| 摘要 |
PURPOSE:To reduce the content of NOx in gaseous CO2 and to improve the purity of refined liquified CO2 by oxidizing NO in crude CO2 into NO2, removing it in a deodorizing unit, and introducing it to a liquifying and refining unit. CONSTITUTION:Gaseous CO2 in the raw gas 2 generated in an LDG boiler 1 is adsorbed in a gaseous CO2 adsorption tower 3 and discharged as a crude gaseous CO2 4 from the tower 3, and compressed 5 to about 15kg/cm<2> and then sent into an NO oxidation unit 6. By the action of metallic catalyst filled in the unit 6, O2 and NO contained in the crude gaseous CO2 4 is reacted into NO2. Then, the gaseous CO2 7 contg. NO2 changed from NO is passed through a dehumidifier 8 packed with a moisture absorbing agent, such as silica gel, to remove the contained moisture. After that, the dehumidified gaseous CO2 9 is introduced into a deodorizing tower 10 and absorptive H2S, SO2, NO2, etc., are adsorbed and removed by the adsorbent, such as activated carbon, packed in the tower 10. Then, the deodorized gas is introduced into a distilling separation type liquifying and refining unit 11, cooled down to about -30 deg.C by a refrigerant, and distilled and liquified in a low temp. distillation tower to obtain refined liquified CO2. |
