Patent Publication Number: US-2023158453-A1

Title: Catalytic decomposition device and integrated waste gas treatment system

Description:
CROSS REFERENCE TO RELATED APPLICATION(S) 
     This application claims priority under 35 U.S.C. § 119 from Korean Patent Application No. 10-2021-0163467, filed on Nov. 24, 2021 in the Korean Intellectual Property Office (KIPO), the contents of which are herein incorporated by reference in their entirety. 
     TECHNICAL FIELD 
     Embodiments are directed to a catalytic decomposition device and an integrated waste gas treatment system. More particularly, embodiments are directed to a catalytic decomposition device that purifies a waste gas generated from a semiconductor manufacturing facility and an integrated waste gas treatment system including the same. 
     DISCUSSION OF THE RELATED ART 
     Waste gas generated from a semiconductor manufacturing facility typically includes organic compounds and organic nitrogen compounds. The organic compounds, such as isopropyl alcohol, are not present in a high concentration but have a large amount of exhaust, so they are removed through an oxidation treatment by direct combustion, such as a regenerative thermal oxidation (RTO) after a concentration treatment using zeolite. In addition, the organic nitrogen compounds, such as ammonia, are removed through a wet treatment using sulfuric acid. However, for the organic compounds, energy consumption due to direct combustion is large, and in the case of ammonia, wastewater is generated by the wet treatment. In addition, since each of the different compounds is removed by an individual treatment, the area of a treatment site increases and facility management is challenging. 
     On the other hand, when purifying the waste gas using a catalyst, since an operator enters the facility and maintains the catalyst, securing the safety of the operation is challenging. 
     SUMMARY 
     Embodiments provide a catalytic decomposition device that can simultaneously purify organic compounds and organic nitrogen compounds and ensuring work stability. 
     Embodiments provide an integrated waste gas treatment system that includes a catalytic decomposition device. 
     According to embodiments, an integrated waste gas treatment system includes an adsorption/desorption device that receives a waste gas that includes an organic compound and an organic nitrogen compound exhausted from a semiconductor manufacturing facility, where the adsorption/desorption device adsorbs the organic compound and the organic nitrogen compound and concentrates and desorbs the organic compound and the organic nitrogen compound, and a catalytic decomposition device disposed adjacent to the adsorption/desorption device, where the catalytic decomposition device includes a catalytic chamber that provides a gas passage through which a gas desorbed from the adsorption/desorption device flows and an oxidation-reduction catalyst disposed in the gas passage that removes the organic compound and the organic nitrogen compound from the desorbed gas. The organic compound and the organic nitrogen compound are subjected to an oxidation treatment by the oxidation-reduction catalyst, and nitrogen oxides (NOx) generated by the oxidation treatment are removed by a selective reduction reaction. 
     According to embodiments, a catalytic decomposition device includes a frame structure that includes a first space in a lower level of the frame structure and a second space in an upper level of the frame structure, a catalytic chamber installed in the second space of the frame structure and that includes a gas passage through which flows a waste gas that includes an organic compound and an organic nitrogen compound exhausted from a semiconductor manufacturing facility, a catalyst bed disposed in the gas passage of the catalytic chamber and that includes a plurality of catalyst blocks assembled into a lattice pattern, where an oxidation-reduction catalyst that removes the organic compound and the organic nitrogen compound from the waste gas is provided in each of the plurality of catalyst blocks, and a lifting device that moves the catalyst bed from the catalytic chamber to the first space under the catalytic chamber. 
     According to embodiments, an integrated waste gas treatment system includes an adsorption/desorption device and a catalytic decomposition device that are sequentially installed in an exhaust line through which a waste gas that includes an organic compound and an organic nitrogen compound is exhausted from a semiconductor manufacturing facility. The adsorption/desorption device includes a rotor-type concentrator that includes an adsorption zone, a desorption zone and a cooling zone. The rotor-type concentrator is rotatable at a predetermined rotational speed by a driving motor and adsorbs the organic compound and the organic nitrogen compound of the waste gas received through the adsorption zone. The adsorption/desorption device also includes a desorbing portion that desorbs the organic compound and the organic nitrogen compound adsorbed to the concentrator with a carrier gas. The catalytic decomposition device includes a frame structure that includes a first space in a lower level of the frame structure and a second space in an upper level of the frame structure, a catalytic chamber installed in the second space of the frame structure and that includes a gas passage through which flows the gas desorbed by the desorbing portion, a catalyst bed disposed in the gas passage of the catalytic chamber and that includes a plurality of catalyst blocks assembled into a lattice pattern, an oxidation-reduction catalyst provided in each of the plurality of catalyst blocks that removes the organic compound and the organic nitrogen compound from the desorbed gas and outputs a purified gas, and a lifting device that moves the catalyst bed from the catalytic chamber to the first space under the catalytic chamber. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a block diagram of an integrated waste gas treatment system in accordance with embodiments. 
