Hydrocarbon Processing - October 2021 - GP-33

MAINTENANCE AND RELIABILITY
Realize the full potential of stationary
gas engine oil with used oil analysis
C. BUHLER, HollyFrontier Lubricants and Specialties, Edmonton, Alberta, Canada
Used oil analysis is widely considered a vital tool for operators
of stationary gas engines. While the extent to which different
operations are able to commit resources to used oil analysis
may vary, many recognize its importance as a maintenance and
reliability tool that enables operators to monitor and optimize
the life of an engine and its lubricating oil.
Major lubricant manufacturers advise making used oil analysis
a central part of a gas engine's maintenance schedule, and most
original equipment manufacturers (OEMs) recommend it as part
of best maintenance practices. It may also be a condition of maintaining
engine warranty, but realizing the full potential of the oil
relies on a holistic approach. Used oil analysis does not replace,
but rather complements, other recommended practices such as
monitoring and trending daily engine oil consumption and performing
combustion chamber borescope inspections (FIG. 1).
Simply put, used oil analysis involves gathering usable data
from the engine's oil and analyzing it to make informed decisions.
When carried out correctly, it is a reliable and cost-effective
way to extract greater value from a lubricant investment and
an effective tool in monitoring the health of both the lubricating
oil and a stationary gas engine.
A suite of standardized, industry-accepted test methods are
needed to analyze the oil. These test methods allow the engine's
overall condition to be trended through wear metal analysis and
provide an evaluation of the lubricant's condition.
What can be analyzed? The sheer number of tests that can
be carried out on used oil can be overwhelming, especially if
maintenance staff are not experienced in used oil analysis. It is
important to monitor the physical and chemical properties, contaminants
and modes of degradation commonly seen in stationary
gas engine oils so that those involved in the process can best
understand the condition of equipment.
Most engine OEMs list specific limits on these properties. It
is crucial that operators are aware of the OEM limits and proactively
compare their data to these limits. To retain a margin of
safety, the oil must be replaced to maintain performance levels
and engine protection prior to the outer limits being reached. It
is advised to trend and forecast the data to proactively plan when
the oil needs to be changed, rather than reacting to the limits being
surpassed and then planning for a maintenance event.
The most important physical property of a lubricating oil is
viscosity-the fluid's thickness or resistance to flow. The oil's
viscosity is what primarily provides separation of metal surfaces
in relative motion to each other, meaning any significant change
FIG. 1. Technical services advisor performing a critical gas engine
borescope inspection.
Gas Processing & LNG | SEPTEMBER/OCTOBER 2021 33
could lead to increased wear and compromise protection, potentially
leading to engine failure.
Stationary gas engine oils naturally experience eventual
chemical degradation over time, from processes such as oxidation
or nitration. Oxidation occurs when the lubricating oil is
exposed to high temperatures and oxygen and can be accelerated
by wear metals that can act like catalysts. Nitration, on the other
hand, is caused by the oil's exposure to nitric oxides (NOX
), as
found in gas engine exhaust gases. All gas engines will have some
level of nitration in the used oil, but it is more pronounced in
stoichiometric gas engines, as they produce high levels of NOX
in the exhaust gas (FIG. 2).
Both forms of degradation can cause the oil to thicken or produce
sludge, varnish and deposits, as well as cause the formation
of acids, which can lead to corrosive wear. Oxidation can also
form carbon deposits in piston ring grooves and on the backside
of piston rings. Nitrated sludge is very difficult to remove from
an engine and can send oil service life into a downward spiral.
Most engine oil OEMs set limits on oxidation and nitration, so
it is important for operators to measure the levels of degradation
and replace the oil if it approaches those limits.
Fourier transform infrared spectroscopy (FTIR) is an efficient
test method that identifies these forms of degradation, as
well as certain contaminants. FTIR compares the spectrum of
used oil to that of new fluid. The difference between the used
and new fluid spectrums indicate what form of degradation is
ongoing and to what degree it has occurred.
Tests also exist to measure the levels of acidity and alkalinity
of the oil, both of which can be influenced by oxidation and nitration.
