Heat-generation element for heating catalyst

Abstract

The present invention relates to a heat-generation element for heating a catalyst, which heats the catalyst to a predetermined temperature or higher by locally applying heat thereto so as to activate the catalyst. The heat-generation element is provided in a volatile organic compound (VOC) reduction device for oxidizing and removing VOC through the catalyst and is configured to directly heat the catalyst, wherein the heat-generation element is made of a metal material and is formed as a mesh-type flat surface having a specific width and length. In particular, the heat-generation element can generate heat through electrical energy by Joule heating with electrodes connected thereto, thereby enabling rapid temperature increase while reducing energy required to heat the catalyst.

Description

Heating element for catalytic heating

[0001] The present invention provides a heating element that activates a catalyst by heating, and has a feature that can optimize the heating performance of the heating element.

[0002] In environments such as factories performing general chemical processes, exhaust gas treatment devices for automobiles and ships, and power plants, air pollutants such as NOx, CO, CO2, and VOCs can be generated during the fuel combustion process. These air pollutants can be converted to ozone through photochemical reactions in the atmosphere, causing air pollution. They also have an irritating odor and can cause nervous system disorders through skin contact or inhalation. Therefore, technology is required to reduce emissions to a certain level or higher. For these air pollutants, methods are generally used to convert the substances through catalytic reactions or to concentrate and increase the concentration of specific gases.

[0003] Among them, volatile organic compounds (VOCs) are organic compounds that have high vapor pressure, low boiling points, and the characteristics of easily evaporating and diffusing into the air even at room temperature. Conventional VOC removal technologies include high-temperature incineration, adsorption treatment, and catalytic oxidation. Among them, catalytic oxidation is a method that removes VOCs by oxidizing them using a catalyst. It has the advantages of not requiring a flame, being highly efficient, having a short residence time, and having low operating costs. In particular, it is suitable for operation in cases where the concentration of VOCs fluctuates greatly depending on the characteristics of the industry, and therefore, it has been the subject of the most research and development recently.

[0004] However, catalysts require a supply of thermal energy to heat them above a certain temperature and become activated. This requires a significant amount of energy to activate the catalyst. Conventional methods involve heating the entire device or the gas passing through it. However, these methods consume a significant amount of thermal energy, resulting in somewhat low energy efficiency.

[0005] The present invention has been devised to solve the above problems, and to solve this problem, a heating unit is configured to directly heat only the necessary part of a catalyst, and at this time, the heating unit is configured to generate heat by using electric energy to heat the heating unit, and further, a heating unit is provided that can maximize electric heating performance, thereby preventing unnecessary carbon dioxide emissions for heat supply and providing a heating element for catalyst heating with improved energy efficiency while reducing the energy used.

[0006] A VOC reduction device for reducing VOCs by oxidizing VOCs (Volatile Organic Compounds) through a catalyst of the present invention, and a catalyst heating heating element that directly heats and activates the catalyst, wherein the heating element is formed of a metal material and is characterized by having a mesh-type plane having a specific width and length.

[0007] The present invention, with the above configuration, relates to a heating element for heating a catalyst, which is configured to supply heat through electric energy to heat the catalyst, but to provide optimal electric heating performance for directly heating the catalyst, and can provide a heating element with improved energy efficiency, is environmentally friendly because there is no carbon dioxide emission due to heat supply, and because intermittent heat supply is possible, it can perform high responsiveness compared to low energy consumption for activating the catalyst, and because it is configured to selectively heat only the catalyst, the temperature conversion time can be shortened and the energy consumption used can be reduced, so that the facility can be operated economically, and there is an effect of reducing carbon emissions by utilizing electric energy.

[0008] Figures 1 to 12 are examples of heating elements for heating catalysts, and graphs of temperature changes over time of the heating elements.

[0009] A VOC reduction device for reducing VOCs by oxidizing VOCs (Volatile Organic Compounds) through a catalyst of the present invention, and a catalyst heating heating element that directly heats and activates the catalyst, wherein the heating element is formed of a metal material and is characterized by having a mesh-type plane having a specific width and length.

[0010] At this time, the heating element is characterized by having a layer structure in which one or more mesh planes are overlapped.

[0011] And, the heating element is characterized in that the mesh plane is formed in a wavelet shape.

[0012] At this time, the heating element is characterized in that it is formed by being folded multiple times along the longitudinal direction of the plane.

[0013] Here, the heating element is characterized in that the two flat surfaces are folded and twisted while overlapping each other.

