[Dioxin-l] TOKYO TO NEUTRALIZE BURNT ASH TO COMBAT DIOXIN

[Neil Tangri]

When Paul Connett & I were in Japan, we saw one incinerator that included a
completely-enclosed furnace for the vitrification of fly ash. They used oil
to heat the ash hot enough to melt the ash into a glass-like substance,
which should make it less likely to contaminate groundwater supplies, etc.
I also understand that these temperatures are sufficient to break down the
dioxin; but I don't know what keeps it from re-forming in the exhaust.

In any case, this is an extremely expensive and energy-intensive operation.
The engineers at the plant told us that the vitrification furnace alone
consumed more energy than the entire waste-to-energy plant produced.

Neil



THURSDAY, JANUARY 13, 2000, EVENING EDITION

SANKEI (SOCIETY PAGE)                  000113E

 TOKYO TO NEUTRALIZE BURNT ASH TO COMBAT DIOXIN
 TOKYO =96 The Tokyo metropolitan government decided by January 13 to
treat
burnt ash with high temperatures to reduce dioxin that is generated in
the
process of disposing of garbage.  The government is planning to apply
this
measure to all burnt ash generated in the 23 wards by 2006.  The measure

will be the first to be adopted by prefectural governments.
 Tokyo=92s flammable waste amounts to three million tons a year.  Ash from
the
incinerators is dumped in the shielded landfill in the Bay of Tokyo so
that
dioxin won=92t escape into the soil.  However, 80% of dioxin generated
while
disposing of waste still comes from the ash.  To trim down the dioxin
generation, Tokyo officials decided to build plants which can make slug
from
the ash by treating it with a temperature of 1,200 degrees or higher.
Incineration can reduce the volume of waste of three million tons to ash
of
300,000 tons.  The new plants can further cut down the volume of ash by
half
as dioxin becomes harmless compounds.  A total cost for the plants is
about
64 billion yen.