VOC reduction device

Abstract

The present invention relates to a VOC reduction device and, more specifically, to a VOC reduction device comprising: a housing having an inlet through which gas is introduced and an outlet through which the gas is discharged; an adsorption layer disposed inside the housing to adsorb volatile organic compounds (VOCs) contained in the gas; a catalyst layer for decomposing volatile organic compounds desorbed from the adsorption layer; and a heating layer for locally and directly heating the catalyst layer, wherein electrodes are connected to the heating layer to generate heat by Joule heating through electrical energy, and thus it is possible to perform rapid VOC oxidation while reducing the consumption of energy used to heat the catalyst.

Description

VOC reduction device

[0001] The present invention relates to a VOC reduction device capable of easily responding to fluctuating VOC concentrations through a faster temperature rise compared to conventional devices by locally heating a catalyst.

[0002] As industry develops, many harmful substances are generated from workplaces in various sectors, petrochemical refining, and automobile exhaust gases. In particular, secondary generation substances such as Volatile Organic Compounds (VOCs), sulfur compounds (SOx), and nitrogen compounds (NOx), which are emitted in a gaseous state and turn into fine dust in the air, are emerging as major causes of air pollution.

[0003] Among these, Volatile Organic Compounds (VOCs) are organic compounds characterized by high vapor pressure, low boiling points, and the ability to easily evaporate and diffuse into the air even at room temperature. They are hazardous substances that cause air pollution by converting into ozone through photochemical reactions in the atmosphere, emit a pungent odor, and can induce neurological disorders through skin contact or respiratory inhalation. Types of VOCs include organic solvents used in chemical processes, carbon chloride used as sprays or refrigerants, gasoline or compounds derived from it, benzene-based compounds found in tobacco and automobile exhaust, and formaldehyde, which serves as a raw material for building materials, paints, and adhesives.

[0004] Countries are strengthening regulations to reduce volatile organic compound (VOC) emissions above a certain level, and there is a demand for technologies capable of achieving such reductions more accurately and clearly. Generally, commercially available VOC removal technologies include high-temperature incineration, adsorption, and catalytic oxidation.

[0005] Conventional high-temperature incineration is a method of decomposing exhaust gases through combustion and is widely used compared to other technologies, and has the advantage of being able to remove 95 to 99% of volatile organic compounds. However, when operating at low VOC concentrations, fuel must be supplied from an external heat source, resulting in high energy consumption and maintenance costs. Additionally, if the exhaust gas contains halogen compounds or a large amount of inorganic metal compounds, an additional incineration device is required, and there are disadvantages such as the risk of NOx emissions at high temperatures.

[0006] In addition, conventional adsorption treatment methods involve contacting gas with a solid adsorbent to collect, capture, and retain pollutants on the surface of the adsorbent. Compared to other methods, they are easy to operate, require low operating costs and equipment investment, can be used even when the concentration of pollutants in the exhaust gas is extremely low or the pollutants are non-combustible, and have the advantage of being able to almost perfectly remove compounds with low volatility and large molecular weights. On the other hand, there were disadvantages such as difficulty in desorbing compounds during adsorbent regeneration, potential for secondary pollution, high volatility, and the requirement for pretreatment processes such as filtration, cooling, and moisture removal because the adsorbent is sensitive to the state of the exhaust gas.

[0007] Meanwhile, catalytic oxidation is a method that removes volatile organic compounds by oxidizing them using a catalyst. It has the advantages of not requiring a flame, high efficiency, short residence time, and low operating costs. In particular, because it is suitable for operation in cases where VOC concentration variability is significant depending on industry characteristics, it has recently been the subject of the most research and development.

[0008] The present invention has been devised to solve the aforementioned problems, and the objective of the present invention is to remove VOCs (Volatile Organic Compounds) through a catalytic oxidation method. In particular, regarding the provision of thermal energy to activate the catalyst, the invention enables rapid VOC oxidation by selectively heating the catalyst using a Joule heating method and directly heating it, thereby achieving a faster temperature rise compared to existing technologies. Furthermore, by appropriately controlling the temperature of the heating element within an appropriate range, the invention provides a VOC reduction device capable of flexibly responding to fluctuating VOCs.

[0009] The VOC reduction device of the present invention comprises: a housing having an inlet for gas inflow and an outlet for gas outflow formed therein; an adsorption layer disposed inside the housing for adsorbing volatile organic compounds (VOCs) contained in the gas; a catalyst layer disposed on one side of the adsorption layer for decomposing volatile organic compounds desorbed from the adsorption layer; and a heating layer disposed inside the housing for locally and directly heating the catalyst layer; wherein the heating layer is characterized by generating heat through electrical energy by connecting electrodes using a Joule heating method.

[0010] The VOC reduction device of the present invention comprises: a housing having an inlet for gas introduction and an outlet for gas discharge; and a composite module disposed inside the housing, comprising an adsorbent for adsorbing volatile organic compounds (VOCs) contained in the gas, a catalyst for decomposing volatile organic compounds desorbed from the adsorbent, and a heat-generating carrier for selectively directly heating the catalyst; wherein the composite module is characterized in that the catalyst is coated on the heat-generating carrier.

[0011] A method for reducing VOCs using a VOC reduction device of the present invention comprises: a) a step of supplying gas to an inlet of a housing; b) a step in which the gas passes through an adsorption layer disposed inside the housing and adsorbs volatile organic compounds (VOCs) contained in the gas; and c) a step of discharging the treated gas through an outlet of the housing; wherein step b) comprises: b-1) a step of heating a heating layer disposed inside the housing; and b-2) a step in which the heating layer locally and directly heats a catalyst layer disposed on one side of the adsorption layer.

