KR20240072959A - Dry Type CO2 Treatment Device for Improving Quality of Recycled Aggregate and System Thereof - Google Patents

Abstract

The present invention relates to a dry carbon dioxide treatment device and treatment method that can improve the quality of recycled aggregate. The aggregate carbon dioxide treatment device of the present invention includes an inlet into which aggregate is input, a basket accommodating the input aggregate, and a homogeneous reaction between aggregate and carbon dioxide. It consists of a reaction tank including an impeller for stirring the aggregate, a driving device for rotating the impeller, a constant temperature water tank for maintaining the temperature of the reaction tank constant, and a supply tank for supplying carbon dioxide to the reaction tank, and circulating aggregate. It has the advantage of improving the physical strength and chemical properties of aggregate by dry treating carbon dioxide to produce calcium carbonate.

Description

Dry Type CO2 Treatment Device for Improving Quality of Recycled Aggregate and System Thereof}

The present invention relates to a dry carbon dioxide treatment device and treatment method, and more specifically, to a dry carbon dioxide treatment device and treatment method that can improve the quality of recycled aggregate.

As global warming gradually accelerates, the importance of carbon capture, utilization, and storage (CCUS) technology, which captures and stores or utilizes emitted carbon dioxide, along with efforts to reduce carbon dioxide emissions, a major greenhouse gas, itself. This is becoming more prominent.

In order to solve the shortage of crushed stone and aggregate due to the depletion of natural resources and environmental destruction caused by extraction, we urge the production and use of recycled concrete aggregate (RCA) using construction waste. However, the engineering/environmental issues of recycled aggregate are urged. Due to its low quality, it is not effectively used as a ground material.

In order to improve the quality of recycled aggregate, a process to remove mortar attached to the aggregate is necessary, and methods of removing it physically and treating it using acid are used. However, existing methods take a long time to process mortar, have problems with waste acid disposal, and have difficulty in scaling up.

In particular, recycled aggregate is a form in which mortar is attached to existing natural aggregate, or crushed residues of cement or mortar are mixed. It is used smoothly due to physical limitations such as low strength, which makes it prone to crushing and abrasion, and chemical limitations, such as the generation of alkaline runoff. It's not working.

In addition, a physical crushing process is applied to produce recycled aggregate for high added value. This consumes a lot of energy as it requires at least three crushing processes, and an additional process to handle the crushed fragments is added, which does not fit the purpose of using recycled aggregate in an environmentally friendly way. In addition, heat is applied as a method of improving the quality of recycled aggregate. There are methods such as acid treatment, polymer treatment, etc., but these methods have problems in that they are difficult to scale up, produce harmful by-products, and are not cost-effective.

Public Patent Publication No. 10-2013-0113803 (published on October 16, 2013) Public Patent Publication No. 10-2018-0033813 (published on April 4, 2018)

The present invention proposes a method to improve the physical/chemical quality of recycled aggregate, contributing to reducing landfill costs and suppressing natural resource depletion and environmental pollution by reusing construction waste that used to be landfill, and economically reducing carbon dioxide by reusing carbon dioxide. We propose a plan to recycle it into a valuable resource.

The aggregate carbon dioxide treatment apparatus of the present invention for achieving the above-described object includes a reaction tank including an inlet into which aggregate is input, and a basket for receiving the aggregate. A driving device for stirring the aggregate to achieve a homogeneous reaction between the added aggregate and carbon dioxide; A constant temperature water tank for maintaining the temperature of the reaction tank constant; and a supply tank for supplying carbon dioxide to the reaction tank.

In addition, it may further include a water spray device that sprays water to supply moisture to the reaction tank.

Additionally, an insulating plate is disposed outside the reaction tank, and a pipe connected to the constant temperature water tank is disposed between the reaction tank and the insulating plate to maintain the temperature of the reaction tank constant through water circulation.

Additionally, the driving device rotates the basket in the reaction tank, or

The aggregate is stirred by rotating an impeller, one end of which is connected to the rotating shaft of the driving device, and the end of which is equipped with a scraper made of a low-friction material to minimize friction with the inside of the reaction tank.

In addition, it may further include a tilt adjustment device for adjusting the tilt of the reaction tank.

Additionally, the tilt adjustment device may include a hydraulic jack for tilting the reaction tank when installing and dismantling the reaction tank.

The aggregate carbon dioxide treatment system according to an embodiment of the present invention includes the first aggregate carbon dioxide treatment device described above, and a data logging device for measuring and recording the pressure and temperature within the reaction tank and the rotation speed of the reaction tank.