[0014] In addition, the heating element is characterized by having a layer structure in which one or more mesh planes are overlapped.

[0015] In addition, the plane of the heating element is characterized by a width to length ratio of 1 to 2:5.

[0016] And, the plane of the heating element is characterized in that the ratio of width to length is 1:20 to 30, and at this time, the length is 20 cm or more.

[0017] In addition, the heating element is characterized by being made of a metal material of FeCrAl or NiCrAl.

[0018] At this time, the heating element is characterized in that it is coated with a coating material of a zeolite group, a metal group, a metal oxide group or a combination thereof, or is manufactured by firing.

[0019] Here, the coating material is characterized in that it is coated with a loading amount of 10 to 30 wt%.

[0020] Hereinafter, the technical concept of the present invention will be described in more detail using the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concept of a term to best explain his or her invention, they should be interpreted in a way that aligns with the technical concept of the present invention.

[0021] Therefore, it should be understood that the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention, and that there may be various modified examples that can replace them at the time of filing this application.

[0022] Hereinafter, the technical concept of the present invention will be described in more detail using the attached drawings. The attached drawings are merely examples provided to more specifically explain the technical concept of the present invention, and therefore, the technical concept of the present invention is not limited to the form of the attached drawings.

[0023] Before explaining the present invention, the volatile organic compounds (VOCs) that the VOC reduction device according to the present invention can treat are acetaldehyde (Acetaldehyde, C2H4O[CH3CHO]), acetylene (Acetylene, C2H2), acrolein (Acrolein, C3H4O), benzene (Benzene, C6H6), 1,3-butadiene (1,3-Butadiene, C4H6), butane (Butane, C4H10), 1-butene (1-Butene, C4H8[CH3CH2CHCH2)]), 2-butene (2-Butene, C4H8[CH3(CH)2CH3]), cyclohexane (C6H12), ethylene (Ethylene, C2H4), formaldehyde (Formaldehyde, CH2O[HCHO]), n-Hexane (C6H14), Isopropyl Alcohol (C3H8O[(CH3)CHOHCH3]), Methanol (C4O[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 (including o-, m-, p-) (C8H10), Styrene (C8H8C8H8) There are some that are made up of hydrocarbon components such as:

[0024] The present invention relates to a VOC reduction device that oxidizes and removes the VOC (Volatile Organic Compounds) through a catalyst, and relates to a catalyst heating heating element (hereinafter referred to as a "heating element") that directly heats the catalyst to activate the catalyst. It is preferable that the heating element be connected and arranged so as to conduct heat with the catalyst. The heating element can generate heat through electric energy, and is characterized in that it generates heat when electric energy is applied from the outside, thereby transferring heat energy to the catalyst.

[0025] Here, the catalyst can be used without limitation as long as it can decompose VOCs by oxidizing them into CO2 and H2O. The catalyst can be activated when heated to a temperature above a certain level. For example, the catalyst of the present invention can be composed of a separate monolithic catalyst carrier, and in this case, it is preferable that the heating element is formed in contact with at least a predetermined surface of the catalyst carrier so that the heat generated by the heating element is conducted to the catalyst carrier. Since the catalyst is composed of a monolithic carrier, there is an advantage in that coating is easy, and a coating amount can be formed that is about 20% higher than that of samples of other shapes.

[0026] In addition, the catalyst of the present invention can be formed by coating on the surface of a heating element, and this can be formed by coating a coating material that performs a catalytic function on the surface of the heating element. At this time, the coating material of the present invention can be a non-platinum metal catalyst, or can be composed of one or more selected from the group consisting of metal oxides such as Pt, Pt, Pd, Rh, Cu, Cr, Mn, Fe, Ni, Co, V, and Zn. In addition, the coating material can be at least one porous zeolite selected from the group consisting of ZSM-11, ZSM-5, Beta, Mordenite, chabazite, and Ferrierite. In addition, the coating material can be at least one support selected from the group consisting of Al2O3, SiO2, TiO2, ZrO2, MgO, and CeO2. In addition, the group of metal oxides or zeolites can be introduced into the support alone or in combination and used.

[0027] Here, in one embodiment of the present invention, the coating material may be a coating material selected from a zeolite group, a metal group, and a metal oxide group, alone or in combination thereof. Here, the zeolite group includes Beta, mordenite, Y, A, X, ZSM-5, and Chabazite, the metal group includes Pt, Rh, Pd, Ru, Ag, Cu, Ni, Fe, Co, V, Cr, and Mn, and the metal oxide group includes Al2O3, SiO2, TiO2, ZnO, CeO2, ZrO2, and MgO. The beta zeolite may be H-beta converted into a hydrogen form by calcination. The coating material may be composed alone or in combination thereof depending on the purpose.

