JP2002326078A - Dredge shell processing method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for treating a dredging shell, which can produce a high-performance desulfurizing agent having a small particle size of a solid content to be recovered. [MEANS FOR SOLVING PROBLEMS]
A hydrothermal reaction process in which the crushed dredged shellfish is subjected to a hydrothermal reaction under subcritical or supercritical water conditions to liquefy the organic substances contained in the dredged shellfish, and a solid-liquid separation of the hydrothermally processed material And a recovery process for recovering solids. In the hydrothermal reaction process, the crushed dredged shells collide with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for treating shells dredged from power plant facilities and the like.

[0002]

2. Description of the Related Art Shells that have adhered to and grow on marine structures such as intakes and drains of power plant facilities or quays are regularly dredged and collected. As a method of treating this dredged shellfish (including only shells and shells having a body), conventionally, after incinerating the dredged shellfish in an incinerator such as a kiln furnace, the treated material is buried in landfill, or a desorbent or A method of using it as a raw material for cement is known.

[0003]

However, incineration methods are being regulated because of the possibility that harmful substances such as dioxin may be generated as exhaust gas.

[0004] Therefore, the present applicant has proposed a method of crushing a dredged shellfish into a slurry and subjecting it to a hydrothermal reaction under subcritical or supercritical water conditions. In this method, the body part of the shellfish, which is an organic substance, is liquefied by the hydrothermal reaction without generating dioxin. Therefore, by separating the solid-liquid of the hydrothermally treated product and collecting the solid content, it is possible to produce a desulfurizing agent having extremely small residual organic components from the solid content.

[0005] Generally, the smaller the particle size of the desulfurizing agent, the higher the desulfurizing performance. Therefore, in the method for treating a dredged shellfish using the above-described hydrothermal reaction, it is more desirable that the particle size of the collected solid is small.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a method of treating a dredging shell capable of producing a high-performance desulfurizing agent having a small particle diameter of a recovered solid content, and an apparatus therefor. The purpose is to provide.

[0007]

According to the method for treating a dredged mussel of the present invention, a crushing process for crushing the dredged mussel and hydrothermal treatment of the crushed dredged mussel under subcritical or supercritical water conditions are performed. A hydrothermal reaction process for liquefying organic matter contained in the dredged shellfish and a recovery process for solid-liquid separation of the hydrothermally processed product to collect solids are included. Means for solving the above-mentioned problem is to make the treated dredging clams collide with each other under subcritical water conditions or supercritical water conditions. A hydrothermal reaction is a reaction in which a substance is exposed to a high-temperature, high-pressure aqueous solution to increase the reaction rate, synthesize a new compound from a plurality of different raw materials, or decompose organic substances. Yes, high-temperature and high-pressure water includes not only subcritical water but also supercritical water.

According to this treatment method, the organic matter contained in the dredged shellfish is liquefied by the hydrothermal reaction treatment, and the solid content of the hydrothermally treated product is separated and recovered, so that the residual organic components are extremely reduced from the solid content. It is possible to produce a small amount of desulfurizing agent. In addition, at the time of the hydrothermal reaction treatment, by making the dredging shells collide with each other, crushing or grinding causes the fineness of the solid content to proceed, and the particle size of the collected solid content becomes small. In this case, in the hydrothermal reaction treatment step, the crushed dredged shells may be caused to collide with each other by circulating them at high speed in the reaction chamber.

In the apparatus for treating dredged shells of the present invention, a crushing apparatus for crushing the dredged shells, and a hydrothermal reaction of the crushed dredged shells under subcritical or supercritical water conditions to form dredged shells. It is equipped with a hydrothermal treatment device that liquefies the organic matter contained therein, and a recovery treatment device that separates the hydrothermal reaction product into solid and liquid and collects the solids. The means for solving the above-mentioned problem is to cause collision with each other under subcritical water conditions or supercritical water conditions.

According to this processing apparatus, since the above-described processing method can be carried out, the particle size of the collected solid content is reduced.

In this case, the hydrothermal treatment device is
It is good to have a high-speed circulation structure in which crushed dredged shells are circulated at high speed in the reaction chamber so that they collide with each other.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
FIG. 1 is a schematic configuration diagram for explaining an embodiment of a dredge shell processing apparatus of the present invention, and reference numeral 1 in FIG. 1 is a dredge shell processing apparatus. This treatment device 1 comprises a crushing treatment device 2 for crushing the dredged shellfish and a hydrothermal reaction treatment of the crushed dredged shellfish under subcritical or supercritical water conditions to liquefy organic matter contained in the dredged shellfish. Hydrothermal reaction equipment 3
And a solid content recovery processing device 4 that separates the hydrothermally processed product from solid and liquid to recover solid content, and reduces the COD and the like of the liquid separated by the solid content recovery processing device 4 to a concentration equal to or lower than the discharge standard. And a discharge treatment device 5.

