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ORNL.2677
Reactors—Power

TiD-4500 (14th ed.)

Contract No, W-7405-eng-26

REACTOR PROJECTS DIVISION

ALUMINUM CHLORIDE AS A THERMODYNAMIC WORKING FLUID

AND HEAT TRANSFER MEDIUM

M. Blander, L. G. Epel, A. P. Fraas, and R. F. Newton

DATE ISSUED

SEP 911959

OAK RIDGE NATIONAL LABORATORY
Uak Ridge, Tennessece
- opesated b

UNION CARBIDE CORFORATION
for the
U.5. ATOMIC ENERGY COMMISSION

MARTIN MARIETTA ENERGY SYSTEMS LIBRARIES

R

3 4456 03LL3LY O
ALUMINUM CHLORIDE AS A THERMODYNAMIC WORKING FLUID AND HEAT TRANSFER MEDIUM

M. Blander L.. G. Epel A. P. Fraas R. F. Newton

ABSTRACT

The basic physical properties ond thermodynamic constants of aluminum chloride have been
calculated to obtain the data required for engineering calculations of thermodynamic cycles
employing aluminum chloride vapor. The possible corrosion problems invelved were evaluated
from the standpoint of basic chemical thermodynamics, and it was concluded that high-nickel-
content alfoys would contain aluminum chloride satisfactorily.

The advantages of gaseous aluminum chloride as an intermediate heat transfer medium in a
molten-salt-fueled reactor were evaluated. It was determined that the temperature range of the
molten-salt heat transfer system was too low to utilize aluminum chloride effectively. A gas.
turbine cycle employing aluminum chleride as the working fluid and a binary vapor cycle employing
water vapor for the lower temperature cycle were also considered. Meither of these studies showed
aluminum chloride to have outstanding advantages. It is believed, however, that special appli-

cations may be found in which it will be possible to exploit the unique characteristics of aluminum

chloride.

 

INTRODUCTION

Gaseous aluminum chloride appears to be attrac-
tive as a heat transfer medium and as a thermeo-
dynamic-cycle working fluid as a consequence of
the fact that it exists as the monomer AICI, at
high temperatures and as the dimer A|2C|6-ct fow
temperatures.  The effective specific heat and
thermal conductivity of a gas that associates are
considerably enhanced because of the association
equilibrium at temperatures ot which there is an
appreciable fraction of both monomer and polymer,
and therefore aluminum chloride may be an excep-
tionally good heat transfer medium for some
applications.  Its possibilities as the working
fluid in a thermodynamic cycle stem from the fact
that, in an idealized gas turbine with a negligible
pressure drop in the system, the pump compressor
will require work proportional to the compressor
inlet temperature times the specific gas constant
of the dimer for any given pressure ratio. In the
high-temperature region at the turbine, on the other
hand, if the gas is completely monomeric, this
same weight of gas will do work proportional to
the turbine inlet temperature times the monomer
gas constant for the same pressure ratio. Because

of the relatively large difference in the gas constant
between the monomer and dimer, the ratio of
turbine work to compressor work will be greater
than for a gos that does not dissociate. Further,
the energy losses due to the inefficiency of both
the compressor and the turbine will have relatively
smaller effects on the over-all thermal efficiency
with a dissociating gos as the working fluid.

BASIC PHYSICAL PROPERTIES OF
ALUMINUM CHLORIDE

The objective of this study was to investigate
the possible advantages of aluminum chloride
arising from its dissociation and the consequent
increase in effective specific heat and thermal
conductivity. Qualitatively the reason for these
increases is simple. Lowering the temperature of
the gas will yield not only the heat given off if
the composition of the gos were ‘‘frozen,”” but,
since the gas is more highly associated at lower
temperatures, it will also give off the chemical
heat due to the association of some of the monomer
molecules as a result of lowering the temperature.
The same phenomenon increases the thermal
conductivity.  The thermal conductivity is the
amount of heat that would be transferred in unit
time across unit area from a temperature T + dT
to 1 divided by the temperature gradient, d7/dx.
The frozen thermal conductivity is that which
would occur if the composition were frozen at an
average weight fraction @ _ of the polymer and w,
of the monomer at both temperatures. Since w,
is higher at 7 + dT and w_ is higher at T than the
average, relatively more monomer would diffuse
from T +dT to T and more polymer from 1" to T +dT
than for a frozen composition. The composition
of the higher-temperature gas molecules diffusing
to the lower temperature would change with a
trend toward the lower equilibrium concentration
of monomer at the lower temperature and would
give off heat in the process. This chemical heat
contribution is part of the heat flux.

Quantitative expressions for these phenomena

 

 

have been given by Butler and Brokaw.! For a
substance which dimerizes,
AH2 w]wzfl + wl)
C, =C, + e (1
be v/ RT?2 4M]
AHZ (PP [y,
A, = A+ - : (2)
€ RT2A\RT /N 2
where
Cpe = effective specific heat in

cal.g™ .deg™ !,

Cpf = frozen specific heat,
AHl = heat change for the reaction
—_—
AlLCl = 2A1CH,,
R, R* = gas constants in proper units,

w, w, = weight fraction of monomer and dimer,
respectively,

A, = effective thermal conductivity in

caleem™ Vsec™ tideg™ !,

)\f = frozen thermal conductivity,

D12 = interdiffusion coefficients of monomer
and dimer,

P = total pressure,

M, = molecular weight of a monomer.

 

). N. Butler and R. S. Brokaw, J. Chem. Phys. 26,
1636 (1957).

The guantities of practical interest, the effective
specific heat, C, , the effective thermal conduc-
tivity, A, and the viscosity, have never been
These and other quantities of interest
must be estimated. It is fortunate that the theory

of gases is well developed and, for some calcu-

measured.

lations, is more reliable than measurements.

Effective Specific Heat

The effective specific heat was calculated by
use of Eq. (1). The frozen specific heat of Al Cl
C,, was estimated according to well-known

bl . 2
statistical mechanical methods* by use of the
infrared vibrational frequencies measured or esti-
mated by Klemperer.® The frequencies for AlCI,
were estimated by analogy with the compound
E’:C!3 (ref 4). The average value of the specific
heat in the temperature range 500 to 1000°K is
0.16 cal.g™.(°C)~' for ALCl, and is 0.14
cc:z]-g"]-(c(f)“1 for A|C|3. At each composition
of the gas, an average value was computed from
the composition-weighted average of these two
values for the monomer and the dimer.

The composition of the gas may be computed
from the equilibrium constant

, (3a)

where

AF® — All ~ TAS® = ~RT In K , (35)

in which AH is the heat of dissociation of the gos,
which was taken as 29.6 kcal/mole (ref 5), and
AS® is the entropy difference between 2 moles of
AICI; at 1 atm pressure and 1 mole of ALLCl, at
1 atm pressure, which was token as 34.6
cal.-mole™'.deg™! (ref 5). The values of )
calculated from Eqs. (3a) and (36) at pressures of
0.1, 1, and 10 atm, respectively, in the temperature
range 500 to 1200°K ore listed in column 2 of
Table 1. Column 3 of the same table lists the

 

2J. E. Mayer and M. G, Mayer, Statistical Mechanics,
Wiley, New York, 1940,

3W. Klemperer, J. Chem, Phys. 24, 353 (1956).

4G. Herzberg, Molecular Spectra and Molecular Struc-
ture, Yan Nostrand, New York, 1945,

SA. Shepp and S. H. Bauver, J. Am. Chem Soc. 76,
265 {1954}).
Table 1. Calculated Values of w,, cpe,if, and A for Aluminum Chloride

 

 

Temperature Weight Fraction Cpe Af Ae

(%) of Menomer, wy (1= Vdeg™ ) (caliem™ Lesec™ Lideg™ 1) (cabrem™Visec™ Vedeg™ )
For a Pressure of 0.1 atm
% 1078 x 1078
500 0.003 0.17 12 14
550 0.013 0.19 13 18
600 0.038 0.25 13 26
650 0.100 0.35 14 42
700 0.223 0.51 15 63
750 0.422 0.66 16 77
800 0.655 0.63 17 68
850 0.831 0.43 18 47
900 0.926 0.28 19 32
950 0.966 0.20 19 25
1000 0.984 0.17 20 23
1050 0.992 0.15 20+ 22
1100 0.996 0.15 21 22
1150 0.998 0.14 21 21+
1200 0.999 0.14 22 29—
For a Pressure of 1 atm
x 10~8 x 1078

500 0.001 0.16 12 13
550 ~ 0,004 0.17 13 15
600 0.012 0.19 13 17
650 0.032 0.22 14 24
700 0.072 0.28 15 34
750 0.145 0.36 15 46
800 0.264 0.47 16 60
850 0.428 0.55 17 68
900 0.612 0.54 18 63
950 0.766 0.44 19 50
1000 0.870 0.32 19 37
1050 0.929 0.24 20 30
1100 0.961 0.19 20 25
1150 0.978 0.17 21 24

1200 0.987 0.16 22 ’ 24
Table 1 {(continuved)

 

 

Temperature Weight Fraction Cpe ’\f ’\e
() of Monomer, 1 (cc[-g"l-deg"l) (cql-cm"']'sec'”]-deg"]) (cal-cm”]-sec“]-degwl)
For a Pressure of 10 atm
x 107° x 1076
500 0.000 0.16 12 12
550 0.001 0.16 13 14
600 0.004 0.17 13 14
650 0.010 0.18 14 17
700 0.023 0.20 14 20
750 0.047 0.23 15 26
800 0.087 0.27 16 34
850 0.148 0.32 16 42
%00 0.240 0.38 17 52
950 0.352 0.43 18 58
1000 0.4%90 0.46 18 59
1050 0.622 0.44 19 54
1100 0.740 0.38 20 47
1150 0.827 0.30 21 40
1200 0.888 0.25 21 33

 

values of € estimated by use of Eq. (1) for the
three pressures and the same temperature range.
A plot of Cpe and the average frozen specific heat
C f vs temperature at the three pressures is
presented in Fig. 1.