         FIG.  2    is a cross-sectional view of an adsorption/desorption device of an integrated waste gas treatment system of  FIG.  1   . 
         FIG.  3 A  is a perspective view of a catalytic decomposition device of a integrated waste gas treatment system of  FIG.  1   . 
         FIG.  3 B  is a cross-sectional view of portion ‘A’ in  FIG.  3 A . 
         FIG.  3 C  is a cross-sectional view of portion ‘B’ in  FIG.  3 B . 
         FIG.  4    is a cross-sectional view of portion ‘B’ in  FIG.  3 B  according to an embodiment. 
         FIG.  5    illustrates simultaneous treatment of first and second compounds by an adsorption/desorption device and a catalytic decomposition device of  FIG.  1   . 
         FIG.  6    is a block diagram of an integrated waste gas treatment system that includes an adsorption/desorption device and a catalytic decomposition device in accordance with embodiments. 
         FIG.  7    is a perspective view of an integrated waste gas treatment system of  FIG.  6    installed in a semiconductor manufacturing facility in accordance with embodiments. 
         FIG.  8    is a perspective view of an adsorption/desorption device of  FIG.  7   . 
         FIG.  9    illustrates the operation of an adsorption/desorption device of  FIG.  8   . 
         FIG.  10    illustrates a catalytic decomposition device in accordance with embodiments. 
         FIG.  11    is a side view of a catalytic decomposition device of  FIG.  10   . 
         FIG.  12    is a cross-sectional view of a pretreatment portion in  FIG.  10   . 
         FIG.  13    is a cross-sectional view of a catalytic chamber of a catalytic decomposition apparatus of  FIG.  10   . 
         FIG.  14    is an exploded perspective view of a portion of a catalytic chamber of  FIG.  13   . 
         FIG.  15    is a perspective view of a catalyst block installed in a catalyst bed in  FIG.  14   . 
         FIG.  16 A  is a cross-sectional view of a catalyst bed disposed in a catalytic chamber in  FIG.  10   . 
         FIG.  16 B  is a cross-sectional view of a catalyst bed in a state in which the catalyst bed is separated and removed from a catalytic chamber in  FIG.  10   . 
         FIGS.  17 A and  17 B  are side views of a hoist that moves a catalyst bed into and out of a catalytic chamber, in accordance with embodiments. 
         FIG.  18    is a cross-sectional view of a catalytic chamber of a catalytic decomposition device in accordance with embodiments. 
         FIGS.  19 A to  19 F  illustrate a catalyst replacement method of a catalytic decomposition device. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. 
       FIG.  1    is a block diagram of an integrated waste gas treatment system in accordance with embodiments.  FIG.  2    is a cross-sectional view of an adsorption/desorption device of an integrated waste gas treatment system of  FIG.  1   .  FIG.  3 A  is a perspective view of a catalytic decomposition device of an integrated waste gas treatment system of  FIG.  1   .  FIG.  3 B  is a cross-sectional view of portion ‘A’ in  FIG.  3 A .  FIG.  3 C  is a cross-sectional view of portion ‘B’ in  FIG.  3 B .  FIG.  4    is a cross-sectional view of portion ‘B’ in  FIG.  3 B  according to another embodiment.  FIG.  5    illustrates simultaneous treatment of first and second compounds by an adsorption/desorption device and the catalytic decomposition device of  FIG.  1   . 
     Referring to  FIGS.  1  to  5   , in an embodiment, an integrated waste gas treatment system  10  includes an adsorption/desorption device  40  and a catalytic decomposition device  50  that are configured to simultaneously purify a waste gas G 1  that includes first and second compounds A 1  and A 2  discharged from an emission source  20 . 
     In embodiments, the integrated waste gas treatment system  10  is a waste gas treatment system that is installed in an exhaust line which is connected to the emission source  20  such as a semiconductor manufacturing facility and through which the waste gas is discharged, and that can simultaneously purify an organic compound such as the first compound A 1  and an organic nitrogen compound such as the second compound A 2  in the waste gas. 
     For example, a semiconductor manufacturing facility discharges a waste gas that includes an organic compound and an organic nitrogen compound. The waste gas treatment system is installed on a site such as a rooftop of a semiconductor manufacturing facility to simultaneously remove the organic compound and the organic nitrogen compound from the discharged waste gas and discharge the purified gas into the atmosphere. The organic compound may include volatile organic compounds (VOC) such as isopropyl alcohol (IPA), and the organic nitrogen compound may include ammonia (NH 3 ). 
     In embodiments, the adsorption/desorption device  40  adsorbs the first and second compounds A 1  and A 2  of the waste gas G 1  received at the same time from the emission source  20  through a first exhaust line  30  connected to the emission source  20  and discharges the purified gas and concentrates and desorbs the first and second compounds A 1  and A 2 . 
     As illustrated in  FIG.  2   , in an embodiment, the adsorption/desorption device  40  includes a rotor-type concentrator  410 . The concentrator  410  is divided into three regions, an adsorption zone  412   a , a desorption zone  412   b  and a cooling zone  412   c . A rotational speed of the rotor-type concentrator  410  is adjusted to within a range of 2 rph to 20 rph according to a concentration of the introduced compound. 
     The concentrator  410  includes a honeycomb-type support  42  inside a cylindrical rotor through which the waste gas passes and an adsorption layer coated on a surface of the support  42 . The adsorption layer includes at least one of zeolite, alumina (Al 2 O 3 ), porous silica (SiO 2 ), a carbon-based adsorbent, etc. The material of the adsorption layer may be doped with a heterogeneous element. 