In addition, the aggregate carbon dioxide treatment system may further include silica gel added to the basket along with the aggregate to maintain humidity inside the reaction tank.

A method of treating carbon dioxide in aggregate using an aggregate carbon dioxide treatment device according to an embodiment of the present invention includes an aggregate input step of introducing aggregate into an inlet of the reaction tank; A carbon dioxide injection step of injecting carbon dioxide into the reaction tank for reaction with the aggregate; A stirring step of stirring the surface of the aggregate so that it comes into smooth contact with carbon dioxide and a homogeneous reaction occurs; A reaction step of maintaining the temperature and carbon dioxide pressure inside the reaction tank to allow a carbon dioxide treatment reaction to occur; and an aggregate recovery step of removing the internal pressure of the reactor and opening the lid of the inlet to remove the aggregate.

In addition, after the aggregate input step, a silica gel input step of adding silica gel to maintain humidity inside the reaction tank may be further included.

In addition, before the carbon dioxide injection step, a moisture treatment step of spraying water to treat moisture of the aggregate in the reaction tank may be further included.

In addition, the initial moisture content of the recycled aggregate after the moisture treatment step is characterized in that 40 to 60%.

Additionally, in the reaction step, the humidity in the reaction tank is maintained at 20 to 40%.

Additionally, in the reaction step, the pressure in the reaction tank is maintained at 400 to 600 kPa.

Additionally, in the reaction step, the temperature in the reaction tank is maintained at 35 to 45°C.

Through these means, the aggregate carbon dioxide treatment device and treatment method of the present invention can improve the physical/chemical quality of the recycled aggregate through a carbon dioxide-based carbonation reaction of the recycled aggregate.

In addition, the reaction is performed at the optimal temperature/pressure/humidity depending on the characteristics of the recycled aggregate, and the reaction process is monitored in real time, so the time required for quality improvement can be reduced, which is effective in reducing costs.

In addition, it can contribute to reducing landfill costs and suppressing natural resource depletion and environmental pollution by reusing construction waste that used to be landfilled.

In addition, the present invention is a carbon resource technology that reuses carbon dioxide as a resource with economic value, and can simultaneously overcome climate change and energy problems.

1 is a conceptual diagram showing the overall configuration of an aggregate carbon dioxide treatment device according to an embodiment of the present invention.
Figure 2 is a conceptual diagram showing a constant temperature maintenance structure of an aggregate carbon dioxide treatment device according to an embodiment of the present invention.
Figure 3 is a photograph of the inside of the basket of the aggregate carbon dioxide treatment device according to an embodiment of the present invention.
Figure 4 is an actual design diagram of an aggregate carbon dioxide treatment device according to an embodiment of the present invention.
Figure 5 is a diagram of a rotating basket according to another embodiment of the present invention.
Figure 6 is a photograph of an aggregate carbon dioxide treatment system according to an embodiment of the present invention.
Figure 7 is a photograph showing the process of treating carbon dioxide in recycled aggregate according to an embodiment of the present invention.
Figure 8 is a flowchart of an aggregate carbon dioxide treatment method according to an embodiment of the present invention.
Figure 9 is a flowchart of an aggregate carbon dioxide treatment method according to another embodiment of the present invention.

Specific embodiments and features of the present invention will be described in detail through the attached drawings. However, the present invention is not limited to the drawings and specific embodiments, and may be implemented in various different forms. The present embodiments are merely provided to ensure that the disclosure of the present invention is complete and that common knowledge in the technical field to which the present invention pertains is not limited. It is provided to fully inform those who have the scope of the invention, and the invention is only defined by the claims. Like reference numerals refer to like elements throughout the specification.

In describing embodiments of the present invention, if a detailed description of a known function or configuration is judged to unnecessarily obscure the gist of the present invention, the detailed description will be omitted. The terms described below are defined in consideration of functions in the embodiments of the present invention, and may vary depending on the intention or custom of the user or operator. Therefore, the definition should be made based on the contents throughout this specification.

Hereinafter, a dry carbon dioxide treatment device and treatment method that can improve the quality of recycled aggregate according to an embodiment of the present invention will be described with reference to the attached drawings.

First, Figure 1 is a conceptual diagram showing the overall configuration of an aggregate carbon dioxide treatment device 1000 according to an embodiment of the present invention. Referring to Figure 1, the aggregate carbon dioxide treatment device according to an embodiment of the present invention is a system in which aggregate is input. A reaction tank 100 including an inlet 110 and a basket 120 for accommodating the input aggregate; A driving device 200 that agitates the aggregate for a homogeneous reaction between the introduced aggregate and carbon dioxide; A constant temperature water tank (400) for maintaining the temperature of the reaction tank (100) constant; and a supply tank 300 for supplying carbon dioxide to the reaction tank 100.

