METHOD OF OXIDATION REACTION FLUE GAS TREATMENT AND ENERGY RECOVERY

摘要

A system in which the amount of contents of oxidation reaction flue gas emitted from the process of aromatic dicarboxylic acid production is reduced and in which the pressure held by the flue gas is recovered as power energy at relatively low temperature range (150°?0°C); and a system unified with the production process in which the thus recovered energy is used as power for compression of air for oxidation reaction and in which flue gas of low pressure (0.1 Kg/cm²G) is used as a supply gas for processing, such as drying or transportation, of produced dicarboxylic acid powder. Oxidation reaction flue gas is first treated at 40°C or below by the use of a high-pressure absorbing tower according to acetic acid/water two-stage washing method (1), and thereafter the pressure held by the flue gas is recovered as power energy by means of a two-stage expansion turbine with the use of steam (5 Kg/cm²G steam) generated at the time of reaction as heating source (2). As a result, the recovered energy can be used as rotating power, and the dew point of low-pressure flue gas becomes 0°C or its vicinity or higher, thereby attaining conversion to gas and energy recycled in the production process.