[0012] The VOC reduction device of the present invention, configured as described above, is environmentally friendly as it can supply heat to the catalyst via electrical energy, thereby eliminating carbon dioxide emissions from the heat supply. Furthermore, since intermittent heat supply is possible, it can achieve high responsiveness relative to low energy consumption. Additionally, because it can respond to VOC concentrations changing in real time, it can perform safe treatment with high efficiency. Moreover, by selectively heating only the catalyst and appropriately controlling the temperature of the heating element, and by finely adjusting the temperature within an appropriate range according to the process—whether for reacting and removing harmful substances or concentrating and recovering useful resources from adsorbed substances—it can reduce energy consumption while shortening the temperature switching time, thereby enabling economical operation of the facility.

[0013] FIG. 1 is a conceptual diagram of a VOC reduction device according to one embodiment.

[0014] Figure 2 is a temperature graph of the VOC reduction device over time.

[0015] Figure 3 is a graph of the conversion rate of the VOC reduction device over time.

[0016] FIG. 4 is a conceptual diagram of a heat-generating carrier according to an embodiment.

[0017] Figure 5 is a flowchart of the VOC reduction method of the VOC reduction device.

[0018] The VOC reduction device of the present invention comprises: a housing having an inlet for gas inflow and an outlet for gas outflow formed therein; an adsorption layer disposed inside the housing for adsorbing volatile organic compounds (VOCs) contained in the gas; a catalyst layer disposed on one side of the adsorption layer for decomposing volatile organic compounds desorbed from the adsorption layer; and a heating layer disposed inside the housing for locally and directly heating the catalyst layer; wherein the heating layer is characterized by generating heat through electrical energy by connecting electrodes using a Joule heating method.

[0019] At this time, the heating layer is characterized by being made of at least one of SiC, carbon, a single metal, and a metal alloy.

[0020] Here, when the heating layer is made of a metal alloy material, it is characterized as being NiCrAl or FeCrAl.

[0021] In addition, the heating layer is characterized by being composed of mesh-type pieces.

[0022] In addition, the housing is characterized by having the inlet port positioned on the other side and the outlet port positioned on one side, so that gas flows in one direction.

[0023] Herein, the VOC reduction device further comprises: a first sensing unit disposed in contact with at least a portion of the adsorption layer to detect the concentration of volatile organic chemicals adsorbed on the adsorption layer; and a second sensing unit disposed on one side of the catalyst layer to detect the concentration of volatile organic chemicals converted by the catalyst layer.

[0024] At this time, the VOC reduction device is characterized by the fact that the heating layer and the first sensing unit are connected, and when the first sensing unit detects that the concentration of volatile organic chemicals is greater than or equal to a reference value, electrical energy is applied to the heating layer to generate heat, thereby heating the catalyst layer.

[0025] In addition, the VOC reduction device is characterized in that the adsorption layer is disposed on the inlet side and the catalyst layer is disposed on the outlet side.

[0026]

[0027] The VOC reduction device of the present invention comprises: a housing having an inlet for gas introduction and an outlet for gas discharge; and a composite module disposed inside the housing, comprising an adsorbent for adsorbing volatile organic compounds (VOCs) contained in the gas, a catalyst for decomposing volatile organic compounds desorbed from the adsorbent, and a heat-generating carrier for selectively directly heating the catalyst; wherein the composite module is characterized in that the catalyst is coated on the heat-generating carrier.

[0028] Here, the heating carrier is characterized by generating heat through electrical energy using a Joule heating method.

[0029] At this time, the heating carrier is characterized by being a carrier composed of any one of a honeycomb structure monolith, a sheet-type structure, and a cologate structure.

[0030] In addition, the heating carrier is characterized by being composed of at least one material selected from SiC, carbon, and metal oxide.

[0031] Here, the heating carrier is characterized by being coated with H-beta or H-ZSM-5.

[0032] In addition, the above-mentioned heating carrier is characterized by generating heat at 150 to 300 degrees.

[0033] At this time, when the heating carrier is formed of SiC material, the heating carrier is characterized by being heated for 60 seconds at a voltage of 8 to 14 V and a current of 2 to 3 A, with a resistance of 3 to 5 Ω.

[0034] In addition, when the heating carrier is formed of SiC material, the heating carrier is characterized by being heated for 120 seconds at a voltage of 6.7 to 9.4 V and a current of 2 to 3 A, at a resistance of 3 to 5 Ω.

[0035] In addition, when the heating carrier is formed of SiC material and coated with H-beta 15 wt% on its surface, the heating carrier is characterized by being heated for 1 to 5 seconds at a voltage of 13.8 to 22 V and a current of 4 to 6 A, at a resistance of 3 to 5 Ω.

[0036] In addition, when the heating carrier is formed of SiC material and coated with H-beta 15 wt% on its surface, the heating carrier is characterized by being heated for 10 to 20 seconds at a voltage of 30 V and a current of 1 A, with a resistance of 30 to 45 Ω.

[0037] In addition, when the heating carrier is formed of carbon or H-beta / carbon material, the heating carrier is characterized by heating for 1 to 2 seconds at a voltage of 30 V and a current of 1 to 2 A, at a resistance of 22 Ω.

