PROCESS FOR TREATMENT OF EXHAUST GAS CONTAINING BOTH SILANE GAS AND FLUORINE GAS AND EXHASUT GAS TREATMENT FACILITY FOR THE PROCESS

摘要

Provided are a process for the treatment of exhaust gas by which by-products formed by thermal decomposition of an exhaust gas containing both a silane gas and a fluorine gas can be separately and efficiently recovered in high concentrations and a facility therefor. The process is characterized by comprising the exhaust gas thermal decomposition step of adding oxygen, moisture, or hydrogen at need to an exhaust gas (E) into which a siliane gas and a fluorine gas are incorporated simultaneously or successively and subjecting the resulting exhaust gas to thermal decomposition to form a heat-treated exhaust gas (T), the silica recovery step of cooling the heat-treated exhaust gas (T) to a temperature which is equal to or above the vaporization temperature of water and which is equal to or below the highest allowable temperature of a bag filter (32) to capture silica dust (which is formed from the silane gas as a by-product in the exhaust gas thermal decomposition step) with the bag filter (32), and then the fluorine recovery step of recovering hydrogen fluoride (which is formed from the fluorine gas as a by-product in the exhaust gas thermal decomposition step) from the heat-treated exhaust gas (T).