KR20230016971A - Treatment process of waste and process using the same - Google Patents

Abstract

Provided is a waste disposal system. According to one embodiment of the present invention, the waste disposal system comprises: a thermal decomposition device which receives a waste in a form of a particle, wherein thermal decomposition of the waste is performed, and wherein a fixation layer catalyst structure is included therein; and a gas injection device flowing the waste particles by supplying a carrier gas to the thermal decomposition device. Provided are the waste disposal system for decomposing and treating a harmful compound contained in the waste, and preventing the same from regenerating in an atmosphere, and a process thereof.

Description

Waste treatment system and its process {TREATMENT PROCESS OF WASTE AND PROCESS USING THE SAME}

The present invention relates to a waste disposal system and its process. Specifically, the present invention relates to a waste treatment system and process for increasing the contact area and contact time between waste particles, the carrier gas, and the catalyst layer by supplying a carrier gas to a pyrolysis device including a catalyst layer and having a fixed-bed catalyst structure.

In general, various domestic wastes generated at home and industrial wastes generated at industrial sites are partially recycled through separate collection, etc. is being processed in a way that

1 is a view showing a conventional wastewater treatment process. In a conventional wastewater treatment process, wastewater is sludged through an aeration tank and a sludge settling unit, and then the sludge containing harmful substances is landfilled or incinerated.

However, industrial waste and wastewater produce harmful chlorine compounds as unwanted by-products in various product production processes, such as chemical processes, pulp processes, and incineration processes. Harmful chlorine compounds contained in water are released into soil, water and air.

In addition, the high-temperature exhaust gas generated in the process of incinerating the waste is gradually cooled in the air, causing a problem in that a small amount of decomposed harmful chlorine compounds are regenerated.

Korean Patent Registration No. 10-1753204 Korean Patent Registration No. 10-2198080

The present invention is to solve the problems of the prior art, to provide a waste treatment system and process for decomposing and treating harmful compounds contained in waste and preventing them from being regenerated in the air.

In addition, the present invention is to provide a waste treatment system and process for reducing the thermal decomposition time of waste particles by including a catalyst layer and a fixed bed catalyst structure in a pyrolysis device.

An exemplary embodiment of the present invention includes a pyrolysis device receiving waste in the form of particles and thermally decomposing the waste and including a fixed bed catalyst structure; and a gas injection device supplying a carrier gas to the pyrolysis device to flow the waste particles.

In one embodiment of the present invention, the pyrolysis device includes a waste supply unit into which the waste is introduced, and the waste supply unit further includes a filter unit for selecting only the waste particles having a particle diameter of 5 mm or less. .

Another embodiment of the present invention is a pyrolysis step of supplying waste and a carrier gas to a pyrolysis device including a fixed bed catalyst structure and bringing the waste into contact with the fixed bed catalyst structure to thermally decompose the waste into exhaust gas and pyrolysis sludge It provides a waste treatment process comprising a.

In the case of using the waste treatment system according to the embodiment of the present invention, it is possible to decompose harmful compounds included in the waste.

In addition, since a catalyst layer is included in the thermal decomposition device and a fixed bed catalyst structure is provided, the thermal decomposition time of the waste particles can be reduced.

1 is a diagram showing a conventional wastewater treatment process.
2 is a block diagram showing a waste treatment system according to an exemplary embodiment of the present invention.
3 is a block diagram showing a waste treatment system according to another embodiment of the present invention.
4 is a perspective perspective view illustrating a thermal decomposition device according to an exemplary embodiment of the present invention.
5(a) is a cross-sectional view of a fixed bed catalyst structure according to an exemplary embodiment of the present invention, FIG. 5(b) is a view showing a base material according to an exemplary embodiment of the present invention, and FIG. 5(c) shows the present invention It is a drawing showing a substrate according to another embodiment of, and FIG. 5 (d) is a drawing showing a substrate according to another embodiment of the present invention.
6(a) is a plan view showing a filter unit according to an exemplary embodiment of the present invention, and FIG. 6(b) is a cross-sectional view showing a portion of a pyrolysis device in which a filter unit according to an exemplary embodiment of the present invention is installed.

Hereinafter, the present invention will be described in detail with reference to the drawings. However, the drawings are for illustrating the present invention, and the scope of the present invention is not limited by the drawings.

2 is a block diagram showing a waste treatment system 100 according to an exemplary embodiment of the present invention.

The waste treatment system 100 includes a pyrolysis device 10 and a gas injection device 20 .

The pyrolysis device 10 performs thermal decomposition of the waste transported from the waste storage unit, and can decompose the waste into exhaust gas and pyrolysis sludge. Here, the waste is supplied in the form of particles, and the pyrolysis sludge refers to liquid and solid sludge produced after waste is pyrolyzed.

And, the pyrolysis device 10 may include a catalyst capable of increasing the pyrolysis rate of waste therein.

5(a) is a cross-sectional view of a fixed bed catalyst structure 11 according to an exemplary embodiment of the present invention, and FIG. 5(b) is a view showing a substrate 1 according to an exemplary embodiment of the present invention. (c) is a view showing a base material 1' according to another embodiment of the present invention, and FIG. 5(d) is a view showing a base material 1" according to another embodiment of the present invention.

