Page 20 - Fuels & Lubes International 2014 - Q2

FUELS & LUBES INTERNATIONAL Volume 20 Issue 2 20
ASTM committee
to vote on proposed
gasoline
volatility
specchange
By: Hank Hogan
He’s vice chair of ASTM Commi-
tee D02 on Petroleum Products, Fuels and
Lubricants, which has a subcommittee, D02.
A, that sets gasoline volatility specifications.
“The issue of ethanol has been handled
by exceptions. Many [U.S.] states have allowed
what I’ll call waivers.” said Simnick, senior
technical advisor at BP Global Fuels Technol-
ogy. “The latest trend from the state regulators
has been to get rid of the waivers. They want
ASTM to handle all these issues by ballot.”
Volatility is specified in various ways. One
is the temperature at which the vapor to liquid
ratio equals 20:1, or the TVL20 point. Another
is the Reid Vapor Pressure (RVP), or the
pressure exerted by a liquid at 100oF. A third
is the 50%, or T50, gas distillation point.
Blending ethanol into gasoline drops
the TVL20 and T50 points while raising RVP.
That can cause one or more of these parameters
to be out of spec.
Changes in volatility can lead to stalling
and other engine failures. Lew Gibbs,
a consultant who retired from Chevron after
more than a half century with the company,
recalled the early days of ethanol use in the
U.S. when a vehicle which was running on
splash-blended ethanol failed to start while
touring at altitude in the Rocky Mountains.
With reporters present to cover the event,
the result was a PR fiasco for the vehicle maker.
Although newer cars are generally able to
tolerate a wider fuel range, older cars may not be
so accommodating. The problem of how older
vehicle technology will react to newer fuels isn’t
academic. The average age of the vehicle fleet
in the U.S. and Europe has risen in recent years,
putting a significant number of older vehicles
at risk in case of any specification change.
That is an issue for everyone. “Suppliers
do not want to have unhappy customers.
Nor do the auto people,” Gibbs said.
Gibbs added that, in general, it’s fairly
easy to subject late model cars to testing,
largely because it’s relatively easy to obtain such
vehicles. What’s hard to do, sometimes, is to find
older cars in sound mechanical condition that
can be put to the test.
Blends of up to 10% ethanol in gasoline
or even higher are becoming common
around the world. As a result, some
ethanol-blended gasoline may fail
the ASTM volatility test. In the U.S.,
this issue was addressed by issuing
waivers, according to James Simnick.
By Hank Hogan
F E A T U R E