Sorry Tom, did not mean to offend you.
The experience that you are referring to should involve the fact that
almost no B100 is sold i Europe. The BD is blended into dino with 4-7%
by weight. That about the experience of EN quality. Furthermore, the
oxidation stability seems to be a topic only when storage time is
discussed. The companies sellning BHT seems to focus on that. But, given
the conditions in a veichle´s fuel tank during operation, it seems
likely that the oxidation stability is of importance there too. The fuel
tanks can become hot 70-80oC I am told. But if you can run your car om
Soy BD without problems under all conditions, then the issue is simply
storage capacity. But then again,if you can store your BD for three
months without any significant changes in peroxide and anidin values,
then it´s ok.
I am not able to give you an ideal OS-IP value, but my personal opinion
is that the CEN value is over the top.
Fresh oils with low peroxide and anidine values have better chance to
stay fresh as biodiesel.
Good thing to avoid copper and zinc. Copper creates disaster with the
BD. All copper alloys should be forbidden in connection with BD,
including brass and bronze.
On Tue, 30 Apr 2013 11:32:46 -0400 (EDT), "Thomas Kelly"
<ontheh...@fairpoint.net> wrote:
The years of experience I am referring to is my
understanding that B100 has been available in Europe
for years. The CEN standards have apparently ensured
satisfactory fuel quality. I'm not aware of the
politics of rapeseed oil or of its cost.
The debate seems to revolve around the question of
whether the CEN standard for oxidation stability is too
high or the ASTM standard is too low.
Your expertise is recognized.
What is an acceptable OS-IP value?
What oils might meet this acceptable value?
I've run cars on biodiesel made from various and
unknown oil types. (These include soy.) My fuel is rarely
stored longer than a month. I avoid metals like copper and
zinc in production, storage, and delivery of fuel.
If there is a question of oxidation the fuel goes to my
heating system, not the cars.
Tom
It is nice indeed that someone finally took this side
of
biodiesel
quality to debate. The years of experience that you are
referring to is
something that I have not seen documented anywhere, can
even less judge
the relevance. It is well known that the CEN 14214 is
tailored for rape
seed oil as raw material and there has been a lot of
critisism for that.
The reason for this tailorship is unknown but it smells
politics and
even nationalism. What is even more disturbing is that
the use of
anti-oxidants is not aloud in the CEN, in order to meet
the parameters.
The truth today is that good rape seed oil is so
expensive that almost
no biodiesel producer can use that raw material.
It is good with quality, of course, but defining
quality
is another cup
of tea.
On Tue, 30 Apr 2013 08:59:41 -0400 (EDT), "Thomas
Kelly"
<ontheh...@fairpoint.net> wrote:
The latest national survey of 100% biodiesel (B100)
"blend stock" samples by the U.S. Department of
Energy's
National Renewable Energy Laboratory (NREL) found that
95% >of the samples from 2011-12 met ASTM International
fuel >quality specifications.
......
"The survey showed a major improvement over results
from
previous years," NREL Senior Chemist Teresa Alleman
said.
{samples}
.... were tested for a range of critical properties,
such >as free and total glycerin content, metals
content, and >cloud point
that could have an immediate impact on operability.
"immediate impact on operability"
I'd like my diesel engine to run trouble-free for
many
thousands of miles.
Why do vehicle manufacturers maintain warrantees on
their vehicles that run on biodiesel (B100) that meets
CEN standards (European Committee for Standardization),
but void warrantees on the same vehicles when run on
B100
made in countries that used ASTM standards (American
Society for Testing and Materials)?
A major concern has been the tendency of the fuel to
oxidize. This tendency is indicated by Iodine Value
(IV) which is part of CEN standards, but not ASTM
standards.
All vegetable oils and the biodiesel made from them
will
eventually oxidize forming a varnish-like goo. Iodine
value has been presumed to accurately indicate the
tendency of oil, and the biodiesel made from it, to
oxidize.
Many Biodiesel fuel standards specify an upper limit
for iodine value of biodiesel. For example, Europe's
EN14214 specification allows a maximum of 120 for the
Iodine number, Germany's DIN 51606 tops out at 115. The
USA ASTM D6751 does not specify an Iodine value.
It might be noted that the European and German
specifications result in a defacto ban on Soy based
biodiesel as it's iodine value is above the acceptable
limit.
While the European standards' iodine value measures
the
number of double bonds in the hydrocarbon chains, there
is some dispute as to whether or not it is a reliable
indication of actual oxidation tendency. (Position of
the double bonds in the molecule, contamination with
metals, and other factors may play a significant role).
ASTM now includes an "Oxidation Stability Index"
(OSI).
It attempts to determine actual oxidation of biodiesel
as
measured by changes in electrical conductivity after
"air
flow" exposure.
It is interesting to note what the CEN and ASTM
consider to be acceptable oxidation tendencies, whether
determined by by Iodine Value or OSI. The CEN accepts
Iodine Values below 120, which allows for biodiesel
made from rapeseed and other oils, but not from soy.
I believe CEN now includes OSI values (6.0 and up) that
allow for the same rapeseed biodiesel, but still
excludes
biodiesel made from soy. The ASTM accepts biodiesel
with
much lower OSI values, which, coincidently, includes
biodiesel made from soy oil.