[0028]

[0029] The heating element of the present invention is characterized by being manufactured from a metal material and having a mesh-type plane. The heating element has a size, a specific width and a length, and the resistance and heating temperature of the metal heating element can change depending on the width and length of the plane. The heating element can be used without limitation as long as it is a metal material that can generate heat by electric energy. Since the heating element is formed from a metal material, it has excellent strength itself, which is advantageous for large-scale production, and since it has excellent ductility and malleability, it has the advantage of being easy to process and can be used in a shape adapted to the site. In addition, the present invention is characterized by improving the reaction effect by forming the metal in a mesh type to improve the surface finish.

[0030] Here, the heating element of the present invention may be a metal material of FeCrAl. In addition, the heating element may be formed of a single metal material, or may be formed by forming a protective film on the surface by firing the heating element, or may be formed by coating the surface of the heating element with a coating material. These may be selected and configured as needed. The FeCrAl has excellent ductility and malleability, so it has good processability, a high melting point and operating temperature, so it is physically stable at high temperatures, and since it contains Al, it forms an aluminum oxide film (Al2O3) on the surface during high-temperature firing, thereby preventing corrosion of the material and enabling stable support when a catalyst is coated.

[0031] In addition, the heating element operates by a Joule heating method, and is characterized in that the electrodes are connected, electric energy is applied, and heat is generated. Therefore, the heating element can perform heat supply using electric energy, so there is no carbon dioxide emission due to heat supply, and there is an advantage of rapid temperature increase while reducing the energy required to heat the catalyst. Here, the heating element of the present invention aims to configure the heating element in a form that can optimize electric heating performance while reducing the energy used to generate heat. To this end, the heating element must have an appropriate resistance value, and since the catalyst itself cannot conduct electricity, it is necessary to composite the heating element and the catalyst, and further, the catalyst must stably maintain activity even under conditions of high temperature and current flow, and it is preferable to configure the heating element while taking these into consideration.

[0032] The heating element may be a planar cross-sectional mesh structure having a specific width and length. In this case, in the case of a single mesh planar structure, it is easy to accumulate heat by increasing the amount of support. As an example of the present invention, Fig. 1 (a) is a heating element of a metal plane composed solely of FeCrAl, and Fig. 1 (b) is a graph showing the temperature change over time for the heating element of Fig. 1 (a) by current. Fig. 2 (a) is a heating element in which a protective film is formed on the surface by firing a metal material of FeCrAl, and Fig. 2 (b) is a graph showing the temperature change over time for the heating element of Fig. 2 (a) by current. Fig. 3 (a) is a heating element in which a coating material of Pt-Pd / Al2O3 is coated on a metal material of FeCrAl, and Fig. 3 (b) is a graph showing the temperature change over time for the heating element of Fig. 3 (a) by current. Fig. 4 (a) is a heating element coated with a Pt-Pd / Al2O3 / H-beta coating material on a metal material of FeCrAl, and Fig. 4 (b) is a graph showing the temperature change over time and by current of the heating element of Fig. 4 (a). Here, referring to Figs. 1 and 2, it can be confirmed that the temperature of the heating element increases as the applied current increases, and it can be confirmed that the lower the resistance of the heating element, the lower the initial power consumption. The resistance of the heating element of Fig. 1 may be 0.328 Ω, and the resistance of the heating element of Fig. 2 may be 0.268 Ω. Also, referring to FIGS. 3 and 4, the resistance of the heating element in FIG. 3 is 0.298 Ω, and the actual energy consumed depending on the current may be 1.61 to 2.21 kJ, and the heating element in FIG. 4 is 0.294 Ω, and the actual energy consumed depending on the current may be 1.63 to 2.13 kJ. From this, it can be seen that the resistance values ​​of the two heating elements are not significantly different, and the actual energy consumed is also similar, but there is a difference in the maximum temperature. Therefore, when coating a coating material on the heating element, the resistance may vary depending on the thickness of the coating.In the present invention, the coating materials can be coated with a loading amount of 12 to 14 wt%, and more precisely, 13 wt%.

