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Technical Data Sheet
Therminol® 59 Heat Transfer Fluid

  • HTF - production of biodiesel
  • Biomass - orc
  • Gas to liquid (gtl)
  • Natural gas purification
  • Oil or gas processing
  • Polymer & plastic
  • Specialty chemicals
  • Waste heat recover + orc
Key Attributes
  • Heating or Cooling Operation
  • Long Life Means Low Cost
  • Superb Low Temperature Pumpability

Product Description

Therminol 59 is a synthetic heat transfer fluid with excellent low temperature pumping characteristics and thermal stability.

Performance Benefits

  • Heating or Cooling Operation—Therminol 59 has surprisingly low viscosity for a high-temperature heat transfer fluid. It is ideally suited for combination heating and cooling applications, delivering excellent heat transfer rates even at 20°C (70°F). Batch processes will benefit from the excellent cooling performance Therminol 59 delivers.
  • Superb Low viscosity at exceptionally cold temperatures makes this an ideal fluid for colder climates. In fact, Therminol 59 was originally developed for use on the North Slope in Alaska, a supreme test of low-temperature pumpability.
  • Long Life Means Low Cost—Users can expect many years of reliable, trouble-free operation, even when operating continuously at the recommended upper temperature limit of 315°C (600°F). Long life means fewer fluid change-outs, and that means low operating cost, which is critical in today’s highly competitive business environment.

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Typical Properties

PropertyTest MethodTypical Value, Units
Appearance Clear yellow to dark amber liquid
Composition Alkyl substituted aromatic
Maximum bulk temperature 315 °C (600 °F)
Maximum film temperature 345 °C (650 °F)
Normal Boiling Point 289 °C (553 °F)
     @300 mm2/s (cSt) -37 °C (-35 °F)
     @ 2000 mm2/s (cSt) -49 °C (-56 °F)
Flash Point 
     COCASTM D92146 °C (295 °F)
     PMCCASTM D93132 °C (270 °F)
Autoignition TemperatureASTM E659372 °C (702 °F)
 DIN 51794404 °C (760 °F)
Pour PointISO 3016-68 °C (-90 °F)
 ASTM D 97-61 °C (-78 °F)
Minimum liquid temperatures for fully developed turbulent flow (NRe > 10000) 
     10 ft/s, 1-in. tube (3.048 m/s, 2.54-cm tube) 17 °C (63 °F)
     20 ft/s, 1-in. tube (6.096 m/s, 2.54-cm tube) 0 °C (32 °F)
Minimum liquid temperatures for transitional region flow, (NRe > 2000) 
     10 ft/s, 1-in. tube (3.048 m/s, 2.54-cm tube) -16 °F (4 °C)
     20 ft/s, 1-in. tube (6.096 m/s, 2.54-cm tube) -24 °C (12 °F)
Coefficient of thermal expansion 
     @ 200°C 0.000946 /°C (0.000525 /°F)
Heat of Vaporizationa 227 kJ/kg (97.5 Btu/lb)
Viscosity, Kinematic 
     @ 100°CASTM D 4451.44 cSt, mm2/s
     @ 40°CASTM D 4454.00 cSt, mm2/s
Liquid Density 
     @ 15°CASTM D 4052978 kg/m3 (8.16 lb/gal)
     @ 25°CASTM D 4052971 kg/m3 (8.10 lb/gal)
AcidityASTM D 664<0.2 mg KOH/g
Molecular Weight (Average) 207
Pseudocritical temperature 514 °C (957 °F)
Pseudocritical pressure 22.3 bar (323 psia)
Pseudocritical density 287 kg/m3 (17.9 lb/ft3)
Copper CorrosionASTM D 130<<1a
Moisture Content, maximumASTM E-203200 ppm
Dielectric Constant 
     @ 23°CASTM D-9242.52

aat maximum use temperature

Properties reported here are typical of average lots. Eastman makes no representation that the material in any particular shipment will conform exactly to the values given.

Eastman and its marketing affiliates shall not be responsible for the use of this information, or of any product, method, or apparatus mentioned, and you must make your own determination of its suitability and completeness for your own use, for the protection of the environment, and for the health and safety of your employees and purchasers of your products. No warranty is made of the merchantability of fitness of any product, and nothing herein waives any of the Seller's conditions of sale.

4/20/2021 9:17:18 AM