Unformatted text preview: 7 H 16 ) are combusted in 20% excess air, how many moles of O 2 are required in the feed? What is the equivalence ratio in this condition? (16%) 10. What is the atmospheric lifetime of formaldehyde (HCHO) with respect to photodissociation and oxidation by hydroxyl radicals, respectively? What is the overall lifetime due to these two atmospheric effects? The rate constants are: k HCHO+OH = 9.37×10-12 cm 3 molecules-1 s-1 , k HCHO+hv = 0.1 min-1 ; [OH] atmosphere = 10 6 molecules cm 3 (16%) 11. Estimate the temperature required for an afterburner to destroy 99.5% of the toluene contained in an air stream within a residence time of 0.5 s. You may assume that the combustion reaction is first order with a rate constant that obeys the Arrhenius expression. The frequency (pre-exponential) factor and activation energy associated with the thermal oxidation of toluene are 2.28×10 13 s-1 and 56.5 kcal mol-1 , respectively. (16%)...
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- Spring '08
- Low Pressure Systems, Pressure Systems, stoichiometric air-fuel ratios, 3-zone Hadley cells, air flow patterns