While some say that the CEN standard is "arbitrarily
high". I'm not sure "arbitrary" is appropriate when
applied to a standard that is based on years of
experience. More likely, the ASTM standard that allows
for soy-based biodiesel is dangerously low.
Note: Veg oil and the biodiesel made from it are
relatively stable. Once oxidation starts the rate of
oxidation rapidly accelerates. This point at which
oxidation becomes clearly measurable is called the
"Induction Period" (OS-IP). The higher the number, (in
hours) the better the oil or biodiesel "resists"
oxidation.
Note: The low OS-IP number allowed in ASTM standards
has
been defended by some by citing a study in which
biodiesel
made from various veg oils (with various OS-IP's)
fueled
engines which were ultimately disassembled and found to
have "no significant differences in build-up on
surfaces."
This suggests that little or no oxidation occurred
during
the high temp and pressure of combustion in the
engines,
regardless of oxidation stability values.
The problem with this is that a major concern with
oxidation involves storage. Although the test to
determine OS-IP is performed on biodiesel at elevated
temp (110C) and with enhanced exposure to air, the
resulting OS-IP is given in hours. Fuel with low OS-IP
values that which has been stored for long periods may
well contain varnish-like products of oxidation that we
wouldn't want to put in our fuel tanks.
Consider that fresh biodiesel mixed with older fuel
in
a storage tank, might well be exposed to the very
oxidation products that will accelerate oxidation. It
would seem prudent to go with high, yet achievable
Oxidation Stability values even if soy oil, a
convenient and profitable feedstock, may have to be
excluded from biodiesel destined for our vehicles. (I
have used biodiesel made from soy to heat my house and
provide domestic hot water for about 10 years w/o
problem. It's easier and cheaper to change a nozzle on
a burner than to replace injectors/fuel pumps on cars.)
An interesting reference article:
http://www.oleotek.org/FichiersUpload/Softsystem/NRCan-OLEOTEK
Study of the Rancimat Test Method in Measuring
the Oxidation Stability of Biodiesel Ester and Blends
NRCan project # CO414 CETC-327
By
David Berthiaume
Alain Tremblay
OLEOTEK Inc.
Tom
----------------------------------------
http://www.sciencecodex.com/nrel_survey_shows_dramatic_improvement_in_b100_biodiesel_quality-110510
NREL survey shows dramatic improvement in B100
biodiesel
quality
Posted By News On April 16, 2013 - 5:00pm
The latest national survey of 100% biodiesel (B100)
"blend
stock"
samples by the U.S. Department of Energy's National
Renewable Energy
Laboratory (NREL) found that 95% of the samples from
2011-12 met ASTM
International fuel quality specifications. The ASTM
standards serve as
guidelines for industry and are designed to ensure
quality
at the pump
for consumers – along with reliable operation of the
nation's vehicles
powered by biodiesel blends.
"The survey showed a major improvement over results
from
previous
years," NREL Senior Chemist Teresa Alleman said. "In
our
2007 survey of
B100 biodiesel, less than half of the samples met
quality
specifications. More stringent quality requirements,
along
with the
voluntary BQ-9000 quality management program, are
among
the reasons for
this marked improvement."
B100 is not commonly used as a fuel, but is blended
with
petroleum
diesel, typically in blends up to 20%, and has been
part
of the
industry's steady growth in the past decade. B100
production increased
from 27.9 million gallons in 2004 to more than 1
billion
gallons in 2012.
For the most recent survey conducted from August 2011
to
February 2012,
NREL researchers collected fuel samples from 53
producers
and 14
terminals from across the United States. Terminals
from
the East and
West Coasts, the Rocky Mountain region, and the
Midwest
were tested for
a range of critical properties, such as free and total
glycerin content,
metals content, and cloud point that could have an
immediate impact on
operability.
To ensure product quality, ASTM published the first
B100
quality
standards in 2002. ASTM International does not enforce
fuel quality, but
it is a leader in the development and delivery of
international
voluntary consensus standards. Its specifications are
frequently adopted
by state and local governments to ensure fuel quality
and
are monitored
by industry members. NREL is among the organizations
participating in
the development of standards.
Source: DOE/National Renewable Energy Laboratory
http://www.nrel.gov/news/press/2013/2171.html
_______________________________________________
Sustainablelorgbiofuel mailing list
Sustainablelorgbiofuel@lists.sustainablelists.org
http://lists.eruditium.org/cgi-bin/mailman/listinfo/sustainablelorgbiofuel
_______________________________________________
Sustainablelorgbiofuel mailing list
Sustainablelorgbiofuel@lists.sustainablelists.org
http://lists.eruditium.org/cgi-bin/mailman/listinfo/sustainablelorgbiofuel
_______________________________________________
Sustainablelorgbiofuel mailing list
Sustainablelorgbiofuel@lists.sustainablelists.org
http://lists.eruditium.org/cgi-bin/mailman/listinfo/sustainablelorgbiofuel
_______________________________________________
Sustainablelorgbiofuel mailing list
Sustainablelorgbiofuel@lists.sustainablelists.org
http://lists.eruditium.org/cgi-bin/mailman/listinfo/sustainablelorgbiofuel
_______________________________________________
Sustainablelorgbiofuel mailing list
Sustainablelorgbiofuel@lists.sustainablelists.org
http://lists.eruditium.org/cgi-bin/mailman/listinfo/sustainablelorgbiofuel
