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Catalytic reduction of NO{sub x}; Katalytisk reduktion av NO{sub x}

Technical Report:

Abstract

The selectivity towards nitrogen has been studied with the aim of reducing the amounts of nitrous oxide formed as a by product in the SCR-process. The results show that addition of small amounts of water vapour has a very beneficial effect on decreasing the nitrous oxide formation to very low values at normal SCR conditions (below 400 deg C). At high temperatures the effect is smaller. The formation of nitrous oxide is reduced anyway, by new reactions, at temperatures above 450 deg C. A study on different crystalline vanadia oxides has shown that V{sub 2}O{sub 5} is the most stable phase during the reaction. V{sub 6}O{sub 13} is not stable but is rapidly oxidised to V{sub 2}O{sub 5}. V{sub 2}O{sub 4}(VO{sub 2}) on the other hand is comparatively stable. A change in structure is observed when the reaction is carried out at 400 deg C. Simultaneously the selectivity for nitrogen increases. This is preferentially caused by depressing of direct ammonia oxidation reactions taking place on specific crystalline planes in V{sub 2}O{sub 4}. The support material used, SiO{sub 2}-TiO{sub 2}, has been characterized using XRD, ESCA, FTIR and adsorption measurements. The effect of promoters, Fe and Cu, on a V{sub 2}O{sub  More>>
Authors:
Odenbrand, I [1] 
  1. Lund Inst. of Tech. (Sweden). Dept. of Chemical Engineering
Publication Date:
Sep 01, 1992
Product Type:
Technical Report
Report Number:
NUTEK-91-51917
Reference Number:
SCA: 010800; PA: SWD-93:007444; EDB-94:016900; NTS-94:008802; ERA-19:006059; SN: 94001129771
Resource Relation:
Other Information: PBD: Sep 1992
Subject:
01 COAL, LIGNITE, AND PEAT; REDUCTION; NITROUS OXIDE; STEAM INJECTION; NITROGEN OXIDES; VANADIUM OXIDES; CATALYST SUPPORTS; SINTERING; FLUE GAS; AIR POLLUTION CONTROL; 010800; WASTE MANAGEMENT
OSTI ID:
10117186
Research Organizations:
Swedish National Board for Industrial and Technical Development (NUTEK), Stockholm (Sweden); Lund Univ. (Sweden). Dept. of Chemical Engineering
Country of Origin:
Sweden
Language:
Swedish
Other Identifying Numbers:
Other: ON: DE94730412; TRN: SE9307444
Availability:
OSTI; NTIS
Submitting Site:
SWD
Size:
16 p.
Announcement Date:
Jun 30, 2005

Technical Report:

Citation Formats

Odenbrand, I. Catalytic reduction of NO{sub x}; Katalytisk reduktion av NO{sub x}. Sweden: N. p., 1992. Web.
Odenbrand, I. Catalytic reduction of NO{sub x}; Katalytisk reduktion av NO{sub x}. Sweden.
Odenbrand, I. 1992. "Catalytic reduction of NO{sub x}; Katalytisk reduktion av NO{sub x}." Sweden.
@misc{etde_10117186,
title = {Catalytic reduction of NO{sub x}; Katalytisk reduktion av NO{sub x}}
author = {Odenbrand, I}
abstractNote = {The selectivity towards nitrogen has been studied with the aim of reducing the amounts of nitrous oxide formed as a by product in the SCR-process. The results show that addition of small amounts of water vapour has a very beneficial effect on decreasing the nitrous oxide formation to very low values at normal SCR conditions (below 400 deg C). At high temperatures the effect is smaller. The formation of nitrous oxide is reduced anyway, by new reactions, at temperatures above 450 deg C. A study on different crystalline vanadia oxides has shown that V{sub 2}O{sub 5} is the most stable phase during the reaction. V{sub 6}O{sub 13} is not stable but is rapidly oxidised to V{sub 2}O{sub 5}. V{sub 2}O{sub 4}(VO{sub 2}) on the other hand is comparatively stable. A change in structure is observed when the reaction is carried out at 400 deg C. Simultaneously the selectivity for nitrogen increases. This is preferentially caused by depressing of direct ammonia oxidation reactions taking place on specific crystalline planes in V{sub 2}O{sub 4}. The support material used, SiO{sub 2}-TiO{sub 2}, has been characterized using XRD, ESCA, FTIR and adsorption measurements. The effect of promoters, Fe and Cu, on a V{sub 2}O{sub 5}/SiO{sub 2}-catalyst has been studied. It was possible to determine the content of V(IV) in the catalyst under working conditions and its effect on the activity of the catalyst. Poisoning by SO{sub 2} caused a lowering of the amount of V(IV) present in the active phase. A certain amount of V(IV) was found to be beneficial to the catalyst activity. Sintering of the active material and the support can cause problems in applications using temperatures above 500 deg C. The use of sepiolite, as a catalyst material, has been investigated. A kinetic study showed that a Langmuir-Hinshelwood rate expression fits the experimental data quite nicely. 13 refs, 2 figs, 2 tabs}
place = {Sweden}
year = {1992}
month = {Sep}
}