[0038] In addition, when the heating carrier is formed of H-beta material, the heating carrier is characterized by being heated for 5 to 25 seconds at a voltage of 8 to 12 V and a current of 7 to 10 A, with a resistance of 1 to 2 Ω.

[0039]

[0040] A method for reducing VOCs using a VOC reduction device of the present invention comprises: a) a step of supplying gas to an inlet of a housing; b) a step in which the gas passes through an adsorption layer disposed inside the housing and adsorbs volatile organic compounds (VOCs) contained in the gas; and c) a step of discharging the treated gas through an outlet of the housing; wherein step b) comprises: b-1) a step of heating a heating layer disposed inside the housing; and b-2) a step in which the heating layer locally and directly heats a catalyst layer disposed on one side of the adsorption layer.

[0041] Hereinafter, the technical concept of the present invention will be explained in more detail using the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, and should be interpreted in a meaning and concept consistent with the technical concept of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0042] Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely one preferred embodiment of the present invention and do not represent all of the technical concepts of the present invention; thus, it should be understood that various modifications capable of replacing them may exist at the time of filing this application.

[0043] Hereinafter, the technical concept of the present invention will be explained in more detail using the attached drawings. The attached drawings are merely examples illustrated to explain the technical concept of the present invention in more detail, and therefore the technical concept of the present invention is not limited to the form of the attached drawings.

[0044]

[0045] Prior to the description of the present invention, volatile organic compounds (VOCs) that can be treated by the VOC reduction system according to the present invention include acetaldehyde (C2H4O[CH3CHO]), acetylene (C2H2), acrolein (C3H4O), benzene (C6H6), 1,3-butadiene (C4H6), butane (C4H10), 1-butene (C4H8[CH3CH2CHCH2]), 2-butene (C4H8[CH3(CH)2CH3]), cyclohexane (C6H12), ethylene (C2H4), and formaldehyde (CH2O[HCHO]). n-Hexane (C6H14), Isopropyl Alcohol (C3H8O[(CH3)CHOHCH3]), Methanol (CH4O[CH3OH]), Methyl Ethyl Ketone (C4H8O[CH3COCH2CH3]), Methyl Tertiary Butyl Ether (MTBE, C5H12O[CH3OC(CH3)2CH3]), Propylene (C3H6), Propylene Oxide (C3H6O), Acetic Acid (C2H4O2), Ethylbenzene (C8H10), Toluene (C7H8), Xylene (C8H10), Styrene (C8H8C8H8) There are substances composed of hydrocarbon components such as the above.

[0046]

[0047] The VOC reduction device (10) of the present invention is a device for reducing VOCs using a catalyst, characterized by removing VOCs by oxidizing them through the activation of the catalyst by heating. Here, the VOC reduction device (10) of the present invention is characterized by configuring the device to selectively generate heat only on the catalyst requiring heat using a Joule heating structure, so as to enable effective catalyst decomposition while reducing the amount of energy input for operating the device, and by configuring the device to generate heat using electrical energy. Furthermore, the device is characterized by configuring the device to finely control the temperature using Joule heating so as to simultaneously perform the operations of reacting to remove harmful substances or concentrating and recovering some resources from the adsorbed substances.

[0048] Referring to FIG. 1, the VOC reduction device (10) according to one embodiment of the present invention may be configured to include a housing (100) having an inlet (101) for gas inflow and an outlet (102) for gas outflow, an adsorption layer (110) disposed inside the housing (100) for adsorbing volatile organic compounds (VOC) contained in the gas, a catalyst layer (120) disposed on one side of the adsorption layer (110) for decomposing volatile organic compounds desorbed from the adsorption layer (110), and a heating layer (130) disposed inside the housing (100) for locally and directly heating the catalyst layer (120). Here, the heating layer (130) is characterized by generating heat through electrical energy by connecting an electrode to the catalyst layer (120) using a Joule heating method.

[0049]

[0050] The housing (100) is a device in which gas passes through an internal space and VOCs contained in the gas are removed, and a space capable of accommodating at least an adsorption layer (110), a catalyst layer (120), and a heating layer (130) is formed within the internal space. Gas can pass through the internal space of the housing (100) through an inlet (101) and an outlet (102), and any material capable of withstanding high temperatures can be used without limitation. The positions of the inlet (101) and the outlet (102) of the housing (100) can be determined by considering the direction in which the gas flowing inside the housing (100) is to be guided. In one embodiment, the housing (100) of the present invention has an outlet (102) disposed on one side and an inlet (101) disposed on the other side, so that gas can be introduced from the other side and flow along one direction. At this time, the present invention is characterized by arranging the adsorption layer (110), the catalyst layer (120), and the heat generation layer (130) according to the direction of gas flow, taking into account their respective roles, so that the VOC reduction process can be smoothly performed in the direction of gas flow.

[0051] The adsorption layer (110) is provided inside the housing (100) and is a device that adsorbs and desorbs VOCs contained in the gas as the gas containing VOCs passes through the adsorption layer (110). The adsorption layer (110) is positioned on the side of the inlet (101) of the housing (100) so that when the gas containing VOCs enters the housing (100), it passes through the adsorption layer (110) first, thereby allowing the VOCs contained in the gas to be preferentially adsorbed and desorbed inside the housing (100). The adsorption layer (110) may include an adsorbent, and the adsorbent may be composed using at least one material among activated carbon, activated carbon fiber, and zeolite, and may be formed with a porous structure so that the gas passes through and the VOCs contained in the gas are adsorbed. The adsorption layer (110) can continue to adsorb VOCs up to a certain concentration depending on the performance of the adsorbent, and when the concentration becomes high above a certain level, the adsorption layer (110) can desorb the adsorbed VOCs. That is, when VOCs are adsorbed to a concentration above a certain level on the adsorption layer (110), the adsorbed VOCs are subsequently desorbed and can move to the catalyst layer (120).

