The formation and emission of dioxins in large scale thermal processes

被引:304
作者
Everaert, K [1 ]
Baeyens, J [1 ]
机构
[1] Katholieke Univ Leuven, Dept Chem Engn, B-3001 Heverlee, Belgium
关键词
dioxins; fingerprints; thermal processes; MSWI; correlation; operating parameters;
D O I
10.1016/S0045-6535(01)00143-6
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
The paper assesses extensive data of PCDD/F measurements on flue gas emissions from thermal processes, including, e.g. municipal solid waste incinerators (MSWIs), combustors of wood and industrial waste, coal fired powerplants and boilers, ferro and non-ferro processes. Numerous investigators have conducted laboratory experiments to assess the formation mechanisms of PCDD/F. The results, obtained from fixed-bed experiments, have been critically evaluated and indicate that de novo synthesis is the dominant mechanism in actual thermal processes where conditions that favour the precursor formation are not experienced. The analysis of PCDD/F profiles from the large scale thermal processes in general, and MSWIs in particular, supports the dominant role of the de novo synthesis, irrespective of the type of thermal process considered. The PCDF/PCDD ratio exceeds 1 and the degree of chlorination points towards the dominant presence of HpCDD and OCDD within the dioxin group, and of PeCDF, HxCDF and HpCDF within the furan group. Since real-time measurement of PCDD/F is impossible, the correlation of PCDD/F emissions with operating parameters and/or emission levels of other more easily measured pollutants could be a tool in predicting the PCDD/F formation levels. Data of Flemish MSWIs were used to statistically assess such correlations. From an evaluation of the data at a given operating temperature, misleading conclusions can be drawn. Only the effect of temperature is evident. After converting all data at a reference temperature of, e.g. 230degreesC, PCDD/F concentrations achieve nearly constant values, irrespective of the values of other parameters, thus stressing that the major controlling parameter for the PCDD/F emission is the temperature of the ESP. The PCDD/F concentrations increase with temperature in the range up to 280degreesC. The ESP temperature should be kept preferably between 180degreesC and 200degreesC, where de novo synthesis is reduced and where PCDD/Fs are increasingly adsorbed on the fly ash, in line with the standard temperature dependence of adsorption isotherms. (C) 2002 Elsevier Science Ltd. All rights reserved.
引用
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页码:439 / 448
页数:10
相关论文
共 35 条
[1]  
ADDINK R, 1992, INT S DIOX 1992 TAMP
[2]  
Akki U., 1997, ORGANOHALOGEN COMPD, V31, P475
[3]  
Altwicker E., 1993, ORGANOHALOGEN COMPD, V11, P269
[4]  
BAEYENS J, 1994, D1994613742 DIV ENV
[5]  
BLUMENSTOCK M, 1998, ORGANOHALOGEN COMPOU, V36, P59
[6]   FLY-ASH MEDIATED REACTIONS OF PHENOL AND MONOCHLOROPHENOLS - OXYCHLORINATION, DEEP OXIDATION, AND CONDENSATION [J].
BORN, JGP ;
MULDER, P ;
LOUW, R .
ENVIRONMENTAL SCIENCE & TECHNOLOGY, 1993, 27 (09) :1849-1863
[7]   QUANTITATIVE COMPARISON OF DENOVO AND PRECURSOR FORMATION OF POLYCHLORINATED DIBENZO-P-DIOXINS UNDER SIMULATED MUNICIPAL SOLID-WASTE INCINERATOR POSTCOMBUSTION CONDITIONS [J].
DICKSON, LC ;
LENOIR, D ;
HUTZINGER, O .
ENVIRONMENTAL SCIENCE & TECHNOLOGY, 1992, 26 (09) :1822-1828
[8]  
DONGHOON S, 1998, ORGANOHALOGEN COMPD, V36, P143
[9]  
DONGHOON S, 1999, ENVIRON SCI TECHNOL, V63, P2657
[10]  
EGLER R, 1998, P S DIOX VRIJ U BRUS