| 主权项 |
1. A method for removing NOx gasses by an absorption process and conversion of NOx to nitric acid (HNO3) in the presence of oxygen and water, wherein the NOx gasses comprise NO, NO2, N2O3 and N2O5, the method is a two-step method comprising:
a) pre-oxidation of nitric oxide (NO) to nitrogen dioxide (NO2) and other HxNyOz species by use of a ionic composition catalyst at an oxidation temperature below the decomposition temperature of the ionic composition catalyst, the pre-oxidation temperature is between 80 and 120° C., thereby forming a pre-oxidized gas mixture, where x, y and z are integers in the ranges x=0-1, y=1-2, z=1-5, and b) absorption of NO2 and other HxNyOz species generated in the pre-oxidation process of step a) and conversion of the absorbed NO2 and other HxNyOz species to form nitric acid (HNO3) wherein the absorption and conversion occurs in a medium in the presence of oxygen and water at an absorption/conversion temperature between 30 and 80° C. which is lower than the pre-oxidation temperature in step a), where the nitric acid (HNO3) accumulates in the medium, wherein the ionic composition catalyst comprises one or more ionic compounds. |