[0052] Here, the VOC reduction device (10) of the present invention may further include a first detection unit (141) for measuring the concentration of VOC adsorbed on the adsorption layer (110). The first detection unit (141) is connected to the heating layer (130), and when it detects that the measured concentration of VOC is greater than or equal to a reference value, it can activate the heating layer (130) to activate the catalyst. Here, the reference value of the concentration of VOC in the first detection unit (141) may be the maximum value of the concentration that the adsorption layer (110) can accept. The first detection unit (141) is connected to the heating layer (130) by an electrical signal, and depending on the concentration of VOC adsorbed on the adsorbent, electrical energy is applied to the heating layer (130) to generate heat, thereby heating and activating the catalyst layer (120).

[0053] As an example of the present invention, the first sensing unit (141) may further include a concentration measuring sensor that directly measures the concentration of VOC contained in the adsorption layer (110), and the concentration measuring sensor may measure the concentration value by calculating the ratio of the surface area of ​​the adsorbent to the adsorbed VOC. It is preferable that the first sensing unit (141) be positioned adjacent to the adsorption layer (110) and may be positioned on the side of the inlet (101) of the housing (100). In addition, when measuring the concentration of VOC with the concentration measuring sensor, it is preferable that the first sensing unit (141) be positioned to be in contact with at least a part of the adsorption layer (110).

[0054] The catalyst layer (120) is a device for oxidizing and decomposing VOCs that are desorbed from the adsorption layer (110). The catalyst layer (120) can decompose VOCs by oxidizing them into CO2 and H2O, and any device capable of performing this can be used without limitation. The catalyst layer (120) can be activated when heated to a temperature above a certain level, and the catalyst layer (120) of the present invention is characterized by being activated by applying heat through the heating layer (130). When the VOCs adsorbed on the adsorption layer (110) exceed a certain level and the VOCs are desorbed from the adsorption layer (110), they can be oxidized and removed by the simultaneously activated catalyst layer (120). It is preferable that the catalyst layer (120) be positioned on the side of the outlet (102) rather than the adsorption layer (110), and when the outlet (102) is positioned on one side of the housing (100), it is preferable that the catalyst layer (120) be positioned on one side of the adsorption layer (110).

[0055] The catalyst layer (120) of the present invention may be a non-platinum metal catalyst, or may be composed of one or more selected from the group of metal oxides such as Pt, Pt, Pd, Rh, Cu, Cr, Mn, Fe, Ni, Co, V, and Zn. Alternatively, it may be composed in a form introduced into a support formed of one or more of Al2O3, SiO2, and TiO2, either alone or in combination from the group of metal oxides. The catalyst layer (120) may be formed by combining at least one VOC.

[0056] Here, the VOC reduction device (10) of the present invention may further include a second detection unit (142) disposed adjacent to the catalyst layer (120) to measure the concentration of VOC converted by the catalyst layer (120). The second detection unit (142) may be a device that measures the concentration of VOC in the gas that has passed through the catalyst layer (120) by being disposed at the rear end of the catalyst layer (120) based on the gas flowing inside the housing (100). When an outlet (102) is disposed on one side of the housing (100), it is preferable that the second detection unit (142) be disposed on one side of the catalyst layer (120) and positioned closer to the outlet (102). The second detection unit (142) may be configured to inspect the gas inside the housing (100) before it is discharged through the outlet (102). The second detection unit (142) can detect VOCs by determining whether there is a VOC in the gas that has passed through the catalyst layer (120), and it is preferable that VOCs are not detected when the catalyst layer (120) is operating normally. However, if the second detection unit (142) detects VOCs, it can detect that there is an error in the operation of the catalyst layer (120), or that the VOC concentration is above an acceptable level, or that a problem has occurred in another device, and can alert the administrator.

[0057] The heating layer (130) is a device that activates the catalyst layer (120) by heating it to a temperature above a certain level. The heating layer (130) can be used without limitation as long as it is in a form capable of heating the catalyst layer (120). The heating layer (130) of the present invention is characterized by selectively and directly heating only the catalyst layer (120). Conventionally, since heat is supplied by burning fossil fuels to heat all the air inside the housing (100), there is a problem in that a large amount of energy is consumed, the heating time is long, the responsiveness is slow, and it is difficult to respond immediately to fluctuating loads. The present invention is intended to solve this problem, and is characterized by the heating layer (130) locally heating only the catalyst layer (120) so that the activated catalyst layer (120) is decomposed as air passes through it, and aims to reduce the amount of energy input for operating the device through the selective heating of the catalyst layer (120).

[0058] More specifically, the heating layer (130) is characterized by selectively heating only the catalyst layer, heating it sufficiently to activate the catalyst layer (120), and heating the catalyst layer (120) through electrical energy so that it can reach the target temperature more quickly. Accordingly, the heating layer (130) is characterized by generating heat using a Joule heating method, which generates heat when electrical energy is applied. It is preferable that the heating layer (130) be arranged in close connection with the catalyst layer (120) so that heat is conducted to each other. However, the heat from the heating layer (130) may also be conducted to the adsorption layer (110) arranged adjacent to it. For example, the heating layer (130) has an electrode connected from a power supply unit, and when the power supply unit applies electrical energy to the heating layer (130) through the electrode, the heating layer (130) is heated, and the generated heat is conducted to the catalyst layer (120), allowing the catalyst layer (120) to be heated to a certain temperature. At this time, the heating layer (130) may be disposed on one side or the other side of the catalyst layer (120), and may be formed without limitation as long as the heating layer (130) is capable of delivering a heated temperature to the catalyst layer (120).

