ILMA Compoundings August 2016 - (Page 21)
THE EVOLUTION OF GROUP II
Growth of Group II in
Marine and Gas Engine Oils
rends in automotive crankcase lubricant formulations,
which account for more than half of the base stock
utilization, are impacting the supply and demand
balance of base stocks globally. As this sector looks to improve
fuel economy and reduce emissions, the use of high-quality
Group II and III base stocks is growing quickly. The inability
of Group I products to deliver the right characteristics for
automotive applications has resulted in a number of capacity
reductions and plant closures in Europe, which have reduced
supply by more than a million tonnes.
Over the same period there has been a significant increase
in the availability of Group II base stocks as new plants and
capacity additions have come on stream. This has driven down
the cost, making their use in application increasingly attractive.
With further capacity additions scheduled over the next two to
three years, a shift to these higher-quality products in both gas
engine and marine applications seems fairly inevitable.
Group II Benefits and Challenges in
Group II base stocks have a number of
benefits over their Group I counterparts
when formulating trunk piston engine oils
(TPEO) for medium-speed, four-stroke
engines. These include:
* Better oxidation control.
challenges - particularly concerning asphaltene handling
Most of the ships that use TPEO run on heavy fuel oil, which
contains large polyaromatic species known as asphaltenes.
During engine operation, these species can migrate into the
engine oil via fuel contamination. Here they can agglomerate
to form "black sludge," which leads to high levels of deposit
formation and results in piston deposits, choked oil galleries
and oil starvation. Deposits on the piston undercrown are of
particular concern because they act as insulation, preventing
the lubricant from effectively transferring heat away from the
piston, which can lead to hot corrosion of the piston crown.
Oils formulated in Group I base oils with salicylate technology
have demonstrated excellent performance over many years of
field operation. Not only do they offer excellent asphaltene
handling capabilities, but also excellent engine protection and
oil life, as well as reduced operating costs. But the picture is very
different when Group II base stocks are used.
Their lower solvency means conventional
additives are less able to handle asphaltenes,
and a new additive system is required to
ensure TPEO formulated in these highquality base stocks deliver the required level
of engine cleanliness.
Group II in Gas Engine Oils
* Improved NOACK stability.
* Enhanced viscosity control.
However, using Group II to develop
TPEO also presents lubricant formulation
Until recently, Group I base stocks have
been the basis of most stationary gas engine
oil formulations. But again, the demand
for higher-performance lubricants from
engine manufacturers means this picture is
Compoundings August 2016 * 21 * Vol. 66 No. 8
Table of Contents for the Digital Edition of ILMA Compoundings August 2016
FROM THE CEO
FROM THE PRESIDENT
NOTES FROM NLGI
THE HEART OF ILMA
In Memoriam Mike Ryterski (1920–2016)
Radco Industries Promotes Brian Finch
Manufacturing Day is Coming! October 7, 2016
THE EVOLUTION OF GROUP II
VOICES & VIEWS
FOCUS ON ETHICS
RULES & REGS
LEGAL EASE Preparing for Brexit
THE WHITE PAPER
ILMA Compoundings August 2016