Patent Application
20080280750
The present invention relates to catalysts for treating acid gases and halogen gases and production methods thereof. In particular, the present invention relates to catalysts for decomposing acid gases and halogen gases produced during the manufacturing processes of semiconductors and photoelectric panels, and to methods for producing the catalysts.
In recent years global climate abnormality becomes more and more significant, and so does damage to the environment due to industry wastes. Advanced countries, environmental protection groups and even high-technology industries therefore have paid much attention to the problems of waste pollution, among which gas emissions impart influences on the environment most directly and immediately. Emissions of acid gases and halogen gases especially are imperative.
The ecological effects of acid gases and halogen gases include occurrence of acid rain and destruction of nearby lives, such as plants. Humans exposed to high-concentration acid gases and halogen gases will suffer chemical burn and inspiration system injury which, when in the worst situation, may lead to death.
Therefore, careful treatments of acid gases and halogen gases massively produced during the manufacturing processes of semiconductors and photoelectric panels should be carried out in order to minimize impacts on the environment.
Nowadays the devices for treating waste gases produced from the manufacturing processes of semiconductors and photoelectric panels generally are of four types, i.e., water-scrubbing, combustion, thermoelectric and dry types. The water-scrubbing type devices are less efficient, need to use a huge amount of water, and can hardly conform to the high environmental protection standards due to the secondary pollution by the generated wastewater. The combustion type devices have the problem of further air pollution by the generated huge amount of CO2 or other acid gases. The thermoelectric type devices are high energy consumptive and less efficient. In comparison with the other types, the dry type devices lead to more satisfactory treatment results since they are efficient, low energy consumptive, easy to maintain and operable during blackout, and also the problem of secondary pollution could be well controlled.
In the treatment in a dry type device, metallic substances having specific catalytic and reactive properties are used to convert acid gases and halogen gases into more stable solid salts or nontoxic gases, such that the end gases from the device meet the environmental requirements.
The present invention relates to a catalyst for treating acid gases and halogen gases and the production method thereof. In particular, the present invention relates to a catalyst for decomposing acid gases and halogen gases produced during the manufacturing processes of semiconductors and photoelectric panels, and methods for producing the catalysts.
The catalyst of the present invention is useful for treating acid gases and halogen gases, including HCl, HF, HBr, HI, F2, Cl2, Br2, I2, ClF3, PH3, PCl3, PCl5, POCl3, P2O5, AsH3, SiH4, SiF4, SiCl4, SiHCl3, SiH2Cl2, BF3, BCl3, GeCl4, GeH4, NO, NO2, SO2, SO3, SF6, etc.
The catalyst of the present invention comprises one or more support materials, such as those selected from activated carbon, argil, diatomite, cement, silica and ceramic materials (including clay, kaolin, alumina, etc.); optionally one or more binders, such as those selected from polyvinyl alcohol (PVA), water glass and silica sol; and one or more metal compounds selected from alkali metal hydroxides, oxides, carbonates and bicarbonates, alkaline earth metal hydroxides, oxides, carbonates and bicarbonates, Group IIIA metal oxides, Group IVA metal oxides, and transition metal oxides, oxide hydrates, sulfates and carbonates.
The catalyst of the present invention may comprise about 10-90% by weight of the support materials, about 10-90% by weight of the metal compounds and about 560% by weight of the binders.
The abovesaid alkali metal or alkaline metal hydroxides, oxides, carbonates and bicarbonates include Ca(OH)2, CaCO3, CaO, K2CO3, KHCO3, KOH, Na2CO3, KHCO3, KOH, Na2CO3, NaHCO3, NaOH, Li2CO3, LiHCO3, LiOH, MgCO3, MgO, etc. The abovesaid Group IA or IVA metal oxides include Al2O3, SiO2, PbO, SnO2, SnO, etc. The abovesaid transition metal oxides, oxide hydrates, sulfates and carbonates include Fe2O3, Fe3O4, Fe2O3.H2O, Fe2(SO4)3, CuO, Cu2O, CuSO4, CuCO3, MnO2, MnO, MnCO3, CeO2, ZrO2, Y2O3, TiO2, NiO, Ni2O3, CoO, CO2O3, etc.
In practical applications, various components can be combined to treat various gases, and a device can be loaded with one or more catalysts in various ratios in accordance with the processes to be carried out.
The production method of the catalyst of the present invention for treating acid gases and halogen gases may comprise the steps of soaking the catalyst support(s) in a solution of the active catalytic ingredient(s) in, for example, water or alcohols, and then drying the resulting product; or may comprise the steps of subjecting the catalyst support(s), the active catalytic ingredient(s) and additives (for example, binders) to mixing, granulating and drying, and then sintering at a high temperature if needed. The purpose of sintering the granular mixture formed by granulation is to give the mixture a porous ceramic-like structure. Due to the porous feature of the catalyst product, the contact area between the catalyst and the acid and halogen gases is increased, thereby the reaction rate is increased and the acid and halogen gases can be decomposed rapidly. The abovesaid active catalytic ingredient is one or more metal compounds selected from alkali metal hydroxides, oxides, carbonates and bicarbonates, alkaline earth metal hydroxides, oxides, carbonates and bicarbonates, Group IIIA metal oxides, Group IVA metal oxides, and transition metal oxides, oxide hydrates, sulfates and carbonates.
The catalyst of the present invention can be granulated into various shapes in order to fit various requirements. The shapes include irregular pieces, chips, powders, granules, cylinders, tablets, grids, hives, crystals, etc. The size, structural strength, specific surface area and heat resistance of the catalyst also can be adjusted to fit various requirements in practice.
