ASTM D7739-11(2016)
(Practice)Standard Practice for Thermal Oxidative Stability Measurement via Quartz Crystal Microbalance
Standard Practice for Thermal Oxidative Stability Measurement via Quartz Crystal Microbalance
SIGNIFICANCE AND USE
3.1 The tendency of a jet fuel to resist the formation of deposits at elevated temperature is indicative of its oxidative thermal stability. This practice provides a technique for the simultaneous determination of deposit formation and oxygen consumption during the thermal oxidation of jet fuels and other hydrocarbon liquids. The practice can be used to evaluate the thermal stability of fuels and to determine the efficacy of additives in inhibiting deposition or slowing oxidation, or both. A test temperature of 140 °C and run length up to 16 h has been found to be effective for the relative evaluation of fuels and fuel additives. This practice has also been employed for other hydrocarbon liquids, such as gasoline and diesel fuels, but additional safety issues may need to be addressed by the user.
SCOPE
1.1 This laboratory practice covers the quantitative determination of surface deposits produced during the thermal oxidation of gas turbine fuels by monitoring the oscillation frequency of a quartz crystal during thermal exposure. In this practice, “thermal oxidative stability” refers to the tendency of a fuel to resist surface deposit formation during heating.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation: D7739 − 11 (Reapproved 2016) An American National Standard
Standard Practice for
Thermal Oxidative Stability Measurement via Quartz Crystal
1
Microbalance
This standard is issued under the fixed designation D7739; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Significance and Use
1.1 This laboratory practice covers the quantitative determi-
3.1 The tendency of a jet fuel to resist the formation of
nation of surface deposits produced during the thermal oxida-
deposits at elevated temperature is indicative of its oxidative
tion of gas turbine fuels by monitoring the oscillation fre-
thermal stability. This practice provides a technique for the
quency of a quartz crystal during thermal exposure. In this
simultaneous determination of deposit formation and oxygen
practice, “thermal oxidative stability” refers to the tendency of
consumptionduringthethermaloxidationofjetfuelsandother
a fuel to resist surface deposit formation during heating.
hydrocarbon liquids. The practice can be used to evaluate the
1.2 The values stated in SI units are to be regarded as the thermal stability of fuels and to determine the efficacy of
standard. The values given in parentheses are for information additivesininhibitingdepositionorslowingoxidation,orboth.
only.
Atesttemperatureof140 °Candrunlengthupto16 hhasbeen
found to be effective for the relative evaluation of fuels and
1.3 This standard does not purport to address all of the
fuel additives. This practice has also been employed for other
safety concerns, if any, associated with its use. It is the
hydrocarbon liquids, such as gasoline and diesel fuels, but
responsibility of the user of this standard to establish appro-
additional safety issues may need to be addressed by the user.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
4. Apparatus
2. Summary of Practice
4.1 All dimensions without tolerance limits are nominal
2.1 A quartz crystal, fitted with gold electrodes, is fully values.
immersed in test fuel contained within a reactor. An oscillator
4.2 Reactor—A T316, 100 mL stainless steel reactor cylin-
circuit, connected to the crystal, supplies energy to excite the
der with an internal diameter of 5.23 cm (2.06 in.) and a depth
quartz crystal and monitors its resonant frequency (nominally
3,4
of 4.93 cm (1.94 in.). A T316 stainless steel reactor head
5 MHz) over time via a computer interface. The reactor is
with several openings (for example, gas inlet via dip tube, gas
equipped with a magnetic stir bar, pressure gauge/transducer,
release fitted with a dial gauge or pressure transducer,
oxygen sensor (not recommended for certain test conditions,
thermocouple, safety rupture disk, frequency signal
see 4.11), and thermocouple to monitor and control test
connection, sleeve for oxygen concentration probe). A
conditions. Prior to testing, the fuel is bubbled with the test gas
3
0.952 cm( ⁄8 in.)holeisdrilledinthecenterofthereactorhead
for 30 min to equilibrate.After equilibration, the reactor vessel
to accommodate the frequency signal connectors. This hole
is isolated and raised to test temperature and pressure. As
3
shall have a 0.952 cm ( ⁄8 in.) clearance from any adjacent
deposits accumulate on the crystal surface during the run, the
opening.
crystal frequency decreases. The shift in resonance frequency
can be quantitatively related, in real time, to surface deposit
4.3 SMACoaxial ConnectorAssembly—This assembly pro-
2
accumulation via a variation of the Sauerbrey equation.
vides the electronic connection through the reactor head to the
quartzcrystalandconsistsofseveralkeyparts(seeFig.1).The
cable from the oscillator (see 4.6) connects to a subminiature
1
This practice is under the jurisdiction of ASTM Committee D02 on Petroleum
Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcom-
mittee D02.J0.03 on Combustion and Thermal Properties.
