OCR Text |
Show Comparison of Tables 5 and 6 shows that the total quantity of volatil e and semi vo 1 at i 1 e compounds was about equa 1 • The highest concentrat ions for specific compounds are found among the volatiles. One compound, methane, accounts for about 20 percent of the tota 1 mass. In genera 1, the vo 1 at i 1 e compound emissions are characterized by higher concentrations and fewer species. The semivolatile compound emissions are characterized by many species all at low concentrations. EMISSIONS DURING OPERATION WITH COMBUSTION TRANSIENTS Tables 7 and 8 present the stack concentrations measured during operation with transient combustion upsets for volatile and semivolatile compounds, respectively. Collection and interpretation of the data was the same as discussed in the previous section. The compounds are all the same as detected duri ng steady state operat ion, except ethyl ene was detected duri ng the transient operation. Runs 5 and 6 had anomalous high THC levels compared to Run 4. Th is phenomena was also refl ected by increased 1 eve 1 s of methane and methylene chloride. For this reason, the data from Runs 5 and 6 for THC, methane, and methylene chloride are felt to be atypical. Table 9 shows the average concentrations for the steady state operation compared to the transient operation. The data show that for most compounds there was no significant difference between the two operating conditions. Some compounds, however, did show an increase in concentration during the transient operation. Methane, ethylene, benzene, and isooctane increased the most. Isooctane was a probable constituent of the waste fed to the incinerator. Other compounds that showed an increased concentrat ion duri ng the transient operation included carbon tetrachloride (a waste constituent), 1,2- dichloropropane, bromoform, and methyl bromide. Of the semivolatile classes of compounds, only the aromatic compounds appeared to increase in concentration during the transient operation. In general, the effect of the transient combustion upsets appeared to be selective to specific compounds. The compounds affected were mostly either low molecular weight or aromatic. COMPARISON OF COMPOUND EMISSION LEVELS TO THC EMISSIONS To allow a comparison between measurements of THC with a flame ionization detector (FLO) and measurements of individual compounds, all data on the organic compounds was converted to a common basis of a methane equivalent response for an FLO. The methane equivalent responses were based on the effective carbon number for each compound. Appropriate assumptions were made for the unknown volatile compound and a single factor of 0.5 was used for the semivolatile compounds. The factor for semivolatile compounds is likely conservative (under estimates the response) since many of the higher molecular weight compounds have structures with an 80 to 100 percent hydrocarbon skeleton. Tab 1 e 10 shows the resu 1 t of thi s compari son for all six test runs. Generally 50 to 60 percent of the total organic emissions as measured by an FLO was accounted for. 5 |