Hydrodynamics and Chemistry of Incineration

Research project

1. Power combustion of wastes and biomass (M. Punčochář, supported by GAČR, grant No. 104/97/S002, see Department of Reaction Engineering in Gas Phase, Final report (in Czech))

2. Cleaning of underground water by coal based sorbents (M. Punčochář, supported by GA Ministry of the Environment of the Czech republic, grant No VaV 550/1/99)

   Calcium loaded coal is used for removing heavy metals and organic pollutants from underground water. Lignite loaded by calcium is an effective ion-exchanger. Coal with metal and organic pollutants is combusted in a fluidized bed with simultaneous capture of fly ash and flue gas pollutants.

3. Continuous pilot plant equipment for detoxification of persistent organic compounds (PCBs, PCDD/Fs) in fly ash, carbon absorbers and soils (v. Pekárek, supported by GA Czech Acad. Sci., grant No.A4072901)

   Supported by ASCR grants for 4 years, dehalogenation of org. compounds on incinerator fly ash has been studied, using hexachlorobenzene, polychlorinated biphenyl (PCB Delor 103), dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF). The knowledge of the dehalogenation mechanism has led to a synthetic ash , the patent protection of which is under way. The high dehalogenating efficiency of the ash was proved on laboratory scale by dehalogenation of Delor in oil and on solid phase. A continuous dehalogenation equipment with a capacity of 30-120 kg/day has been designed. The subject of the project is the manufacture of this unit and its testing for:

   1. Detoxification of Delor in oils and in solids
   2. detoxification of fly ash from municipal waste incinerators (PCBs, PCDDs, PCDFs)
   3. detoxification of contaminated soils and sediments
   4. detoxification of carboneous components used in MWI absorbers
4. Deactivation of fly ash as a catalyst in de novo synthetic reactions producing persistent organic pollutants (POP) (V. Pekarek, supported by GA ASCR, grant No. S 4072206)

   On the basis of the knowledge of the dehalogenation and de novo synthetic reactions occurring in the gaseous phase at the fly ash microparticles, to search for a solution of the problem of deactivation of the catalytic activity of fly ashes at temperatures over those required for the de novo syntheses. The formation of polychlorinated benzenes is a model for verification of the fly ash catalytic activity; congener analyses for PCB, PCDD and PCDF will be carried out if catalyst deactivation is successful. Test de novo syntheses will be performed in a flow-through laboratory instrumentation using model synthetic fly ashes that have been investigated previously under conditions corresponding to the technology of incinerators in the presence of about 10 % vol. of oxygen. The prospective experiments will be extended to the oil combustion under pilot plant conditions and possibly also to a 100 kW fluid incinerator that is available at the applicant institution.