Abstract: Fluorine compounds such as C2F6, CF4, CHF3, SF6 and NF3, are made in contact with a fluorine compound decomposition catalyst and a catalyst the decomposition oft least one of CO, SO2F2 and N2O in the presence of water or in the presence of water and oxygen. The catalyst the decomposition oft least one of CO, SO2F2 and N2O preferably contains at least one selected from Pd, Pt, Cu, Mn, Fe, Co, Rh, Ir and Au in the form of a metal or an oxide. According to the invention, the fluorine compound can be converted to HF, which is liable to be absorbed by water or an alkaline aqueous solution, and a substance, such as CO, SO2F2 and N2O, formed by decomposition of the fluorine compound can also be decomposed.

Abstract: In order to prevent exhaust pipe for exhausting perfluorocompound (PFC) decomposition gas after washing from corrosion, a mist separating apparatus is provided at a rear stage of the washing tower for washing the PFC decomposition gas. The corrosion of the exhaust pipe can be prevented by removing the mist from the washed gas.

Abstract: Fluorine compounds such as C2F6, CF4, CHF3, SF6 and NF3, are made to contact with a fluorine compound decomposition catalyst and a catalyst for the decomposition of at least one of CO, SO2F2 and N2O in the presence of water or in the presence of water and oxygen. The catalyst for the decomposition of at least one of CO, SO2F2 and N2O preferably contains at least one selected from Pd, Pt, Cu, Mn, Fe, Co, Rh, Ir and Au in the form of a metal or an oxide. According to the invention, the fluorine compound can be converted to HF, which can be absorbed by water or an alkaline aqueous solution. Furthermore, a substance such as CO, SO2F2 and N2O which is formed by decomposition of the fluorine compound can also be decomposed.

Abstract: An exhaust gas containing a perfluoride component (PFC) and SiF4 is conducted into a silicon remover and brought into contact with water. A reaction water supplied from a water supplying piping and air supplied from an air supplying piping are mixed with the exhaust gas exhausted from the silicon remover. The exhaust gas containing water, air, and CF4 is heated at 700° C. by a heater. The exhaust gas containing PFC is conducted to a catalyst layer filled with an alumina group catalyst. The PFC is decomposed to HF and CO2 at a high temperature exhausted from the catalyst layer is cooled in a cooling apparatus. Subsequently, the exhaust gas is conducted to an acidic gas removing apparatus to remove HF. In this way, the silicon component is removed from the exhaust gas before introducing the exhaust gas into the catalyst layer. Therefore, the surface of the catalyst can be utilized effectively, and the decomposition reaction of the perfluoride compound can be improved.

Abstract: In a PFC decomposing apparatus according to the present invention, PFC contained in a discharged gas is decomposed in catalyst cartridge 3 packed with a catalyst containing 80% Al2O3 and 20% NiO. The discharged gas containing acid gases as a decomposition gas is cooled in cooling chamber 6 and led to discharged gas washing column 13, where the acid gases are removed. Mists of acid gases (SO3 mists or NOx mists) entrained in the discharged gas are separed in cyclone 16. Compressed air at about 0.1 Mpa is fed to ejector 24 through air feed pipe 56. The interior of ejector 24 is brought into a negative pressure state by the compressed air to such the discharged gas from cyclone 16 and ejector. Ejector 24 can reduce a frequency of maintenance inspection, as compared with a blower.

Abstract: An exhaust gas containing a perfluoride component (PFC) and SiIF4 is conducted into a silicon remover and brought into contact with water. A reaction water supplied from a water supplying piping and air supplied from an air supplying piping are mixed with the exhaust gas exhausted from the silicon remover. The exhaust gas containing water, air, and CF4 is heated at 700° C. by a heater. The exhaust gas containing PFC is conducted to a catalyst layer filled with an alumina group catalyst. The PFC is decomposed to HF and CO2 at a high temperature exhausted from the catalyst layer is cooled in a cooling apparatus. Subsequently, the exhaust gas is conducted to an acidic gas removing apparatus to remove HF. In this way, the silicon component is removed from the exhaust gas before introducing the exhaust gas into the catalyst layer. Therefore, the surface of the catalyst can be utilized effectively, and the decomposition reaction of the perfluoride compound can be improved.

Abstract: A gas stream containing at least one fluorine compound selected from the group consisting of compounds of carbon and fluorine, compounds of carbon, hydrogen and fluorine, compounds of sulfur and fluorine, compounds of nitrogen and fluorine and compounds of carbon, hydrogen, oxygen and fluorine is contacted with a catalyst comprising at least one of alumina, titania, zirconia and silica, preferably a catalyst comprising alumina and at least one of nickel oxide, zinc oxide and titania in the presence of steam, thereby hydrolyzing the fluorine compound at a relatively low temperature, e.g. 200°-800° C., to convert the fluorine of the fluorine compound to hydrogen fluoride.

