Environmental Engineering Reference
In-Depth Information
TABLE 9.4
MSDS Descriptions of Trichloroethylene Purity in the 1980s and 1990s
Trichloroethylene
(%)
1,2-Butylene
Oxide (%)
Company
Date
Id Number
Name/Info
Dow Chemical USA 12/14/81
FSC: 6810
Trichloroethylene,
99.4
0.6
NIIN: 00-924-7107
Technical O-T-634
Dow Chemical USA 12/14/81
FSC: 6810
NIIN: 00-924-7107
Neu-Tri
Trichloroethylene #56530
99.4
0.6
Dow Chemical USA 1/1/85
FSC: 6810
Trichloroethylene-E
>95
0.6
NIIN: 00-754-2813
Allied Chemical
Corp.
1/1/85
FSC: 6810
NIIN: 01-031-5512
Trichloroethylene
Low Mobile Ion
—
>97
Ashland Chemical
Company
3/1/86
FSC: 6810
NIIN: 00-678-4418
Trichloroethylene Deg Cold/
Vap; Trichloroethylene,
Technical O-T-634; ASTM
D 4080
95
—
Baxter Healthcare
Corp/Burdick and
Jackson Div
12/1/89
FSC: 6505
NIIN: Liin: 00f038115
Trichloroethylene
99
1
Chem Central
Kansas City
12/1/94
FSC: 6810
NIIN: 00-184-4800
Trichloroethylene, Technical
99.4
0.5
Whether or not PCEMI occurs in the part per million range or in the percent range, if present, it
is likely to become concentrated in TCE through use. In vapor degreasing operations, TCE volatil-
izes more rapidly than PCE, and PCE is concentrated in the remaining liquid TCE. Morrison et al.
(2006) explained that even at sites where PCE was allegedly never used, it may be found where
spent TCE vapor degreasing waste was discharged because of the concentration of PCE as a high-
boiling impurity in TCE.
Morrison et al. (2006) estimated the accumulation of PCEMI in TCE by assuming a starting
ratio of 1% PCEMI, calculating the total volume of PCEMI in the volume of TCE present in the
vapor degreaser solvent reservoir, and then estimating how much PCEMI volatilizes during opera-
tions. They also accounted for the addition of PCEMI in new TCE added to the degreaser between
batch changes. In their example evaluation of the potential for PCEMI to become concentrated, they
assumed a degreaser with a 350-gallon solvent capacity and the addition of 55 gallons of new TCE
per week to make up the volume lost to volatilization, drag-out, and carryout. Morrison et al. further
assumed that the degreaser is cleaned out four times per year and that a total of 100 gallons of TCE
and accumulated oils and other waste are removed per year.
To estimate the rate of volatilization of PCEMI in TCE, the vapor pressure of PCE at TCE's boil-
ing point is determined by using the Clausius-Clapeyron equation, shown here in two forms:
k
(
1
T
)
,
1
___
__
ln
P
vap
=
T
B
−
(9.1a)
ln
(
P
1
R
(
1
P
2
)
=
Δ
H
vap
T
1
)
,
1
___
_____
__
__
T
2
−
(9.1b)
where
P
vap
is the vapor pressure of PCE at the TCE boiling point in atmospheres,
T
B
is the boiling
point of PCE (394.35 K),
T
is the TCE boiling point (360.35 K), and
k
is a constant relating the ideal
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