Dioxin formation

[Emmanuel de Broux <emmanuel.debroux@ping.be>]

At 01:49 23/10/99 -0400, you wrote: 

> We are being asked to pay
> for a retrofit to the Wheelabrator MSW incinerator in our community for
> the purpose of "reducing" mercury emissions. The plan is for a
> carbon injection system that cools flue gases allowing extra mercury to
> be captured. A dastardly option! If I'm understanding some of how dioxin
> is formed in the incineration process, cooling the stack gases produces
> more dioxin. Correct? If this is the case, it would be another argument
> against retrofit. Thanks for any help. Jackie

Activated carbon injection is supposed to catch mercury and dioxins
provided the flue gases pass through a bag filter. Carbon particulates
cling to the bag to form an rather effective filter. When bags are shaken
to clean them, filtering dioxins and mercury losses much of its
efficiency. Activated carbon is often lignite coke powder which exists in
an activated variety.

Of course, disposing of the "dirty" cokefied lignite supposes a
careful process to avoid evaporation of the mercury. That process is not
cheap.

Best regards, Emmanuel

- Mr Emmanuel de Broux, avenue du Sacre-Coeur 7, B-5590 Leignon, Belgium.

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