The pyrolysis device 10 may include a substrate 1 and a fixed bed catalyst structure 11 including a catalyst layer 2 on the surface of the substrate 1 .

Referring to FIG. 5(b) , the substrate 1 may include a first set 1a and a second set 1b. Substrate 1 includes wires, including a first set 1a in which two or more wires are positioned in parallel and a second set 1b in which two or more wires are positioned in parallel and intersect with the first set 1a. can do. In addition, the second set 1b may be positioned opposite to the first set 1a in an inclination direction so that the first set 1a and the second set 1b may be provided in a lattice shape.

Here, the fact that two or more wires are positioned in parallel means that virtual straight lines connecting both ends of each wire are arranged at the same angle without crossing each other.

In addition, the wires included in the first set 1a and the second set 1b may be provided in a straight form without being bent, or may include a form bent more than once.

Two or more wires included in the first set 1a and the second set 1b may be spaced apart from each other by a predetermined distance. At this time, the distance between adjacent wires may be 1 mm to 5 mm, preferably 1 mm to 5 mm. It may be 3 mm, more preferably 2 mm to 3 mm.

If the one or more wires included in the substrate 1 are spaced apart by a distance of less than 1 mm, the area of the lattice provided by the first set 1a and the second set 1b becomes small and waste in the form of particles. It does not pass through the fixed bed catalyst structure 11, so it does not come into contact with the catalyst, and there is a problem that the thermally decomposed sludge cannot be discharged.

In addition, when the separation distance of one or more wires exceeds 5 mm, the lattice-shaped area is increased to reduce the area and time in which the waste is in contact with the catalyst, thereby reducing the thermal decomposition rate of the waste.

The wires included in the first set 1a and the second set 1b may have a diameter of 0.1 mm to 5 mm, preferably 0.3 mm to 3 mm, more preferably 0.5 mm to 2 mm. .

The first set 1a and the second set 1b may be positioned transversely inside the pyrolysis device 10, and the angle θ between the first set 1a and the second set 1b is 45°. to 90°.

Referring to FIG. 5(c) , a substrate 1' according to another embodiment may further include a third set 1c. The third set 1c includes two or more wires, and the wires may be positioned parallel to each other. Also, the third set 1c may form an angle of 10° to 80° with at least one of the first set 1a and the second set 1b.

For example, the third set 1c may be positioned so as to diagonally connect a plurality of intersection points provided as the first set 1a and the second set 1b intersect. Accordingly, in the substrate 1', the first set 1a, the second set 1b, and the third set 1c may intersect to provide one intersection point.

Alternatively, the third set 1c is positioned to cross the lattice pattern formed by the first set 1a and the second set 1b, and both the first set 1a and the second set 1b are positioned to cross each other. It can be. Therefore, the base material 1 'is provided by crossing the first set 1a and the second set 1b, and the third set 1c, the first set 1a, and the second set 1b, respectively. Since two crossing points are provided, the substrate 1' according to another embodiment may include a total of three crossing points.

Referring to FIG. 5(d) , a substrate 1" according to another embodiment may further include a fourth set 1d. The fourth set 1d includes a third set 1c of two or more wires. ) and the inclination direction may be oppositely parallel to each other, that is, the third set 1c and the fourth set 1d may be provided in a lattice shape, and the first set 1a and the second set 1b It may be provided in a grid shape formed by crossing and a form rotated at a certain angle.

The fourth set 1d diagonally crosses the intersection provided by the intersection of the first set 1a and the second set 1b, or intersects both the first set 1a and the second set 1b. can provide two intersection points.

For example, if the first set 1a and the second set 1b, the third set 1c and the fourth set 1d intersect at an angle of 90°, the third set 1c and the fourth set 1c The set 1d may be rotated by 10° to 80° based on the first set 1a and the second set 1b.

The substrate 1 may include a stainless steel (Steel Use stainless, SUS) material. In more detail, the substrate 1 may include a metal or alloy including at least one selected from chromium (Cr), manganese (Mn), nickel (ni), and iron (Fe).

The catalyst layer 2 is coated on the surface of the lattice-shaped substrate 1, and the thermal decomposition time of the waste can be shortened by bringing the waste into contact with the catalyst.

The catalyst layer 2 may be formed by depositing a catalyst on one surface of the substrate 1 . At this time, the catalyst may be deposited through a sputtering method, a vacuum deposition method, a chemical vapor deposition (CVD) method, a plating method, a method of immersing the substrate 1 in a catalyst solution, etc., but the catalyst is deposited on one surface of the substrate 1 If it can be done, the method is not limited.

In the pyrolysis device 10, one or more fixed-bed catalyst structures 11 may be stacked therein. At this time, 5 to 50 fixed bed catalyst structures 11 may be included, and the fixed bed catalyst structures 11 may be stacked along the longitudinal direction y of the thermal decomposition device 10 . Here, the longitudinal direction (y) may mean the longest direction when both ends of the pyrolysis device 10 are connected.