The inlet 110 for inputting aggregate is located vertically on the upper side of the reaction tank 100 and is used to input recycled aggregate for carbon dioxide treatment and to recover the treated recycled aggregate.

The input aggregate is accommodated in the basket 120 inside the reaction tank 100. Referring to FIG. 5, an internal mesh network 121 with perforations of a predetermined diameter is disposed in the basket 120 so that the crushed fine particles are discharged. The rotation axis of the basket 120 is connected to and rotates with the driving device 200 for stirring, and as the basket 120 rotates, the aggregate tumbles and is configured to maximize the contact surface with carbon dioxide. As another example of agitating the aggregate, an impeller 130 may be connected to the rotation shaft of the driving device 200 to additionally agitate the aggregate.

A constant temperature water tank 400 for maintaining the temperature within the reaction tank 100 constant during the reaction between the aggregate and carbon dioxide, and a supply tank 300 for supplying carbon dioxide for the reaction with the aggregate are disposed outside the reaction tank 100. do.

Meanwhile, one side of the reaction tank 100 further includes a water spray device that sprays water to supply moisture to the reaction tank 100. The water spray device is a device that sprays water to treat the moisture of the aggregate in the reaction tank 100, and the carbon dioxide treatment effect is most excellent when the initial moisture content of the recycled aggregate is 40 to 60%.

Figure 2 is a conceptual diagram showing a constant temperature maintenance structure of an aggregate carbon dioxide treatment device according to an embodiment of the present invention. Referring to Figure 2, an insulating plate 410 is disposed on the outside of the reaction tank 100, and the reaction tank 100 and A pipe 420 is disposed between the insulation plates 410 and is connected to the constant temperature water tank 400 to maintain the temperature of the reaction tank 100 constant through water circulation.

That is, a constant temperature water tank 400 is installed outside the reaction tank 100 to control the temperature during carbon dioxide treatment, and the constant temperature water tank 400 is a pipe surrounding the inside of the insulation plate 410 surrounding the outside of the reaction tank 100. It is connected to 420 to control the temperature by circulating water, and a temperature sensor may be installed inside the constant temperature water tank 400 and the reaction tank 100.

Figure 3 is a photograph of the inside of the basket 120 of the aggregate carbon dioxide treatment device according to an embodiment of the present invention. The left side is a view from the top through the inlet 110, and the right side shows the aggregate, impeller 130, and scraper arranged with one side open.

Figure 4 is an actual design diagram of the reaction tank 100 according to an embodiment of the present invention. Referring to Figure 4, the reaction tank 100 according to an embodiment of the present invention is a sealed cylindrical shape that can withstand high pressure of carbon dioxide. It is designed with a metal structure. It can be placed into an aggregate inlet connected vertically within the reaction tank 100. For carbon dioxide treatment, carbon dioxide at a desired pressure is injected into the metal reaction tank 100 and stirred so that the surface of the aggregate comes into smooth contact with the carbon dioxide. In the design of FIG. 4, it is designed as a cylindrical metal cell with an inner diameter of about 208.4 mm and a length of 520 mm, and a scraper made of Teflon (PTFE) is installed at the end of the impeller 130 to reduce friction with the inside of the reaction tank 100. It is designed to minimize and efficiently stir.

Figure 6 is a photograph of an aggregate carbon dioxide treatment system according to an embodiment of the present invention. The actually implemented aggregate carbon dioxide treatment system includes a basket 120 to put aggregate, a constant temperature water tank for controlling the internal temperature of the reaction tank 100, and a carbon dioxide supply tank. (300), a pressure gauge and solenoid valve for maintaining the carbon dioxide pressure inside the reaction tank (100), a stirrer, a tilt control device (500) for the reaction tank (100), an instrument panel, and the pressure and rotation speed (rpm) of the reaction tank (100) are measured and recorded. It is configured to include possible data logging devices, etc.

The carbon dioxide pressure inside the reaction tank 100 was controlled through a solenoid valve, and a constant temperature water tank was installed outside the reaction tank 100 to control the temperature during carbon dioxide treatment. The constant temperature water tank is connected to a pipe 420 surrounding the inside of the insulating plate 410 surrounding the outside of the reaction tank 100 to circulate water to control the temperature, and a temperature sensor is installed inside the constant temperature water tank and the reaction tank 100. .

