screw conveyor 3. In this embodiment, the wood vinegar liquid produced by the wood vinegar liquid production apparatus 1 is supplied to the biaxial screw conveyor 3, but a commercially available wood vinegar liquid may be used instead of the wood vinegar liquid produced by the wood vinegar liquid production apparatus 1. Good.
On the other hand, the sewage sludge is supplied to the twin screw conveyor 3 by the supply equipment 2. The sewage sludge and the wood vinegar liquid supplied to the biaxial screw conveyor 3 are conveyed while being mixed, and quantitatively charged into the dryer 5 by the screw conveyor 4.

The dryer 5 is an externally heated rotary kiln that heats the inside of the furnace by indirect heating. The dryer 5 is a device that is provided with a heating jacket around the furnace and heats sewage sludge in the dryer 5 by circulating a high-temperature gas from the boiler 8 through the heating jacket.
In the dryer 5, the sewage sludge is heated and dried. The heating and drying temperature is preferably about 100 to 300 ° C.
Thus, by drying with the dryer 5, the acid such as acetic acid in the wood vinegar is neutralized by reacting with ammonia which is a main component of the odor component of the sewage sludge and the base, and the odor is suppressed. . Further, odor components other than the base (for example, hydrogen sulfide, trimethylamine, methyl mercaptan, etc.) do not neutralize with acids such as acetic acid in the wood vinegar solution, but the odor is suppressed by the masking effect by the wood vinegar solution.

The dried sludge with reduced odor obtained by drying in the dryer 5 is guided to the deodorizing device 6 and comes into contact with the terpene (C ₅ H ₈ ) _n- containing steam generated in the heater 7. The deodorizing device 6 is a device that makes the terpene-containing vapor contact from below through a plurality of through holes provided in the inclined surface 61 while passing the dried sludge on the inclined surface 61 provided in the device.
The terpenes deodorizing device 6 as (C ₅ H ₈₎ is contacted with _n-containing vapor, neutralization of ammonia by terpenes, and further suppressing the odor by the masking effect.
Thus, the dried sludge that has come into contact with the terpene-containing vapor in the deodorizer 6 is a solid fuel product mainly composed of sewage sludge.

Further, regarding the heater 7 that generates steam containing terpenes (C ₅ H ₈ ) _n and the bag filter 51 that processes exhaust gas generated in the dryer 5, the cooler 52, the oil / water separator 53, and the exhaust gas treatment device 54 The same as in the first embodiment.

  The present invention can be used as a solid fuel mainly composed of sewage sludge having a high commercial value as a solid fuel and a production apparatus thereof, which suppress a unique odor derived from sewage sludge.

It is a block diagram of the solid fuel manufacturing apparatus which uses the sewage sludge which concerns on Example 1 as a main raw material. It is a block diagram of the solid fuel manufacturing apparatus which uses the sewage sludge which concerns on Example 2 as a main raw material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wood vinegar production apparatus 2 Supply equipment 3 Twin screw conveyor (mixing means)
4 Screw conveyor 5 Dryer 6 Deodorizing device 7 Heater 54 Exhaust gas treatment device

Claims (8)

Solid fuel made mainly from sewage sludge obtained by heating and drying sewage sludge,
A solid fuel comprising sewage sludge as a main raw material, obtained by heating and drying the sewage sludge in the presence of a wood vinegar solution. Add woody biomass to the sewage sludge and mix,
The sewage sludge is obtained by heating and drying the mixture of the sewage sludge and the woody biomass at a temperature at which the wood vinegar is extracted from the woody biomass. Solid fuel. Add and mix wood vinegar to the sewage sludge,
The solid fuel comprising sewage sludge as a main raw material, obtained by heating and drying a mixture of the sewage sludge and wood vinegar.   A solid fuel mainly composed of sewage sludge, which is obtained by bringing the solid fuel mainly composed of sewage sludge according to any one of claims 1 to 3 into contact with terpene-containing steam generated from woody biomass. A solid fuel mainly composed of sewage sludge having a dryer for heating and drying sewage sludge and a supply means for supplying the sewage sludge to the dryer. Manufacturing equipment,
Comprising a mixing means for mixing the sewage sludge with woody biomass,
The supply means supplies the dryer with a mixture of sewage sludge and woody biomass obtained by the mixing means,
The dryer is a solid mainly composed of sewage sludge, characterized in that the mixture of the sewage sludge and the woody biomass is at a temperature at which the wood vinegar is extracted from the woody biomass and is heated and dried in the sewage sludge. Fuel production equipment. A solid fuel mainly composed of sewage sludge having a dryer for heating and drying sewage sludge and a supply means for supplying the sewage sludge to the dryer. In manufacturing equipment,
Comprising mixing means for mixing the sewage sludge with pyroligneous acid,
The supply means supplies the dryer with a mixture of sewage sludge and wood vinegar obtained by the mixing means,
The said drier heat-drys the mixture of the said sewage sludge and a wood vinegar liquid, The solid fuel manufacturing apparatus which has a sewage sludge as a main component characterized by the above-mentioned. Means for heating woody biomass to generate terpene-containing steam;
The sewage sludge mainly comprising the terpene-containing steam and a solid fuel mainly composed of sewage sludge obtained by heating and drying with the dryer. Solid fuel production equipment as a component.   The means for generating the terpene-containing steam heats the woody biomass using waste heat obtained by heating and drying the sewage sludge in the dryer, and the sewage sludge as a main component. Solid fuel production equipment.

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