     The waste gas G 1  generated from the emission source  20  is introduced into the adsorption/desorption device  40  through the first exhaust line  30  connected to the emission source  20 . The waste gas G 1  introduced into the adsorption/desorption device  40  passes through the adsorption zone  412   a  of the support  42  of the concentrator  410 , and the first compound A 1  and the second compound A 2  in the waste gas are adsorbed in the adsorption layer on the surface of the support and the waste gas purified by the adsorption layer is discharged through a second exhaust line  31 . 
     The portion of the adsorption layer in which the first and second compounds A 1  and A 2  are concentrated moves to the desorption zone  412   b  by the rotation of the rotor, and a carrier gas for desorption passes the desorption layer of the desorption zone  412   b  of the concentrator  410  to desorb the first and second compounds A 1  and A 2  adsorbed in the portion of the adsorption layer. The waste gas from which the first and second compounds A 1  and A 2  are desorbed is introduced into the catalytic decomposition device  50  through a third exhaust line  34  connected to the adsorption/desorption device  40 . 
     The portion of the adsorption layer moves to the cooling zone  412   c  by the rotation of the rotor and is cooled, and moves back to the adsorption zone  412   a  to further purify the waste gas, and the purified waste gas is discharged through the second exhaust line  31 . 
     In embodiments, the catalytic decomposition device  50  simultaneously decomposes the waste gas received from the adsorption/desorption device  40  through the third exhaust line  34 . For example, the catalytic decomposition device  50  simultaneously decomposes the first and second compounds A 1 , A 2  of the desorbed gas through a catalytic reaction. 
     Referring to  FIGS.  3 A to  3 C , in an embodiment, the catalytic decomposition device  50  includes a catalytic chamber that includes a gas passage through which the introduced waste gas flows, and an oxidation-reduction catalyst  52  installed in the gas passage of the catalytic chamber. For example, the oxidation-reduction catalyst includes an ammonia oxidation catalyst (AOC). The oxidation-reduction catalyst  52  further includes a catalyst body  54  installed in the gas passage and that includes a plurality of passages through which the waste gas flows, and a carrier  56  coated on the catalyst body  54  and that includes first and second catalytic materials  58  and  59 . 
     The catalyst body  54  includes, for example, silicon carbide (SiC) or cordierite, etc. The catalyst body  54  is formed in a metal foam shape that includes many pores. The oxidation-reduction catalyst  52  may include a single catalyst body that has the same composition and structure, or may include two or more catalyst bodies having different compositions and structures. 
     The carrier  56  includes a porous material such as zeolite, alumina, silica, or a carbon-based material, etc. The carrier  56  includes 5 wt % or less of the first catalytic material  58  and 30 wt % or less of the second catalytic material  59  based on the total weight. For example, the first catalytic material  58  includes a noble metal such as platinum (Pt), palladium (Pd), rhodium (Rh), iridium (Ir), ruthenium (Ru), silver (Ag), or gold (Au), etc., and the second catalytic material  59  includes a transition metal such as copper (Cu), iron (Fe), cerium (Ce), cobalt (Co), zinc (Zn), zirconium (Zr), manganese (Mn), vanadium (V), titanium (Ti), nickel (Ni), chromium (Cr), or molybdenum (Mo), etc. 
     In an embodiment, the oxidation-reduction catalyst  52  is formed by coating a base material with a catalyst layer in which the first catalytic material  58  and the second catalytic material  59  have been simultaneously impregnated with a metal carrier. Alternatively, in an embodiment, the oxidation-reduction catalyst  52  includes the single-layered carrier  56  formed by coating a substrate with a catalytic material in which are physically mixed a first catalyst layer impregnated with the first catalytic material  58  and a second catalyst layer impregnated with the second catalytic material  59 . 
     For another example, as illustrated in  FIG.  4   , in an embodiment, the oxidation-reduction catalyst  52  includes first and second carrier layers  56   a  and  56   b  sequentially stacked on a catalyst body  54 . The first carrier layer  56   a  includes a first catalytic material  58 , and the second carrier layer  56   b  includes a second catalytic material  59 . The oxidation-reduction catalyst  52  includes a multi-layered carrier formed by coating a substrate with a first catalyst layer impregnated with a first catalytic material  58  and then coating a second catalyst layer impregnated with a second metal material  59  on the first catalyst layer. 
     As illustrated in  FIG.  5   , in an embodiment, the adsorption/desorption device  40  simultaneously concentrates and desorbs the organic compound as the first compound and ammonia (NH 3 ) as the second compound of the waste gas received from the emission source  20 , and the catalytic decomposition device  50  is disposed at a rear end of the adsorption/desorption device  40  that oxidizes and converts the organic compound received from the adsorption/desorption device  40  into carbon dioxide (CO 2 ), and that oxidizes and reduces the desorbed ammonia (NH 3 ) into nitrogen (N 2 ), to purify the waste gas. 
     The first catalytic material, such as Pt, of the catalytic decomposition device  50  purifies the organic compound, such as IPA (isopropyl alcohol), into carbon dioxide (CO 2 ) by an oxidation catalyst function under conditions of the organic compound, such as IPA, and oxygen (O 2 ) as shown in Reaction Formula (1) below. 
       2C 3 H 8 O+9O 2 →6CO 2 +8H 2 O   Reaction Formula (1)
 