Meanwhile, a hydraulic jack 510 using nitrogen can be installed to tilt the reaction tank 100 when installing and dismantling the reaction tank 100, and carbon dioxide and nitrogen are supplied from a compressed gas tank located on the side of the reaction tank 100.

Figure 7 is a photograph showing the process of treating carbon dioxide in recycled aggregate according to an embodiment of the present invention.

Figure 7 (a) shows the process of saturating the prepared aggregate by 50%. As shown in the photo, the aggregate is sprayed separately into the reaction tank 100 by spraying water or using a water spray device placed on one side of the reaction tank 100. Water can be sprayed while injected. Figure 7 (b) is a photograph showing silica gel placed in a mesh. In order to maintain humidity inside the reaction tank 100, silica gel can be put into the basket 120 together with the aggregate. It is appropriate to use approximately 100 to 300 g of silica gel per 1 kg of aggregate. In order to minimize mixing of the aggregate and silica gel and breakage by tumbling, silica gel was placed in several meshes and placed inside the basket 120.

Figure 7 (c) is a photograph of the basket 120 seen from the side, Figure 7 (d) is a photograph of the aggregate carbon dioxide treatment system control and data logging system, and Figure 7 (e) is a photograph of the basket 120. This is the appearance of the aggregate, and Figure 7(f) is a photograph showing the fine powder generated by tumbling after carbon dioxide treatment attached to the outside of the basket 120.

The carbon dioxide dry treatment method of recycled aggregate according to an embodiment of the present invention is as follows. The recycled aggregate is placed in the reactor, and the reactor is maintained at a specific temperature and completely sealed. Carbon dioxide is injected at a certain pressure through the injection port. When the reaction is completed, the pressure inside the reactor is removed and the lid of the inlet 110 is opened to take out the aggregate.

Figure 8 is a schematic flowchart showing the aggregate carbon dioxide treatment method according to an embodiment of the present invention. The aggregate carbon dioxide treatment method according to an embodiment of the present invention involves inputting aggregate into the inlet 110 of the reaction tank 100. Aggregate input step; A carbon dioxide injection step of injecting carbon dioxide into the reaction tank 100 for reaction with the aggregate; A stirring step of stirring the surface of the aggregate so that it comes into smooth contact with carbon dioxide and a homogeneous reaction occurs; A reaction step of maintaining the temperature and carbon dioxide pressure inside the reaction tank 100 to allow a carbon dioxide treatment reaction to occur; and an aggregate recovery step of opening the lid of the inlet 110 to remove the aggregate after removing the internal pressure of the reactor.

Figure 9 is a schematic flowchart showing an aggregate carbon dioxide treatment method according to another embodiment of the present invention, which includes a silica gel injection step of adding silica gel to maintain humidity inside the reaction tank 100 after the aggregate injection step. It may be included, and the amount of silica gel added is preferably 10 to 30% of the amount of aggregate added. If the amount of silica gel added is less than 10%, there is a limit to lowering the humidity, and if the amount of silica gel added is more than 30%, treatment efficiency drops sharply.

In addition, before the carbon dioxide injection step, a moisture treatment step of spraying water to moisture the aggregate in the reaction tank 100 may be further included, and after the moisture treatment step, the initial moisture content of the recycled aggregate is 40 to 60%. It is desirable to be

In the reaction step, it is important to keep the temperature, temperature, and pressure in the reaction tank 100 constant, and the humidity in the reaction tank 100 is preferably maintained at 20 to 40%, and the carbon dioxide treatment efficiency is within the above range. can be maximized. Meanwhile, the pressure within the reaction tank 100 is preferably maintained at 400 to 600 kPa, and the temperature within the reaction tank 100 is preferably maintained at 35 to 45°C.

In addition, when fine aggregate (4.75-12.5mm) obtained from a waste concrete structure is treated by injecting carbon dioxide, the lower the temperature, the higher the pressure, the lower the relative humidity in the reaction tank 100, the initial moisture content of the aggregate is 50%. It was found that the closer to , the more likely the carbonation reaction occurs.

Since it is not easy to control the temperature in the actual field, there will be differences in the carbonation effect depending on the season in which the recycled aggregate is processed, and if a temperature control system is not provided, the carbonation effect is expected to be greater in winter.

However, if the pressure is greater than 500 kPa, the carbonation effect that increases as the pressure increases is not large, and treatment at high pressure requires a lot of initial cost to build an infrastructure system, so about 500 kPa is practical in industrial sites. It is expected to be more suitable.