Effective Thermal Conductivities

The effective thermal conductivities were calcu-
lated using Eq. (2). The frozen thermal conduc-
tivities of monomer and of dimer were calculated
from the equation®

(1.9891 x 10~ (T/M )2 [, € 4

A - S e
f ’

 

where M is the molecular weight of o polymer,

o, is the average effective molecular diameter of

 

8J. 0. Hirschfelder, C. F. Curtiss, and R. B. Byrd,
Molecular Theory of Gases and Liquids, pp 14, 528,
534, Wiley, New York, 1954.

a polymer in angstroms, and {) is a factor which
corrects for intermolecular interactions and can
be calculated theoretically for simple potential
functions in terms of the parameters of the potential
function.”

A crude estimate of 02 was made for Al Cl. and
AlCI,. From electron diffraction data on A|2C|6
(ref g), structural estimates for A]Cl3 (ref 5), and
the van der Waals radii of chlorine atoms, the
dimensions of A|2C|6 and AICI; were estimated.
By comparison of the relative dimensions of
similar compounds to their effective collision
diameters,? the effective collision diameters of
Al,‘_)Cl‘5 and AICI; were estimated. For the

 

For a more accurate equation see J. O. Hirschfelder,
J. Chem. Pbhys. 26, 282 (1957). The use of the more
accurate equation leads to only a relatively small dif-
ference from the values calculated here.

BL. R. Maxwell, J. Opt. Soc. Am. 30, 374 (1940).

9Hirschfeic|er, Curtiss, and Byrd, op, cit., Table {-A,
pp 111112, 162.
Lennard-Jones 6-12 interaction potential, € has
been calculated as a function of the parameter
kT/€c, where € is the depth of the potential well,
The volue of ¢ is unknown for either AIZCié or
AICl,. We may, however, estimate € by analogy
with other halogen-containing compounds.  Of
several halogen-containing compounds? the lowest
value of €/k is 324 for HI and the highest is 1550
for SnCl,. With these values as limits, the fol-
lowing values were obtained for (:

T {°K) €/k Q
500 324 1.3
1550 2.7

1000 324 1.0
1550 2.0

The range of values of O listed is 1,0 to 2.7, and
a value of & = 2 was arbitrarily chosen as being
reasonable. The value of D, P was estimated
from the equation !9

i ]/2
0.0026280 [ M1+ M,
12 Peoon — — | T ——o ’ (5)

sz % QMIMZ
where M, and M, are the molecular weights of
monomer and dimer, respectively, Tig= (a] + 02)/2,
and 7 is o correction for intermolecular inter-
actions. [t does not differ greatly from 0, and
therefore the value 2.0 was used. The calculated
values of I\, P in the temperature range 500 to

1200°K are listed in column 2 of Table 2. The
average frozen thermal conductivities, A, and the
effective thermal conductivity, A, calcu{afed' from
Fa. (2), ot pressures of 0.1, 1, and 10 atm were
listed in Table 1. Plots of —Xf and A_ vs tempera-
ture at the three pressures are presented in Fig. 2.

The constants and parameters used in these
calculations are summarized below:

R =1.9869 cal-mole™ T.deg™ !
R’ = 82.057 em®.atm-mole™ .deg™ !

AH = 29.6 keal for the reaction
AI2C|6 === 2A|C|3
AS®=34.6 e.u., entropy change for reaction

Al Cl, &= 2AICI, with both monomer and
dimer at their standard state of 1 atm

 

19pid., p 530.

UNCLASSIFIED
ORNL--LR-0OWG 35264R2

 

 

 

 

500 600 700 800 200 1000 1100 1200
TEMPERATURE [°K}

Fig. 1. The Calculated Effective Specific Heot of
Aluminum Chloride as a Function of Temperature at

Three Pressures.

UNCLASSIFIED
ORNL —~ LR DWG 397132

   
   
  

 

__ 8o [—~' T T T T
’g 70 L )_\9 ,,,,,,,,,,,,,,
g R
Tl BO bmevreemebeeeeeeee e AN L R
o I

S B0 e P N N N
T 40

5 3

- 30 ___________ 1
Q

< +

2

o 10 ............... Sreesmemmrssrmsesccsooseego
~< | )

O ——

 

 

 

 

 

500 600 700 800 200 1000 1100 1200
TEMPERATURE {°K)

Fig. 2. The Calculated Effective Thermol Conductivi-
ties of Aluminum Chloride as a Function of Temperature

at Three Pressuyres.

o2 = 40 A2

o2 - 65 A2

02, =51.7 A2

M, =M,/2=133.35 g/mole
Q=0 =20

Cv = Cp - R

Viscosity

The viscosity was estimated from the equation®

2.6693 x 105 (M _T) 1/2

N, = (6)
5 a2

n

 
Table 2. Valves of Dyy P, 74, and 175

 

 

T Dy, P Viscosity of Monomer, 17, Viscosity of Dimer, 7,
(°K) (cmz-atm-sec" } (g-cm“1-sec" ) (geem™ 'esec” )
x 10™3 x 107° x 1076
500 21.3 36 75
550 24.6 g0 79
600 28.0 94 82
650 31.6 98 86
700 35.3 102 89
750 39.2 106 92
8060 43.1 109 95
850 47,2 112 98
900 51.5 116 101
950 55.8 119 103
1000 60.3 122 106
1650 64.8 125 109
1100 69.6 128 111
1150 74.3 131 114
1200 79.2 134 116

 

for both monomer and dimer. The calculated values
are listed in columns 3 and 4 of Table 2.
mixture

For a
of monomer and dimer, a composition
weighted average would be an adequate approxi-
mation to the viscosity.

Vapor Pressure

The vapor pressure of solid aluminum chloride
in equilibrium with the gaseous phase may be
calculated from the equotion'!

| P(T)_~6360
og P (atm) = -

 

+3.77 log T —

~ 0.00612T7T + 6.78 . (7}
The vapor pressure is 1 atm at 180°C {453°K).

VYelocity of Sound in Aluminum Chleride

The velocity of sound, Cor in the working fluid

is needed for turbine design. At frequencies low

 

0. Kubaschewski and E. L. Evans, Metallurgical
Thermochemistry, Wiley, New York, 1956,

enough so that the velocity of association and
dissociation of the aluminum chloride is fast
enough to follow the compression and rarefaction
of the gas, the velocity of sound may be calcu-

lated from®
2
~1
co._ . 8
° (ov/oP), ' ®
where C is the velocity of sound in cm/sec, v is

the specific volume of the gas in cm>/g, P is the
pressure in dynes/cm2, and § is the entropy. The
value of (au/ap)s can be calculated from the
exact thermodynamic relation!?

; Ov ‘O \2
(@L) H(_é_) 4_1.(3__) (9)
or /. \op c, \oT /p

AT pe

 

12(3. N. Lewis and M. Randall, Thermodynamics and
the Free Energy of Chemical substances, p 164, McGraw-
Hill, New York, 1923.
and the equation

1 T
po=|— ') RT (10)
Mz

in which the reasonable assumption is made that
the gaseous monomer and dimer individually
behave as ideal gases and that all deviations from
an ideal gas are due to the association or dissoci-
ation of the goseous monemer or dimer. An evalu-
ation of (dv/dP) . and (du/3T), from Eq. (10) and

the thermodynamic relation

dlnk A dln [4w$1’/(] - w%)]
dT 2 aT

 

 

(1

leads to

/av v ZU.ILU2
) = (14
JP)p P 2

 

 

and
av> v( A11w1wz>
3T), T \ RT 2
]+w ) 5 14/
R i AH Y12
—_— 14+ — . (13)
P M2 RT 2

Substitution of Egs. (12) and (13) into Eq. (9}

leads to

L. RT (1 +wI> [ wyw,
-5
P /¢ p2 M, 2
R(1 +wl) < AH w‘wz)zl
- | T 4 e . (14)
M, Co RT 2 _

THERMODYNAMIC PROPERTIES

 

 

 

 

 

 

In the gaseous phase the state of an equilibriuvm
mixture of AlCl, and AICI, is determined by any
two independent properties, and knowledge of the
thermodynamic state makes it possible to determine
the thermodynamie properties. The two independent
defining properties
fraction of monomer, enthalpy, entropy, and specific

used to calculate weight

volume were temperotuwre and pressure. The
relations used in the computational procedure are
summarized below.

Determination of Weight Froction of Monomer,

 

 

wy. =~ It hos been shown by Newton, from free-
energy-change relationships, that
1 1 1/2
w] = (—5 +—2—tanh u) ' (]5)
where
1 P 13420
u=8.016 ~ —1In - ,
2 14.6%96 T

T is in °R, ond P is pressure in psia.