For example, the thermal decomposition device 10 may include a fixed-layer catalyst structure 11 in which the lattice shape of the substrate 1 is a square and a fixed-bed catalyst structure 11 in which the lattice shape of the substrate 1 is a rhombus. When five fixed-layer catalyst structures 11 are stacked in the device 10, the fixed-layer catalyst structure 11 in which the lattice shape of the base material 1 is a square starting from the position closest to the position where the waste is introduced into the pyrolysis device 10 and the fixed bed catalyst structure 11 having a rhombic lattice shape of the substrate 1 may be sequentially stacked.

The fixed bed catalyst structure 11 may be provided with a thickness of 50 nm to 2,000 nm, preferably 50 nm to 1,500 nm, more preferably 100 nm to 1,000 nm.

If the thickness of the fixed bed catalyst structure 11 is less than 50 nm, the contact time between the waste and the catalyst is short, so the effect of shortening the thermal decomposition time is insignificant, and if the thickness of the catalyst layer 2 exceeds 2,000 nm, the amount of catalyst used increases In comparison, the effect of reducing the pyrolysis time may be insignificant.

The pyrolysis device 10 may include a waste supply unit 12 into which particle-type waste is introduced and a decomposition discharge unit 13 which discharges at least one of exhaust gas and pyrolysis sludge generated after the waste is pyrolyzed.

The waste supply unit 12 may further include a filter unit 14 that selects only waste particles having a predetermined particle diameter or less. The filter unit 14 may select waste particles having a particle size of 5 mm or less, preferably 3 mm or less, more preferably waste particles having a particle size of 1 mm or less.

When the waste particles exceed 5 mm, heat is not transferred to the inside of the waste particles, so thermal decomposition may not occur uniformly.

6(a) is a plan view illustrating a filter unit 14 according to an exemplary embodiment of the present invention, and FIG. 6(b) is a pyrolysis device 10 in which the filter unit 14 according to an exemplary embodiment of the present invention is installed. ) is a cross-sectional view showing a part of.

The filter part 14 may be provided with the same area and shape as the inner area and shape of the waste inlet part 12, and a perforated hole having a diameter of 5 mm or less in order to select waste particles having a particle diameter of 5 mm or less. A plurality of these may be included.

Therefore, waste having a particle diameter exceeding 5 mm may be supplied to a crushing device (not shown), subjected to an additional crushing process, and then re-supplied to the pyrolysis device 10 .

The pyrolysis device 10 may further include a prevention part 15 at an inner lower end to prevent waste particles from entering the gas injection device 20 to be described later.

The prevention part 15 may have the same area and shape as the internal area and shape of the pyrolysis device 10, and may include a plurality of perforated holes having a diameter of 5 mm or less. At this time, the diameter means the farthest distance of the perforated hole, and if the diameter exceeds 5 mm, a problem may occur in that waste in the form of particles passes through the prevention part 15 and enters the gas injection device 20 .

The pyrolysis device 10 may pyrolyze waste at a process temperature of 200°C to 600°C. If the process temperature of the pyrolysis device 10 is less than 200° C., the waste is not sufficiently pyrolyzed, and harmful compounds may be included in exhaust gas and pyrolysis sludge, which are pyrolysis products of the waste. In addition, when the process temperature of the thermal decomposition device 10 exceeds 600° C., the effect of increasing the thermal decomposition rate of harmful compounds is insignificant compared to the energy input for thermal decomposition of the waste.

The gas injection device 20 may supply a carrier gas to the pyrolysis device 10 to cause waste particles to flow. Therefore, the gas injection device 20 can be located in a direction opposite to the disassembly and discharge unit 13 . That is, when the decomposition unit 13 is positioned above the pyrolysis device 10, the gas injection device 20 may be positioned below the pyrolysis device 10.

Therefore, the gas injection device 20 may supply a carrier gas from the bottom to the top of the pyrolysis device 10 to flow the waste introduced into the waste supply unit 12 .

The gas injection device 20 may raise the carrier gas to a preset temperature and supply the carrier gas to the thermal decomposition device 10 . That is, the gas injection device 20 may supply hot air into the pyrolysis device 10 to flow particle-type waste to contact the waste, and supply heat to the waste to thermally decompose the waste.

The gas injection device 20 includes a gas storage unit 21 for storing carrier gas and a heating unit 22 for heating the carrier gas before receiving the carrier gas from the gas storage unit and supplying the carrier gas to the pyrolysis device 10. can include

For example, the heating unit may include an in-line heater or a heat exchanger.

The gas injection device 20 may heat the carrier gas to a temperature of 200°C to 600°C, preferably 350°C to 550°C, and more preferably 400°C to 500°C.

Accordingly, the internal temperature of the thermal decomposition device 10 may be adjusted to a temperature of 200° C. to 600° C. by receiving the carrier gas having the above temperature from the gas injection device 20 .

As the carrier gas satisfies the above temperature range, waste thermal decomposition occurs in the above temperature range, and when the temperature of the carrier gas is less than 200 ° C, the removal of harmful compounds contained in the waste does not sufficiently occur, and when it exceeds 600 ° C, the removal efficiency of harmful compounds While the improvement is negligible, only the energy consumption increases significantly, which can deteriorate the economics of the overall process.