     The first catalytic material, such as Pt, of the catalytic decomposition device  50  purifies ammonia (NH 3 ) into nitrogen (N 2 ), or generates nitrogen oxides (NOx) by an oxidation catalyst function under conditions of the organic nitrogen compound, such as ammonia, and oxygen (O 2 ) conditions as shown in Reaction Formulas (2) to (4) below. 
       4NH 3 +3O 2 →2N 2 +6H 2 O   Reaction Formula (2)
 
       4NH 3 +5O 2 →4NO+6H 2 O   Reaction Formula (3)
 
       4NH 3 +7O 2 →4NO 2 +6H 2 O   Reaction Formula (4)
 
     The second catalytic material, such as Cu, of the catalytic decomposition device  50  purifies nitrogen oxide (NOx) into nitrogen (N 2 ) by a reduction catalyst function under conditions of ammonia (NH 3 ), nitrogen oxide (NOx) and oxygen (O 2 ) as shown in Reaction Formulas (5) and (6) below. 
       4NH 3 +4NO+O 2 →4N 2 +6H 2 O   Reaction Formula (5)
 
       2NH 3 +NO+NO 2 →2N 2 +3H 2 O   Reaction Formula (6)
 
     Referring back to  FIG.  1   , the waste gas purified by the catalytic decomposition device  50  is discharged through a fourth exhaust line  37 . The second exhaust line  31  and the fourth exhaust line  37  are joined into a fifth exhaust line  39 . Accordingly, the waste gas purified by the adsorption/desorption device  40  and the catalytic decomposition device  50  is discharged through the fifth exhaust line  39 . 
     Table 1, below, shows compound gas concentrations (ppm) detected in exhaust lines of the integrated waste gas treatment system of  FIG.  1   . 
     
       
         
           
               
               
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                 First 
                 Second 
                 Third 
                 Fourth 
                 Fifth 
               
               
                 Exhaust 
                 Exhaust 
                 Exhaust 
                 Exhaust 
                 Exhaust 
                 Exhaust 
               
               
                 Line 
                 Line (30) 
                 Line (31) 
                 Line (34) 
                 Line (37) 
                 Line (39) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 NH 3  (ppm) 
                 185 
                 2.3 
                 1830 
                 7 
                 3 
               
               
                 IPA (ppm) 
                 148 
                 1.4 
                 1470 
                 17 
                 3.1 
               
               
                 NOx (ppm) 
                 — 
                 — 
                 — 
                 12 
                 1.2 
               
               
                   
               
            
           
         
       
     