Determinction of Enthalpy, 5. — The enthalpy
of the mixture is the sum of the enthalpy the gas
would have if it were all in the dimer state plus
the enthalpy of dissociotion. Choosing absolute
zero temperature as the base for enthalpy and
0.1575 Btu.1b~ 1.(°R)~ ' as the frozen specific heat
averaged for the temperatures and pressures under
consideration, the ‘‘sensible” enthalpy, in Btu/lb,
is

b, = 0.1575T .

The enthalpy of dissociation is 199.7 Btu for each
pound of A|2CI6 monomerized. Therefore the total
enthalpy is

h=0,1575T + 199.71,0] . (16)

Determination of Entropy, s. — From the definition
of entropy in Btu.lb~ L(°R)™ 1,

erevarsible

 

 

 

ds = '
T
it can be shown'? that
du + P dv
ds =
T
Noting that
dh =du+ P dv +v dP
gives
dbh — v dP
ds = o
5

 

13568, for instance, J. H. Keenan, Thermodynamics,

p 85, Wiley, New York, 1941,
Then, for an isobaric process, that is, constant

pressure,
T
2 db Ab
,_\s]';‘zf — 17)
T T T

for small variations in T, where 1 and 2 are thermo-
dynamic states.

The entropy was considered equal to zero at
900°R and 150 psia, and the entropy ai other
temperatures at this pressure was approximated
by a stepwise, finite-difference procedure using
the approximation given above. To get the entropy
at 900°R and some other pressure, it is possible

to use one of Maxwell’s relations '4

s\ jo
(), = ~{3),

\ %

For a constant temperafure process, then

Py s
,\s]? = wf ? (—-L-> dP
o1,

Py NP

As shown below, tf I’ is expressed in pounds per
square foot (psf),

T
v =5.793(1 +u,)

=
Since (1 + u,) does not vary from unity by more

than about 0.3% at 900°R for the pressures under
consideration, it can be stated that

T 5.793
)

so that at constant temperature

\ P35.793
A\slt = ~ —dr
1 p

 

9
Pl
=5793 In— in ft-lb-lb~= 1.(°R) ™!
P2
P]
= 0.007444 In——  in Btu.lb™ LERY!
P2

 

14,04, p 342.

Determination of Specific Volume, v. —~ The
perfect gas law states that
RO -
Pv=—T, (18)
! m
where
R, = 1545 ff-lbf-mole”]e(oR)"“! ,
and M_ is the molecular weight of the mixture and

is 266??7/(1 + w]). Numerically this becomes

T
v=5793(01 4 w)) - inft3/lb
P ¥

where P is expressed in psf, or
T
v=0.00023(1 + w))— inft’/lb,

where P is in psia.

Example of Numerical Procedure. — As an example
of the calculational procedure employed, a compu-
tation of weight fraction of monomer, w,, enthalpy,
h, entropy, s, and specific volume, v, at a pressure
of 30 psia and a temperature of 1260°R follows:

1. For the weight fraction of monomer calcu-

 

 

 

lation,
/1 1 \N1/2
Wy = (——+—-fon'r| u) ,
2 2 ;
where | P 13420
©=8.016 ——in-——
2 14.696 T
] 30 13420
= 8.016 —— In -
2 14.696 1260
= —2.9923

ond therefore
11/2
1 1
_____ + —tanh (~2.9923)
2 2

Wy o=
1

 

= 0.05055
2. For the enthalpy calculation,
b= 0.15757 + 199.7u |
= (0.1575 x 1260) + (199.7 x 0.05055)
- 208.53 .
3. For the entropy calculation, at a constant
pressure,

AS]% 0y ——
T

__ 208.53 — 203.79
1260

A2 0.003792

und

s ~ 0.07298 .

4. For the specific volume calculation

T
v = 0.04023(1 + w1)—P-

1260
- 0.04023(1 + 0.05055) ——

= 1.7751

Data obtained for these functions at temperatures
from 900 to 2000°R and pressures of 1.5, 5, 15,
30, 60, 100, and 150 psia are listed in Table 3,
and an enthalpy-entropy chart is presented in

Fig. 3.

CORROSION BEHAVIOR

The corrosiveness of the gas is another important
consideration. The free energies of formation of
aluminum chloride and the chlorides of some

possible container materials at 500 and 1000°K

UNCLASSIFIED
ORNL-LR--DWG 39596

 

 

500 |——

450 [

400 |-

3150

 

300

ENTHALPY {Btu/Ib)

250

 

200 -

    
 

5'\ 0\
‘SO \SJ 1 \(p

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.15 0.20 0.25 .20

ENTROPY [Bm gt (GR)—A]

Fig. 3. Enthalpy-Entropy Diagram for Aluminum Chloride Vaper.
Table 3. Thermodynamic Data for Aluminum Chloride at Various Pressures

 

Temperature Weight Fraction Enthalpy Entropy Specific Volume
°R) of AICI, (Btu/Ib) (Bru b~ 1. (°R)™ ] (F3/1b)
At a Pressure of 1.5 psia
900 0.00321 142.39 0.03425 24.193
920 0.00442 145.78 0.03794 24.761
940 0.00605 149.25 0.04164 25.340
960 0.00811 152.81 0.04535 25.932
980 0.01083 156.51 0.04911 26.544
1000 0.01422 160.33 0.05294 27.176
1020 0.01848 164.33 0.05686 27.836
1040 0.02382 168.55 0.06092 28.531
1060 0.03037 173.00 0.06512 29.266
1080 0.03836 177.75 0.06951 30.049
1100 0.04808 182.84 0.07414 30.892
1120 0.05973 188.31 0.07903 31.803
1140 0.07361 194.23 0.08422 32.795
1160 0.09006 200.66 0.08%976 33.882
1180 0.10933 207.66 0.09569 35.076
1200 0.13176 215,28 0.10204 36.391
1220 0.15765 223.60 0.10886 37.844
1240 0.18725 232.65 0.11616 39.448
1260 0.22072 242.48 0.12396 41.214
1280 0.25820 253.11 0.13226 43.154
1300 0.29959 264.51 0.14104 45.270
1320 0.34464 276.65 0.15023 47.560
1340 0.39288 289.42 0.15977 50.013
1360 0.44360 302.70 0.16952 52.608
1380 0.49587 316.27 0.17936 55.314
1400 0.54854 329.93 0.18912 58.091
1420 0.60041 343,43 0.19862 60.895
1440 0.65030 356.53 0.20772 63.678
1460 0.69718 369.03 0.21629 66.396
1480 0.74025 380.78 0.22422 69.014
1500 0.77900 391.66 0.23148 71.504
1520 0.81324 401.64 0.23804 73.852
1540 0.8429% 410.72 0.24394 76,052
1560 0.86851 418.96 0.24922 78.106
1580 0.89016 426.43 0.25395 80.024
1600 0.20837 433,22 0.25819 81.818
1620 0.92359 439.40 0.26201 83.501
1640 0.93625 445,08 0.26547 85.088
1660 0.94676 450.32 0.26863 86.593
1680 0.95546 455.21 0.27154 88.028
1700 0.96267 459.80 0.27424 89.405
1720 0.96863 464.14 0.27676 90.731
1740 0.97358 468,27 0.27914 92.017
1760 0.97768 472.24 0.2813%9 93.268
1780 0.98109 476.07 0.28355 94,491
Table 3 (continued)

 

 

Temperature Weight Fraction Entholpy Entropy Specific Yolume
R) of AICI, (Btu/1b) [Bro- 1= 1Ry~ 11 (#3/1b)
At a Pressure of 1.5 psia
1800 0.98394 479.79 0.28561 95.690
1820 0.98631 483.42 0.28760 96.869
1840 0.98830 486.96 0.28953 28.031
1860 0.98997 490.45 0.29140 99.180

1880 0.99138 493.88 0.29323 100.31
1900 0.99257 497.26 0.29501 101.44
1920 0.99357 500.61 0.29675 102.56
1940 0.99443 503.93 0.29847 103.67
1960 0.99516 507.23 0.30015 104.78
1980 0.99578 510.50 0.30180 105.88
2000 0.99631 513.76 0.30343 106.98
At a Pressure of 5 psia
900 0.00174 142.10 0.02530 7.2476
920 0.00242 145.38 0.02886 7.4135
940 0.00331 148.71 0.03241 7.5814
960 0.00444 152.08 0.03592 7.7515
280 0.00593 155.53 0.03944 7.9247
1000 0.00777 159.05 0.04296 8.1012
1020 0.01012 162.67 0.04650 8.2825
1040 0.01305 166.40 0.05010 8.4694
1060 0.01662 170.26 0.05374 8.6627
1080 0.02102 174.29 0.05747 8.8643
1100 0.02636 178.50 0.06130 9.0757
1120 0.03274 182.93 0.06525 9.2981
1140 0.04039 187.60 0.06935 9.5343
11460 0.04947 192.57 0.07363 9.7862
1180 0.06013 197.84 0.07810 10.056
1200 0.07260 203.48 0.08280 10,346
1220 0.08712 209.53 0.08776 10.661
1240 0.10384 216.01 0.09299 11.003
1260 0.12300 222.99 0.09852 11.374
1280 0.14484 230.49 0.10438 11.779
1300 0.16951 238.56 0.11059 12.221
1320 0.19714 247.23 0.11715 12,703
1340 0.22784 256.50 0.12408 13.226
1360 0.26166 266.40 0.13135 13.793
1380 0.29850 276.90 0.13895 14.404
1400 0.33816 287.96 0.14686 15.060
1420 0.38032 299.52 0.15500 15.756
1440 0.42452 311.49 0.16332 16.489
1460 0.47013 323.74 0.17171 17.254
1430 0.51642 336.12 0.18007 18.041
1500 0.56258 348,48 0.18831 18.841
1520 0.60782 360.66 0.19632 19.645

i
Table 3 {(continued)

