Re: Tires burning and Dioxin?

[Alan Muller <amuller@dca.net>]

At 12:47 AM 9/20/99 -0400, Tony Tweedale wrote:
>For one, Neoprene a DuPont synthetic rubber), which is basically
>chloroprene, is part of mixed scrap tires.  I don't know if neoprene is the
>polychloroprene that makes up 2% of '93 USA rubber consumption in pie chart
>in ACS' _Chemical & Engin. News ( 29 Aug '94,  p. 14). 

I would think so.

 'Other' makes up
>10% of the market... Neoprene is such a familair name that I might have
>guessed it made up more of the market than that, but maybe c. 2% is
>right...

Neoprene was the first synthetic rubber of consequence to be commercialized
in the US. (DuPont, c 1938).  It's hard to make and very much a niche
product these days.  2% may be correct.

>PCDD/F are said to be in the same range as the non-TDF burn, but the
>summary gives no numbers.  I'd imagine that if Neoprene is ~2% of the tire
>market, it'd be well mixed by the time tires end up as fuel--ie there'd be
>a uniform concentration of chlorprene in all TDFs...but maybe I'm missing
>something.  There's no way that adding, say, 1% of chlorine to a fuel
>wouldn't significantly increase dioxin emissions...

To the best of my (limited) knowledge neoprene isn't used in tires at all.
I would look elsewhere for chlorine content of same.
>
>I see a train derailment in July '97 near Flora MS caused authorities to
>dynamite 35,000 gal of the highly flammable & reactive chloroprene.  I'm
>sure that created a nice dose of dioxins and other o-Cl's into the
>atmosphere...

That would probably have been the monomer, chlorobudadiene ("CD").  It is
shipped cold in refrigerated tank cars.  If delayed in transit it's subject
to spontaneous polymerization and explosion....  Very nasty stuff.

am

"It isn't pollution that's harming the environment. It's the impurities in
our air and water that are doing it."

former Vice-president Dan Quayle