[0059] The present invention is characterized by configuring the heating layer (130) in a row heating manner so that the required temperature can be finely controlled. At this time, when electrical energy is applied to the heating layer (130), the temperature can be conducted not only to the heating layer (130) but also to the catalyst layer (120) and the adsorption layer (110). The reason for using the heating layer (130) may be to first activate the catalyst section (120) to react with and remove harmful substances such as VOCs, and also to concentrate and recover useful resources among the substances adsorbed on the adsorption layer (110). At this time, if the temperature of the heating layer (130) is too low, the above process does not occur well, and if the temperature is too high, each heating layer (130), catalyst layer (120), and adsorption layer (110) may be damaged by heat, resulting in reduced performance or unwanted side reactions, and the resource recovery rate may be reduced. Accordingly, it is important that the heating layer (130) of the present invention is formed so that temperature control can be performed finely within an appropriate temperature range. In one embodiment of the invention, the heating layer (130) preferably generates heat at 100 to 450 degrees when removing harmful substances, and more specifically, at 150 to 300 degrees. In addition, it is preferable that the heating layer generates heat at 150 to 300 degrees when concentrating and recovering resources.

[0060] Here, the heating layer (130) of the present invention is characterized by being made of at least one of SiC, a single carbon metal, or a metal alloy. When the heating layer (130) is made of a metal alloy, it may be NiCrAl or FeCrAl. Furthermore, the heating layer (130) is connected to the adsorption layer (110), so that when the desorption of VOC from the adsorption layer (110) is detected, the power supply unit operates and electrical energy can be generated. More specifically, the heating layer (130) is connected to the first detection unit (141), so that when the concentration of VOC in the adsorption layer (110) is detected to be above a certain level, a signal is applied to the power supply unit, and the power supply unit applies electrical energy to the heating layer (130). As the metal heating layer (130) heats up, the catalyst layer (120) adjacent to the heating layer (130) is heated and activated. The heating layer (130) can be used without limitation as long as it is made of a material capable of generating heat through electrical energy.

[0061] In addition, the heating layer (130) of the present invention is characterized by having a structure that expands the heating surface area to improve the heat conduction effect. Accordingly, it is preferable that the heating layer (130) be composed of mesh-type pieces made of a metal material and be arranged in close contact with the catalyst layer (120). Here, as the heating layer (130) is formed in a mesh type, it may be arranged to surround or in contact with the catalyst layer (120), or the heating layer (130) may be in a form that is folded at regular intervals or folded in a wave shape. Gas can pass through the mesh structure of the heating layer (130) and move in one direction. The heating temperature of the heating layer (130) of the present invention can be controlled by adjusting at least one variable among the width or length of the metal mesh pieces.

[0062] Accordingly, the VOC reduction device (10) of the present invention is characterized in that a heating layer (130) is formed of a metal material and generates heat through electrical energy using a Joule heating method, wherein the heating layer (130) is formed to locally heat only the catalyst layer (120). Accordingly, the heating layer (130) can selectively heat the catalyst layer (120) according to a signal. FIG. 2 is a graph showing the time it takes for a VOC reduction device that selectively heats the catalyst layer using Joule heating of the present invention to reach a certain temperature, and the time it takes for a conventional VOC reduction device that heats the entire device to reach a certain temperature. FIG. 3 is a graph showing the conversion rate over time of a VOC reduction device using Joule heating of the present invention and the conversion rate over time of a conventional VOC reduction device. As can be seen from FIG. 2 and 3, the VOC reduction device of the present invention has the advantage of significantly reducing energy consumption by allowing the time it takes to reach a 95% conversion rate to be shortened compared to a conventional device and enabling a faster temperature rise within the same amount of time. Accordingly, since heat can be generated by the electrical energy of the present invention, a faster temperature rise compared to existing technology is possible, enabling rapid VOC oxidation. Furthermore, even if the concentration of VOCs fluctuates, it can quickly respond to the fluctuating concentration, and there is an effect of significantly reducing the energy consumption used to activate the catalyst.

[0063]

[0064] In another embodiment of the present invention, the VOC reduction device (10) may include a housing having an inlet for gas and an outlet for gas discharge, and a composite module disposed inside the housing that adsorbs volatile organic compounds (VOCs) contained in the gas, a catalyst that decomposes volatile organic compounds desorbed from the adsorbent, and a heat-generating carrier that selectively directly heats the catalyst. Here, the composite module is characterized in that the catalyst is coated on the heat-generating carrier.