The crushing apparatus 2 crushes the dredging shell to a size of, for example, 1 mm or less in particle size while adding water to the dredging shell, and slurries the dredging shell. As the crushing device 2, for example, a device such as a cutter pump or a ball mill is used.

The hydrothermal reaction apparatus 3 crushes the dredged shell crushed by the crushing apparatus 2 and sent into the reaction chamber by a pump or the like under a high-temperature high-pressure subcritical water condition or a supercritical water condition, specifically. Is a hydrothermal reaction treatment under conditions of, for example, 150 to 400 ° C. and a saturated vapor pressure corresponding to the temperature, and hydrolyzes and liquefies organic substances (mainly shellfish) contained in the dredged shellfish. . More specifically,
The hydrothermal reaction device 3 reacts by means of a boosting pump as a boosting means for boosting the crushed dredging shell and sending it into the reaction chamber, a flow control device for controlling the flow rate of the boosted dredging shell, an induction heating method, or the like. It is configured to include a heating device for heating the room, a cooling device such as a heat exchanger for cooling the hydrothermally processed product to a temperature that can be discharged to the downstream side (neither is shown), and the like. If the processing temperature in the hydrothermal reaction processing apparatus 3 exceeds 400 ° C., it is considered that the apparatus cost is increased due to a complicated apparatus configuration and the like. Therefore, the processing temperature is more preferably 200 to 300 ° C.

Further, as shown in FIG. 2, the hydrothermal reaction apparatus 3 has a high-speed circulation structure for circulating the crushed dredged shellfish in the reaction chamber at a high speed. That is, in the present embodiment, a tubular reactor 10 (pressure vessel) is used as a reaction chamber, and the dredging shell sent from the crushing device is configured to circulate at a high speed in the tubular reactor 10. I have. A flow rate control device 11 such as a pump for controlling the flow rate of the processed material flowing in the tubular reactor 10 is provided in the middle of the tubular reactor 10. The flow rate of the processed material in the reactor 10 is, for example, 0.5
３3 m / s. Further, in the present embodiment, the processed material (dredge shell) is continuously circulated at a high speed in the tubular reactor 10, and the treated material is continuously introduced into the tubular reactor 10 through the inlet. A substantially same amount of the processed product as the introduced product is discharged from the tubular reactor 10 through the discharge port. That is, the processed material is repeatedly circulated at high speed in the tubular reactor until it is discharged from the outlet.

The solid content recovery processing device 4 is for solid-liquid separation of the product derived from the hydrothermal reaction processing device 3 to recover solid content. As the solid content recovery processing device 4, a membrane separation device,
Known ones such as a decanter and a filtration device are used.

The discharge processing device 5 includes a solid content recovery processing device 4.
In the liquid separated by the pump and sent by the pump etc.
OD (CODmn; chemical oxygen demand) and the like are reduced to a concentration equal to or lower than the discharge standard (for example, about 10 mg / 1 or less). In the present example, the discharge treatment device 5 comprises an aerobic treatment device, and is configured to include sludge containing aerobic microorganisms.

The dredging shell processing method of the present invention will be described based on the processing method by the dredging shell processing apparatus 1 having such a configuration. First, the dredging mussels to be treated are introduced into the crushing device 2 and, while appropriately adding water, the dredging mussels are, for example, 1 m in particle diameter.
crushed to a size of less than m. In addition, as an example, the properties of the dredging shellfish have a solid content of about 51%,
Moisture consists of about 49%.

Next, the dredged shellfish made into a slurry is introduced into the hydrothermal treatment apparatus 3. In this hydrothermal reaction apparatus 3, under subcritical water conditions or supercritical water conditions, for example, 15
The hydrothermal reaction is performed under the conditions of 0 to 400 ° C. and a saturated vapor pressure corresponding to the temperature, and the organic matter contained in the dredging shell is decomposed and liquefied.

In this embodiment, during the hydrothermal reaction, the crushed dredged shell is circulated at high speed in the tubular reactor. As a result, the crushed dredged shells collide with each other, and the solid content is refined by crushing and grinding.

Subsequently, a product (hydrothermal reaction product) from the hydrothermal reaction device 3 is introduced into the solid content recovery device 4. Then, in the solid content recovery processing device 4, the hydrothermal reaction product is subjected to solid-liquid separation, and the solid content is recovered as valuables. The solid content recovered is mainly calcium carbonate (C
aCO ₃ ). The liquid component of the separated hydrothermally treated product is introduced into the discharge treatment device 5 by a pump or the like.