The closer the initial saturation is to about 50%, the higher the carbonation efficiency. Therefore, moisture treatment of the aggregate using spray, etc. before treatment can promote the carbonation reaction, and the overall humidity of the reaction tank 100 must be kept low for circulation. It was confirmed that carbon dioxide treatment of aggregate was optimal.

During large-scale carbon dioxide treatment, continuous agitation of the aggregate is necessary to maximize the contact area between the aggregate and carbon dioxide. When using the agitating scraper type, a large amount of aggregate can be processed, but problems may occur due to the aggregate getting stuck, interfering with operation. When using the basket (120) type, the amount of aggregate that can be input is reduced, but stable operation for a long period of time is possible. There is an advantage to being able to do it. If the power of the stirring motor is sufficient, the basket 120 type that allows stable operation is more suitable.

When the aggregate is stirred using the basket 120, a large amount of fine powder is generated due to the tumbling of the aggregate. In the case of a full-scale reaction tank 100, a system capable of processing the generated fine particles may be additionally provided.

The present invention is not limited to the above-described embodiments, and its scope of application is diverse, and anyone skilled in the art can understand it without departing from the gist of the invention as claimed in the claims. Of course, various modifications are possible.

1000: Aggregate carbon dioxide treatment device
100: reaction tank
110: Inlet
120: Basket 121: Internal mesh net
130: impeller 131: scraper
140: water spray device
200: driving device
300: supply tank
400: constant temperature water bath
410: insulation plate 420: pipe
500: Tilt adjustment device
510: Hydraulic jack

Claims (10)

A reaction tank including an inlet into which the aggregate is input, and a basket for receiving the input aggregate;
A driving device for stirring the aggregate to achieve a homogeneous reaction between the introduced aggregate and carbon dioxide;
A constant temperature water tank for maintaining the temperature of the reaction tank constant; and
Including a supply tank for supplying carbon dioxide to the reaction tank.
Aggregate carbon dioxide treatment unit.

According to paragraph 1,
Aggregate carbon dioxide treatment device further comprising a water spray device that sprays water to supply moisture to the reaction tank.
According to paragraph 2,
The driving device rotates the basket in the reaction tank, or
An aggregate carbon dioxide treatment device that agitates aggregate by rotating an impeller, one end of which is connected to the rotating shaft of the driving device, and the end of which is equipped with a scraper made of a low-friction material to minimize friction with the inside of the reaction tank.
According to paragraph 2,
Further comprising a tilt adjustment device for adjusting the tilt of the reaction tank,
The tilt adjustment device is an aggregate carbon dioxide treatment device including a hydraulic jack for tilting the reaction tank when installing and dismantling the reaction tank.
The aggregate carbon dioxide treatment device of any one of claims 1 to 4,
An aggregate carbon dioxide treatment system comprising a data logging device for measuring and recording pressure and temperature within the reactor and reactor rotation speed.
A method of treating carbon dioxide in aggregate using the aggregate carbon dioxide treatment device of any one of claims 1 to 4,
An aggregate input step of inputting aggregate into the inlet of the reaction tank;
A carbon dioxide injection step of injecting carbon dioxide into the reaction tank for reaction with the aggregate;
A stirring step of stirring the surface of the aggregate so that it comes into smooth contact with carbon dioxide and a homogeneous reaction occurs;
A reaction step of maintaining the temperature and carbon dioxide pressure inside the reaction tank to allow a carbon dioxide treatment reaction to occur; and
An aggregate carbon dioxide treatment method comprising: an aggregate recovery step of removing the internal pressure of the reactor and opening the lid of the inlet to remove the aggregate.
According to clause 6,
After the aggregate input step,
It further includes a silica gel injection step of adding silica gel to maintain humidity inside the reaction tank,
In the reaction step, the humidity in the reaction tank is maintained at 20 to 40%. Method for treating aggregate carbon dioxide.
According to clause 6,
Before the carbon dioxide injection step,
It further includes a moisture treatment step of spraying water to moisture the aggregate in the reaction tank,
A method of treating aggregate carbon dioxide, characterized in that the initial moisture content of the recycled aggregate after the moisture treatment step is 40 to 60%.
According to clause 6,
In the reaction step,
A method of treating aggregate carbon dioxide, characterized in that the pressure in the reaction tank is maintained at 400 to 600 kPa.
According to clause 9,
In the reaction step,
A method of treating aggregate carbon dioxide, characterized in that the temperature in the reaction tank is maintained at 35 to 45 ° C.