     Referring to Table 1, when the first catalytic material includes platinum (Pt) and the second catalytic material includes copper (Cu), all of the emission concentrations of ammonia (NH 3 ), IPA and nitrogen oxides (NOx) satisfy the legal standards. For example, the legal standard for nitrogen oxides (NOx) is 35 ppm or less. 
     In embodiments, the oxidation reaction rate of the volatile organic compound, such as IPA, and the organic nitrogen compound, such as ammonia (NH 3 ), is increased by the first catalytic material, such as Pt. Accordingly, the oxidation reaction temperature of IPA and ammonia (NH 3 ) can be lowered to a temperature of 400° C. to 500° C. 
     In addition, since the first catalytic material, such as Pt, and the second catalytic material, such as Cu, coexist on the same surface of the catalyst body of the catalytic decomposition device  50 , the oxidation reaction and the reduction reaction in the catalytic decomposition device  50  of the organic nitrogen compound, such as ammonia (NH 3 ), occurs repeatedly at the same or a similar ratio. Accordingly, nitrogen oxides (NOx) generated by the oxidation reaction of ammonia (NH 3 ) are converted into nitrogen (N 2 ) and discharged by the reduction reaction that uses ammonia (NH 3 ) supplied after being desorbed. 
     Thus, since the oxidation reaction can be induced at a lower temperature than an oxidation reaction temperature of 800° C. or higher by a conventional thermal oxidizing method, such as a direct combustion method, fuel consumption for combustion can be reduced. Furthermore, the treatment cost of secondary products, such as nitrogen oxides (NOx) generated when ammonia (NH 3 ) is oxidized using a conventional general oxidation catalyst, can be reduced. 
     Hereinafter, detailed configurations of an adsorption/desorption device and a catalytic decomposition device of an integrated waste gas treatment system according to embodiments of the disclosure will be described in detail. 
       FIG.  6    is a block diagram of an integrated waste gas treatment system that includes an adsorption/desorption device and a catalytic decomposition device in accordance with embodiments.  FIG.  7    is a perspective view of an integrated waste gas treatment system of  FIG.  6    installed in a semiconductor manufacturing facility.  FIG.  8    is a perspective view of an adsorption/desorption device in  FIG.  7   .  FIG.  9    illustrates the operation of an adsorption/desorption device of  FIG.  8   . 
     Referring to  FIGS.  6  to  9   , in an embodiment, an integrated waste gas treatment system  10  includes an adsorption/desorption device  40  and a catalytic decomposition device  50  that are sequentially installed in an exhaust line through which the waste gas is discharged from an emission source  20 . For example, the adsorption/desorption device  40  and the catalytic decomposition device  50  are installed on a site such as a rooftop of a semiconductor manufacturing facility to simultaneously remove organic compounds and organic nitrogen compounds from the exhausted waste gas and discharge the purified gas. 
     As illustrated in  FIGS.  8  and  9   , the adsorption/desorption device  40  includes a rotor-type concentrator  410  and a desorbing portion. Waste gas G 1  received from a first exhaust line  30  from an emission source  20  is introduced into the rotor-type concentrator  410  that adsorbs and concentrates an organic compound A 1  and ammonia A 2  of the waste gas G 1  and desorbs the concentrated organic compound A 1  and ammonia A 2 . The desorbing portion desorbs the organic compound A 1  and ammonia A 2  adsorbed to the concentrator  410  with a carrier gas G 4 . The desorbing portion includes a heater  420  that heats the carrier gas G 4  to a temperature suitable for desorption and an adsorption fan  434  that discharges the desorbed gas G 3 . 
     The rotor-type concentrator  410  has a cylindrical shape and is rotated by a driving motor  411  inside a housing  400  of the adsorption/desorption device  40 . The rotor-type concentrator  410  includes three regions: an adsorption zone  412   a , a desorption zone  412   b  and a cooling zone  412   c . The rotor-type concentrator  410  is rotated at a predetermined rotation speed by the driving motor  411 . 
     The rotor-type concentrator  410  includes a honeycomb-type support that extends about a rotational axis inside a cylindrically shaped rotor and an adsorption layer coated on a surface of the support. The adsorption layer includes at least one of zeolite, alumina (Al 2 O 3 ), porous silica (SiO 2 ), or a carbon-based adsorbent, etc. The material of the adsorption layer may be doped with a heterogeneous element. 
     The waste gas G 1  received from the emission source  20  is introduced into the adsorption/desorption device  40  through the first exhaust line  30 . The waste gas G 1  introduced into the adsorption/desorption device  40  passes through a filter  430 , through the adsorption layer of the adsorption zone  412   a  of the concentrator  410 , and the organic compound A 1  and ammonia A 2  in the waste gas are adsorbed into the adsorption layer to purify the waste gas, and the purified waste gas G 2  is discharged through the second exhaust line  31 . An exhaust fan  432  is installed in the second exhaust line  31 , so that the purified air G 2  can be discharged through the second exhaust line  31  and the fifth exhaust line  39 . 
     A portion of the adsorption layer into which the organic compound A 1  and ammonia A 2  are adsorbed moves into the desorption zone  412   b  as the rotor rotates, and the carrier gas G 4  passes through the adsorption layer in the desorption zone  412   b  of the concentrator  410  such that the organic compound A 1  and ammonia A 2  are desorbed and concentrated from the portion of the adsorption layer. For example, the concentration ratio is within a range of 3 to 30 times. 
     The desorption portion provides the carrier gas G 4  that desorbs the adsorbed organic compound A 1  and ammonia A 2  through the desorption zone  412   b  and into the adsorption layer of the concentrator  410 . A portion of the waste gas G 1  or a portion of the gas purified by the catalytic decomposition device  50  may be used as a portion of the carrier gas G 4 . Alternatively, external air other than the waste gas may be used as at least a portion of the carrier gas. 