The discharged material is subjected to aerobic treatment in the discharge treatment device 5 so that its COD (CODm
n; chemical oxygen demand) and the like are reduced to a concentration equal to or lower than the discharge standard (for example, approximately 10 mg / 1 or lower).

Thereafter, if necessary, a treatment for satisfying the discharge standard is performed, and then this treated material is discharged to general sewage or a river.

In the dredging shell processing apparatus 1 having such a configuration and a processing method using the same, the organic matter contained in the dredging shell is liquefied by the hydrothermal reaction processing, and the solid matter of the hydrothermally processed substance is solidified. By recovering calcium carbonate, calcium carbonate having a very small amount of residual organic components can be recovered as a valuable resource from the solid content. This calcium carbonate is refined by crushing or grinding during a hydrothermal reaction and has a small particle size, and can be used as a high-performance desulfurizing agent. In addition, the liquid hydrothermal reaction product after the solid content recovery is subjected to predetermined simple processing as necessary, such as by aerobic processing, so that it can be easily discharged as wastewater.

Next, in order to confirm the effect of the present invention, a result obtained when the dredging shellfish is processed in the processing apparatus 1 of the present invention shown in FIG. 1 is shown in FIG. Here, the hydrothermal reaction conditions were 250 ° C. and 8 MPa.

As shown in FIG. 3, the solid content contained in the dredged shellfish (processed material) was reduced to 19 to 2 due to the hydrothermal treatment with high-speed circulation.
From 0% to 11%, the organic component in the solid content (combustibility C in this case) also decreased from 5 to 15% to about 1%. Therefore, it was confirmed that the hydrothermal reaction treatment can reduce the residual organic components in the solid content.

FIG. 4 shows the properties of the processed product (solid content) obtained by the processing apparatus 1 of the present invention. From FIG. 4, it was found that the treated product according to the present invention had a small residual organic component (combustibility C) and was mainly composed of calcium carbonate (95.5%). Therefore, it was confirmed that it can be used as a desulfurizing agent.

Next, FIG. 5 shows a comparison of physical properties between a commercially available general desulfurizing agent (actual desulfurizing agent) and a processed product (solid content) obtained by the processing apparatus 1 of the present invention. As shown in FIG. 5, the treated product obtained by the hydrothermal reaction treatment of the present invention has a small average particle diameter (about 2 μm), and accordingly, the specific surface area (3.5).
m ² / G or more) was confirmed to be large.

Subsequently, the actual desulfurizing agent having the above-mentioned physical properties
And SO according to the present invention _TwoThe following absorption effect
I looked up like that. Sample as desulfurizing agent in beaker (actual machine
(A desulfurizing agent or a treated product according to the present invention)
1000ppm SO_Two(N_TwoThrough the gas)
Gas SO_TwoThe concentration was determined. Progress of each sample
Time and SO_TwoFIG. 6 shows the relationship between the concentrations.

FIG. 6 shows that the treated product according to the present invention shows a high absorption performance of nearly 100% with respect to SO ₂ until the elapsed time of about 40 minutes from the start, as compared with the actual desulfurizing agent. Do you get it. That is, the processed material according to the present invention is:
It was confirmed to have high desulfurization performance.

Further, the treated product of the hydrothermal reaction treatment of the present invention does not show a decrease in performance due to foaming even when it is mixed with about 30% by weight in an actual desulfurizing agent, and it is confirmed that high desulfurization performance is maintained. Was.

As described above, in the treatment apparatus 1 of the present invention, by miniaturizing the dredged shellfish in the hydrothermal reaction process together with the hydrothermal reaction process, a desulfurizing agent having a small residual organic component and high desulfurization performance can be obtained. It was confirmed that it could be manufactured.

The various shapes and combinations of the constituent members shown in the above-described embodiments are merely examples, and various changes can be made based on design requirements without departing from the gist of the present invention. In the above example, in order to miniaturize the dredging shell, the dredging shell is circulated at high speed using a tubular reactor under subcritical water conditions or supercritical water conditions. Although the dredging shells collide with each other in the reactor, the method of causing the dredging shells to collide in the hydrothermal reaction process is not limited to this. For example, dredging shells may collide with each other in the hydrothermal reaction process by moving another member such as a stirring member at a high speed in the reaction chamber. Further, in the above-described example, since the treatment product (dredge shell) is continuously introduced into the tubular reactor, it is possible to improve the treatment capacity. However, the treatment method in the tubular reactor is not limited to this continuous method, and may be, for example, a batch method. In this case, for example, an opening / closing valve may be provided at an inlet and an outlet of the processed product, and the opening / closing valve may be opened and closed to introduce and discharge the processed product into and from the tubular reactor. This makes it possible to reliably circulate the processed material in the tubular reactor at a high speed for a certain time. Further, in the above-described example, in the discharge treatment device, the introduced treatment product is subjected to aerobic treatment to reduce COD and the like, but is not limited thereto.
Other known methods such as anaerobic treatment and oxidation treatment may be used. Further, in the above example, the case where the processed material as the desulfurizing agent obtained by the processing apparatus of the present invention is used as wet desulfurization (desulfurized SO ₂ ) is described, but the present invention is not limited to this. Absent. That is, the desulfurization agent obtained by the processing device of the present invention, the dry desulfurization (de SO _3), or can be used as a cement raw material. Further, it goes without saying that the present invention can be applied to other uses.