Total acid number (TAN) measures the level of corrosive
acids that have formed in the oil from oxidation and nitration and
is especially required when extending oil drain intervals. TAN

Hydrocarbon Processing - October 2021

Table of Contents for the Digital Edition of Hydrocarbon Processing - October 2021

Contents
Hydrocarbon Processing - October 2021 - Cover1
Hydrocarbon Processing - October 2021 - Cover2
Hydrocarbon Processing - October 2021 - Contents
Hydrocarbon Processing - October 2021 - 4
Hydrocarbon Processing - October 2021 - 5
Hydrocarbon Processing - October 2021 - 6
Hydrocarbon Processing - October 2021 - 7
Hydrocarbon Processing - October 2021 - 8
Hydrocarbon Processing - October 2021 - 9
Hydrocarbon Processing - October 2021 - 10
Hydrocarbon Processing - October 2021 - 11
Hydrocarbon Processing - October 2021 - 12
Hydrocarbon Processing - October 2021 - 13
Hydrocarbon Processing - October 2021 - 14
Hydrocarbon Processing - October 2021 - 15
Hydrocarbon Processing - October 2021 - 16
Hydrocarbon Processing - October 2021 - 17
Hydrocarbon Processing - October 2021 - 18
Hydrocarbon Processing - October 2021 - 19
Hydrocarbon Processing - October 2021 - 20
Hydrocarbon Processing - October 2021 - 21
Hydrocarbon Processing - October 2021 - 22
Hydrocarbon Processing - October 2021 - 23
Hydrocarbon Processing - October 2021 - 24
Hydrocarbon Processing - October 2021 - 25
Hydrocarbon Processing - October 2021 - 26
Hydrocarbon Processing - October 2021 - 27
Hydrocarbon Processing - October 2021 - 28
Hydrocarbon Processing - October 2021 - 29
Hydrocarbon Processing - October 2021 - 30
Hydrocarbon Processing - October 2021 - 31
Hydrocarbon Processing - October 2021 - 32
Hydrocarbon Processing - October 2021 - 33
Hydrocarbon Processing - October 2021 - 34
Hydrocarbon Processing - October 2021 - 35
Hydrocarbon Processing - October 2021 - 36
Hydrocarbon Processing - October 2021 - 37
Hydrocarbon Processing - October 2021 - 38
Hydrocarbon Processing - October 2021 - 39
Hydrocarbon Processing - October 2021 - 40
Hydrocarbon Processing - October 2021 - 41
Hydrocarbon Processing - October 2021 - 42
Hydrocarbon Processing - October 2021 - 43
Hydrocarbon Processing - October 2021 - 44
Hydrocarbon Processing - October 2021 - 45
Hydrocarbon Processing - October 2021 - 46
Hydrocarbon Processing - October 2021 - 47
Hydrocarbon Processing - October 2021 - 48
Hydrocarbon Processing - October 2021 - 49
Hydrocarbon Processing - October 2021 - 50
Hydrocarbon Processing - October 2021 - 51
Hydrocarbon Processing - October 2021 - 52
Hydrocarbon Processing - October 2021 - 53
Hydrocarbon Processing - October 2021 - 54
Hydrocarbon Processing - October 2021 - 55
Hydrocarbon Processing - October 2021 - 56
Hydrocarbon Processing - October 2021 - 57
Hydrocarbon Processing - October 2021 - 58
Hydrocarbon Processing - October 2021 - 59
Hydrocarbon Processing - October 2021 - 60
Hydrocarbon Processing - October 2021 - 61
Hydrocarbon Processing - October 2021 - 62
Hydrocarbon Processing - October 2021 - 63
Hydrocarbon Processing - October 2021 - 64
Hydrocarbon Processing - October 2021 - 65
Hydrocarbon Processing - October 2021 - 66
Hydrocarbon Processing - October 2021 - 67
Hydrocarbon Processing - October 2021 - 68
Hydrocarbon Processing - October 2021 - 69
Hydrocarbon Processing - October 2021 - 70
Hydrocarbon Processing - October 2021 - 71
Hydrocarbon Processing - October 2021 - 72
Hydrocarbon Processing - October 2021 - 73
Hydrocarbon Processing - October 2021 - 74
Hydrocarbon Processing - October 2021 - 75
Hydrocarbon Processing - October 2021 - 76
Hydrocarbon Processing - October 2021 - 77
Hydrocarbon Processing - October 2021 - 78
Hydrocarbon Processing - October 2021 - 79
Hydrocarbon Processing - October 2021 - 80
Hydrocarbon Processing - October 2021 - 81
Hydrocarbon Processing - October 2021 - 82
Hydrocarbon Processing - October 2021 - 83
Hydrocarbon Processing - October 2021 - 84
Hydrocarbon Processing - October 2021 - 85