Preferred embodiments of the catalyst of the present invention include the following three groups:
Activated carbon granules are soaked in a 20˜70% solution of K2CO3, KHCO3, KOH, Na2CO3, NaHCO3, NaOH, Li2CO3, LiHCO3 and/or LiOH in water or alcohol(s) for several hours, drained, and dried at a temperature 60˜250° C. for 2˜48 hours to obtain the product. High performance catalysts for treating various gases can thus be produced, and the species of the basic solutions for soaking activated carbon granules depend on the species of the gases to be treated. The catalysts are especially useful for treating halogen gases and hydrogen halide gases, and also are useful for treating perfluorocarbons (PFCs) gases.
The following materials (1), (2) and (3) in weight ratio of about 10˜90%:10˜90%: 5˜60% are thoroughly mixed, granulated and dried to obtain the product:
(1) one or more active catalytic ingredients selected from Ca(OH)2, CaCO3, CaO, SiO2, Fe2O3.H2O, Fe2O3, Fe3O4, Fe2(SO4)3, CuO, Cu2O, CuSO4, CuCO3, MnO2, MnO, MnCO3, Al2O3, K2CO3, KHCO3, KOH, Na2CO3, NaHCO3, NaOH, Li2CO3, LiHCO3, LiOH, MgCO3, MgO, NiO, Ni2O3, CoO, CO2O3, PbO, SnO2 and SnO;
(2) one or more support materials selected from activated carbon, argil, diatomite, cement, silica and ceramic materials;
(3) one or more binders selected from polyvinyl alcohol (PVA), water glass and silica sol.
The catalysts thus obtained are especially useful for treating hydrogen halide gases, and also are useful for treating PFCs gases.
The following materials (1), (2) and (3) in weight ratio of about 20˜80%:20˜80%:5˜60% are thoroughly mixed, granulated, and sintered at a high temperature of 600˜1500° C. for 8˜80 hours to obtained the product:
(1) one or more active catalytic ingredients selected from Ca(OH)2, CaCO3, CaO, SiO2, Fe2O3.H2O, Fe2O3, Fe3O4, Fe2(SO4)3, CuO, Cu2O, CuSO4, CuCO3, MnO2, MnO, MnCO3, Al2O3, MgCO3, MgO, CeO2, ZrO2, Y2O3, TiO2, NiO, Ni2O3, CoO, CO2O3, PbO, SnO2 and SnO;
(2) one or more support materials selected from activated carbon, argil, diatomite, cement, silica and ceramic materials;
(3) one or more binders selected from polyvinyl alcohol (PVA), water glass and silica sol.
The catalysts thus obtained are particularly useful for treating gases such as F2, Cl2, Br2, I2, ClF3, PH3, PCl3, PCl5, POCl3, P2O5, AsH3, SiH4, SiF4, SiCl4, SiHCl3, SiH2Cl2, BF3, BCl3, GeCl4, GeH4, NO, NO2, SO2, SO3, SF6, etc., and also are useful for treating PFCs gases.
As tested by Fourier Transform Infrared Spectroscopy (FTIR) (the sample may be, for example, collected at the sampling port as shown in
Actual test results obtained by treating various gases with the catalysts of the present invention are shown in
The catalysts of the present invention and their production methods will now be described by reference to the following examples which are for illustrative purposes and are not to be construed as a limitation of the scope the present invention.
A catalyst belonging to the abovesaid Group DT-H-001 can be produced by performing the following steps:
1. 10˜30 g of KOH and 10˜30 g of K2CO3 are added into 100 ml of water and completely stirred to dissolve;
2. 20˜70 g of activated carbon is added into the resulting solution to soak the activated carbon at a temperature of from room temperature to 90° C. for 2˜36 hours; and
3. the activated carbon is taken out of the solution, drained, and then dried in a drying oven at a temperature of 60˜250° C. for 2˜48 hours to obtain the final product.
A catalyst belonging to the abovesaid Group DT-H-002 can be produced by performing the following steps:
1. 20˜80 g of Ca(OH)2, 5˜50 g of CaCO3, 5˜50 g of MgO, 2˜10 g of Ni2O3, 2˜10 g of Fe2O3.H2O, 20˜50 g of Fe2O3 and 30 g of SiO2 are mixed and stirred to be homogeneous;
2. 20˜50 ml of a 2˜40% PVA and 5˜20 ml of water are added into the resulting mixture and thoroughly stirred;
3. the resulting mixture is granulated into the desired shape and size; and
4. the granulated mixture is dried in a drying oven at a temperature of 60˜300° C. for 6˜48 hours to obtain the final product.
A catalyst belonging to the abovesaid Group DT-H-003 can be produced by performing the following steps:
1. 1˜5 g of Fe2O3, 10˜80 g of CuO, 1˜5 g of Cu2O, 5˜50 g of CuSO4, 5˜50 g of CuCO3, 1˜5 g of MnO, 1˜5 g of MnCO3, 5˜50 g of Al2O3, 1˜5 g of CeO2, 1˜5 g of ZrO2, 1˜5 g of Y2O3, 1˜5 g of TiO2, 1˜5 g of Ni2O3, 1˜5 g of SnO2, 10˜50 g of pottery clay, 5˜40 g of clay and 5˜30 g of activated carbon powders are mixed and stirred to be homogeneous;
2. 10˜70 ml of a 2˜40% PVA and 5˜40 ml of water are added into the resulting mixture and thoroughly stirred;
3. the resulting mixture is granulated into the desired shape and size;
4. the granulated mixture is dried in a drying oven at a temperature of 60˜300° C. for 6˜48 hours; and
5. the dried product is sintered in a high temperature furnace at a temperature of 600˜1500° C. for 8˜80 hours to obtain the final product.
| Number | Date | Country | Kind |
|---|---|---|---|
| 96116521 | May 2007 | TW | national |
