Reaction Rates of Hydrogen, Ammonia, and Methane with Mixtures of Atomic and Molecular Oxygen

Abstract

Calculation of the rate constant for the reaction of atomic hydrogen with molecular oxygen to form the free radical HO2 J. Chem. Phys. 73, 765 (1980); 10.1063/1.440182 Product distributions and rate constants for ionmolecule reactions in water, hydrogen sulfide, ammonia, and methaneThe stirred-reactor technique was used to measure the reaction rates of H2, NH3, and CH, with mixtures of atomic and molecular oxygen (0+02) at temperatures ranging from 350° to 6OO 0 K. A mass spectrometer capable of detecting atomic oxygen and hydrogen was used to analyze the reacting mixture in the stirred reactor. It was discovered that atomic oxygen could be quantitatively monitored by the mass spectrometer at a mass-to-charge ratio of 8. The reaction of H2 with the 0+02 mixture was found to be a chain reaction, with four to six atoms of oxygen consumed for each hydrogen molecule. The rate constant for the disappearance of atomic oxygen was 3XlO '3 exp(-8300/RT) ccmole-lsec l . The products of the reaction were H20 and H. The reactions of NH3 and CH, with the 0+02 mixture were complex chain reactions, with a minimum of eight atoms of oxygen disappearing for each molecule of NH3 or CH,. Rate constants for atomic-oxygen disappearance were 3 X 10'2 exp ( -4800/ RT) cc mole-l secl and 2 X 10'3 exp ( -6900/ RT) cc mole-l sec-l, respectively. The products of the former reaction were NO, H20, and small amounts of H2 and H. The products of the latter reaction were H20, CO2, and small amounts of CO, H2, and H.

Progress and Prospective of Nitrogen-Based Alternative Fuels

“…Early measurements significantly overestimated the reaction rate coefficient of eq 30 due to low sensitivity, 335 incorrect fitting values, 336,337 and ignoring possible reactions by the products at high pressures. 338−340 Of all measurements carried out prior to the 1980s, only those by Oganesyan and Nalbandyan were comparable to modern values.…”

The O + NH3reaction: A review

“…The reaction of ammonia with oxygen atoms has been studied at moderate temperatures in flowing [1][2][3][4][5][6][7][8] and static systems [9,101 and at high temperatures (above 1000 K) in flames [ l l l or in a shock tube [12-151. The data through 1969 were reviewed by Cohen and Heicklen [161 and by Baulch et al [17].…”

Oxidation of contaminative methane traces with radio-frequency discharge

“…Although this reaction quotient was less than thermodynamic equilibrium, it nevertheless obeyed Le Chatelier's law and was nearly constant above 0.5 torr. Furthermore, Reaction 5 as well as ^effective and the true thermodynamic equilibrium constant for C0+^02 = C02 (8) are favored by increasing total pressure. Several kinetic studies also provide indirect evidence that C02 and water should be the principal products under the present conditions of higher pressure and extremely small [CH4]/[02].…”