Hitachi, Ltd.

Hitachi Kyowa Engineering Co., Ltd.

Hitachi Engineering Co., Ltd.

Hitachi Information & Control Solutions, Ltd.

Kazuyoshi Irie

Shin Tamata

Shuichi Kanno

Shigeru Azuhata

Hisao Yamashita

Toshiaki Arato

Shinzo Ikeda

Ken Yasuda

Toshihide Takano

Hisao Yokoyama

Toshihiro Mori

Takayuki Tomiyama

Osamu Ito

Masayuki Taniguchi

Hironobu Kobayashi

Kenji Yamamoto

Akio Honji

Yoshiki Shibano

Ri Koukun

An exhaust gas containing a perfluoride compound (PFC) and SiFis 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 CFis heated at 700&#xb0; 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 COby the catalyst. The exhaust gas containing HF and COat 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.

Method for processing perfluorocarbon, and apparatus therefor

An exhaust gas containing a perfluoride component (PFC) and SiIFis 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 CFis heated at 700&#xb0; 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 COat 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.

Apparatus for processing perfluorocarbon

A catalytic exhaust gas decomposition 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 react with the reactant gas after the spiral flow has been rectified. For rectifying the spiral flow of the exhaust gas and the reactant gas, a plate-like baffle wall has therein a through hole at a portion near its center. 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. The method helps minimize variations in gas velocity of the exhaust gas flowing into the catalyst bed, thereby allowing a desired decomposition rate to be obtained substantially consistently.

Catalytic exhaust gas decomposition apparatus and exhaust gas decomposition method

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&#xb0;&#x2013;800&#xb0; C., to convert the fluorine of the fluorine compound to hydrogen fluoride.

Process for treating fluorine compound-containing gas

Fluorine compounds such as CF, CF, CHF, SFand NF, are made in contact with a fluorine compound decomposition catalyst and a catalyst the decomposition oft least one of CO, SOFand NO in the presence of water or in the presence of water and oxygen. The catalyst the decomposition oft least one of CO, SOFand NO 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, SOFand NO, formed by decomposition of the fluorine compound can also be decomposed.

Method and apparatus for disposing of fluorine-containing compound by decomposition

Fluorine compounds such as CF, CF, CHF, SFand NF, are made to contact with a fluorine compound decomposition catalyst and a catalyst for the decomposition of at least one of CO, SOFand NO in the presence of water or in the presence of water and oxygen. The catalyst for the decomposition of at least one of CO, SOFand NO 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, SOFand NO which is formed by decomposition of the fluorine compound can also be decomposed.

Process and apparatus for the decomposition of fluorine compounds

An exhaust gas containing a perfluoride component (PFC) and SiFis 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 CFis heated at 700&#xb0; 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 COat 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.

In a PFC decomposing apparatus according to the present invention, PFC contained in a discharged gas is decomposed in catalyst cartridgepacked with a catalyst containing 80% AlOand 20% NiO. The discharged gas containing acid gases as a decomposition gas is cooled in cooling chamberand led to discharged gas washing column, where the acid gases are removed. Mists of acid gases (SOmists or NOx mists) entrained in the discharged gas are separed in cyclone. Compressed air at about 0.1 Mpa is fed to ejectorthrough air feed pipe. The interior of ejectoris brought into a negative pressure state by the compressed air to such the discharged gas from cycloneand ejector. Ejectorcan reduce a frequency of maintenance inspection, as compared with a blower.

Method and apparatus for treating perfluorocompounds

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.

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&#xb0;-800&#xb0; C., to convert the fluorine of the fluorine compound to hydrogen fluoride.

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Hitachi, Japan

Kazuyoshi Irie