Abstract: A gas stream containing at least one fluorine compound selected from the group consisting of compounds of carbon and fluorine, compounds of carbon, hydrogen and fluorine, compounds of sulfur and fluorine, compounds of nitrogen and fluorine and compounds of carbon, hydrogen, oxygen and fluorine is contacted with a catalyst comprising at least one of alumina, titania, zirconia and silica, preferably a catalyst comprising alumina and at least one of nickel oxide, zinc oxide and titania in the presence of steam, thereby hydrolyzing the fluorine compound at a relatively low temperature, e.g. 200.degree.-800° C., to convert the fluorine of the fluorine compound to hydrogen fluoride.

Abstract: The catalytic exhaust gas decomposition apparatus spirals an exhaust gas containing therein a substance to be decomposed and a reactant gas, rectifies the spiral flow, and lets the substance to be decomposed contained in the exhaust gas react with the reactant gas after the spiral flow has been rectified. This arrangement rectifies the spiral flow of the exhaust gas and the reactant gas with a plate-like baffle wall having therein a through hole at a portion near the center thereof. The spiral flow is allowed to pass through the through hole so as to be centralized temporarily. The spiral flow then passes through an enlarged section of a flow path downstream of the through hole before being introduced into the catalyst bed.

Abstract: In a catalytic exhaust gas decomposition apparatus according to the preferred embodiment of the present invention, it is possible to suppress variations in velocity distribution of the gases introduced to the catalyst bed. The catalytic exhaust gas decomposition apparatus spirals an exhaust gas containing therein a substance to be decomposed and a reactant gas, rectifies the spiral flow, and lets the substance to be decomposed contained in the exhaust gas react with the reactant gas after the spiral flow has been rectified. This arrangement uses, as a means for rectifying the spiral flow of the exhaust gas and the reactant gas, a plate-like baffle wall having therein a through hole at a portion near the center thereof. The spiral flow is allowed to pass through the through hole so as to be centralized temporarily. The spiral flow then passes through an enlarged section of a flow path downstream of the through hole before being introduced into the catalyst bed.

Abstract: A gas stream containing at least one fluorine compound selected from the group consisting of compounds of carbon and fluorine, compounds of carbon, hydrogen and fluorine, compounds of sulfur and fluorine, compounds of nitrogen and fluorine and compounds of carbon, hydrogen, oxygen and fluorine is contacted with a catalyst comprising at least one of alumina, titania, zirconia and silica, preferably a catalyst comprising alumina and at least one of nickel oxide, zinc oxide and titania in the presence of steam, thereby hydrolyzing the fluorine compound at a relatively low temperature, e.g. 200°-800° C., to convert the fluorine of the fluorine compound to hydrogen fluoride.

Abstract: Fluorine compounds such as C2F6, CF4, CHF3, SF6 and NF3, are made in contact with a fluorine compound decomposition catalyst and a catalyst the decomposition oft least one of CO, SO2F2 and N2O in the presence of water or in the presence of water and oxygen. The catalyst the decomposition oft least one of CO, SO2F2 and N2O preferably contains at least one selected from Pd, Pt, Cu, Mn, Fe, Co, Rh, Ir and Au in the form of a metal or an oxide. According to the invention, the fluorine compound can be converted to HF, which is liable to be absorbed by water or an alkaline aqueous solution, and a substance, such as CO, SO2F2 and N2O, formed by decomposition of the fluorine compound can also be decomposed.

Abstract: A gas stream containing at least one fluorine compound selected from the group consisting of compounds of carbon and fluorine, compounds of carbon, hydrogen and fluorine, compounds of sulfur and fluorine, compounds of nitrogen and fluorine and compounds of carbon, hydrogen, oxygen and fluorine is contacted with a catalyst comprising at least one of alumina, titania, zirconia and silica, preferably a catalyst comprising alumina and at least one of nickel oxide, zinc oxide and titania in the presence of steam, thereby hydrolyzing the fluorine compound at a relatively low temperature, e.g. 200°-800° C., to convert the fluorine of the fluorine compound to hydrogen fluoride.