[0065] The adsorbent, catalyst, and heat carrier of the composite module may have the same or some different features as the adsorption layer (110), catalyst layer (120), and heat layer (130) described above. In the composite module of the present invention, the adsorbent is positioned on the side of the inlet (101) of the housing (100), similar to the adsorption layer (110) described above, so that when a gas containing VOC enters the housing, it passes through the adsorbent first, thereby allowing the VOC contained in the gas to be preferentially adsorbed and desorbed inside the housing. That is, the adsorbent may be composed using at least one material among activated carbon, activated carbon fiber, and zeolite, and may be formed with a porous structure so that the gas passes through and the VOC contained in the gas is adsorbed. Depending on the performance, the adsorbent may continue to adsorb VOC up to a certain concentration, and if the concentration becomes high above a certain level, it may desorb VOC above a certain level from the adsorbent. Here, the adsorbent is equipped with a first sensing unit to monitor the concentration of VOCs adsorbed by the adsorbent. When VOCs are adsorbed to a concentration above a certain level, the adsorbed VOCs are subsequently desorbed and can move to a catalyst. The adsorbent may be positioned at the inlet side of the housing to remove VOCs by adsorbing them first from the gas introduced into the housing.

[0066] The composite module of the present invention is characterized by comprising a heat-generating carrier and a catalyst. The catalyst is a catalyst that decomposes VOCs desorbed from the adsorbent by oxidizing them into CO2 and H2O, and may be configured with the same characteristics as the catalyst layer (120) described above. It is preferable that the composite module be controlled to generate heat within an appropriate temperature range in order to react and remove harmful substances such as VOCs, or to concentrate and recover useful resources among the adsorbed substances. At this time, when removing harmful substances, it is preferable that the heat-generating carrier generate heat at 100 to 450 degrees, and more specifically, at 150 to 300 degrees. Additionally, when concentrating and recovering resources, it is preferable that the heat-generating carrier generate heat at 150 to 300 degrees.

[0067] In addition, the composite module may be formed by synthesizing and coating a catalyst or adsorbent onto a heating carrier. It is characterized by coating the surface of the heating carrier with a catalyst or adsorbent to impart the function of performing reactions such as adsorption, oxidation, or reduction. Here, the heating carrier may be configured to generate heat through electrical energy using a Joule heating method. That is, the composite module requires a heating carrier structure for Joule heating, which generates heat by receiving electricity.

[0068] Referring to FIG. 4, the heating carrier of the present invention may be composed of at least one of SiC, carbon single metal, or metal alloy. In the case of a metal alloy, it may be formed as a honeycomb structure monolithic carrier made of NiCrAl or FeCrAl. Alternatively, the heating carrier may be a carrier composed of any one of a honeycomb structure monolith, a sheet structure, or a cologated structure. That is, a catalyst or an adsorbent may be coated on the surface of a heating carrier formed with a specific structure. In this case, the heating carrier may be coated with H-beta or H-ZSM-5 as the coating material. To explain in detail with an example, if the heating carrier is made of SiC, H-beta or H-ZSM-5 may be coated on its surface. In this case, if H-beta is used, the coating amount may be typically 15 to 30 wt%, and in particular, it may be coated with a coating amount of 15 wt%, 19 wt%, or 23 wt%. In addition, in the case of H-ZSM-5, it can be coated with a coating amount of 19 wt%. Furthermore, if the heating carrier is carbon, H-beta can be coated with a coating amount of 25 wt%. Moreover, if it is a metal alloy, H-beta can be coated with a coating amount of 6.5 wt%. The heating carrier can be formed with a honeycomb structure to increase the surface area to which heat can be applied, and the maximum surface area of ​​the catalyst can be activated by forming a coating of the catalyst on that surface area. The composite module may have a structure in which an electrode is connected from a power supply unit, so that when the power supply unit applies electrical energy to the composite module through the electrode to generate heat, heat is conducted to the coated catalyst and the catalyst is activated.

[0069] Accordingly, the present invention is characterized by configuring a VOC reduction device (10) by providing a catalyst and supplying heat using electrical energy by using a Joule heating method to selectively heat only the catalyst part to activate the catalyst. As shown in the graphs of FIGS. 2 and 3, since the catalyst is heated directly, the energy consumed to activate the catalyst can be significantly reduced compared to existing technology, and since only a localized area is heated using electrical energy, the time required to convert the catalyst to a certain temperature can be significantly reduced, thus having the advantage of being able to easily respond to rapid temperature rise and fluctuating VOC concentration.

[0070] Meanwhile, the present invention discloses a method for reducing VOCs using a VOC reduction device (10). The VOC reduction method may include a) a step of supplying gas to an inlet (101) of a housing (100), b) a step of adsorbing volatile organic compounds (VOCs) contained in the gas through an adsorption layer (110) disposed inside the housing (100), and c) a step of discharging the treated gas through an outlet (102) of the housing (100). Here, the b) step may include b-1) a step of heating a heating layer (130) disposed inside the housing (100) and b-2) a step of the heating layer locally directly heating a catalyst layer (120) disposed on one side of the adsorption layer (110). At this time, the heating layer (130) is characterized by heating using a Joule heating method, wherein electrodes are connected to control the temperature through electrical energy.

[0071] An experimental example according to one embodiment of the present invention will be described below.

[0072] Table 1 shows the voltage and current according to resistance and the temperature range according to heating time when the heating carrier is formed of SiC material. Referring to Table 1, it can be seen that the resistance is formed to be 3.56 to 5.66Ω, a voltage of 3.58 to 15.80V and a current of 1 to 4A are applied, and the temperature reaches a range of 79.40 to 360.30℃ through heating for 60 to 120 seconds.

[0073]

[0074]

[0075]

[0076] Next, referring to , it can be seen that when the heating carrier is formed as a SiC Monolith and H-beta is coated at 15 wt% (80 g / L) on the surface of the SiC Monolith, the resistance is formed to be 12.0 to 13.1 Ω, and when a voltage of 20.3 to 20.6 V and a current of 2 A are applied, the temperature reaches a range of 394.9 to 400.0 ℃ by heating for 15 to 20 seconds.