3
Current edition approved April 1, 2016. Published May 2016. Originally The sole source of supply of the apparatus (Parr Instrument cylinder model
approved in 2011. Last previous edition approved in 2011 as D7739 – 11. DOI: #452HC8 (100 mL)) known to the committee at this time is Parr Instrument
10.1520/D7739-11R16. Company, 211 Fifty-Third St., Moline, IL 61265-1770.
2 4
Klavetter, E. A., Martin, S. J., and Wessendorf, K. O., “Monitoring Jet Fuel If you are aware of alternative suppliers, please provide this information to
Thermal Stability Using a Quartz Crystal Microbalance,” Energy & Fuels, Vol 3, ASTM International Hea
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D7739 − 11 D7739 − 11 (Reapproved 2016) An American National Standard
Standard Practice for
Thermal Oxidative Stability Measurement via Quartz Crystal
1
Microbalance
This standard is issued under the fixed designation D7739; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This laboratory practice covers the quantitative determination of surface deposits produced during the thermal oxidation of
gas turbine fuels by monitoring the oscillation frequency of a quartz crystal during thermal exposure. In this practice, “thermal
oxidative stability” refers to the tendency of a fuel to resist surface deposit formation during heating.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Summary of Practice
2.1 A quartz crystal, fitted with gold electrodes, is fully immersed in test fuel contained within a reactor. An oscillator circuit,
connected to the crystal, supplies energy to excite the quartz crystal and monitors its resonant frequency (nominally 5 MHz)
5 MHz) over time via a computer interface. The reactor is equipped with a magnetic stir bar, pressure gauge/transducer, oxygen
sensor (not recommended for certain test conditions, see 4.11), and thermocouple to monitor and control test conditions. Prior to
testing, the fuel is bubbled with the test gas for 30 min 30 min to equilibrate. After equilibration, the reactor vessel is isolated and
raised to test temperature and pressure. As deposits accumulate on the crystal surface during the run, the crystal frequency
decreases. The shift in resonance frequency can be quantitatively related, in real time, to surface deposit accumulation via a
2
variation of the Sauerbrey equation.
3. Significance and Use
3.1 The tendency of a jet fuel to resist the formation of deposits at elevated temperature is indicative of its oxidative thermal
stability. This practice provides a technique for the simultaneous determination of deposit formation and oxygen consumption
during the thermal oxidation of jet fuels and other hydrocarbon liquids. The practice can be used to evaluate the thermal stability
of fuels and to determine the efficacy of additives in inhibiting deposition or slowing oxidation, or both. A test temperature of
140°C140 °C and run length up to 16 h 16 h has been found to be effective for the relative evaluation of fuels and fuel additives.
This practice has also been employed for other hydrocarbon liquids, such as gasoline and diesel fuels, but additional safety issues
may need to be addressed by the user.
4. Apparatus
4.1 All dimensions without tolerance limits are nominal values.
4.2 Reactor—A T316, 100 mL 100 mL stainless steel reactor cylinder with an internal diameter of 5.23 cm (2.06 in.) 5.23 cm
3,4
(2.06 in.) and a depth of 4.93 cm (1.94 in.).4.93 cm (1.94 in.). A T316 stainless steel reactor head with several openings (for
example, gas inlet via dip tube, gas release fitted with a dial gauge or pressure transducer, thermocouple, safety rupture disk,
1
This practice is under the jurisdiction of ASTM Committee D02 on Petroleum Products Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.J0.03 on Combustion and Thermal Properties.
Current edition approved June 1, 2011April 1, 2016. Published August 2011May 2016. Originally approved in 2011. Last previous edition approved in 2011 as D7739 – 11.
DOI: 10.1520/D7739–11.10.1520/D7739-11R16.
2
Klavetter, E. A., Martin, S. J., and Wessendorf, K. O., “Monitoring Jet Fuel Thermal Stability Using a Quartz Crystal Microbalance,” Energy & Fuels, Vol 3, 1993, pp.
582-588.
3
The sole source of supply of the apparatus (Parr Instrument cylinder model #452HC8 (100 mL)) known to the committee at this time is Parr Instrument Company, 211
Fifty-Third St., Moline, IL 61265-1770.
4
If you are aware of alternative suppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful consid
...
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