In addition, since the gas injection device 20 supplies a carrier gas to the pyrolysis device 10, an oxygen-free or low-oxygen atmosphere can be maintained inside the pyrolysis device 10. That is, the carrier gas may include an inert gas. Here, the oxygen-free or low-oxygen atmosphere may include a nitrogen atmosphere, an inert atmosphere, and a vacuum atmosphere. Alternatively, the low-oxygen atmosphere may include an atmosphere in which the oxygen content is 3 vol% or less.

The low-oxygen or oxygen-free atmosphere is not limited to a specific gas, and may be, for example, a nitrogen atmosphere, an inert atmosphere, or a vacuum atmosphere. An argon atmosphere or a helium atmosphere may be used as the inert atmosphere, but is not limited thereto. Among these, when a nitrogen atmosphere is applied to a low-oxygen or anoxic atmosphere, it is economical because relatively inexpensive nitrogen can be used, and there are advantages in that the atmosphere is easy to create. For example, the pyrolysis device 10 may include a gas supply unit receiving nitrogen gas (N ₂ ) from the outside to maintain an internal atmosphere.

The waste disposal system 100 according to the present invention may further include a drying device 30 . The drying device 30 dries the waste and discharges the dried waste to the pyrolysis device 10, and can reduce the liquid content in the waste before supplying the waste to the pyrolysis device 10. And, the drying device 30 may crush the waste to a certain particle size or less.

The drying device 30 includes a main body that determines the shape of the drying device 30, a waste input unit 31 provided at the front end of the main body to input waste, and a powder discharge provided at the rear end of the main body to discharge dried and pulverized waste powder. Part 32, steam is supplied to transfer heat to the disk or rotary blade provided on the outer circumferential surface, and the moving disk or moving screw for moving the waste through rotation, the exhaust gas for discharging the exhaust gas generated as the waste is dried. Including the discharge part.

Then, the powder discharge unit 32 may further include a filter unit 14 that selects only waste particles having a particle diameter of 5 mm or less.

That is, the filter unit 14 according to the present invention may be located on a path through which waste flows into the pyrolysis device 10, and more specifically, the filter unit 14 is a waste inlet of the pyrolysis device 10. (12) and the powder discharge unit 32 of the drying device 30.

The drying device 30 may include a method in which high-temperature gas directly contacts waste, or may include a method in which waste is dried in a non-contact manner using a disk or screw capable of receiving heat from the high-temperature gas. .

In one embodiment, the drying apparatus 30 according to the present invention increases the temperature of the disk or screw by supplying the high-temperature gas to the rotating shaft of the moving disk or moving screw in a way that the hot gas does not come into contact with the waste. can make it

And, the drying device 30 may move the waste from the front end to the rear end of the main body through rotation. In addition, the drying device 30 may increase the efficiency of drying the waste by pulverizing the waste to increase the contact area between the hot gas or the high-temperature medium and the waste.

The drying device 30 may include a disc dryer, a ribbon dryer, a twin screw dryer, a paddle dryer, and the like.

However, the drying device 30 is not particularly limited as long as it can continuously dry and pulverize waste.

3 is a block diagram showing a waste disposal system 100' according to another embodiment of the present invention.

The waste treatment system 100' according to another embodiment includes a dehydration device 40, a drying device 30, a pyrolysis device 10, a gas injection device 20, a dust collector 50, a combustion device 60, It includes a cooling device (70) and a scrubber (80).

Here, the pyrolysis device 10, the gas injection device 20, and the drying device 30 have the same configuration as the continuous waste treatment system 100 according to an embodiment of the present invention, and detailed descriptions thereof are omitted.

The dewatering device 40 dehydrates the waste before supplying the waste to the drying device 30, and may be located between the waste storage unit and the drying device 30.

Also, the waste treatment system 100' may further include a waste pump, and the waste pump may move waste from the waste storage unit to the dewatering device 40. The movement of waste from the dewatering device 40 to the drying device 40 may use any one of gravity, a moving screw, and a conveyor belt, but is not limited as long as the waste can be moved.

The dust collector 50 may be located between the pyrolysis device 10 and the combustion device 60 to be described later, receive exhaust gas and pyrolysis sludge from the pyrolysis device 10, and separate the exhaust gas and pyrolysis sludge. .

The dust collector 50 may include any one or more of a cyclone and a bag filter. For example, when the dust collector 50 is a cyclone, the dust collector 50 may include a bag filter therein. However, the dust collector 50 is not limited as long as it can separate exhaust gas and pyrolysis sludge.

In one embodiment, when the dust collector 50 included in the waste treatment system 100' is a cyclone, the dust collector 50 may separate the exhaust gas and the pyrolysis sludge using centrifugal force and inertial force.

And, the dust collector 50 may be provided with a pyrolysis sludge supply port through which exhaust gas and pyrolysis sludge are supplied to the upper side of the outer circumferential surface. Therefore, in the dust collector 50, the exhaust gas and pyrolysis sludge supplied from the upper side collide with the inner wall to rotate, and the exhaust gas and pyrolysis sludge to rotate have centrifugal and inertial forces.

In the dust collector 50, light-weight exhaust gas is discharged upward, and pyrolyzed solid sludge and water are heavy-weight and discharged downward.