 

 

12

Temperature Weight Fraction Enthalpy Entropy Specific Velume
(°R) of AICI, (Btu/Ib) [Btu-1b~1.CR)™ ] (/1)
At a Pressure of 5 psia
1540 0.65132 372.48 0.20400 20.442
1560 0.69243 383.84 0.21128 21,223
1580 0.73062 394,60 0.21810 21.981
1600 0.76553 404.72 0.22442 22.708
1620 0.79699 414.15 0.23024 23.401
1640 0.824%7 422.88 0.23556 24,059
1660 0.84940 430.94 0.24042 24.681
1680 0.87106 438.37 0.24484 25.268
1700 0.88963 445.23 0.24887 25.823
1720 0.90560 451,56 0.25256 26,348
1740 0.91926 457.44 0.25593 26.845
1760 0.93093 462.92 0.25%05 27.319
1780 0.94085 468.05 0.26193 27.771
1800 0.94929 472.88 0.26461 28.205
1820 0.95645 477.46 0.26713 28.624
1840 0.96254 481.82 0.26950 29.028
1860 0.96771 486.01 0.27175 29.421
1880 0.97211 490.03 0.27389 29.804
19200 0.97586 493.93 0.27594 30.178
1920 0.97906 497.72 0.27792 30.545
1940 0.98179 501.41 0.27982 30.906
1960 0.98413 505.03 0.28167 31.261
19806 0.98614 508.58 0.28346 31.612
2000 0.98786 512.07 0.28521 31.959
At a Pressure of 15 psia
900 0.00100 141.94 0.01713 2.4140
920 0.00141 145.18 0.02064 2.4686
940 0.00189 148.42 0.02409 2.5235
960 0.00256 151.71 0.02751 2,5789
930 0.00342 155.03 0.03090 2.6349
1000 0.00448 158.39 0.03426 2.6915
1020 0.00586 161.81 0.03762 2.7491
1040 0.00753 165,30 0.04097 2.8077
1060 0.00959 168.86 0.04433 2.8676
1080 0.01215 172.52 0.04772 2.9291
1100 0.01522 176.28 0.05114 2.9923
1120 0.01891 180.17 0.05461 3.0578
1140 0.02335 184.20 0.05815 3.1260
1160 0.02858 188.40 0.06176 3.1971
1180 0.03475 192,78 0.06548 3.2717
1200 0.04199 197.37 0.06931 3.3505
1220 0.05043 202.21 0.07327 3.4339
1240 0.06017 207.30 0.07738 3.5226
1260 0.07137 212.69 0.08145 3.6172
Table 3 (continued}

 

 

Temperature Weight Fraction Enthalpy Entropy Specific Volume
(°R) of AICL, (Btu/1b) [Btu-lb*]-(c’R)"l] (Ft?’/ib)
At a Pressure of 15 psia
1280 0.08421 218.40 0.08611 3.7186
1300 0.09882 224.46 0.09078 3.8276
1320 0.11532 230.90 0.09564 3.9449
1340 0.13388 237.75 0.10077 4.0713
1360 0.15464 245.05 0.10613 4.2077
1380 0.17770 252.80 0.11175 4,3549
1400 $.20313 261.02 0.11762 4.5134
1420 0.23099 269.73 0.12375 4.6839
1440 0.26129 278.92 0.13014 4.8668
1460 0.29395 288.59 0.13676 5.0621
1480 0.32831 298.69 0.14359 5.2697
1500 0.36567 309.20 0.15059 5.4891
1520 0.40421 320.04 0.15772 5.7192
1540 0.44404 331.13 0.16492 5.9588
1560 0.484467 342.39 0.17214 6.2061
1580 0.52559 353.70 0.17930 6.4589
1600 0.56622 364.96 0.18634 6.7148
1620 0.60601 376.04 0.19318 6.9715
1640 0.64443 386.86 0.19977 7.2264
1660 0.68101 397.31 0.20607 7.4773
1680 0.71540 407.32 0.21203 7.7222
1700 0.74732 416.84 0.21763 7.9595
1720 0.77661 425.83 £.22285 8.1881
1740 0.80320 434.28 0.22771 8.4073
1760 0.82712 442.21 0.23222 8.6168
1780 0.84848 449.62 0.23628 8.8166
1800 0.86741 456.54 0.24023 9.0069
182¢ 0.88410 463.02 0.24379 2.1884
1840 0.89874 469.10 0.24709 9.3616
1860 0.91154 474,80 0.25015 9.5271
1880 0.92270 480.18 0.25301 9.6858
1900 0.93242 485.26 0.25569 9.8383
1920 0.94085 490,10 0.25821 9.9852
1940 0.94818 494.71 0.26059 10.127
1960 0.95454 499.13 0.26284 10.265
1980 0.95006 503.38 0.26499 10.399
2000 0.96486 507.49 0.26704 10.529
At a Pressure of 30 psia
900 0.00072 141.89 0.01197 1.2066
920 0.000%7 145.09 0.01545 1.2338
940 0.00134 148.32 0.01888 1.2611
960 0.00179 151.55 0.02225 1.2885
980 0.00241 154,83 0.02559 1.3161
1000 0.00318 158.13 0.02889 1.3440

13
Table 3 (continued)

 

Temperoture Weight Froction Enthalpy Entropy Specific Volume
°R) of AICI, (Btu/Ib) (Bt b~ 1.(°R)™ 1] (#3/1b)

 

At a Pressure of 30 psia

1020 0.00412 161.47 0.03217 1.3722
1040 0.00534 164.86 0.03543 1.4008
1060 0.00680 168.30 0.03867 1.4298
1080 0.00857 171.81 0.04192 1.4593
1100 0.01075 175.39 0.04518 1.48%96
1120 0.01338 179.07 0.04846 1.5206
1140 0.01649 182.83 0.05177 1.5525
1160 0.02020 186.73 0.055172 1.5855
1180 0.02459 190.75 0.05853 1.6198
1200 0.02971 194,92 0.06201 1.6555
1220 0.03566 199.26 0.06556 1.6928
1240 0.04258 203.79 0.06922 1.7320
1260 0.05055 208.53 0.07298 1.7734
1280 £.05965 213.50 0.07686 1.8172
1300 0.07003 218.72 0.08087 1.8637
1320 0.08181 224.22 0.08504 1.9132
1340 0.09510 230,02 0.08937 1.9660
1360 0.11001 236.14 0.09387 2.0225
1380 0.12664 242.61 0.09856 2.0830
1400 0.14513 249.45 0.10345 2.1479
1420 0.16558 256.68 0.10854 2.2175
1440 0.18800 264.30 0.11383 2.2920
1460 0.21249 272.34 0.11933 2.3717
1480 0.23905 280.79 0.12504 2.4568
1500 0.26767 289.65 0.13095 2.5476
1520 0.29827 298.90 0.13704 2.6439
1540 0.33071 308.52 0.14328 2.7456
1560 0.36481 318.48 0.14967 2.8525
1580 0.40031 328.71 0.15614 2,9642
1600 0.43692 339.16 0.16268 3.0802
1620 0.47426 349.76 0.16922 3.1998
1640 0.51192 360.42 0.17572 3.3220
1660 0.54945 371.06 0.18213 3.4460
1680 0.58643 381.59 0.18839 3.5708
1700 0.62244 391.92 C.19447 3.6953
1720 0.65708 401.98 0.20032 3.8186
1740 0.65004 411.71 0.20591 3.9398
1760 0.72105 421.05 0.21122 4.0582
1780 0.74994 429.96 0.21622 4,1732
1800 0.77659 438.42 0.22093 4.2844
1820 0.80097 446.44 0.22533 4.3915
1840 0.82310 454.00 0.22%944 4.4943
1860 0.84305 461.14 0.23328 4.5929
1880 0.86095 467.85 0.23685 4.6873

1900 0.87691 474,19 0.24018 4,7778
Table 3 (continued)

 

Temperature Weight Fraction Enthalpy Entropy Specific Yolume
CR) of AICI, (Btu/Ib) [Btuib~ L.R)™ Y (3 /1b)

 

At o Pressure of 30 psia

1920 0.82110 480.17 0.24330 4.8646
. 1940 0.90367 485.83 0.24622 4,9479
1960 0.91477 491.19 0.24895 5.0281%
1980 0.92456 496.30 0.25153 5.1054
2000 0.93318 501.17 0.25397 5.1801

