SUMMARY OF STATUS OF VOC REACTIVITY ... - CE-CERT

SUMMARY OF STATUS OF VOC REACTIVITY ESTIMATES AS OF 3/6/98
Table A-4. Documentation notes and comments.
Note.
Documentation or Comment [a]
38 Several alternative mechanisms were developed as part of a paper study on the
potential ranges of reactivity of this compound (Atkinson and Carter [36]), but no
preferred version was implemented in the model.
39 The mechanism which best fits the chamber data uses an adjustment to the
quantum yields which was not incorporated in the standard mechanism.
Therefore, this mechanism may slightly overestimate the reactivity of acetone.
See Carter et al (1993) [13].
40 An estimated mechanism was developed and adjusted by Carter et al (1984)
[9b], and was subsequently updated. However, some aspects may be out of
date.
41 Photolysis rates were adjusted based on simulations of early chamber
experiments during development of 1990 mechanism, and have not been reevaluated.
Re-adjustment not expected to affect reactivity predictions.
42 Mechanism based on the empirical mechanism derived for o-cresol. Cresol
isomers assumed to have the same mechanism as o-cresol. Phenol
mechanism is derived by analogy.
43 Empirical, highly parameterized and over-simplified mechanism was adjusted to
fit results of a limited number of cresol - NOx chamber runs [5,10].
44 Results of the chamber experiments could not be simulated unless some
unknown process, represented by reaction of O3 with HBr forming radical
initiating species, is assumed. The role of surface reactions in affecting the
chamber results is uncertain.
45 Some process in the TCE photooxidation is not adequately represented in the
mechanism. Mechanism might somewhat underestimate MIR reactivities but is
expected to significantly overestimate MOIR and low NOx reactivities.
46 Mechanism estimated based on the mechanism for toluene, with 20% Cl
formation from PCBTF, as discussed in a consulting report [37].
47 A parameterized mechanism was adjusted to fit mini-surrogate reactivity data
with varying NOx. See Carter et al (1992) [11]. The siloxane reactions have
not been incorporated into the current model.
[a] Numbers in brackets refer to reference number on Table 5.
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