Solar parabolic trough systems for electricity production are receiving renewed attention, and new solar plants are under construction to help meet the growing demands of the power market in the Western United States. The growing solar trough industry will rely on operating experience it has gained over the last two decades. Recently, researchers found that trough plants that use organic heat transfer fluids (HTFs) such as Therminol VP-1 are experiencing significant heat losses in the receiver tubes. The cause has been traced back to the accumulation of excess hydrogen gas in the vacuum annulus that surrounds the steel receiver tube, thus compromising the thermal insulation of the receiver. The hydrogen gas is formed during the thermal decomposition of the organic HTF that circulates inside the receiver loop, and the installation of hydrogen getters inside the annulus has proven to be insufficient for controlling the hydrogen buildup over the lifetime of the receivers. This paper will provide an overview of the chemical literature dealing with the thermal decomposition of diphenyl oxide and biphenyl, which are the two constituents of Therminol VP-1.

1.
Price
,
H.
,
Lüpfert
,
E.
,
Kearney
,
D.
,
Zarza
,
E.
,
Cohen
,
G.
,
Gee
,
R.
, and
Mahoney
,
R.
, 2002, “
Advances in Parabolic Trough Solar Power Technology
,”
ASME J. Sol. Energy Eng.
0199-6231,
124
, pp.
109
125
.
2.
Moens
,
L.
,
Blake
,
D. M.
,
Rudnicki
,
D. L.
, and
Hale
,
M. J.
, 2003, “
Advanced Thermal Storage Fluids for Parabolic Trough Systems
,”
ASME J. Sol. Energy Eng.
0199-6231,
125
, pp.
112
116
.
3.
Bevacqua
,
B.
,
Prakash
,
R.
, and
Gamble
,
C.
, 2008, “
Extending Organic Heat Transfer Fluid Life in Aging Solar Energy Generating Systems
,”
Proceedings of the 2008 Biennial CSP SolarPACES Conference
, Las Vegas, NV, Mar. 4–7.
4.
Labaton
,
I. J.
, 1989, “
Hydrogen Pump
,” U.S. Patent No. 4,886,048.
5.
Burkholder
,
F.
,
Brandemuehl
,
M.
,
Kutscher
,
C.
, and
Wolfrum
,
E.
, 2008, “
Heat Conduction of Inert Gas-Hydrogen Mixtures in Parabolic Trough Receivers
,”
ASME
Paper No. ES2008-54176.
6.
Grebe
,
J. J.
, and
Stoesser
,
S. M.
, 1933, “
Synthetic Lubricant and Method of Making Same
,” U.S. Patent No. 1,905,850.
7.
Grebe
,
J. J.
, and
Stoesser
,
S. M.
, 1936, “
Heat Storage and Transfer Agent
,” U.S. Patent No. 2,033,702.
8.
Rainey
,
W. T.
, Jr.
, and
Yeatts
,
L. B.
, Jr.
, 1963, “
Studies on Pyrolysis Products of Pure Biphenyl
,” USAEC Report No. TID-7641, p.
189
.
9.
Rainey
,
W. T.
, Jr.
,
Attrill
,
J. E.
, and
Yeatts
,
L. B.
, Jr.
, 1963, “
Gas Chromatographic Analysis of Biphenyl Pyrolytic Products
,” Report No. ORNL-TM-523.
10.
Adam
,
A. W.
,
Niggemann
,
R. E.
, and
Sibert
,
L. W.
, 1968, “
Thermal Stability Determination of Biphenyl and the Eutectic of Biphenyl and Phenyl Ether in a Rankine Cycle System
,”
IECEC, Intersociety Energy Conversion Conference
- 1968 Record,
IEEE
,
New York
, Vol.
1
, pp.
398
406
.
11.
Leighton
,
G. S.
, 1968, “
The Organic Rankine Cycle
,”
IECEC, Intersociety Energy Conversion Conference
- 1968 Record,
IEEE
,
New York
, Vol.
1
, pp.
389
397
.
12.
Proksch
,
E.
,
Strigl
,
A.
,
Wagner-Löffler
,
M.
, and
Szinovatz
,
W.
, 1985, “
Zur thermischen Stabilität von Diphenyl
,”
Chem.-Ing.-Tech.
0009-286X,
57
, pp.
148
151
.
13.
Cook
,
B. R.
,
Wilkinson
,
B. B.
,
Culross
,
C. C.
,
Holmes
,
S. M.
, and
Martinez
,
L. E.
, 1997, “
Hydrogen Transfer Induced Cleavage of Biaryl Bonds
,”
Energy Fuels
0887-0624,
11
, pp.