At a Pressure of 60 psia

900 0.00049 141.84 0.00681 0.60320
920 0.00071 145,04 0.01028 0.61674
940 0.00093 148.23 0.01368 0.63029
960 0.00130 151.46 0.01704 0.64393
9280 0.00171 154.69 0.02034 0.65762
1000 0.00223 157.94 0.02359 0.67139
1020 0.00293 161.23 0.02682 0.68529
1040 0.00374 164.54 0.03000 0.69929
1060 0.00479 167.90 0.03317 0.71349
1080 0.00608 171.31 0.03632 0.727883
1100 0.00759 174.76 0.03946 0.74247
, 1120 0.00945 178.28 0.04261 0.75737
) 1140 0.01168 181.88 0.04576 0.77260
1160 0.01430 185.55 0.04892 0.78818
. 1180 0.01737 189.31 0.05211 0.80420
1200 0.02100 193.19 0.05534 0.82075
1220 0.02524 197.18 0.05862 0,83790
1240 0.03013 201.31 0.06194 0.85569
1260 0.03575 205.58 0.06533 0.87424
1280 0.04221 210.02 0.06880 0.89366
1300 0.04959 214.64 0.07236 0.91405
1320 0.05795 219.46 0.07601 0.93550
1340 0.06738 224.49 0.07976 0.95814
1360 0.07801 229.76 0,08364 0.98213
1380 0.08993 235,29 0.08764 1.0075
1400 0.10318 241.08 0.09178 1.0346
1420 0.11788 247.16 0.09607 1.0633
1440 0.13412 253.55 0.10050 1.0940
1460 0.15197 260,26 0.10510 1.1266
1480 0.17151 267.31 0.10986 1.1614
1500 0.19276 274.70 0.11479 1.1985
. 1520 0.21576 282,44 0.11988 1.2379
1540 0.24050 290.53 0.12513 1.2797
1560 0.26699 298.96 0.13054 1.3240
- 1580 0,29515 307.73 0.13609 1.3708
1600 0.32485 316.80 0.14176 1.4200
1620 0.35597 326.16 0.14753 1.4715
1640 0.38830 335.76 0.15339 1.5252
Table 3 (continued)

 

Weight Fraction

 

16

Temperature Enthalpy Entropy Specific Volume
(°R) of AICI, (Btu/1b) [Brutb= 1. o)1) (73 /1b)
At o Pressure of 60 psia
1660 0.42164 345.56 0.15929 1.5809
1680 0.45570 355.51 0.16521 1.6382
1700 0.49016 365.53 0.171n 1.6970
1720 0.52471 375.57 0.17695 1.7567
1740 0.55899 385.56 0.18269 1.8171
1760 0.59269 395.44 0.18830 1.8777
1780 0.62547 40513 0.19374 1.9382
1800 0.65706 414,58 0.19899 1.9981
1820 0.68721 423.75 0.20403 2.0570
1840 0.71573 432.59 0.20883 2.1148
1860 0.74248 441,07 0.21340 2171
1880 0.76737 44919 0.21771 2.2258
1900 0.79036 456.92 0.22178 2.2787
1920 0.81146 464,28 0.22562 2,3298
1940 0.83070 A71.27 0.22922 2.3791
1960 0.84818 477.91 0.23261 2.4266
1980 0.86397 484,21 0.23579 2.4723
2000 0.87819 490.19 0.23878 2.5163
At a Pressure of 100 psio
900 0.00039 141.82 0.00301 0.36188
920 0.00054 145.00 0.00647 0.36998
940 0.00074 148,19 0.00986 0.37809
960 0.00099 151.39 0.01320 0.38624
980 0.00132 154.61 0.01648 0.39441
1000 0.00174 157.84 0.01971 0.40263
1020 0.00224 161.10 0.02290 0.41090
1040 0.00291 164.38 0.02605 0.41923
1060 0.00371 167.69 0.02918 0.42763
1080 10.00470 171.03 0.03228 0.43613
1100 0.00589 174.42 0.03536 0.44473
1120 0.00732 177.86 0.03842 0.45346
1140 0.00904 181.35 0.04149 0.46234
1160 0.01107 184.90 0.04455 0.47140
1180 0.01346 188.53 0.04763 0.48067
1200 0.01627 192.24 0.05072 0.49017
1220 0.01955 196.05 0.05383 0.49994
1240 0.02334 199.95 0.05698 0.51003
1260 0.02770" 203.97 0.06018 0.52047
1280 0.0327¢ 208.12 0.06342 0.53130
1300 0.03843 212.41 0.06672 0.54259
1320 0.04491 216.86 0.07009 0.55438
1340 0.05225 221.47 0.07353 0.56673
1360 0.06051 226.27 0.07706 0.57970
1380 0.06976 231.26 0.08068 0.59336
Table 3 (continued)

 

 

Temperature Weight Fraction Enthalpy Entropy Specific Volume
°R) of AICI, {(Btu/Ib) [Btustb=1.(%R)~ 1] (53 /1b)
At a Pressure of 100 psia
1400 0.08009 236.47 0.08440 0.60777
1420 0.09156 241.91 0.08823 0.62301
1440 0.10426 247.60 0.09218 0.63913
1460 0.11827 253.54 0.09625 0.65623
1480 0.13363 259.76 0.10045 0.67436
1500 0.15043 266.26 0.10478 0.69359
1520 0.16870 273.05 0.10925 0.71401
1540 0.18849 280.15 0.11386 0.73565
1560 0.20982 287.56 0.11861 0,75858
1580 0.23270 295.27 0.12349 0.78284
1600 0.25711 303.29 0.12850 0.80844
1620 0.28299 311.60 0.13363 0.83540
1640 0.31029 320.20 0.13887 0.86370
1660 0.33888 329.05 0.14421 0.89331
1680 0.36862 338.14 0.14961 0.92416
1700 0.39935 347.42 0.15507 0.95616
1720 0.43085 356.85 0.16056 0.98919
1740 0.46289 366.39 0.16604 1.0230
1760 0.49520 375.99 0.17149 1.0577
1780 0.52752 385.59 0.17689 1.0928
1800 0.55%956 395.13 0.18219 1.1283
1820 0.59106 404.56 0.18737 1,1639
1840 0.62176 413.84 0.19241 1.1993
1860 0.65141 422.90 0.19729 1.2346
1880 0.67984 431.72 0.20198 1.2693
1900 0.70686 440.26 0.20647 1.3034
1920 0.73235 448.50 0.21076 1.3368
1940 0.75624 456,42 0.21484 1.3694
1960 0.77849 464.00 0.21871 1.4010
1980 0.79907 471,26 0.22238 1.4317
2000 0.81802 478.19 0.22584 1.4614
At o Pressure of 150 psia
200 0.00032 141.81 0.00600 0.24123
920 0.00044 144,98 0.00344 0.24662
940 0.00060 148.17 0.00683 0.25203
960 0.00081 151.36 0.01015 0.25744
980 0.00108 154,56 0.01342 0.26288
1000 0.00142 157.78 0.01664 0.26833
1020 0.00184 161.01 0.01981 0.27382
1040 0.00238 164.27 0.02295 0.27933
1060 0.00303 167.55 0.02604 0.28489
1080 0.00383 170.86 0.02910 0.29050
1100 0.00481 174.21 0.03215 0.29617
1120 0.00598 177.59 0.03517 0.30190

17
Table 3 (continued)

 

 

Temperature Weight Fraction Enthalpy Entropy Specific Yolume
(R) of AICI, (Btu/Ib) [Btu-tb™ 1 (R)™ ] (#3/1b)
At a Pressure of 150 psia

1140 0.00738 181.02 0.03817 0.30772
1160 0.00%204 184.50 0.04117 0.31364
1180 0.01099 188.04 0.04418 0.31966
1200 0.01328 191.65 0.04718 0.32582
1220 0.01596 195.33 0.05020 0.33212
1240 0.01906 199.10 0.05324 0.33859
1260 0.02262 202.96 0.05630 0.34526
1280 0.02671 206.92 0.05940 0.35214
1300 0.03138 211.01 0.06254 0.35927
1320 0.03668 215.21 0.06573 0.36668
1340 0.042468 219.56 0.06897 0.37438
1360 0.04943 224.06 0.07228 0.38243
1380 0.05700 228.72 0.07566 0.39086
1400 0.06546 233.56 0.07911 0.39969
1420 0.07487 238.58 0.08265 0.40898
1440 0.08529 243.81 0.08628 0.41876
1460 0.09679 249,26 0.09001 0.42908
1480 0.10944 254,93 0.09385 0.43997
1500 0.12329 260.84 0.09779 0.45149
1520 0.13840 267.01 0.10184 0.46366
1540 0.15482 273.43 0.10602 0.47654
1560 0.17259 280.13 0.11031 0.49016
1580 0.19174 287.10 0.11472 0.50455
1600 0.21228 294.35 0.11925 0.51974
1620 0.23421 301.87 0.12389 0.53576
1640 0.25751 309.67 0.12865 0.55261
1660 0.28214 317.73 0.13351 0.57031
1680 0.30804 326.05 0.13846 0.58883
1700 0.33510 334.60 0.14349 0.60817
1720 0.36320 343.36 0.14858 0.62828
1740 0.39221 352.29 0.15371 0.64911
1760 0.42194 361.37 0.15887 0.67059
1780 0.45220 370.56 0.16403 0.69264
1800 0.48277 379.81 0.16917 0.71517
1820 0.51342 389.07 0.17426 0.73806
1840 0.54391 398.31 0.17928 0.76121
1860 0.57402 407.46 0.18420 0.78449
1880 0.60352 416.50 0.18901 0.80778
1900 0.63219 425.37 0.19368 0.83097
1920 0.65985 434.04 0.19819 0.85395
1940 0.68635 442,47 0.20254 0.87662
1960 0.71155 450.65 0.20671 0.89890
1980 0.73537 458.55 0.21070 0.92071
2000 0.75774 466.17 0.21451

0.94200

 

18
(ref 15) are listed in Table 4. Aluminum chloride
is stable on a free-energy basis relative to these
pure container materials. |f, however, the products
of a possible corrosion reaction are gaseous or
form a solid or liquid solution and if a mechanism
exists for the removal of the reaction products
from the region of the reaction, a corrosion reaction
might proceed.
two positive valence states,

Unfortunately aluminum exists in
The chlorides AICI
and AICl; are both gaseous in the temperature
range of interest.