[0033] In addition, the heating element of the present invention is formed as a plane having a specific width and length, and is characterized in that the effect of heating varies depending on the ratio of the width and length. In the heating element of the present invention, when the length is fixed and the width increases, it can be confirmed that the temperature rise is small as the resistance decreases as the width increases. This is because when the resistance decreases, the voltage decreases for the same amount of current, so it can be seen that the energy consumption decreases and the temperature rise is small. Accordingly, it is preferable that the plane of the heating element has a width and length ratio of 1 to 2:5, or 1:10. In addition, in the heating element of the present invention, when the width is fixed and the length increases, the resistance increases as the length increases, so that the energy consumed may increase, but the temperature rise is the same because the total volume increases. This may be because the heating element is formed of a mesh material and thus the heat is quickly dissipated over a large area, so the temperature cannot rise above a certain temperature. However, in order for the heating element to reach 300°C or higher at 0.5 Ω or higher, it is preferable that the length be at least 20 cm or longer, and the plane of the heating element preferably has a width to length ratio of 1:20 to 30.

[0034] And since the heating element of the present invention is formed as a flat surface of a metal material, it can be provided by changing its shape into various shapes as needed. For example, when the heating element is arranged to surround the surface of a catalyst, the heating element can have a shape corresponding to the outer shape of the catalyst. Alternatively, the heating element can have a specific shape for energy efficiency depending on the temperature to be generated by the heating element. For example, the heating element can have a cross-sectional mesh structure of a flat surface having a specific width and length, and can also have a layer structure in which one or more mesh planes are overlapped and arranged. In addition, the heating element can have a wavelet shape in which the mesh planes are folded multiple times at regular intervals along the length direction. In this case, two or more heating elements folded in a wavelet shape can be woven so that the folded areas intersect each other to form a dense passage through which gas passes, thereby facilitating mass transfer and heat accumulation. In addition, the heating element can have a layer structure in which a plurality of heating elements folded in a wavelet shape are arranged in a parallel manner and overlap each other. In this case, it is preferable to manufacture the heating element by forming a dense folded interval to increase the density.

[0035] In one embodiment of the present invention, (a) of FIG. 5 is a heating element having a layer structure in which three overlapping metal planes of sintered FeCrAl are arranged, and (b) of FIG. 5 is a graph showing the temperature change over time for the heating element of (a) of FIG. 5 by current. (a) of FIG. 6 is a heating element having a layer structure in which three overlapping metal planes of sintered FeCrAl are formed in a wavelet shape in which the metal planes are folded multiple times at regular intervals, and (b) of FIG. 6 is a graph showing the temperature change over time for the heating element of (a) of FIG. 6 by current. Here, referring to FIGS. 5 and 6, the resistance of the heating element of FIG. 5 may be 0.202 Ω, and the resistance of the heating element of FIG. 6 may be 0.327 Ω, but it can be confirmed that the heating elements of FIGS. 5 and 6 do not reach 200 ℃ at a current of 10 A. Accordingly, when the heating element is composed of a metal plane of sintered FeCrAl, the temperature responsiveness to current can be controlled by changing the layer structure of the heating element.

[0036] In addition, as an embodiment of the present invention, (a) of Fig. 7 is a layer structure heating element in which a coating material of H-beta is coated on a metal plane of FeCrAl, the coating material is formed into a wavelet shape that is folded multiple times at regular intervals, and then arranged in three layers, and (b) of Fig. 7 is a graph showing the temperature change over time for the heating element of Fig. 7 (a) by current. Fig. 8 (a) is a layer structure heating element in which a coating material of Pt-Pd / Al2O3 / H-beta is coated on a metal plane of FeCrAl, the coating material is formed into a wavelet shape that is folded multiple times at regular intervals, and then arranged in three layers, and (b) of Fig. 8 is a graph showing the temperature change over time for the heating element of Fig. 8 (a) by current. Here, referring to FIGS. 7 and 8, the resistance of the heating element of FIG. 7 may be 0.506 Ω, and the resistance of the heating element of FIG. 8 may be 0.430 Ω, and it can be seen that the maximum temperature rise is higher when the coating material of FIG. 8 is used than when the coating material of FIG. 7 is used. Through this, it can be confirmed that the heating element in the form of a wavelet can improve the heating characteristics depending on the composition of the coating material.

