III International Conference

PP-II-53INVESTIGATION OF CATALYSTS FOR NITRIC OXIDE AND NITROUS OXIDEABATEMENT IN THE TAIL GAS FROM NITRIC ACID PLANTSKolesnikov V.P., Peshkova L.V., Strelnikov E.A.Nevinnomyssk technological institute (a branch) SEI HPE “Northern -Caucasus statetechnical university”, NevinnomysskE-mail: pelar_nti@mail.ruAt present, nitric acid plants are to be the main man-caused sources of the nitric oxideemissions and, particularly, of the nitrous oxide – N 2 O. Basing on the literature information,at the pilot plant, operating on real gas flows of the nitric acid plant, there have been preparedand investigated six types of catalysts, designed for decomposition and reduction of the nitricoxides by ammonia. The special attention has been paid to the catalyst ability for the nitrousoxide abatement.The Russia has ratified the Kyoto Protocol, in the addendum of which there have beenspecified six the most dangerous greenhouse gases. The nitrous oxide, which is alsoconsidered to be the ozone damaging gas, has been included in this number. The mostsignificant man-caused sources of the nitric oxides – NO x , (NO + NO 2 ) and N 2 O are nitricacid plants.Generally, NO x abatement in the tail gases from such plants has been made through theircatalytic reduction by ammonia, but for all that, N 2 O has not been reduced. Nowadays, all aroundthe world, there are made trials in search of efficient ways of its decomposition and reduction.The Foreign researchers have cited several works [1-4], indicating the possibility of N 2 Odecomposition. However, as a rule, they have been made on the laboratory scale, using thesimulated gas flows.At the moment, all the abatement methods are divided into three types: primary,secondary and tertiary. The primary ones cover the making of the selective catalytic systemsfor ammonia oxidation, not producing N 2 O, the secondary ones – the making of the catalyticsystems, decomposing N 2 O immediately in the ammonia oxidation reactor, the tertiary ones –N 2 O reduction after NO x absorption stage, i.e. virtually jointly with the nitric oxide abatementfrom the tail gases at temperatures 220-280 o C.We demonstrated [5], that existing in Russia the nitric acid plants: UKL-7, combinedlines 1/3, 5 ata, have been equipped by ammonia oxidation catalytic packages, producingfrom hundreds to tenth portions of N 2 O volume percentage, i.e. the primary methods have notyet been realized.260