[0077] In addition, it can be seen that when formed with a SiC monolith and coated with H-beta at 18.8 wt% (105 g / L) on the surface of the SiC monolith, the resistance is formed to be 13.7 to 14.1 Ω, and when a voltage of 24.2 to 25.0 V and a current of 2 A are applied, the temperature reaches a range of 180.7 to 205.4 ℃ by heating for 5 to 6 seconds.

[0078] In addition, it can be seen that when formed with a SiC monolith and coated with H-beta at 24.1 wt% (144 g / L) on the surface of the SiC monolith, the resistance is formed to be 10.9 to 12.1 Ω, and when a voltage of 18.2 to 21.5 V and a current of 2.0 A are applied, the temperature reaches a range of 149.0 to 400.0 ℃ by heating for 5 to 20 seconds.

[0079] In addition, it can be seen that when formed with SiC Monolith and H-beta is 19.8 wt% (112 g / L) on the surface of SiC Monolith, the resistance is formed to be 7.8 to 9.6 Ω, and when a voltage of 15.5 to 17.1 V and a current of 2.0 A are applied, the temperature reaches a range of 113.6 to 272.9 ℃ by heating for 7 to 15 seconds.

[0080] Table 2

[0081]

[0082] Next, referring to , it can be seen that when the heating carrier is formed as a SiC Monolith and H-beta is coated at 15 wt% (80 g / L) on the surface of the SiC Monolith, the resistance is formed to be 3.62 to 45.45 Ω, and when a voltage of 5.94 to 29.6 V and a current of 1.01 to 6.00 A are applied, the temperature reaches a range of 107.00 to 400.00 ℃ by heating for 1 to 30 seconds.

[0083] In particular, referring to Examples 5, 6, 7, and 16 of Table 3, it can be confirmed that when a voltage of 27.29 to 29.36 V and a current of 4 to 6 A are applied so that the resistance of the heating carrier is formed to be 4.9 to 7.1 Ω, the surface temperature of the heating element reaches the range of 243.3 to 303.6℃ with only 1 to 2 seconds of heating. This reaches the VOC oxidation reaction initiation temperature range in a significantly shorter time compared to conventional SiC heating elements that take tens to hundreds of seconds or more, and consequently, it demonstrates the effect of securing a VOC conversion rate of 95% or more in just 1 to 2 seconds.

[0084] Table 3

[0085]

[0086] Next, referring to , it can be seen that when the heating carrier is formed as a carbon monolith, the resistance is formed to be 20.98 to 22.06 Ω, and when a voltage of 30.00 V and a current of 1.68 to 1.98 A are applied, the temperature reaches a range of 185.10 to 289.60 ℃ by heating for 1 second.

[0087] In addition, when the heating carrier is formed of Carbon Monolith and coated with H-beta 15 wt% (80 g / L), the resistance is formed to be 21.74 to 23.08 Ω, and it can be seen that when a voltage of 30 V and a current of 1.67 to 1.85 A are applied, the temperature reaches a range of 204.60 to 317.30°C by heating for 1 second. In particular, referring to Examples 1, 2, and 3 in Table 3, where the heating carrier is formed of Carbon Monolith and coated with H-beta 15 wt% (80 g / L), it is confirmed that the heating temperature rises rapidly from 244.10°C to a maximum of 317.30°C depending on the change in current even under the same voltage condition (30 V), which indicates significantly improved heating response characteristics compared to Carbon Monolith alone.

[0088] Table 4

[0089]

[0090] Next, shows that when the heating carrier is formed of Metal Oxide, the resistance is formed to be 0.59 to 0.63Ω, and when a voltage of 4.74 to 5.56V and a current of 8.00 to 10.00A are applied, the temperature reaches a range of 114.50 to 165.20℃ by heating for 300 seconds.

[0091] In addition, when the heating carrier is formed of Metal Oxide and coated with 6.5 wt% H-beta, the resistance is formed to be 1.05 to 1.39 Ω, and when a voltage of 8.17 to 13.87 V and a current of 7.07 to 10.00 A are applied, it can be seen that the temperature reaches a range of 199.90 to 334.90 ℃ by heating for 5 to 24 seconds.

[0092] Table 5

[0093]

[0094] As described above, the present invention has been explained with specific details such as specific constituent elements and limited exemplary drawings; however, this is provided merely to aid in a more comprehensive understanding of the invention, and the invention is not limited to the above-mentioned exemplary embodiment. Those skilled in the art can make various modifications and variations from this description.

[0095] Accordingly, the scope of the present invention should not be limited to the described embodiments, and all things equivalent to or having equivalent variations to the claims set forth below, as well as the claims set forth below, shall be considered to fall within the scope of the concept of the present invention.

[0096] This invention is designed to remove Volatile Organic Compounds (VOCs) through a catalytic oxidation method. It is environmentally friendly as it produces no carbon dioxide emissions, offers high responsiveness relative to low energy consumption, and enables safe treatment with high efficiency. Furthermore, by selectively heating only the catalyst and appropriately controlling the temperature of the heating element, and by precisely adjusting the temperature within an appropriate range depending on the process—whether for reacting and removing harmful substances or concentrating and recovering useful resources from adsorbed materials—it is possible to reduce energy consumption and shorten the temperature switching time, thereby enabling economical equipment operation.

