A flow reactor study of HNCO oxidation chemistry
- Technical Univ. of Denmark, Lyngby (Denmark)
An experimental and theoretical study of HNCO oxidation has been carried out. The experiments were performed in an isothermal quartz flow reactor, and the effects of temperature, CO concentration, and NO concentration were investigated at atmospheric pressure in the temperature range 1,025--1,425 K. Oxidation of HNCO proceeds mainly through NCO, which subsequently is oxidized to NO or reacts with NO to form N[sub 2] and N[sub 2]O. This sequence of reactions is chain terminating, and for reaction to occur, radicals must be generated either by alternative oxidation pathways or by the presence of other combustibles. A chain-branching oxidation route initiated by reaction of HNCO with O[sub 2] is proposed in order to explain the observed HNCO decay in the absence of inlet CO. Addition of CO enhances HNCO oxidation and the RAPRENO[sub x] process chemistry, since CO oxidation acts to replenish the radical pool. The experimental results show that the mutual presence of HNCO and NO strongly inhibits CO oxidation at lower temperatures. In addition to the chain terminating HNCO/NCO reactions, a second inhibition mechanism involving NO is necessary to explain this behavior. This mechanism is presently believed to be NO/NO[sub 2] interconversion, but additional work is needed to confirm this. Further progress in the understanding of the HNCO chemistry is dependent on an accurate determination of the rate and/or mechanism of a number of key reactions, including HNCO + OH, HNCO + O[sub 2], NCO + NO and NO + O + M.
- OSTI ID:
- 6958800
- Journal Information:
- Combustion and Flame; (United States), Journal Name: Combustion and Flame; (United States) Vol. 98:3; ISSN CBFMAO; ISSN 0010-2180
- Country of Publication:
- United States
- Language:
- English
Similar Records
The reduction of NO[sub x] by HNCO. [RAPRENOx process]
Modeling and sensitivity analysis study of the reduction of NO{sub x} by HNCO
Related Subjects
400800* -- Combustion
Pyrolysis
& High-Temperature Chemistry
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CARBONIC ACID DERIVATIVES
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
ELEMENTS
HYDROXYL RADICALS
ISOCYANIC ACID
KINETICS
NITRIC OXIDE
NITROGEN
NITROGEN COMPOUNDS
NITROGEN DIOXIDE
NITROGEN OXIDES
NITROUS OXIDE
NONMETALS
ORGANIC COMPOUNDS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
RADICALS
REACTION INTERMEDIATES
REACTION KINETICS