Cw. Lee et al., EFFECTS OF COPPER CONTAMINATION ON DIOXIN EMISSIONS FROM CFC INCINERATION, Combustion science and technology, 116(1-6), 1996, pp. 455-478
A test program was developed and implemented for investigating the eff
ects of copper contamination on dioxin emissions from incinerating chl
orofluorocarbons (CFCs). Experiments were performed using a turbulent
flame reactor (TFR) with a capacity of 21 kW to investigate the effect
of copper contamination in the combustor refractory on dioxin emissio
ns. Distillate fuel oil doped with copper naphthenate was fired, follo
wed by a copper nitrate solution which was injected into the TFR fired
by natural gas, with 1 g/hr copper injection rate for a total of 20 h
ours prior to the incineration of the unused, pure CFC-12 (8.7 vol% CF
C-12, 92.3 vol% propane fuel). High dioxin emissions (454 ng/dscm tota
l polychlorinated dibenzo-p-dioxins and dibenzofurans) were observed.
Subsequent firing of the TFR with the propane fuel for 54 hours reduce
d the dioxin emissions to about 386 ng/dscm during the following CFC-1
2 incineration test. The test results suggest that high dioxin emissio
ns could be caused by a strong promotional effect when highly chlorina
ted wastes, such as CFCs, are incinerated in a facility on which the r
efractory is contaminated with trace levels of copper from the previou
s treatment of a cooper-containing waste. Incineration tests were also
performed on a recovered CFC-11,refrigerant which contains 5 vol% res
idual oil (with 4 ppm copper contaminant in the oil). The test results
show that the level of copper contaminant contained in the recovered
CFC-11 is insufficient to cause dioxin emissions. The high levels (>99
.999%) of destruction efficiency and the low levels of products of inc
omplete combustion (PICs) emissions from the incineration of the recov
ered CFC-11 are found to be very similar to those from the incineratio
n of unused, pure CFCs.