Claims

1. A housing having an inlet for gas to enter and an outlet for gas to exit; An adsorption layer disposed inside the above housing and adsorbing volatile organic compounds (VOCs) contained in the gas; A catalyst layer disposed on one side of the adsorption layer and decomposing volatile organic compounds desorbed from the adsorption layer; and A heating layer disposed inside the above housing and locally directly heating the catalyst layer; comprising, The above heating layer is, A VOC reduction device characterized by a Joule heating method in which electrodes are connected to control temperature and generate heat through electrical energy.

2. In Paragraph 1, A VOC reduction device characterized in that the heating layer is made of at least one of SiC, carbon, a single metal, and a metal alloy.

3. In Paragraph 2, When the above heating layer is made of a metal alloy material, VOC reduction device characterized by being NiCrAl or FeCrAl.

4. In Paragraph 2, A VOC reduction device characterized in that the heating layer is composed of mesh-type pieces.

5. In Paragraph 1, The above housing is, A VOC reduction device characterized by having the inlet port positioned on the other side and the outlet port positioned on the one side, so that gas flows in one direction.

6. In Paragraph 5, The above VOC reduction device is, A first sensing unit disposed in contact with at least a portion thereof with the adsorption layer to detect the concentration of volatile organic chemicals adsorbed on the adsorption layer; and A VOC reduction device further comprising: a second sensing unit disposed on one side of the catalyst layer and detecting the concentration of volatile organic chemicals converted by the catalyst layer.

7. In Paragraph 6, The above VOC reduction device is, The above heating layer and the above first sensing unit are connected, A VOC reduction device characterized by applying electrical energy to the heating layer to generate heat and thereby heating the catalyst layer when the first sensing unit detects that the concentration of volatile organic chemicals detected is greater than or equal to a reference value.

8. In Paragraph 5, The above VOC reduction device is, A VOC reduction device characterized by the adsorption layer being disposed on the inlet side and the catalyst layer being disposed on the outlet side.

9. A housing having an inlet for gas to enter and an outlet for gas to exit formed therein; and A composite module comprising: an adsorbent disposed inside the housing and adsorbing volatile organic compounds (VOCs) contained in the gas; a catalyst that decomposes volatile organic compounds desorbed from the adsorbent; and a heat carrier that selectively directly heats the catalyst. The above composite module is, A VOC reduction device characterized by the catalyst being coated on the above-mentioned heat carrier.

10. In Paragraph 9, The above-mentioned heat carrier is, A VOC reduction device characterized by generating heat through electrical energy using a Joule heating method.

11. In Paragraph 10, A VOC reduction device characterized in that the above-mentioned heating carrier is a carrier composed of any one of a honeycomb structure monolith, a sheet-type structure, and a corrugated structure.

12. In Paragraph 11, The above-mentioned heat carrier is, A VOC reduction device characterized by a carrier composed of at least one of SiC, carbon, and metal oxide.

13. In Paragraph 12, A VOC reduction device characterized in that the above-mentioned heat carrier is coated with H-beta or H-ZSM-5.

14. In Paragraph 12, A VOC reduction device characterized by the above-mentioned heating carrier generating heat at 150 to 300 degrees.

15. In Paragraph 14, When the above heating carrier is formed of SiC material, At a resistance of 3 to 5 Ω of the above heating carrier, A VOC reduction device characterized by heating for 60 seconds at a voltage of 8~14 V and a current of 2~3 A.

16. In Paragraph 14, When the above heating carrier is formed of SiC material, At a resistance of 3 to 5 Ω of the above heating carrier, A VOC reduction device characterized by heating for 120 seconds at a voltage of 6.7 to 9.4 V and a current of 2 to 3 A.

17. In Paragraph 14, When the above heating carrier is formed of SiC material and coated on the surface with H-beta 15 wt%, At a resistance of 3 to 5 Ω of the above heating carrier, A VOC reduction device characterized by heating for 1 to 5 seconds at a voltage of 13.8 to 22 V and a current of 4 to 6 A.

18. In Paragraph 14, When the above heating carrier is formed of SiC material and coated on the surface with H-beta 15 wt%, At a resistance of 30 to 45 Ω of the above heating carrier, A VOC reduction device characterized by heating for 10 to 20 seconds at a voltage of 30 V and a current of 1 A.

19. In Paragraph 14, When the above heating carrier is formed of carbon material or coated with H-beta on the carbon surface, At the resistance of the above heating carrier is 22 Ω, A VOC reduction device characterized by heating for 1 to 2 seconds at a voltage of 30 V and a current of 1 to 2 A.

20. In Paragraph 14, When the above heating carrier is formed of a metal material or coated with H-beta on a carbon surface, At a resistance of 1 to 2 Ω of the above heating carrier, A VOC reduction device characterized by heating for 5 to 25 seconds at a voltage of 8 to 12 V and a current of 7 to 10 A.

21. A method for reducing VOCs using the VOC reduction device of claim 1, a) Step of supplying gas to the inlet of the above housing; b) a step in which the gas passes through the adsorption layer disposed inside the housing and adsorbs volatile organic compounds (VOCs) contained in the gas; and c) step of discharging the treated gas through the outlet of the above housing; and The above step b) is, b-1) step of heating the heating layer disposed inside the housing; and A VOC reduction method characterized by including step b-2) in which the heating layer locally and directly heats the catalyst layer disposed on one side of the adsorption layer.

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