Hydrocarbon Processing - October 2021 - 86
Hydrocarbon Processing - October 2021 - 87
Hydrocarbon Processing - October 2021 - 88
Hydrocarbon Processing - October 2021 - 89
Hydrocarbon Processing - October 2021 - 90
Hydrocarbon Processing - October 2021 - Cover3
Hydrocarbon Processing - October 2021 - Cover4
Hydrocarbon Processing - October 2021 - GP-1
Hydrocarbon Processing - October 2021 - GP-2
Hydrocarbon Processing - October 2021 - GP-3
Hydrocarbon Processing - October 2021 - GP-4
Hydrocarbon Processing - October 2021 - GP-5
Hydrocarbon Processing - October 2021 - GP-6
Hydrocarbon Processing - October 2021 - GP-7
Hydrocarbon Processing - October 2021 - GP-8
Hydrocarbon Processing - October 2021 - GP-9
Hydrocarbon Processing - October 2021 - GP-10
Hydrocarbon Processing - October 2021 - GP-11
Hydrocarbon Processing - October 2021 - GP-12
Hydrocarbon Processing - October 2021 - GP-13
Hydrocarbon Processing - October 2021 - GP-14
Hydrocarbon Processing - October 2021 - GP-15
Hydrocarbon Processing - October 2021 - GP-16
Hydrocarbon Processing - October 2021 - GP-17
Hydrocarbon Processing - October 2021 - GP-18
Hydrocarbon Processing - October 2021 - GP-19
Hydrocarbon Processing - October 2021 - GP-20
Hydrocarbon Processing - October 2021 - GP-21
Hydrocarbon Processing - October 2021 - GP-22
Hydrocarbon Processing - October 2021 - GP-23
Hydrocarbon Processing - October 2021 - GP-24
Hydrocarbon Processing - October 2021 - GP-25
Hydrocarbon Processing - October 2021 - GP-26
Hydrocarbon Processing - October 2021 - GP-27
Hydrocarbon Processing - October 2021 - GP-28
Hydrocarbon Processing - October 2021 - GP-29
Hydrocarbon Processing - October 2021 - GP-30
Hydrocarbon Processing - October 2021 - GP-31
Hydrocarbon Processing - October 2021 - GP-32
Hydrocarbon Processing - October 2021 - GP-33
Hydrocarbon Processing - October 2021 - GP-34
Hydrocarbon Processing - October 2021 - GP-35
Hydrocarbon Processing - October 2021 - GP-36
Hydrocarbon Processing - October 2021 - GP-37
Hydrocarbon Processing - October 2021 - GP-38
Hydrocarbon Processing - October 2021 - GP-39
Hydrocarbon Processing - October 2021 - GP-40
Hydrocarbon Processing - October 2021 - GP-41
Hydrocarbon Processing - October 2021 - GP-42
Hydrocarbon Processing - October 2021 - GP-43
Hydrocarbon Processing - October 2021 - GP-44
https://www.nxtbook.com/gulfenergyinfo/gulfpub/HPI-Market-Data-2023-v3
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https://www.nxtbook.com/nxtbooks/gulfpub/hp_202101
https://www.nxtbook.com/nxtbooks/gulfpub/catalyst_handbook_2020_v2
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https://www.nxtbook.com/nxtbooks/gulfpub/hp_202012
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https://www.nxtbook.com/nxtbooks/gulfpub/hp_202009
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202008
https://www.nxtbook.com/nxtbooks/gulfpub/refining_processes_handbook_2020
https://www.nxtbook.com/nxtbooks/gulfpub/refining_processes_handbook_2020_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202007
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202006
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https://www.nxtbook.com/nxtbooks/gulfpub/hp_201912
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201911
https://www.nxtbook.com/nxtbooks/gulfpub/hpimarket_2020_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hpimarket_2020
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201910
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https://www.nxtbook.com/nxtbooks/gulfpub/hp_201901
https://www.nxtbook.com/nxtbooks/gulfpub/petrochemical_2018_v2
https://www.nxtbook.com/nxtbooks/gulfpub/petrochemical_2018
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201812
https://www.nxtbook.com/nxtbooks/gulfpub/hpimarket_2019_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hpimarket_2019
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201811
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