Table 4. Free Energies of Formation of Aluminum
Chloride and the Chlorides of Some Possible

Container Materials

 

Free Energy of Formaiion

 

 

 

Metal {kcal per mole of CI)
Chloeride
At 500%K At 1000%
AlCl, _48(g) —46(z)
C:r('ll3 -35 --26
CrC12 ~40 -32
FE;C‘3 -23 -21
FeC|2 ~33 -27
NiCl2 -27 —-18
AICH =22g) -32(g)
M0C|2 -15 -8
M0C|3 - 14 )
MoC|4 -12 ~7
MoCls ~10 -7
MoCl6 -7 -3
As an illustration of the possible corrosion
behavior, the corrosion of an alloy containing

chromium and nickel in a system in which gaseous
aluminum chloride is circulated at temperatures
in the range 500 to 1000°K is discussed here.
The most likely corrosion reactions involving
chremium are:

Reaction A
ZAICI,(g) + Cr &= CrCl,(s) + Al
AF® gt 500°K = +16 kcal
AF®at 1000°K = 428 kcal

Reaction B
AlClB(g) + Cr == AlCI(g) + CrCl{s)

AFé at 500°K = +42 keal
AF® at 1000°K = +42 keal

Reaction C

3AICHg) == 2Al + AICI {2)

AF® at 500°K = ~78 kcal
AF®at 1000 %K = ~42 kcal

The equilibrium constant, K, for reaction A is

2/3
“al dCrCtz

K, = p~NF/RT _ T {19)
p2/3 '
AlClB Cr
= 10~7 at 500°K
= 16-%-1 at 1000°K

If pure aluminum is produced from the reaction of

pure chromium and AICI, at a pressure of 1 atm,
. . ~-6.1 o

the activity of CrCl,, aCrCIQ’ is 10 at 1000°K

and 10~7 at 500°K. The partial pressure of CrCl,

under these conditions, P, , may be calculated
from the relation 2

0
P = q P , (20)
CrCI2 CrCI2 CrCi2

0
where PCrC|2

solid, which may be calculated from the relation

~14,000

is the vapor pressure of the pure
1

log Po

crcl, (atm) =

~ 0.62 log T -

-~ 0.00058T +12.26 . (21)

The vapor pressure Pg is 10418 or 6.6 x 1075
rCl,

atm ot 1000°K and 10~ '77% or 2 x 10~'8 atmat

500°K. The calculated partial pressures of CrCl,

under the stated conditions are then 5.3 x jo-1
atm at 1000°K and 2 x 10725 atm at 500°K. In a

system in which aluminum chloride gas was being

 

154, Glassner, The Thermochemical Pr%perzz'es of the
(le(}z'des, Fluorides, and Chlorides to 25007 K, ANL-5750
57).

19
circulated, if reaction A were the only significant
one, it would take a minimum of 2 x 109 moles
of aluminum chloride gas to move 1 mole of CrCl
from the hot zone and deposit it as solid CrC|2
in the cold zone. The fact that the aluminum
metal produced in reaction A might form a solid
solution with the metal wall in the reaction zone
would increase the initial portial pressure and
transport of CrCl,. After an initial deposit of
aluminum metal had formed on the surface, the
reaction would yield a smaller partial pressure
of CrCl,, with diffusion of aluminum into the
metal in the hot zone being one controlling factor
for this partial pressure if reaction A were im-
portant. Not only is the initial activity of chro-
mium in an alloy lower than that of the pure metal,
but the depletion of the surface chromium concen-
tration would further lower the activity of chromium
at the surface and, hence, lower the maximum
partial pressure of CrCl, in the circulating gas
at the hot end. This would lead to a smaller
transport of CrCl, from the hot to the cold zone.
The chromium concentration on the reaction
surface and, hence, the corrosion rate, would then
be controlled by the diffusion of chromium to the
surface in the hot zone. This diffusion would be
a second controlling factor if reaction A were
important.

The equilibrium constant for reaction B is

PAIClaCrCi2
K = o-NF/RT _
B - P a
Alciy“ce
PAICIPCrCI2
= (22)
p pe

A|c13“cr crCl,
= 10— 184 4t 500°K
=10~ 72 43¢ 1000°K

For pure chromium exposed to aluminum chloride
at a pressure of 1 atm,

p =]O“9'2X]0“4°]8:’:10"]3'4

e
AlCH CrCI2

at 1000°K and

_ _ -6.7 ~7
PAICi‘PCrCI2‘m or 2 x 10

20

This pertial pressure is higher than that which
would be present above a chromium-containing
alloy in which the activity of the chromium was
lower than the activity of pure chromium metal.
The partial pressure of Cr(:l2 from reaction B is
higher than that from reaction A. Reaction B
should be, therefore, the important corrosion
reaction and should result in the transport, at the
very most, of about 2 x 107 mole of chromiym
per mole of circulating gas. At the low-tempera-
ture zone, CrCl, will initially deposit as the
solid, AICI will disproportionate according to
reaction C, and a small concentration of aluminum
will deposit on the surface of the alloy. After a
small activity of aluminum is built up in the metal,
the reaction at the low-temperature zone should
be the reverse of reaction B, with chromium metal
being deposited on the walls, At the hot zone,
after the surface chromium has been depleted, the
reaction will be limited by the diffusion of chro-
mium from the interior of the metal to the surface.
If reaction B is important, this diffusion of chro-
mium fo the surface at the hot zone will probably
be the rate-controlling step in the transport of
chromium metal from the hot to the cold zone.
l.owering the temperature of the hot zone would
decrease the rate of corrosion, mainly by lowering
the diffusion rate of chromium. The formation of
an adherent nonmetallic film on the surface that
is not attacked by aluminum chloride would also
decrease the corrosion rate,

The corrosion of nickel would be much less
severe, The reactions significant for nickel
corrosion are:

Reaction D
%AICH,(g) + Ni =2 NiCl,(s) + %Al
AF® at 500°K = +42 kcal
AF° at 1000°K = +56 keal

Reaction E
AlCls(g) + Ni &= AICI(g) + NiCl,{s)
AF° at 500°K = +68 kcal
AF®at 1000°K = + 70 kcal
The equilibrium constants for reactions D and E

are:
2/3
Al aNiClz
K == DE/RT _
D g p2/3
NIt AICH,
2/3
Sy PNiCI2
——— ()
2/3  p0
aNiPA|CI3INiC12
= 10~ 18-4 4 500°K
= 10~ 12:2 4 1000°K ,
PAICl“NiClz
K :e-AF/RTz ]
PA!C!3“Ni
P P

AlICITNICH,
—- (24)
0
aNipAlC!BPNiClz
= 10~29-8 4 500°K

= 10— 153 44 1000°K

The vapor pressure of pure NiCl,, PgiClzf may be

calculated from the equation’

13,300
log PgiClz (atm) =

- 2.68log T +19.00 . (25)

At 1000°K, Pg‘CI is 10234 or 4.6 x 102 atm
12

and at 500°K it is 10- 1483 or 1.5 x 10~ 15 atm.

At the high-temperature zone, reaction E leads to
a higher partial pressure of NiCl, than does

reaction D. For the corrosion of pure nickel,

P !

- P
NiCl, — © AlICI

2
- (10=15-3 , 10-2:3) /2

=10-8-8 o 1.6 x 1077 atm

At the low-temperature zone, the reverse of re-
action E will probakly take place, and nickel
metal will deposit on the surface. The limiting
factoer in the corrosion of nickel from an alloy
composed principally of nickel would be the total
volume of gas passing over the surface. One mole
of nickel would be transperted per 6 x 10% moles

of gus at 1 otm passing the surface at 1000°K.
One mole of AICH, transports roughly 20 keal of
heat in going from 1000 to 500°K, so about 1 mole
of nicke! would be transported per 1.2 x 1010
keal, 1.4 x 107 kwhr, or about 600 Mwd of heat.
The transport corrosion of iron and molybdenum
as minor constituents of an alloy should be less
than that of chromium,

In conclusion, corrosion of an alloy composed
mainly of nickel and contoining some chromium
might not be negligible for long-term operation of
a system circulating gaseous aluminum chloride
at temperatures in the range 500 and T1000°K, but
the corrosion would be small enough for short-term
operation of such a system. The corrosion rate
could be decreased considerably by operating with
the hot zone of the loop at temperatures lower
than the 1000°K for which these calculations were
made or by the formation of an oxide coating on
the surface of the metal. The estimated values
of the thermal conductivity, heat capacity, and
viscosity indicate that aluminum chleride may be
a unique gaseous heat exchange medium that
requires very low pumping power. It should be
emphasized that these cre crude estimates based
on a limited amount of data of varying degrees of
reliability. Although a conscious attempt has been
made to moke these estimates conservative, some
of the estimates should be checked experimentally.

ENGINEERING PROBLEMS OF SOME
TYPICAL APPLICATIONS

Where cluminum chloride vapor is used as «
working fluid in a thermodynamic cycle or as a
heat transfer medium, the pressures and tempera-
tures must be carefully chosen to exploit to the
fullest the extra performance obtainable from
dissociation. MNormally a temperature range will
be defined by the structural strength of the metals
in the system or by other considerations, such as
corrosion, so that the only variable available to
the designer will be the pressure. This meons
that the pressure level must be chosen with care
to give the best over-all system design. It is
likely that it will be necessary to compromise the
design of other components if the fullest benefits
are to be derived from the use of aluminum chloride.

