METHOD FOR PURIFICATION OF NITROGEN OXIDE AND APPARATUS FOR PURIFICATION OF NITROGEN OXIDE

摘要

Disclosed is an apparatus for purification of a nitrogen oxide comprising a gas absorption vessel (1) and a concentration vessel (6). The gas absorption vessel (1) can receive an absorption solution for absorbing NO which comprises liquefied N2O4 and accept a raw material gas to alter the temperature and/or the pressure of the raw material gas and the absorption solution. The concentration vessel (6) can accept the gas supplied from the gas absorption vessel (1) to alter the temperature and/or the pressure of the gas. In the gas absorption vessel (1), for example, a raw material gas containing NO is reacted with an absorption solution containing liquefied N2O4 to cause the absorption of NO into the absorption solution. Subsequently, the absorption solution is increased in its temperature and/or decreased in its pressure to generate an intermediate gas containing a relatively large amount of NO and a relatively small amount of NO2 from the absorption solution. In the concentration vessel (6), the intermediate gas is decreased in its temperature and/or increased in its pressure to generate concentrated N2O3 and/or concentrated N2O4.