Influence of variation in the operating conditions on PCDD/F distribution in a full-scale MSW incinerator.
Optimizing the operating parameters to minimize polychlorodibenzo-p-dioxins and polychlorodibenzofurans (PCDD/F) emission is the common interest of the municipal solid waste (MSW) incineration industry. In this study, we investigated the distribution of tetra- to octa-CDD/F along the flue gas line in a full-scale reciprocating grate incinerator and evaluated the effects of temperature control and O(2) level on PCDD/F formation. Six runs were laid out and all performed under sufficient burning conditions, in which the combustion efficiency of MSW was more than 99.9%. The total concentration of tetra- to octa-CDD/F measured at the boiler outlet showed an increasing tendency with the increase of boiler outlet temperature (T(B)) from 214 degrees C to 264 degrees C. When flue gas ran across the semi-dry scrubber and cyclone precipitator, in which the temperature varied from 264 degrees C to 162 degrees C, the concentrations of the lower chlorinated dioxins and furans were significantly raised, especially for the TCDF. Increasing O(2) supply from 6.0% to 10.5% essentially led to a higher yield of tetra- to octa-PCDD/F, suggested that under sufficient burning conditions the lower O(2) level was favorable for reducing PCDD/F formation and emission. The variation of O(2) level did not give rise to a systematical change of PCDD/F homologue pattern. For all measurements, the isomer distributions of tetra- to hepta-PCDD/F were more or less the same, nearly independent of variations in the operating conditions and sampling positions. Only the significant increase of the sum of 1,3,7,8-TCDF and 1,3,7,9-TCDF was found in the zone after the boiler section.
Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, PR China.
Hai-Jun
HJ
Zhang
Yu-Wen
YW
Ni
Ji-Ping
JP
Chen
Qing
Q
Zhang
D001572:Benzofurans / Q000032:analysis / Q000737:chemistry*; D017745:Incineration / Q000295:instrumentation / Q000379:methods*; D008962:Models, Theoretical; D010100:Oxygen / Q000737:chemistry; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry; D011108:Polymers / Q000032:analysis / Q000737:chemistry*; D013696:Temperature
D001572:Benzofurans; D000072317:Polychlorinated Dibenzodioxins; D011108:Polymers; C016068:polychlorodibenzofuran; D010100:Oxygen