Therefore, the dust collector 50 may have an exhaust gas discharge port through which exhaust gas is discharged at the upper side and a pyrolysis sludge discharge port through which pyrolysis sludge is discharged at the lower side.

The dust collector 50 may further include a pyrolysis sludge storage unit 51 for storing pyrolysis sludge.

The pyrolysis sludge storage unit 51 is connected to the pyrolysis sludge discharge port to store pyrolysis solid sludge and water, and can measure the concentration of harmful chlorine compounds in the pyrolysis solid sludge. When harmful chlorine compounds are detected in the pyrolysis sludge storage unit 51, the pyrolysis solid sludge may be re-supplied to at least one of the pyrolysis device 10, the drying device 30, and the combustion device 60.

Combustion promoting gas may be supplied to the dust collector 50 to increase the combustion efficiency of the exhaust gas in the combustion device 60 . The location of the combustion-promoting gas supply unit for supplying the combustion-promoting gas is not limited as long as the direction in which the exhaust gas and pyrolysis sludge are turned inside the dust collector 50 is not hindered.

In one embodiment, the combustion-promoting gas supply unit may be provided on the same line as the location where the exhaust gas inlet is provided in the longitudinal direction or in the circumferential direction of the main body of the dust collector 50.

The combustion device 60 burns the exhaust gas discharged from the pyrolysis device 10, burns the exhaust gas at a high temperature, and decomposes the exhaust gas into low molecular weight substances. That is, the combustion device 60 decomposes harmful chlorine compounds contained in the exhaust gas into carbon dioxide and water, which are difficult to re-synthesize.

The combustion device 60 is a combustion burner located on one side of the inside, an exhaust gas supply unit connected to the decomposition discharge unit 13 of the pyrolysis device 10 or the dust collector 50 to receive exhaust gas, and the burned exhaust gas to stand by. It includes a purification gas discharge unit for discharging to.

In the combustion device 60 , an exhaust gas supply unit and a purification gas discharge port may be connected to a passage pipe to prevent mixing of exhaust gas supplied and purification gas purified after combustion. Here, the flow pipe may be formed in various shapes such as a straight line or a spiral, but is preferably formed in a spiral shape to increase the contact time and area with the combustion heat generated from the combustion burner.

The combustion device 60 may receive exhaust gas and pyrolysis sludge from the decomposition discharge unit 13 of the fluidized bed pyrolysis device 10 . At this time, the combustion device 60 is provided with a classification unit for classifying the pyrolysis sludge at the front end of the flow pipe, and can separate and discharge the pyrolysis sludge by gravity and the weight difference between the exhaust gas and the pyrolysis sludge.

And, the combustion device 60 may further include a combustion promoting gas supply port for supplying combustion promoting gas to the inside or the flow pipe. Here, the combustion-promoting gas means that the content of oxygen is at least 5% by volume or more in the total gas content.

In one embodiment, the waste treatment system 100 according to the present invention includes the decomposition discharge unit 13 of the fluidized bed pyrolysis device 10 and the combustion device to supply combustion promoting gas to the inside of the combustion device 60 or to the flow pipe. Combustion promoting gas can be supplied to a pipe connecting the exhaust gas supply unit of (60).

In the waste treatment system 100 according to the present invention, a duct connects the decomposition discharge unit 13 of the fluidized bed pyrolysis device 10 and the exhaust gas supply port of the combustion device 60, or the decomposition discharge unit of the pyrolysis device 10 A blower is included in the pipe connecting 13 and the exhaust gas supply unit, so that the exhaust gas can be supplied to the combustion device 60.

The cooling device 70 rapidly cools the exhaust gas discharged from the combustion device 60.

In one embodiment, the cooling device 70 may be provided in the form of a cooling tube wound around a container in which exhaust gas is stored. The cooling device 70 has a low internal temperature by means of a cooling pipe, and rapidly cools exhaust gas having a high temperature due to high-temperature combustion.

The cooling device 70 may include a plurality of containers having different temperatures.

In another embodiment, the cooling device 70 may be formed on an outer surface of a pipe through which exhaust gas is discharged from the combustion device 60 . By forming a cooling pipe on the outer surface of the pipe through which the exhaust gas is discharged, the exhaust gas can be rapidly cooled at the same time as the exhaust gas is discharged.

Cooling water or gas such as carbon dioxide or helium may be supplied to the inside of the cooling pipe.

The scrubber 80 filters the exhaust gas cooled in the cooling device 70 and discharges the purified gas. The scrubber 80 according to the present invention is a wet scrubber and may include an organic solvent scrubber and a base solution scrubber. At this time, one or more organic solvent scrubbers may be provided.

The scrubber 80 includes a measuring unit (not shown), and the measuring unit can measure the concentration of organic matter and harmful chlorine compounds in the waste liquid discharged after filtering.

The measuring unit can recover the waste liquid to the sludge storage unit when the concentrations of organic matter and harmful chlorine compounds in the waste liquid are measured above a certain standard.

The waste disposal system 100' according to another embodiment may further include a dust collector (not shown).

The dust collector includes a bag filter and is connected to the scrubber 80 to receive filtered purified gas and remove fine particles included in the gas.

