What is DIOX-BLOKŪ?
DIOX-BLOKŪ is a patented sorbent that prevents de novo dioxin synthesis in combustion processes. Although modern incineration processes completely destroy dioxins, they form anew (de novo) as the flue gas cools below 400ºC. On cool-down, trace organics adsorb on the fly ash and are converted to dioxins by reaction with the metal chlorides on the surface of the ash.
How Does DIOX-BLOKŪ Work?
DIOX-BLOKŪ accomplishes two things:
- it "starves" the fly ash of dioxin reactants by removing organics before they can be adsorbed by the ash,
- DIOX-BLOKŪ does not cause a dioxin-contaminated ash problem.
Unlike powdered activated carbon (PAC), DIOX-BLOKŪ is chemically
inert and adsorbed organics are not converted to dioxins.
Usage and Cost
DIOX-BLOKŪ is used at rates of from 1-2 lbs/ton of waste burned. The delivered cost of DIOX-BLOKŪ is generally less than, or equal to, the cost of PAC, depending on location. Because DIOX-BLOKŪ prevents dioxins from forming, rather than adsorbing them after they have formed, the environmental cost of DIOX-BLOKŪ is far less than PAC.
Results
Because of the high plastics content, dioxin formation is a particularly severe problem in medical waste incineration. Annual stack tests on several large regional medical waste incinerators in the U. K. using DIOX-BLOKŪ in Beco "Alka/Sorb" Dry/Wet scrubber units are shown in Table I. Stack tests at MSW installations in Korea, and hazardous waste incinerators in Japan using DIOX-BLOKŪ in Beco Systems have also shown dioxin emissions of 0.001 to 0.006 ng/dscm, TEQ. Recent results with DIOX-BLOKŪ at the Ul-San MSW facility in South Korea show consistent levels of 0.001 ng/dscm, TEQ. This compares to EU 2002 limits of 0.10 and USEPA limits of 0.2 ng/dscm, TEQ.
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