Реферат: Number: PP-33 Pages: 242-243 Abstract: Nitric acid production is one of the major sources of NO and N2O in the chemical industry. To reduce NO emission in nitric acid production, conventional de-NOX systems for selective catalytic reduction (SCR) NO by ammonia (UKL-7 and AK-72M plants) or non-selective by CH4 (AK-72 plant) are used in Russia. Concentration of N2O in tail gases depends not only on the primary platinum gauzes catalyst selectivity but on the de-NOX conditions as well, because N2O concentration may substantially increase in the case of SCR by ammonia. Emission of N2O from one UKL-7 plant was found to be more than 450 tons per year. High impact of N2O on the environment as greenhouse gas, and the international agreements and regulations require the development of efficient and economical systems for N2O abatement in nitric acid production. Combination of de-NOX SCR unit with N2O decomposition unit in one reactor is one of attractive ways. To this purpose, EnviNOx® technology developed by Uhde is the exemplary embodiment of combined removal of N2O and NOX from tail gas at temperatures 330-600°C [1]. A similar combined system was proposed [2] for Russian UKL-7 plant which was comprised of vanadia-alumina de-NOX catalyst working at 220-300°C as the primary bed, and Fe-zeolite de-N2O catalyst working at 350-400°C as the secondary bed. This work is devoted to the development of de-N2O catalyst working at lower temperature 250-300°C, and modeling one-reactor scheme for combined processing of NOX and N2O in tail gases. Experimental data on the catalytic activity of different oxide systems for N2O decomposition at moderate temperatures are shown in Table 1. The oxide catalyst based on NixCo3-xO4 doped with Cs cations has the spinel-like structure and is the most active and promising system for N2O decomposition at 250-300°C.

Библиографическая ссылка: Ivanova Y.A. , Ivanov D.V. , Chumachenko V.A. , Isupova L.A. , Noskov A.S.
One-Reactor Scheme for NO and N2O Low Temperature Abatement from Tail Gas in Nitric Acid Production
XII International Conference on Chemical Reactors 19-23 Sep 2016