     In particular, a portion of the waste gas G 1  is supplied through a first branch line  30   a  that branches from the first exhaust line  30  to a first purge line  32 . A portion of the waste gas discharged from the catalytic decomposition device  50  is supplied through a second branch line  38  branched from the fourth exhaust line  37  to the first purge line  32 . The carrier gas G 4  supplied to the first purge line  32  is heated to from about 50° C. to about 350° C. by the heater  420 , and the heated carrier gas G 4  is supplied through a second purge line  33  to the desorption zone  412   b  to desorb the organic compound A 1  and ammonia A 2 . The desorbed gas G 3  includes the organic compound A 1  and ammonia A 2  and is introduced through the third exhaust line  34  into the catalytic decomposition device  50  by the adsorption fan  434 . 
     The adsorption layer portion moves to the cooling zone  412   c  by rotation of the rotor to be cooled, and moves to the adsorption zone  412   a  again to purify the waste gas, and the purified waste gas discharged through the second exhaust line  31 . 
     Hereinafter, a catalytic decomposition device of an integrated waste gas treatment system of  FIG.  6    will be described in detail. 
       FIG.  10    is a perspective view of a catalytic decomposition device in accordance with embodiments.  FIG.  11    is a side view of a catalytic decomposition device of  FIG.  10   .  FIG.  12    is a cross-sectional view of a pretreatment portion in  FIG.  10   .  FIG.  13    is a cross-sectional view of a catalytic chamber of a catalytic decomposition apparatus of  FIG.  10   .  FIG.  14    is an exploded perspective view of a portion of a catalytic chamber of  FIG.  13   .  FIG.  15    is a perspective view of a catalyst block installed in a catalyst bed in  FIG.  14   . 
     Referring to  FIGS.  10  to  15   , in an embodiment, a catalytic decomposition device  50  includes a frame structure  500 , a catalytic chamber  510  installed in the frame structure  500  and that provides a gas passage  512  through which a waste gas containing a first compound A 1  and a second compound A 2  flows, a catalyst bed  520  disposed in the gas passage  512  of the catalytic chamber  510  and that includes an oxidation-reduction catalyst  52  provided therein that removes the first and second compounds from the waste gas, and a lifting device  560  that withdraws the catalyst bed  520  from the catalytic chamber  510  to replace the oxidation-reduction catalyst  52 . The catalytic decomposition device  50  further includes a pretreatment portion  530 , a heat exchanger  540  and a heater  550 . 
     In embodiments, the frame structure  500  is installed on a specific installation site, such as a roof top of a semiconductor manufacturing facility. A separate lower support that fixes the frame structure  500  to the roof may be further provided. The frame structure  500  provides a first space  502  in a lower level of the frame structure  500  and a second space  504  in an upper level of the frame structure and that is separated from the first space  502 , where the upper level is above the lower level. The catalytic chamber  510  is installed in the second space  504  of the frame structure  500 . As will be described below, after the lifting device  560  lowers the catalyst bed  520  through a lower opening  511   a  of the catalytic chamber  510  into the first space  502  of the lower level below the catalytic chamber  510 , an operator on the ground replaces a catalyst block  522  mounted in the catalyst bed  520 . 
     In embodiments, the pretreatment portion  530  includes a pretreatment chamber  531  disposed in a front end of the catalytic chamber  510  and that receives a pretreatment agent  533  that pre-adsorbs an adhesive material (catalyst poison) that reduces catalyst performance. The pretreatment agent  533  includes alumina (Al 2 O 3 ) gel particles that adsorb and remove toxic catalyst components. The pretreatment chamber  531  is installed in the first space  502  of the frame structure  500 . The pretreatment agent  533  has superior adsorption performance at a low temperature (room temperature) than a high temperature environment, and thus the pretreatment chamber  531  is disposed in front of the catalytic chamber  512  to minimize equipment size and improve adsorption performance of the pretreatment agent  533 . 
     As illustrated in  FIG.  12   , the pretreatment chamber  531  includes an inlet portion  531   a  and an outlet portion  531   b  that face each other and provide an accommodation space for the pretreatment agent  533 . The inlet portion  531   a  is in communication with a third exhaust line  34  so that a gas G 4  desorbed from the adsorption/desorption device  40  is introduced. The inlet portion  531   a  and the outlet portion  531   b  each have a mesh shape to allow gas to flow therethrough. 
     The pretreatment agent  533  requires periodic replacement due to an irreversible adsorption (one-time) reaction. Since the pretreatment chamber  531  is separately located from the catalytic chamber  510 , it can be replaced independently of the catalyst. The pretreatment portion  530  further includes an airflow-type conveying device  532  that is used to replace the pretreatment agent  533 . The airflow-type conveying device  532  fills the pretreatment chamber  531  with the pretreatment agent  533  through a replacement pipe  534 . For example, the airflow-type conveying device  532  includes an air-operated particle conveying device that uses a Venturi effect, such as a vacuum conveyor. 
     In embodiments, the heat exchanger  540  is installed in the second space  504  of the frame structure  500 . The heat exchanger  540  is disposed above the pretreatment portion  530  and along a side of the catalytic chamber  510 . The waste gas that has passed through the pretreatment portion  530  is introduced through the heat exchanger  540  into the catalytic chamber  510 . The waste gas that has passed through the heat exchanger  540  is introduced through a first connection line  35  to the heater  550 . The heater  550  is disposed between the heat exchanger  540  and the catalytic chamber  510  to heat the waste gas flowing into the catalytic chamber  510  to a temperature suitable for the catalyst reaction. For example, the waste gas flowing into the catalytic chamber  510  is heated to a temperature of 400° C. to 500° C. 
     As illustrated in  FIGS.  13  to  15   , the catalyst bed  520  is disposed in the gas passage  512  of the catalytic chamber  510 , the catalyst blocks  522  are assembled and fixed to a catalyst bed frame in a lattice pattern, and the oxidation-reduction catalyst  52  is provided in each of a plurality of the catalyst blocks  522 . A sealing member such as a gasket is provided on a rear surface of the catalyst bed frame and interposed between the catalyst bed  520  and the catalytic chamber, and a flange  514  is disposed inside the catalytic chamber  510 . The catalyst bed  520  is compressed with the flange  514  and the sealing member and sealed between the catalyst bed  520  and sidewalls of the catalytic chamber  510 . 
