Document BywKdKjZaMKN5B0GaXxmdBVVo

MAY-09-1994 03:06 FROM ADMINISTRATION 1803 BLDG TO 69899 SUMMARY OF WHAT IS KNOWN ABOUT THE RELATIONSHIP BETWEEN FVC INPUT TO MSW'S AND FCDD/F OUTPUT Conclusions It has been shown in laboratory experiments that pyrolysis of PVC under certain conditions of incomplete combustion can lead to formation of PCDD/F's. The question however, is what correlation, if any, exists between PVC loading and output of dioxins and furans (PCDD/F's), during the operation of municipal waste incinerators (MSW's). The data would appear to indicate that under good operating conditions, or with good particulate control, that increasing the O2 load, or FVC load in an MSW will not lead to an increase in FCDD/F emissions. The data would also appear to indicate that under poor operating conditions, i.e. in "upset" conditions, or conditions of poor combustion, that there likely is a positive correlation between Q2 levels and FCDD/F post formation concentrations. Studies In addition to anecdotal information, there are a number of well conducted studies designed to address the PVC question. One such study is the NYSERDA study (New York State Energy Research and Development Authority, 1987). This study, using a full scale operating municipal incinerator was designed to investigate the effect of operating conditions, PVC loading and waste moisture content on PCDD/F emissions. The study also examined the relationship between combustion gas variables. The major conclusions from this study are "There is no evidence that the amount of PVC in the waste stream affects the levels of PCDD/F's at any of the measurement locations. " "Incinerator operating temperatures significantly affected the levels of FCDD/Fs "The levels of PCDD/Fs and carbon monoxide are related; ..." but there may be a threshold level above which CO must be above. Po*t-it~ Fax Note 7671 Phone# F"# &-???? Co. DRAFT MAY-09-1994 08:07 FROM ADMINISTRATION 1803 BLDG TO 69899 P.02 Wastes used in the portion of the study examining the FVC questions were typical MSW MSW + PVC FVC-free (generally cardboard plus wood that had been sorted out of incoming MSW) PVC free+PVC Chlorine load for the experimental runs was about 0.2% for MSW, 0.05% for PVC-free and 1.1% for MSW + PVC. Another series of experiments in Otto HutzingePs lab produced similar conclusions. Lenoir et al (1991) studied PCDD/F emissions in a fluidized bed incinerator. As fuels they used typical municipal waste (RDF) with a CI2 level of 0.9%, RDF + lime, RDF + 2% plastic, RDF + polyethylene (PE), PE alone, PE + 2% NaQ, PE + 3% PVC, wood chips, cellulose,and cellulose + PVC. Their general conclusions are as follows: " Under normal [good] operating conditions, high fluidized bed temperatures ... PCDD/F emissions did not depend on the HO concentration in the flue gas." and specifically 'The lack of relationship between PCDD/F and HQ levels described above indicates that the chlorine of the fuel, from which HO is formed, had no influence on PCDD/F emissions. Indeed, burning RDF with 0.9% Q2, wood chips with 0.2% 02, and PE with 0.01% CI2 led to about the same PCDD/F emissions. ... Adding NaQ to PE and to cellulose fiber, and adding 0.5% FVC to cellulose fiber did not increase PCDD/F concentrations. However, adding 3% PVC to [pure] PE increased PCDD/F levels by a factor of 3 compared to the mean value for PE combustion. This statement lacks statistical significance, since the treatment was not repeated, but it is one of the few experiments where an influence of larger amounts of PVC on PCDD/F emissions were observed in waste incinerators. Conversely it has been frequently published that the addition of PVC to municipal waste and waste paper did not increase PCDD/F emissions (ref. 1 - 5)" DRAFT R&S 150389 MAY-09-1994 03=07 FROM ADMINISTRATION 1803 BLDG TO 69899 P.03 Consistent with the NYSERDA study, they found that PCDD/F emissions changed with operating conditions and correlated with CO concentrations, with a likely threshold in the correlation. Thus, they found only one fuel condition showed increased PCDD/F emissions, and that condition (pure polyethylene plus 3% PVC) has no relevance to actual conditions in an operating MSW. Other authors (ref) have aiduded that there may be a correlation between chlorine or PVC load and PCDD/F emissions, but these studies are based upon correlating results across different incinerators, and are therefore measuring the effectiveness of the air pollution control equipment, rather than the correlation between input streams and emissions. Conclusions Control of PCDD/F emissions in municipal incinerators is attained through proper combustion and operating discipline, and the use of appropriate pollution control equipment. Under those conditions PCDD/F emissions are independent of Q2 load into the MSW incinerator. Waste streams As of 1990, EPA reports that 16.2 million tons of plastic are in the nations MSW. This represents about 8.3% of the total or about 9-8% after recycling. (Still looking for % PVC) Colin Park Don Townsend David Wilson R&S150390 DRAFT TOTAL P.03