|
PANOCHE BURN SITE REMEDIATION
<br /> anhydride, and N-nitrosodiphenylamine. Protectants may include amines, phenols, metal salts
<br /> of dithioacides, and antioxidants (e.g., N-phenyl-N-isopropyl-p-phenylenediamine and
<br /> N-phenyl-o-napthylamine). Table 6 lists the typical composition of a tire.
<br /> TABLE 6
<br /> Typical Passenger Tire Recipe
<br /> (CIWMB, 1996)
<br /> Tire Composition Compound Name(s) Mass%
<br /> Rubber Styrene butadiene 46.78
<br /> Dry Pigments Carbon black 45.59
<br /> Softeners Aromatic oil 1.74
<br /> Plasticizers 2,2-dibenzamidodiphenyl disulfide; <0.1"
<br /> dithiobisbenzanilide
<br /> Activators Zinc oxide 1.4
<br /> Stearic acid 0.94
<br /> Accelerators P-phenylenediamine derivatives 3.0 to 3.3
<br /> Sulfur containing compounds
<br /> Protectants Wax 0.23
<br /> Flame Retardants Red phosphorous, metal hydroxides, halogens <0.1*
<br /> Structural Materials Steel Belts, rayon, nylon, and polyester Generally<5.0 of the
<br /> final mass
<br /> *Assumed range and values were based on a review of"Effects of Waste Tires ..." CIWMB 1996
<br /> A tire fire in a canyon can create a tremendous amount of heat. With the 30- to 50-foot-high
<br /> piles of tire and canyon walls at the Panoche Tire Site, pyrolysis of the waste tires began soon
<br /> after the fire started. Although the tire fire probably did not generate or sustain the typical
<br /> 2,600 degree Fahrenheit of a cement kiln that uses tires as a fuel source, the gas emissions
<br /> and ash constituents from a tire fire and cement kiln are comparable.
<br /> Pyrolysis of a tire produces three prominent products: pyrolytic char, oil, and gas. The
<br /> quantity and composition of these products depend on the temperature of the fire. Generally,
<br /> char is composed of ash, steel belts, carbon black, sulfur, zinc oxide, calcium and magnesium
<br /> carbonates, and silicates. The pyrolytic oil consists of heavy and light oils, benzene, toluene,
<br /> and other semi-volatile and volatile organic chemicals. Gas emissions will consist of sulfur
<br /> dioxide, nitrogen oxides, particulate matter, metals (Al, Cr, Fe, Mn, Hg, Ni, K, Na, Zn),
<br /> semi-volatile organic compounds (naphthalene, phenol, butyl benzyl phthalate, etc.), and
<br /> volatile organic compounds (BTEX).
<br /> Based on a comparison of the analytical results and published information, constituents
<br /> detected at the site were typical. Calcium, magnesium, and zinc were detected orders of
<br /> magnitude above background levels. These metals are consistent with the composition of tire
<br /> char. The level of total hydrocarbons in GIS-2 and GIS-3 confirms the presence of light and
<br /> heavy oils, while the concentrations of ethylbenzene, toluene, styrene, xylenes, and benzene
<br /> also verifies the presence of pyrolytic oil. These volatile organics provide a direct link to the
<br /> known constituents when a tire decomposes from heat. The presence of naphthalene, a semi-
<br /> CIWMB 30
<br />
|