     As illustrated in  FIGS.  3 A to  3 C , the oxidation-reduction catalyst  52  includes the catalyst body  54 , which includes a plurality of passages through which the waste gas flows, and the carrier  56 , which is coated on the catalyst body  54  and includes the first and second catalysts  58  and  59  therein. 
     When the gas G 4  desorbed from the adsorption/desorption device  40  passes through the oxidation-reduction catalyst  52  of the catalyst bed  520 , an organic compound (IPA) as the first compound and ammonia as the second compound in the desorbed gas G 4  are removed. In particular, the organic compound and the ammonia are subjected to an oxidation treatment by the oxidation-reduction catalyst  52 , and nitrogen oxides (NOx) generated by the oxidation treatment are removed by a selective reduction reaction. 
     The waste gas purified in the catalytic chamber  510  is discharged through a second connection line  36 , a fourth exhaust line  37  and a fifth exhaust line  39  after passing through the heat exchanger  540 . When the waste gas discharged from the catalytic chamber  510  passes through the heat exchanger  540 , the overall thermal efficiency is improved through heat exchange with the waste gas that has passed through the pretreatment portion  530 . 
     Hereinafter, a catalyst bed that is detachable from a catalytic chamber will be described in detail. 
       FIG.  16 A  is a cross-sectional view of a catalyst bed disposed in a catalytic chamber in  FIG.  10   , and  FIG.  16 B  is a cross-sectional view of a catalyst bed when the catalyst bed is separated and removed from the catalytic chamber in  FIG.  10   . 
     Referring to  FIGS.  16 A and  16 B , in an embodiment, a catalytic chamber  510  includes a lower opening  511   a  provided in a lower wall and an upper opening  511   b  provided in an upper wall that corresponds to and is vertically aligned with the lower opening  511   a . The catalytic chamber  510  includes a lower cover  513   a  that covers the lower opening  511   a  and an upper cover  513   b  that covers the upper opening  511   b . A sidewall opening  515  is provided in a sidewall of the catalytic chamber  510  to facilitate replacement of the catalyst bed  520 . 
     As illustrated in  FIG.  16 A , in an embodiment, the catalyst bed  520  is disposed inside the catalytic chamber  510 . The catalyst bed  520  is compressed with the flange  514  of the catalytic chamber  510  and sealed between the catalyst bed  520  and the sidewall of the catalytic chamber  510 . The lower cover  513   a  and the upper cover  513   b  cover the lower opening  511   a  and the upper opening  511   b , respectively. In addition, a sidewall cover  516 , shown in  FIG.  19 A , covers the sidewall opening  515 . 
     As illustrated in  FIG.  16 B , in an embodiment, the catalyst bed  520  can be separated and removed from the catalytic chamber  510 . The lower cover  513   a  and the upper cover  513   b  are respectively removed, and the catalyst bed  520  is removed from the catalytic chamber  510  through the lower opening  511   a  of the catalytic chamber  510 . The catalyst bed  520  is supported by a cable of the lifting device that extends through the upper opening  511   a  of the catalytic chamber  510 . 
       FIGS.  17 A and  17 B  are side views of a hoist for moving the catalyst bed into and out of the catalytic chamber. 
     Referring to  FIGS.  17 A and  17 B , in an embodiment, a lifting device  560  includes a hoist that includes a cable  561  that withdraws the catalyst bed  520  out of the catalytic chamber  510 . 
     As illustrated in  FIG.  17 A , the catalyst bed  520  is lowered by the cable  561  into the lower space under the catalytic chamber  510  for catalyst replacement. As illustrated in  FIG.  17 B , after the catalyst replacement is completed, the catalyst bed  520  is raised into the catalytic chamber  510  by the hoist using the cable  561 . 
     In an embodiment, the lifting device  560  includes a lifter that functions similar to the hoist. The lifter can raise and lower the catalyst bed  520  while supporting a lower portion of the catalyst bed  520 . The catalytic chamber  510  does not have an upper opening. 
       FIG.  18    is a cross-sectional view of a catalytic chamber of a catalytic decomposition device in accordance with embodiments. 
     Referring to  FIG.  18   , in an embodiment, a catalytic decomposition device includes at least first and second catalyst beds  520   a  and  520   b  that are sequentially disposed in a catalytic chamber  510  and at least one lifting device  600  that can withdraw the first and second catalyst beds  520  from the catalytic chamber  510 . 
     In embodiments, the first catalyst bed  520   a  and the second catalyst bed  520   b  are spaced apart from each other in a gas flow direction (X direction) in the catalytic chamber  510 . 
     The catalytic chamber  510  includes two lower openings  511   a  provided in a lower wall and two upper openings  511   b  provided in an upper wall that respectively correspond to the lower openings  511   a . In addition, the catalytic chamber  510  includes two lower covers that cover the lower openings  511   a  and two upper covers that cover the upper openings  511   b.    
     The first catalyst bed  520   a  and the second catalyst bed  520   b  can be selectively removed from the catalytic chamber  510  by the lifting device  600  for catalyst replacement. Only one of the first catalyst bed  520   a  and the second catalyst bed  520   b  may be removed, or both of the first catalyst bed  520   a  and the second catalyst bed  520   b  may be removed. When both the first catalyst bed  520   a  and the second catalyst bed  520   b  are removed, the first catalyst bed  520   a  and the second catalyst bed  520   b  are spaced apart from each other in an open space outside the facility, so that an operator can freely access each bed. 
     Hereinafter, a catalyst replacement method of a catalytic decomposition device will be described. 
       FIGS.  19 A to  19 F  illustrate a catalyst replacement method of a catalytic decomposition device, according to an embodiment. 
     Referring to  FIGS.  19 A to  19 C , a lifting device  560  is connected to a catalyst bed  520 . 
     In embodiments, a lower cover  513   a , an upper cover  513   b  and a sidewall cover  516  are removed from a catalytic chamber  510  and a fixing device of a catalyst bed  520  is released. Accordingly, an upper end of a frame of the catalyst bed  520  is exposed through an upper opening  511   b.    
     Then, a hook  562  of the lifting device  560  is lowered and connected to a shackle  564  fixed to the upper end of the frame of the catalyst bed  520 . 