Also, in the waste disposal system 100' according to another embodiment, a blower (not shown) may be further included in a pipe through which air purified by the dust collector is discharged.

The waste disposal system (100, 100') according to the present invention includes an opening and closing device capable of opening and closing the supply inlet, inlet and outlet of each configuration, and a valve is included in the pipe connecting the supply inlet and the inlet and the outlet, The internal atmosphere, temperature, flow rate of sludge or exhaust gas, etc. of each component can be adjusted.

Pyrolysis step (S1)

Waste treatment process according to an exemplary embodiment of the present invention includes a thermal decomposition step (S1) of thermally decomposing the waste.

More specifically, in the thermal decomposition step (S1), waste and carrier gas are supplied to a thermal decomposition device including a fixed bed catalyst structure, and the waste is brought into contact with the fixed bed catalyst structure to thermally decompose the waste into exhaust gas and pyrolysis sludge. .

That is, the waste is pyrolyzed in contact with the carrier gas, and at this time, the pyrolysis rate of the waste may be increased by contacting the fixed bed catalyst structure.

The carrier gas may include an inert gas, and may be heated to a high temperature and supplied to the pyrolysis device. Here, the high temperature may be 200 °C to 600 °C.

In the pyrolysis step (S1), high-temperature inert gas may apply heat to the waste to decompose the waste into exhaust gas and pyrolysis sludge. And, in the pyrolysis step (S1), by supplying a high-temperature inert gas into the pyrolysis device, the waste may be pyrolyzed in a low-oxygen atmosphere or an oxygen-free atmosphere.

In the present specification, an oxygen-free atmosphere means an atmosphere in which oxygen among gases constituting the atmosphere does not substantially exist. The thermal decomposition step (S1) is preferably carried out in an atmosphere in which the concentration of oxygen is 3 vol% or less, preferably 1 vol% or less, and oxygen is not present at all, that is, the oxygen concentration is 0 vol%. there is.

When the thermal decomposition step (S1) is performed under a low-oxygen or anoxic atmosphere, at a temperature of 200 ° C to 600 ° C and low-oxygen or anoxic conditions, along with a dechlorination reaction in which the C-Cl bond of the harmful chlorine compound in the sludge is broken, the harmful chlorine compound Partial and complete degradation can occur smoothly. On the other hand, under conditions where oxygen is present in an amount exceeding 3 vol%, oxygen reacts with organic matter and harmful chlorine compounds in the sludge to form another harmful chlorine compound or the decomposed harmful chlorine compound may be re-synthesized.

The low-oxygen or oxygen-free atmosphere is not limited to a specific gas, and may be, for example, a nitrogen atmosphere, an inert atmosphere, or a vacuum atmosphere. The inert atmosphere may be an argon atmosphere or a helium atmosphere, but is not limited thereto. Among them, when a nitrogen atmosphere is applied to a low-oxygen or non-oxygen atmosphere, it is economical because relatively inexpensive nitrogen can be used, and there are advantages in that the atmosphere is easy to create. A hypoxic or anoxic atmosphere can be controlled by introducing a carrier gas into the pyrolysis unit used in the pyrolysis step.

The temperature condition of the thermal decomposition step (S1) may be 200 °C to 600 °C, preferably 350 °C to 450 °C. When the temperature of the thermal decomposition step is within the above-described range, the final harmful compound removal rate may be higher in terms of connection with the combustion step described later. In particular, when the temperature of the thermal decomposition step (S1) is lower than the above range, sufficient removal of harmful compounds may not occur, and when the temperature of the thermal decomposition step (S1) is higher than the above range, the removal efficiency of harmful chlorine compounds is hardly improved. On the other hand, only energy consumption increases significantly, which may deteriorate the economic feasibility of the overall process.

The performance time of the thermal decomposition step (S1) may be 1 hour to 6 hours, preferably 2 hours to 6 hours, and more preferably 3 hours to 5 hours. If the time of the thermal decomposition step (S1) is too short, sufficient thermal decomposition of harmful compounds cannot be achieved, and if the time of the thermal decomposition step (S1) is too long, the effect of increasing the removal rate of harmful compounds compared to the increase in energy consumption is insignificant

In the thermal decomposition step (S1), thermal decomposition sludge and exhaust gas are generated by thermal decomposition of the waste, and the thermal decomposition sludge can be treated by measuring the concentration of remaining chlorine compounds. For example, when the concentration of chlorine compounds in the pyrolysis sludge exceeds the reference value, the pyrolysis sludge may completely decompose chlorine compounds by re-performing the pretreatment step (S0) or the pyrolysis step (S1).

And, the thermal decomposition step (S1) may further include a step of classifying the exhaust gas and the thermal decomposition sludge. Exhaust gas produced by pyrolysis of waste may be discharged through a combustion device (S2) to post-processing step (S4) described later, and pyrolysis sludge is discharged to the outside, or, as described above, the sludge recovery step (described later) The chlorine compound may be completely decomposed by re-performing the pretreatment step (S0) or the thermal decomposition step (S1) through S5).