[0034]

As described above, the method and apparatus for treating a dredged shellfish of the present invention liquefy the organic matter contained in the dredged shellfish by hydrothermal reaction treatment and separate the solid content of the hydrothermally treated material. By recovering from the solid content, a desulfurizing agent having extremely small residual organic components can be produced from the solid content. In addition, in the hydrothermal reaction process, the solid content of the dredged shell is reduced by crushing or grinding by colliding the crushed dredged shells with each other, and the particle size of the collected solid can be reduced. . Therefore, a high-performance desulfurizing agent can be manufactured.

[Brief description of the drawings]

FIG. 1 is a view for explaining a schematic configuration of an embodiment of a dredge shell processing apparatus of the present invention.

FIG. 2 is a view showing a tubular reactor of the hydrothermal reaction apparatus.

FIG. 3 is a diagram showing a processing result of the processing device of FIG. 1;

FIG. 4 is a view showing properties of a solid content obtained by the processing apparatus of FIG. 1;

FIG. 5 is a view showing a comparison of physical properties of a commercially available general desulfurizing agent (actual desulfurizing agent) and a processed product (solid content) obtained by the processing apparatus 1 of the present invention.

FIG. 6 is a view showing the results of an experiment for examining the absorption effect of the actual desulfurizing agent and the treated product (solid content) according to the present invention on SO ₂ .

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Dredging shell processing apparatus, 2 Crushing processing apparatus, 3 ... Hydrothermal reaction processing apparatus, 4 ... Solid content recovery processing apparatus, 5 ... Discharge processing apparatus, 10 ... Tube type reactor.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Fumihiko Tamamushi 3-2-16-1 Toyosu, Koto-ku, Tokyo Ishikawajima-Harima Heavy Industries, Ltd. Tokyo Engineering Center (72) Inventor Keiichi Miwa Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa No. 1 Ishikawashima Harima Heavy Industries, Ltd. Machinery & Plant Development Center (72) Inventor Shigeo Watanabe 3-16-16 Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries, Ltd. Tokyo Engineering Center (72) Inventor Sugihiro Konishi Tokyo Engineering Center (72) Ishikawajima Harima Heavy Industries, Ltd. 3-2-1 Toyosu, Koto-ku, Tokyo (72) Inventor Yu Usami 4-1, Egasakicho, Tsurumi-ku, Yokohama, Kanagawa Prefecture Tokyo Electric Power Company (72) Inventor Satoru Kanamori Kana 4-1, Egasaki-cho, Tsurumi-ku, Yokohama-shi, Tokyo Prefecture F-term in the Energy and Environment Research Laboratory, Tokyo Electric Power Company 4D004 AA04 AB07 BA10 CA04 CA13 CA19 CA39 CB44 DA02 DA07 DA08 4D067 CG06 GA01 GA20

Claims (4)

[Claims] Claims: 1. A crushing process for crushing a dredged shellfish;
A hydrothermal reaction process in which the crushed dredged shellfish is subjected to a hydrothermal reaction under subcritical or supercritical water conditions to liquefy the organic substances contained in the dredged shellfish, and a solid-liquid separation of the hydrothermally processed material A method for treating the dredged shells, wherein the crushed dredged shells collide with each other under subcritical or supercritical water conditions in the hydrothermal reaction step. . 2. The method for treating a dredged shell according to claim 1, wherein in the hydrothermal reaction step, the crushed dredged shells collide with each other by circulating them at high speed in a reaction chamber. 3. A crushing device for crushing a dredged shellfish,
A hydrothermal reaction device that hydrothermally treats the crushed dredged shellfish under subcritical or supercritical water conditions to liquefy the organic matter contained in the dredged shellfish, and solid-liquid separation of the hydrothermally reacted material A recovery treatment device for collecting solids, wherein the hydrothermal reaction treatment device is characterized in that the crushed dredged clams collide with each other under subcritical water conditions or supercritical water conditions. . 4. The dredging shell according to claim 3, wherein the hydrothermal reaction apparatus has a high-speed circulation structure in which the crushed dredging shells are circulated at high speed in the reaction chamber so that they collide with each other. Processing equipment.