Abstract: The catalytic exhaust gas decomposition apparatus spirals an exhaust gas containing therein a substance to be decomposed and a reactant gas, rectifies the spiral flow, and lets the substance to be decomposed contained in the exhaust gas react with the reactant gas after the spiral flow has been rectified. This arrangement rectifies the spiral flow of the exhaust gas and the reactant gas with a plate-like baffle wall having therein a through hole at a portion near the center thereof. The spiral flow is allowed to pass through the through hole so as to be centralized temporarily. The spiral flow then passes through an enlarged section of a flow path downstream of the through hole before being introduced into the catalyst bed.

Abstract: A gas stream containing at least one fluorine compound selected from the group consisting of compounds of carbon and fluorine, compounds of carbon, hydrogen and fluorine, compounds of sulfur and fluorine, compounds of nitrogen and fluorine and compounds of carbon, hydrogen, oxygen and fluorine is contacted with a catalyst comprising at least one of alumina, titania, zirconia and silica, preferably a catalyst comprising alumina and at least one of nickel oxide, zinc oxide and titania in the presence of steam, thereby hydrolyzing the fluorine compound at a relatively low temperature, e.g. 200°-800° C., to convert the fluorine of the fluorine compound to hydrogen fluoride.

Abstract: A gas stream containing at least one fluorine compound selected from the group consisting of compounds of carbon and fluorine, compounds of carbon, hydrogen and fluorine, compounds of sulfur and fluorine, compounds of nitrogen and fluorine and compounds of carbon, hydrogen, oxygen and fluorine is contacted with a catalyst comprising at least one of alumina, titania, zirconia and silica, preferably a catalyst comprising alumina and at least one of nickel oxide, zinc oxide and titania in the presence of steam, thereby hydrolyzing the fluorine compound at a relatively low temperature, e.g. 200°-800° C., to convert the fluorine of the fluorine compound to hydrogen fluoride.

Abstract: A gas stream containing at least one fluorine compound selected from the group consisting of compounds of carbon and fluorine, compounds of carbon, hydrogen and fluorine, compounds of sulfur and fluorine, compounds of nitrogen and fluorine and compounds of carbon, hydrogen, oxygen and fluorine is contacted with a catalyst comprising at least one of alumina, titania, zirconia and silica, preferably a catalyst comprising alumina and at least one of nickel oxide, zinc oxide and titania in the presence of steam, thereby hydrolyzing the fluorine compound at a relatively low temperature, e.g. 200°-800° C., to convert the fluorine of the fluorine compound to hydrogen fluoride.

Abstract: A gas stream containing at least one fluorine compound selected from the group consisting of compounds of carbon and fluorine, compounds of carbon, hydrogen and fluorine, compounds of sulfur and fluorine, compounds of nitrogen and fluorine and compounds of carbon, hydrogen, oxygen and fluorine is contacted with a catalyst comprising at least one of alumina, titania, zirconia and silica, preferably a catalyst comprising alumina and at least one of nickel oxide, zinc oxide and titania in the presence of steam, thereby hydrolyzing the fluorine compound at a relatively low temperature, e.g. 200°-800° C., to convert the fluorine of the fluorine compound to hydrogen fluoride.

Abstract: An object of the present invention is to improve the decomposition at low temperatures of perfluorocompounds containing only fluorine as a halogen, such as CF4, C2F6 and the like. In the present invention, a perfluorocompound containing only fluorine as a halogen is brought into contact with a catalyst comprising Al, Ni and W as catalytically active ingredients and comprising a mixed oxide or complex oxide of Ni and Al and a mixed oxide or complex oxide of W and Ni, in the presence of steam or a combination of steam and air at a temperature of 500 to 800° C. to convert the fluorine in the perfluorocompound to hydrogen fluoride. Employment of the catalyst of the present invention improves the decomposition at low temperatures and hence makes it possible to decompose the perfluoro-compound at a high percentage of decomposition at a lower temperature.

Abstract: An exhaust gas containing a perfluoride compound (PFC) and SiF4 is conducted into a silicon remover and brought into contact with water. A reaction water supplied from a water supplying piping and air supplied from an air supplying piping are mixed with the exhaust gas exhausted from the silicon remover. The exhaust gas containing water, air, and CF4 is heated at 700° C. by a heater. The exhaust gas containing PFC is conducted to a catalyst layer filled with an alumina group catalyst. The PFC is decomposed to HF and CO2 by the catalyst. The exhaust gas containing HF and CO2 at a high temperature exhausted from the catalyst layer is cooled in a cooling apparatus. Subsequently, the exhaust gas is conducted to an acidic gas removing apparatus to remove HF. In this way, the silicon component is removed from the exhaust gas before introducing the exhaust gas into the catalyst layer.