Preprocessing step (S0)

The waste treatment process according to an exemplary embodiment of the present invention includes a pretreatment step (S0) of drying the waste before the pyrolysis step (S1).

The pretreatment step (S0) may be performed so that the moisture content of the waste is 20 wt% or less. In the case of having such a water content, it is possible to increase the removal efficiency and energy efficiency of harmful compounds in the thermal decomposition step (S1) and the combustion step (S2) described later. After the pretreatment step (S0), the moisture content of the waste may be preferably 10 wt% or less, more preferably 5 wt% or less.

The pretreatment step (S0) may be performed in a manner, condition, and time to satisfy the moisture content range as described above, and is not particularly limited. For example, it may be performed by flowing the waste at a temperature higher than room temperature and lower than the temperature of the pyrolysis step until the above-described moisture content is satisfied.

Control of the drying temperature and control of the moisture content described above may be performed using a known method, and may be performed using a general device used for drying.

The pretreatment step (S0) may further include a step of crushing the waste, if necessary, and then may further include a classification step to separate particles having a specific particle diameter. Here, the specific particle diameter may include 5 mm or less.

When sludge-type waste is pulverized and produced in particle form, not only can it be controlled to have a relatively low moisture content compared to the state of the sludge-type waste as it is, but it is easy to control the moisture content and can be controlled to have a desired moisture content Therefore, it is advantageous for heat transfer to harmful compounds to be decomposed in the thermal decomposition and combustion stages. In addition, by controlling the particles of the waste to be relatively uniform, it is possible to minimize heat transfer to harmful compounds due to non-uniform particle sizes in the sludge. In addition, based on the same mass, particle-type waste can have a larger surface area than sludge-type waste, and this large surface area is a factor that facilitates heat transfer, thereby increasing the efficiency of the subsequent pyrolysis and combustion steps. can be further increased.

The grinding step may use a general method known to be used for grinding a material in the form of sludge, and may be performed, for example, using a general grinder. Specifically, a jaw crusher or the like can be used. In the classifying step, a known method of separating particles by size may be used, and a method using a sieve may be used.

And, the pretreatment step (S0) may further include, if necessary, dewatering the waste before drying the waste.

The dehydration step is a step of forming sludge having a moisture content of 50 wt% to 60 wt% from sludge having a moisture content of 95 wt% or more.

A method necessary for dehydration may be employed, and for example, a semi-solid material having a moisture content of 50 wt% to 60 wt% may be recovered using a filter press or a decanter.

Combustion stage (S2)

In the thermal decomposition step, harmful compounds in the waste are decomposed to form gases, and some of the formed gas components may still have harmful properties. Therefore, it is necessary to additionally burn and remove gaseous harmful compounds. Hazardous compounds in the gaseous phase remaining through combustion in this step can be converted into harmless low-molecular compounds such as carbon dioxide or water.

In the combustion step, it is preferable to introduce air or oxygen together with the gas generated in the above-mentioned pyrolysis step.

According to one embodiment, the temperature in the combustion step may be 900 °C to 1,200 °C, preferably 1,000 °C to 1,200 °C. When the temperature in the combustion step is lower than the lower limit of the above range, the remaining gaseous hazardous compounds cannot be sufficiently oxidized, and when it is higher than the upper limit of the above range, the amount of energy used for combustion is excessive, which may deteriorate the economics of the overall treatment process. can

The time of the burning step may be 5 to 60 minutes, preferably 15 to 30 minutes. If the time of the combustion step is too short, sufficient oxidation cannot be performed, and if it is too long, the amount of energy used for combustion is excessive, as in the case of temperature, and thus the economic feasibility of the overall treatment process may be deteriorated.

Cooling stage (S3)

Waste treatment process according to another embodiment of the present invention may further include a step (S3) of cooling the combustion gas generated by combustion in the combustion step. Harmful compounds that are not completely decomposed and removed may remain even after the above-described pyrolysis step (S1) and combustion step (S2), and harmful compounds that are partially decomposed may be re-synthesized into harmful compounds thereafter. Therefore, in order to prevent such resynthesis, it is preferable to remove energy required for resynthesis by cooling the combustion gas in which undecomposed harmful compounds may remain.

The cooling may be performed through a commonly used method, for example, a method using low-temperature water or cooling water, and rapid cooling is preferable to minimize resynthesis. For example, cooling may be performed by allowing low-temperature water or cooling water to pass through a circulator around a tube through which exhaust gas passes.

Post-processing step (S4)

The waste treatment process according to one embodiment may further include a post-processing step (S4) for removing, when trace amounts of harmful gas and acid gas still remain after the above-described cooling step. For example, the waste treatment process includes a scrubbing step of passing the combustion gas cooled in the cooling step through a scrubber (S4-1) and/or a dust collecting step of passing the combustion gas cooled in the cooling step through a dust collector (S5-2). may further include. The scrubbing step (S4-1) and the dust collecting step (S5-2) may include either one or both.

Most of the harmful compounds can be removed through the post-treatment step.

The scrubber used in the scrubbing step (S4-1) may include at least one of an organic solvent scrubber for removing organic gas and a base solution scrubber for removing acid gas. The combustion gas may pass through an organic solvent scrubber and then a base solution scrubber. A toluene scrubber may be used as the organic solvent scrubber, and a sodium hydroxide scrubber may be used as the base solution scrubber. When using the above scrubber, the effect of removing harmful compounds can be maximized.