     Referring to  FIGS.  19 D and  19 E , the catalyst bed  520  is lowered to a space under the catalytic chamber  510  and then a catalyst installation or maintenance operation can be performed. 
     As the catalyst bed  520  is lowered by the lifting device  560 , the catalyst bed  520  is moved into a first space  502  of a lower level through the lower opening  511   a  of the catalytic chamber  510 . The catalyst bed  520  is supported in the first space  502  of a frame structure  500  under the catalytic chamber  510  by the lifting device  560  during catalyst replacement. 
     An operator can freely access the catalyst bed  520  outside the catalytic chamber  510  in the first space  502  of the frame structure  500  to replace a catalyst block  522 . Accordingly, by performing the installation and maintenance of the catalyst outside the facility without the need to enter the facility, the stability of the operation can be ensured. 
     Referring to  FIG.  19 F , after installation or maintenance of the catalyst is performed, the catalyst bed  520  is moved back into the catalytic chamber  510 . 
     As the catalytic bed  520  is raised by the lifting device  560 , the catalyst bed  520  is lifted into the catalytic chamber  510  through the lower opening  511   a  of the catalytic chamber  510 . The catalytic bed  520  is compressed with a flange  514  of the catalytic chamber  510  and sealed between the catalyst bed  520  and the sidewall of the catalytic chamber  510 . The lower cover  513   a  and the upper cover  513   b  are respectively fastened to the lower opening  511   a  and the upper opening  511   b . In addition, the sidewall cover  516  is also fastened to the sidewall opening  515 . 
     As described above, the integrated waste gas treatment system  10  include the adsorption/desorption device  40  and the catalytic decomposition device  50  that are sequentially installed in the discharge line and through which a waste gas that includes an organic compound and an organic nitrogen compound is discharged from the emission source  20 , such as a semiconductor manufacturing facility. The adsorption/desorption device  40  adsorbs the organic compound and the organic nitrogen compound and concentrates and desorbs them. 
     The catalytic decomposition device  50  includes the catalytic chamber  510  that provides the gas passage  512  through which the gas desorbed from the adsorption/desorption device  40  flows, and the oxidation-reduction catalyst  52  disposed in the gas passage  512  in the catalytic chamber  510  to remove the organic compound and the organic nitrogen compound from the desorbed gas. The organic compound and the organic nitrogen compound are subjected to oxidation treatment by the oxidation-reduction catalyst  52 , and nitrogen oxides (NOx) generated by the oxidation treatment are removed by a selective reduction reaction. 
     The oxidation-reduction catalyst  52  includes a first catalytic material, such as Pt, that oxidizes the organic compound and the organic nitrogen compound by an oxidation catalytic function and a second catalytic material, such as Cu, that reduces nitrogen oxide (NOx) generated by the oxidation treatment by a reduction catalyst function. 
     The oxidation reaction rate of the organic compound, such as IPA, and the organic nitrogen compound, such as ammonia (NH 3 ), is increased by the first catalytic material. Accordingly, the oxidation reaction temperature of IPA and ammonia (NH 3 ) is lowered to a temperature of 400° C. to 500° C. 
     In addition, since the first catalytic material and the second catalytic material are present together on the same surface of the catalyst body of the catalytic decomposition device  50 , nitrogen oxides (NOx) generated by the oxidation reaction of ammonia (NH 3 ) is converted into nitrogen (N 2 ) by the reduction reaction that uses ammonia (NH 3 ) that is desorbed, supplied and discharged. 
     Thus, since an oxidation reaction can be induced at a lower temperature than the oxidation reaction temperature (800° C. or higher) of a conventional thermal oxidizing method, such as a direct combustion method, fuel consumption for combustion is reduced. Further, the cost for further treatment of secondary products, such as nitrogen oxides (NOx) generated when ammonia (NH 3 ) is oxidized using the conventional general oxidation catalyst, is reduced. 
     Further, the catalytic decomposition device  50  includes the frame structure  500  that provides the first space  502  and the second space  504  that are separated into a lower level and an upper level, the catalytic chamber  510  installed in the second space  504  of the catalytic chamber  510  and that provides the gas passage  512  through which the gas desorbed from the adsorption/desorption device  40  flows, the catalyst bed  520  disposed in the gas passage  512  of the catalytic chamber  510  and that includes the oxidation-reduction catalyst  52  that removes the organic compound and the organic nitrogen compound from the desorbed gas, and the lifting device  560  that can withdraw the catalyst bed  520  into the first space  502  below the catalytic chamber  510 . 
     As the catalyst bed  520  is lowered by the lifting device  560 , the catalyst bed  520  moves into the first space  502  of the lower level through the lower opening  511   a  of the catalytic chamber  510 . The catalyst bed  520  is supported in the first space  502  of the frame structure  500  below the catalytic chamber  510  by the lifting device  560  during catalyst replacement. 
     An operator can freely access the catalyst bed  520  in the first space  502  of the frame structure  500  outside the catalytic chamber  510  to replace the catalyst block  522 . Accordingly, by performing the installation and maintenance of the catalyst outside the facility without the need to enter the existing facility, the stability of the operation is ensured. 
     Semiconductor devices manufactured by an above-described semiconductor manufacturing facility include semiconductor devices such as logic devices or memory devices. The logic devices include central processing units (CPUs), main processing units (MPUs), or application processors (APs), etc., and the memory devices include volatile memory devices such as DRAM devices, HBM (high bandwidth memory) devices, or non-volatile memory devices such as flash memory devices, PRAM devices, MRAM devices, ReRAM devices, ETC. 
     The foregoing is illustrative of embodiments and is not to be construed as limiting thereof. Although a few embodiments have been described, those skilled in the art will readily appreciate that many modifications are possible in embodiments without materially departing from the novel teachings and advantages of the present invention. Accordingly, all such modifications are intended to be included within the scope of embodiments as defined in the claims.