FIELD: chemistry.
SUBSTANCE: removal of NOx from gaseous effluents, in particular the removal of NOx from gaseous effluents generated during the production of fertilizers. The method for reducing the content of NOx in the outgoing gaseous stream includes acid decomposition of phosphate ore in the presence of urea. Said emerging effluent gaseous stream has an NOx composition containing 70-100 mole% NO2 and 0-30 mole% NO. The method includes the following steps: a) exposure of the effluent gaseous stream for 0.5-15 seconds with ozone, thereby providing a resulting gas mixture in which NO and NO2 present in NOx are oxidized to higher oxides of nitrogen. Next step: b) removing higher oxides of nitrogen from the specified resulting gas mixture. The urea is present during said acid decomposition of the phosphate ore in an amount of 0.25% by weight or less based on the weight of said phosphate ore. Ozone is added to said gaseous effluent at an ozone/NOx ratio in the range of 0.5-1.4. Also claimed are the use of ozone and urea as additives for the removal of nitrogen monoxides from the exiting gaseous streams and a plant for the production of fertilizers.
EFFECT: group of inventions provides reduction of NOx content in outgoing gaseous streams formed during fertilizer production.
13 cl, 2 dwg