61
75
.
14.
van Scheppingen
,
W.
,
Dorrestijn
,
E.
,
Arends
,
I.
, and
Mulder
,
P.
, 1997, “
Carbon-Oxygen Bond Strength in Diphenyl Ether and Phenyl Vinyl Ether: An Experimental and Computational Study
,”
J. Phys. Chem. A
1089-5639,
101
, pp.
5404
5411
.
15.
Poutsma
,
M. L.
, 1990, “
Free-Radical Thermolysis and Hydrogenolysis of Model Hydrocarbons Relevant to Processing of Coal
,”
Energy Fuels
0887-0624,
4
, pp.
113
131
.
16.
Arnold
,
C.
, Jr.
, 1978, “
Evaluation of Organic Coolants for the Transportation of LMFBR Spent Fuel Rods
,” Report No. SAND77-1486.
17.
Gambell
,
J. W.
,
Herber
,
J. F.
, and
Thompson
,
Q. E.
, 1991, “
Heat Transfer Fluids
,” U.S. Patent No. 5,075,022.
18.
Fishel
,
N. A.
, 1977, “
Conversion of Diphenylethers to Dibenzofurans Using Catalysts Containing Ceria
,” U.S. Patent No. 4,009,185.
19.
Walsh
,
W. D.
, and
Gunn
,
R. W.
, 1963, “
Preparation of Dibenzofuran
,” U.S. Patent No. 3,108,121.
20.
Okazaki
,
H.
,
Inoue
,
M.
, and
Ishida
,
H.
, 1994, “
Heat-Transfer Medium Compositions
,” U.S. Patent No. 5,281,349.
21.
Gierszewski
,
P.
, and
Hollies
,
R. E.
, 1987, “
Organic Coolants and Their Applications to Fusion Reactors
,”
Nucl. Eng. Des./Fusion
,
4
, pp.
223
236
.
22.
Gierszewski
,
P.
, and
Hollies
,
R. E.
, 1986, “
Organic Coolants and Their Applications to Fusion Reactors
,” Canadian Fusion Fuels Technology Project, Report No. AECL-8405.
23.
Smee
,
J. L.
,
Puttagunta
,
V. R.
,
Robertson
,
R. F. S.
, and
Hatcher
,
S. R.
, 1975, “
Organic Coolant Summary Report
,” Report No. AECL-4922.
24.
Natalizio
,
A.
,
Hollies
,
R. E.
, and
Gierszewski
,
P.
, 1993, “
Safety and Enviromental Aspects of Organic Coolants for Fusion Facilities
,”
J. Fusion Energy
0164-0313,
12
, pp.
177
181
.
25.
Mahoney
,
C. L.
,
Barnum
,
E. R.
,
Kerlin
,
W. W.
,
Sax
,
K. J.
, and
Saari
,
W. S.
, 1960, “
Polyphenyl Ethers as High-Temperature Radiation-Resistant Lubricants
,”
J. Chem. Eng. Data
0021-9568,
5
, pp.
172
180
.
26.
Mahoney
,
C. L.
,
Barnum
,
E. R.
,
Saari
,
W. S.
,
Sax
,
K. J.
, and
Kerlin
,
W. W.
, 1959, “
Nuclear Radiation Resistant High Temperature Lubricants
,” WADC Technical Report No. 59-173.
27.
Blake
,
E. S.
,
Hammann
,
W. C.
,
Edwards
,
J. W.
,
Reichard
,
T. E.
, and
Ort
,
M. R.
, 1961, “
Thermal Stability as a Function of Chemical Structure
,”
J. Chem. Eng. Data
0021-9568,
6
, pp.
87
98
.
28.
Ravner
,
H.
,
Moniz
,
W. B.
, and
Blachly
,
C. H.
, 1972, “
High-Temperature Stabilization of Polyphenyl Ethers by Inorganic Salts
,”
ASLE Trans.
0569-8197,
15
, pp.
45
53
.
29.
Archer
,
W. L.
, and
Bozer
,
K. B.
, 1966, “
Oxidative Degradation of the Polyphenyl Ethers
,”
Ind. Eng. Chem. Prod. Res. Dev.
0196-4321,
5
, pp.
145
149
.
30.
Ravner
,
H.
,
Russ
,
E. R.
, and
Timmons
,
C. O.
, 1963, “
Antioxidant Action of Metals and Metal-Organic Salts in Fluoroesters and Polyphenyl Ethers
,”
J. Chem. Eng. Data
0021-9568,
8
, pp.
591
596
.
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