OCR Text |
Show Table 2. Target V O C Reactivities [20]. Compound ethylene (ppbv) acetylene (ethyne) (ppbv) ethane (ppbv) propylene (propene) (ppbv) propane (ppbv) Methylacetylene (propyne) (ppbv) isobutane (ppbv) isobutylene (ppbv) 1-butene (ppbv) 1,3-butadiene (ppbv) n-butane (ppbv) 2,2-dimethylpropane (ppbv) Isopentane (ppbv) n-pentane (ppbv) MIR (gOj/gVOC) 7.29 0.50 0.25 9.40 0.48 4.10 1.21 5.31 8.91 10.89 1.02 0.37 1.38 1.04 Compound Methyl tert-butyl ether (MTBE) (ppbv) 2-methylpentane (ppbv) 3-methylpentane (ppbv) n-hexane (ppbv) benzene (ppbv) Cyclohexane (ppbv) 3-methylhexane (ppbv) n-heptane (ppbv) Methylcyclohexane (ppbv) toluene (ppbv) 2,3,4-trimethylpentane (ppbv) m-xylene (ppbv) styrene (vinyl benzene) (ppbv) Formaldehyde MIR (gOj/gVOC) 0.62 1.53 1.52 0.98 0.42 1.28 1.40 0.81 1.85 2.73 1.60 7.64 2.22 7.15 As suggested in [16], to calculate the net reactivity of the V O C s emitted from a single source emitting n VOCs, the VOC mass concentrations, expressed in g/m3, are multiplied by their respective MIRs (in units of g CVg VOC), and then summed to yield the potential concentration of O3 formed, Le., Potential [03] = ^JVOC\ MIR, (4) ;=i As an example, Fig. 9 shows the speciated VOC concentrations and the corresponding potential O3 production for case 2. This particular case was chosen because a large number of different VOC species were identified in the emissions sample. The histogram clearly illustrates 15 |