Aluminum Chloride as a Heat Transfer Medium

A typical applicetion for which aluminum chloride
may have promise is as an intermediate heat

21
transfer fluid between the fluoride fuel of a molten-
salt-fueled reactor and the steam generator. The
use of a gas rather than a liquid in the intermediate
loop would facilitate removal of the heat transfer
medium; it would not be necessary to design the
system to avoid the presence of low spots which
would present difficult drainage or scavenge
problems. It would make possible the placing of
flanged joints in cool zones at the top of the
system and outside of the heat exchanger pressure
envelope so that leaks of the molten fuel into the
aluminum chloride would be contained within the
pressure envelope. The pressure required, namely,
20 to 60 psi in the aluminum chloride, would
present no serious structural problems in the
design of the containing vessel. From Fig. 4,
which is a plot of data obtained from Eq. (7), it
is evident thot there would be no solid aluminum
chloride precipitated at the temperatures and
pressures prevailing in a molten-salt-fueled re-
actor. . Aluminum chloride would have the ad-
vantage as a heat transfer fluid thot it would

UNCLASSIFIED
ORNL-LR~DWG 39597

 

e . . .
1 | S —
© SOLID PHASE l

 

 

 

PRESSURE (psia}

 

 

 

 

 

 

i
wf— - ——T
|
1 ‘ l“
800 4000 1200 1400 1600 1800 2000
TEMPERATURE (°R)
Fig. 4. Ges-5clid Equilibriom Diagrem for Aluminum
Chloride.

22

be chemically inert relative to either the molten
salt or water. This would make it desirable from
the hazards standpoint and would give o system
relatively insensitive to leaks between any two
sets of fluid; that is, a small leak from one
system into another would not lead to the formation
of a set of deposits which would be very difficult
to remove. |t would be necessary, of course, to
make the steam generator, as well as the fuel~
to—aluminum chloride heat exchanger, of arelatively
expensive high-nickel-content alloy.

The principal disadvantage of this arrangement
is that it would require a larger amount of heat
transfer surface area and a higher pumping power
than would be the case for an inert molten salt,
for example. However, it would have a major
in that there would be no freezing
problem in the intermediate heat exchanger circuit.
The freezing problem presents exceedingly dif-
ficult design problems if a fluid such as sodium
or NaK is employed as the intermediate heat
transfer medium.

advantage

The temperature range for such an application
is lower than is desirable in that the heat transfer
surfaces for the molten salt would be at about
1100 to 1200°F, while those inthe steam generator
would be at 700 to T000°F. As may be seen in
Fig. 1, this temperature range is below that which
gives the maximum obtainable average effective
specific heat if the pressure is maintained high
enough (30 to 100 psi) to keep pumping losses to
acceptable levels,

Aluminum Chioride Vapor in a Gas-Turbine Cycle

The features of a gas-turbine cycle utilizing
aluminum chloride deserve special attention. The
cycle contemplated is indicated schematically in
Fig. 5. The pressures and temperatures should
be chosen so that the gas will be mostly in the
form of A|2CI(, during compression, while during
the expansion process it will be mostly AlCI,.
This, in effect, will cut the compression work
roughly in half and thus produce a marked improve-
The naoture of this
effect can be visualized readily by examining the

ment in cycle efficiency.

P-V diagrams of Fig. 6, which compare similar
ideal gas-turbine cycles for helium, aluminum
It should be remembered that

the work involved in each compression or ex-

chloride, and water.

pansion process is directly proportional to the

area of the P-V diagram, and the net work is
UNCLASSIFIED

ORNL~~LR—-DWG 39538

I GENERATOR I

 

 

 

 

 

 

REACTCOR

 

 

FRESSURE {psia}

PRESSURE {psiaj

URE {psial

 

 

TUR

 

 

 

 

 

 

 

 

Fig. 5. Aluminum Chloride Gas-Turbine Cycle.

COMPRESSOR

 

 

DM OO0

 

 

 

 

RANKINE CYCLE (H,0)

BRAYTON CYCLE (Ai,Clg— AICly)

proportional to the net area for the cycle. The
Rankine cycle utilizing water vapor was included
in Fig. 6 to show that the proposed aluminum
chloride cycle is between a gas-turbine (or
Brayton) cycle utilizing helivm and a Rankine
cycle utilizing water in its requirements for work
input during the compression process.

The diagrams of Fig. 6 were prepared for ideal
cycles with no allowances for losses. The most
important of these losses are associaoted with the
efficiencies of the compressor and the turbine,
which are likely to be of the order of 85%. This
means that, with an 85% efficient compressor, the
ideal work input will be 85% of the actual work
input, while the actual work output of the turbine
will be only 85% of the ideal. in addition, pressure
drops between the compressor and the turbine will

UNCLASSIFIED
CRNL--LR--UWG 34577R

BRAYTON CYCLE (He}

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

    

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
    

S 1 sl 4 T
- 0 W
; o <
| L L
...... I oo Ira
| - 2 o
IDEAL WORK INPUT =6.43 Bfu/lb ffu) IDEAL W PUT =251 Btu/lp o ICEAL WORK INPUT =477 Btu/ip
4- A « I R e | o o
[T T a I - a ‘
| | |
f i o
‘ E | ] | \ \ \ Y
{IDEAL WORK QUTPRUT =6338tu/lb IDEAL WORK GQUTPUT = 62.7 Btu/lb
~ i oo 5 Moo b el Sl N
2 B |
o o
L L
- B o pee-eeee-eer- e o
2 > |
oy [9p]
& @ IDEAL WORK GUTPUT = 604 Bitu/ib
B &
N R S s x L | B e e
N——
\_M
i | \ I | ] J
IDZAL NET WORK =832.6 Btu /b INEAL NET WORK = 37.6 Btu/lb
| T L L] L] sl ]
n Yy
A | &
L { L |
e o ... e - [ e e e b !
D = . | |
oy o) . .
0 ‘ A IDEAL NET WORK =1Z7 Btu/lp
Lt L
o @ | |
[ 4 T ‘ ,,,,,,,,,,,,,,,, — o b e | ]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VOLUME (F13/ 1)

Fig. 6.

VOLUME (f13/10)

P-V Diagrams for Typical !deal Thermodynamic Cycles.

23
also cause major losses in net output from the
cycle. The nature of these effects can be seen
readily in Fig. 7. It should be emphasized that
the shaded portions of these diagrams are merely
propertional to the losses they represent and thot
the actual paths
shown. A rough allowance for these pressure

of the processes cannot be
losses can be made by using lower values for the
turbine and compressor efficiencies, for example,
80% in each case.

If allowances are made for these losses to
obtain the actual net outputs for the cycles of
Fig. 6, the diagrams of Fig. 8result. The relatively
large work input required for the compression
process of the Brayton cycle makes the cycle
efficiency very sensitive to compressor inlet
temperature because the compression work in-
creases rapidly with temperature. As a result, the
net work output and over-all cycle efficiency of
the Brayton cycle drop off so rapidly with in-
creasing temperature at the compressor inlet that,

for any practicable plant, the compressor inlet

UNCLASSIFIED
ORNL~-LR-DWG 34727

 

 

  
   
    
 
    

 

 

 

T T
80 PRESSURE L 0SS THROUGH HEATER
I e ST
i |
TURBINE INLET TEMPERATURE =
’ 4500"1;—-
60 | b R
—NET EFFECTIVE AREA |
> —EDDY LOSSES IN TURBINE
40 Lo b

 

20 }EDDY LOSSESIN —
COMPRESSOR

 

 

 

  
   
    
   

 

 

 

 

= . -
e | | PRESSURE LOSS
L { J THROUGH COOLER
X 0 s ! 1 i
s}
? [ N ! f
o —~PRESSURE LOSS THROUGH HEATER
O_ BO - o e '*" I ‘
TURBINE INLET TEMPERATURE =
1200°F
B0 [ B e |
NET EFFECTIVE AREA ‘
20 —EDDY LOSSES IN TURBINE

 

EDOY LOSSES IN!
20 — COMPRESSOR -

THROUGH COOLER

 

 

 

 

|
o 4 8 12 16 20 24 28

0
SPECIFIC VOLUME (ft7Ib)
Fig. 7. P-V Diagrams for ldeal Gas Turbine Air

Cycles with Cross-Hoatched Areas to Indicate the Magni-

tude of the Principal Losses.

24

temperature must be held below 150°F if con-
ventional working fluids are used. At the same
time, the turbine inlet temperature must be at
least 1200°F, and preferably should be above
1400°F if there is to be an appreciable positive
net area for the P-V diagram.

The wunusual properties of aluminum chloride
make it possible to go to higher compressor inlet
temperatures than with other fluids. The effects
of variations in both the compressor inlet tempera-
ture and the compressor pressure ratio are indicated
in Fig. 9 for a turbine inlet temperature of 1540°F,
While this temperature is high by steam power
plant standards, the much lower pressures in the
aluminum chloride system reduce stresses suf-
ficiently to compensate for most of the temperature
difference. In any event, it is necessary to go to
peak temperatures in this range to take full od-
vantage of the unusual properties of the aluminum
chloride. Itisevident from Fig. 9 that the aluminum
chloride vapor cycle should be designed for a
compressor inlet temperature of around 540 to
640°F and a pressure ratio of 20 to 40. Further
lowering of the compressor inlet temperature will
do little to enhance efficiency, since at 540°F
most of the gas is in the dimer state already.