The dust collector used in the dust collection step (S4-2) may include a bag filter or the like.

In the post-processing step, when both the scrubbing step (S4-1) and the dust collection step (S4-2) are included, the order is not particularly limited, and after passing the cooled combustion gas through the dust collector, the scrubber Alternatively, the cooled combustion gas can be passed through a scrubber and then through a dust collector. From the viewpoint of removing harmful gases, it may be more preferable to first pass through a dust collector among scrubbers and dust collectors.

Sludge recovery step (S5)

The waste treatment process according to one embodiment may further include a step (S5) of recovering pyrolysis sludge generated by pyrolysis of waste after the pyrolysis step described above.

The sludge recovery step is a step of recovering the sludge in a pyrolysis device or a dust collector to continuously perform the pyrolysis step, and the sludge can be recovered when the temperature of the sludge is reduced to room temperature or below room temperature.

The sludge can be cooled naturally in the pyrolysis unit or rapidly cooled when discharged through the sludge outlet.

Hazardous compounds that are not completely decomposed and removed may remain in the sludge, and toxic compounds that are partially decomposed may be re-synthesized into toxic compounds later. Therefore, in order to prevent such resynthesis, it is preferable to remove the energy required for resynthesis by cooling the sludge in which undecomposed harmful compounds may remain.

The sludge recovery step may further include resupplying the sludge to the pyrolysis device (S5-1).

Harmful compounds included in the waste may be completely decomposed through the pyrolysis step, or may be included in gas and sludge generated by pyrolysis of the waste. Therefore, after measuring the concentration of harmful compounds (toxic) in the sludge, if the concentration of harmful compounds exceeds the standard value, the sludge can be re-supplied to the pyrolysis device.

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art can variously modify and change the present invention within the scope not departing from the spirit and scope of the present invention described in the claims below. You will understand that it can be done.

100, 100': waste treatment system
10: pyrolysis device
11: fixed bed catalyst structure
1, 1': description
1a: first set
1b: second set
1c: 3rd set
1d: 4th set
2: catalyst layer
12: waste supply
13: decomposition discharge unit
14: filter unit
15: prevention part
20: gas injection device
21: gas storage unit
22: heating unit
30: drying device
31: waste input unit
32: powder discharge unit
40: dewatering device
50: dust collector
51: pyrolysis sludge storage unit
60: combustion device
70: cooling device
80: scrubber

Claims (14)

A thermal decomposition device receiving waste in the form of particles and thermally decomposing the waste and including a fixed bed catalyst structure; and
A gas injection device for flowing the waste particles by supplying a carrier gas to the pyrolysis device
Waste treatment system comprising a.
The waste treatment system of claim 1, wherein the fixed-bed catalyst structure included in the pyrolysis device includes a substrate and a catalyst layer coated on a surface of the substrate.
3. The method according to claim 2, wherein the substrate includes wires, the wires comprising a first set of two or more positioned parallel to each other and a second set of two or more wires positioned parallel to each other and intersecting the first set waste disposal system.
The method according to claim 3, wherein the substrate further comprises a third set comprising wires forming an angle of 10° to 80° with at least one of the first set and the second set, at least two of which are parallel to each other. system.
The waste treatment system according to claim 2, wherein in the pyrolysis device, one or more fixed-bed catalyst structures are stacked along a longitudinal direction of the pyrolysis device.
The waste disposal system of claim 1, wherein the pyrolysis device includes a waste supply unit into which the waste is introduced, and the waste supply unit further comprises a filter unit that selects only the waste particles having a particle size of 5 mm or less.
The method according to claim 1, further comprising a drying device for drying the waste and discharging the dried waste to the pyrolysis device, wherein the drying device includes a powder discharge unit for discharging the dried waste, wherein the powder discharge unit has a particle size Waste treatment system further comprising a filter unit for screening only the waste particles of 5 mm or less.
The waste disposal system of claim 1, wherein the gas injection device includes a gas storage unit for storing the carrier gas and a heating unit receiving the carrier gas from the gas storage unit and heating the carrier gas.
The waste treatment system according to claim 1, wherein the process temperature of the pyrolysis unit is 200 °C to 600 °C.
The waste disposal system of claim 1 , wherein the pyrolysis device further includes a prevention unit at an inner lower portion of the pyrolysis device to prevent the waste particles from entering the gas injection device.
A waste treatment process comprising a thermal decomposition step of supplying waste and a carrier gas to a pyrolysis device including a fixed bed catalyst structure and allowing the waste to come into contact with the fixed bed catalyst structure to thermally decompose the waste into exhaust gas and pyrolysis sludge.
The waste treatment process according to claim 11, further comprising a pretreatment step of drying the waste and crushing the waste to a particle size of 5 mm or less.
12. The process of claim 11, wherein the carrier gas comprises an inert gas.
The waste treatment process of claim 11 , wherein the carrier gas is heated to a temperature of 200° C. to 600° C. and supplied to the pyrolysis device.

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