[0037] Here, when the heating element is in the form of a wavelet folded multiple times at regular intervals, the smaller the pitch, the higher the maximum temperature rise can be. As an embodiment of the present invention, Fig. 9 (a) is a heating element in which 13 pitches are formed in a region of 5 cm among a metal plane of FeCrAl having a length of 30 cm, and Fig. 9 (b) is a graph showing the temperature change over time for the heating element of Fig. 9 (a) by current. Fig. 10 (a) is a heating element in which 13 pitches are formed in a region of 8 cm among a metal plane of FeCrAl having a length of 30 cm, and Fig. 10 (b) is a graph showing the temperature change over time for the heating element of Fig. 10 (a) by current. Fig. 11 (a) shows a heating element in which 13 pitches are formed in a 10 cm area among a metal plane of FeCrAl with a length of 30 cm, and Fig. 11 (b) is a graph showing the temperature change over time by current for the heating element of Fig. 11 (a). Referring to Figs. 9 to 11, when the heating element is formed with a specific length and the number of pitches is different within a certain area of ​​the length of the heating element (difference in frequency), there is no difference in the resistance value of each sample, but when the area is smaller based on forming the same number of pitches, that is, when the pitches exist at a higher density, it can be confirmed that the energy consumption is similar but the maximum temperature rises to a considerably high temperature. Through this, it can be confirmed that as the heating element exists at a higher density, heat dissipation to the outside decreases and the maximum temperature increases.

[0038] And, the heating element may be formed by weaving two or more heating elements in a wavelet shape folded multiple times at regular intervals so that the folded surfaces of each heating element intersect each other. Fig. 12 (a) is a heating element formed by weaving two metal planes formed in a wavelet shape by folding at multiple intervals among metal planes of FeCrAl having a regular length so that they intersect each other, and Fig. 12 (b) is a graph showing the change in temperature and resistance according to the amount of power applied to the heating element of Fig. 12 (a). Referring to this, it can be confirmed that the heating element of Fig. 12 undergoes oxidation from the time point of 4 A application, and rapidly combusts from the time point of 5 A application, and the temperature at this time is 272.2℃.

[0039] As described above, the present invention has been described with specific details such as specific components and limited example drawings, but these are provided only to help a more general understanding of the present invention, and the present invention is not limited to the above-described embodiment, and those skilled in the art to which the present invention pertains can make various modifications and variations from this description.

[0040] Therefore, the idea of ​​the present invention should not be limited to the described embodiments, and all things that are equivalent or equivalent to the scope of the patent claims as well as the scope of the patent claims are considered to fall within the scope of the idea of ​​the present invention.

[0041] The present invention relates to a catalyst heating element that can be used as an eco-friendly and economical VOC reduction device that effectively oxidizes and removes VOCs by directly and quickly heating only the necessary part of a catalyst using a Joule heating method, and reduces energy consumption without emitting carbon dioxide while having high responsiveness and excellent temperature conversion efficiency, and can contribute to improving energy efficiency and reducing facility operating costs in various industrial fields such as semiconductors, painting, and chemical processes.

Claims

1. A VOC reduction device that reduces VOC by oxidizing VOC (Volatile Organic Compound) through a catalyst, and a catalyst heating heating element that directly heats and activates the catalyst, A heating element for catalytic heating, characterized in that the heating element is formed of a metal material and has a mesh-type plane having a specific width and length.

2. In paragraph 1, A heating element for catalytic heating, characterized in that the heating element has a layer structure in which one or more mesh planes are overlapped.

3. In paragraph 1, The above heating element is a heating element for catalytic heating, characterized in that the mesh plane is formed in a wavelet shape.

4. In paragraph 3, A heating element for catalytic heating, characterized in that the heating element is formed by being folded multiple times along the longitudinal direction of the plane.

5. In paragraph 4, The above heating element is a heating element for catalytic heating, characterized in that the two above-mentioned flat surfaces are folded and twisted while overlapping each other.

6. In paragraph 3, A heating element for catalytic heating, characterized in that the heating element has a layer structure in which one or more mesh planes are overlapped.

7. In paragraph 1, A heating element for catalytic heating, characterized in that the plane of the heating element has a width to length ratio of 1 to 2:

5.

8. In paragraph 1, A heating element for catalytic heating, characterized in that the plane of the heating element has a width to length ratio of 1:20 to 30, and at this time, the length is 20 cm or more.

9. In paragraph 1, A heating element for catalyst heating, characterized in that the heating element is made of a metal material of FeCrAl or NiCrAl.

10. In paragraph 9, A heating element for catalytic heating, characterized in that the heating element is coated with a coating material of a zeolite group, a metal group, a metal oxide group or a combination thereof, or is manufactured by firing.

11. In paragraph 10, A heating element for catalytic heating, characterized in that the above coating material is coated with a loading amount of 10 to 30 wt%.

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