| 摘要 |
<p>The invention relates to a method for the combined elimination of both ammonia in one or more waste gas streams containing ammonia, and nitrogen oxides in one or more additional waste gas streams containing nitrogen oxide, in a combined ammonia-urea synthesis plant, after the selective non-catalytic reduction in a temperature range of 850°C to 1100°C, with which nitrogen oxide decomposition rates of up to 80% are reached, or after the selective catalytic reduction in a temperature range of 150°C to 550°C, with which nitrogen oxide decomposition rates of up to 99% are reached. The ammonia and the nitrogen oxides react with each other and are converted into nitrogen and water. The waste gas stream containing ammonia that is to be treated from a low-pressure absorber and/or an atmospheric absorber of the urea synthesis part of the plant, and the waste gas stream containing nitrogen oxide to be treated from a flue gas duct of a primary reformer of the ammonia synthesis part of the plant belonging to the combined ammonia-urea synthesis plant are mixed and, depending on the temperature of the mixture and depending on the decomposition rate of the nitrogen oxides to be achieved, a selective non-catalytic reduction or a selective catalytic reduction is carried out, wherein both the ammonia and the nitrogen oxides from the mixed waste gas streams are decomposed simultaneously in the same method step.</p> |