A point of interest is that it was found in the
cycle analysis that during the compression and
expansion processes there was little change in
the percentage of the gas dissociated. This will
simplify the design of compressors and turbines
for such an application.

The hect transfer coefficient for the aluminum
chloride is sufficiently high for the high-pressure
portion of the cycle, and therefore good heat
transfer could be cobtained in a reactor core. |In
the cooler, however, the heat transfer performance
of the aluminum chloride would be poor, and a
large surface area would be required. The poor
heat transfer coefficient of aluminum chloride in
the cocler stems from the fact that the pressure
at the turbine outlet would be only approximately
1/10 otm, and this would give a low Reynolds
number. The pressure ahead of the turbine, on
the other hand, would be 20 to 40 times greater,
which would give heat transfer coefficients corre-
spondingly higher.

Binary Vapor Cycle Applications

If aluminum chloride were used as a reactor
coclant or as an intermediate heat transfer fluid
RANKINE CYCLE {H,0)

BRAYTON CYCLE [A1LCIg-AICIg)

UNCLASSIFIED
ORNL~LR ~-DWG 34578R

BRAYTCN CYCLE (He)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

   
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

     

 

 

 

 

 

 

 

ACTUAL WORK INPUT = 12.88 Btu/1h | | ACTUAL WORK INPUT = 31.2 Btu/lb
— L ) I —~L W] — R ]
53] ! Lt
@ L el L o
D -1 T T T = o
s oy wy
h o+ U}
w i w
e o o
- ~ - 4 - —
l
.. / ; | _J - > i ] J
b r i I 7
it ACTUAL WORK OUTPUT = 51¢ Biu/ib = 50.2 Btu/!b 77
3 | t /, -
ol M __fiq ] - . — h_J LGN e y
& | & 2 7 2
& I N - e Z
2 2 > : - |
o) o o
; E ’ IR
L|J‘ J L i |
o _ R & 3§ ACTUALWORK OUTPUT = 493 Biu/lp |
< |
] o |
T T b
ACTUAL NET WORK =498 Btu/Ib 19 8tu/lb L ACTUAL NET WORK =— 104 Btu/Ib
— T A o I —_ Lo I [V
2 - =
o o o
. L
oW L L] el sl ] o
D -2 o
W 3 )
) o )y
Ll ul i
[ vy i '
a. - a— A Q. =1 T T N
S———— i | . ‘| i

 

 

 

 

 

 

  

 

 

 

 

 

 

 

 

 

 

 

VOLUME (£13/1b)

Fig. 8.

VOLUME (1 ¥1p)

 

VOLUME (1 3/1n)

P-¥ Diagrams for Typical {deal Thermodynamic Cycles with Cross-Hatched Areas to Represent the

l.osses Entailed by Compressor and Turbine Efficiencies of 80%.

for a molten-salt-fueled reactor, it appears that a
binary vapor cycle employing aluminum chloride
in the high-temperature portion and water vapor in
the lower-temperature region ought to be con-
sidered. Such a cycle would resemble in many
ways the binary mercury vapor~steam cycle which
has been used in a number of U.S, power plants.
It would have the advantage that it would permit
operation at high temperctures (which would be
advantogeous from the thermodynamic standpeint)
while avoiding the expense associated with the
high pressures characteristic of high-temperature
steom cycles. While there are a host of different
combinations of conditions that might be employed,

a typical case is presented in Table 5. The
aluminum chloride would be expanded through a
turbine similar to that described above. The
cooler for the aluminum chloride would also serve
as the boiler and superheater for the steam sys-
tem. It may be seen from Table 5 that this system
gives a very much higher over-all thermal efficiency
than is obtainable from the gas-turbine cycle
alone. A corresponding steam system designed
for a pressure of 2400 psi and a peak temperature
out of the superheater of 1050°F would give an
over-all thermal efficiency of about 38%, some-
what less than the efficiency that the typical
binary vapor cycle chosen would attain.

25
UNCLASSIFIED
ORNL—LR~DWG 39601
14 r T I

TURBINE INLET TEMPERATURE = 2000°R
TURBINE INLET PRESSURE = 60 psia

 

COMPONENT EFFICIENCIES
COMPRESSOR 80%

  
 
     

12y TURBINE 80 %
GENERATOR 90%
COMPRESSOR
INLET
10 #—‘ __________________ __ TEMPERATURE
°oR

 

 

 

 

i grsas

o

LLJ

O

Z 8 -
b

S /

& 1200°R

o] ‘fi'-n_._‘_._.‘-
-

|

a Y AN 4 o
o

!

w ———

O

 

 

 

 

 

 

 

 

 

 

 

20 30 40
PRESSURE RATIO

Fig. 9. Cycle Efficiency vs Pressure Ratio for AlCl,.

CONCLUSIONS

Thermodynamic data have been prepared and are
presented in the form of tables and charts to
facilitate engineering calculations on systems
employing aluminum chloride vapor either as a
heat transfer medium or as the working fluid in a
thermodynamic cycle. A number of typical appli-
cations have been considered, but in none of these

26

has the aluminum chloride shown outstanding
advantages over more conventional media. How-
ever, it is believed that for some special appli-
cations it may well prove to have some outstanding
advantages where the characteristics of the other
system components are such as to make it possible
to exploit to the fullest the unique characteristics
of aluminum chloride.
Table 5, Binary Yaper Cycle

ldeal mass rotio = 0.18487 Ib of water per Ib of aluminum chloride

Actual mass ratio = 0.19585 lb of water per Ib of aluminum chleride

ldeal cycle efficiency = 53.2%

Actual cycle efficiency = 41.4%

 

 

Specific Weight Fraction
Condition Temp;rafure Enthalpy En?ropzf Presmsure Volume Dissociated or
( F) (B?IJ/“)) (BfU/Of‘) (pSlG) (1&3/”\_)) S‘hecm QUG“"Y
Aluminum Chloride
Compre ssor inlet 440 142 0.02530 5 7.2476 0.00176
Compressor outlet 570 164 0.02530 100 0.41506 0.00259
{isentropic)
Compressor outlet 615 169.5 0.0311 100 0.4344 0.00447
(80% eHiciency)
Turbine inlet 1540 478 0.22584 100 1.4614 0.818
Turbine outlet 1150 406 0.22584 5 23.07 0.781
(isentropic)
Turbine outlet 175 420.4 0.2343 5 23.92 0.812
(80% efficiency)
Steam™
Pump inlet 91.72 59.71 0.1147 0.7368 0.01611 Saturated liquid
Fump outlet 91.72 66.14 0.1147 2400 0.01600 Compressed liquid
(isentropic)
Fump outlet 91.72 72.57 0.1243 2400 0.01600 Compressed liquid
{(50% efficiency)
Tuwbine inlet 1050 1494 1.5554 2400 0.3373 Superheated vapor
Turbine outlet 91.72 855 1.5554 0.7368 339.5 0.763
(isentropic)
Turbine outlet 21.72 983 1.790 0.7368 394.2 0.884

{80% efficiency)

 

*The bases for enthalpy and entropy of aluminum chloride and steam are not the same. Hence comparisen of the
absolute values of these properties between the two fluids is meaningless.

27
ORNL-2677
Reactors~Power

TiD-4500 (14th ed.)

INTERNAL DISTRIBUTION

1. L. G. Alexander 58. R.S. Livingston
2. D. S. Billington 59. H. G. MacPherson
3. M. Blonder 60. W. D. Manly
4, F. F. Blankenship 61. J. R. McNally
5. E. P. Blizard 62. K. Z. Morgan
6. A. L. Boch 63. J. P. Murray (Y-12)
7. C. J. Borkowski 64. M. L. Nelson
8. G. E. Boyd 65. R. F. Newton
9. M. A, Bredig 66. A. M. Perry
10. E. J. Breeding 67. P. M. Reyling
11. R. B. Briggs 68. G. Samuels
12. C. E. Center (K-25) 6%2. H. W. Savage
13. R. A. Charpie 70. A. W. Savolainen
14. F. L. Culler 71. H. E. Seagren
15. L. B, Emlet (K-25) 72. E. D. Shipley
16-17. L. G. Epel 73. J. R, Simmons
18. W. K. Ergen 74. M. J. Skinner
19. D. E. Ferguson 75. A. H. Snell
20-45. A. P. Fraas 76. J. A. Swartout
46. J. H. Frye, Jr. 77. E. H. Taylor
47. W. R. Grimes 78. A. M. Weinberg
48. E. Guth 79. C. E. Winters
49, C. S. Harrill 80. Biology Library
50. H. W. Hoffman 81. Health Physics Library
51. A. Hollaender 82. Reactor Experimental
52. A.S. Householder Engineering Library
53. W. H. Jordan 83-84. Central Research Library
54. G. W. Keilholtz 85-104. Laboratory Records Department
55. C. P. Keim 105. Laboratory Records, ORNL R.C.
56. M. T. Kelley 106-110. CRNL -~ Y-12 Technical Library,
57. J. A, Lane Document Reference Section

111.
112.
113.
114.
115-696.

EXTERNAL DISTRIBUTION

W. C. Cooley, NASA, Washington

F. E. Rom, NASA, Cleveland, Ohio

W, D. Weatherford, Southwest Research Institute

Division of Research and Development, AEC, ORO

Given distribution as shown in TID-4500 (14th ed.) under Reactors-Power
category {75 copies — OT3)

29