Evolving technology
may generate profit
from biodiesel
glycerin
glut
By Anthony Crooks, Ag Economist
USDA Rural Development
lycerin (glycerin,
glycerol) is the main
co-product resulting
from biodiesel
production. The name
comes from the Greek word glykys,
meaning sweet. It is a colorless,
odorless, viscous and nontoxic liquid
with a sweet taste and literally
thousands of uses – at least for pure
glycerin. The biodiesel glycerin coproduct
is in crude form. Once
separated from the soaps, lye and other
byproducts, however, this glycerin has
significant market value.
Every gallon of biodiesel produced
generates 1.05 pounds of glycerin. So a
30-million-gallon-per-year plant will
generate about 12,700 tons annually of
99.9 percent pure glycerin. Along with
the 600 million gallons of biodiesel
soon to be added to the nation’s
production capacity will come about
315,000 tons of glycerin. With an
expected U.S. production of 1.4 billion
pounds of glycerin between 2006 and
2015, North American glycerin markets
will be significantly affected by industry
growth.
A glutted glycerin market is more
than a concern for the farmer-owned
co-ops and limited liability corporations
(LLC) and other producers of biodiesel.
The European glycerin supply is
already in over supply. When combined
with fatty acid production from palm
kernel oil and coconut oil in Southeast
Asia, all are adding to the world's
glycerin surplus. Biodiesel production is
now the most important determinate in
the supply of glycerin.
The nation’s synthetic glycerin
market has also felt the effects. Dow
Chemical, once the only synthetic
producer of glycerin in the United
States, recently closed its Freeport,
Texas, plant, saying that the flood of
glycerin from U.S. biodiesel plants was
at least partially responsible.
Like biodiesel itself, glycerin quality
is a concern for refiners. Crude glycerin
quality may be as varied as the process
technology used to produce biodiesel.
Typically, the large, professionally
engineered plants have a more
consistent glycerin because more
attention is paid to refining the coproduct.
Smaller, self-designed facilities
are more often just trying to get
biodiesel produced and pay less
attention to glycerin quality.
Useful molecule
While some community-based
biodiesel producers tout soap-making
or aerobic composting as potential
solutions, that’s hardly sufficient for
commercial-scale operations. The most
likely use for glycerin will be to replace
petroleum-based chemicals. Within five
years, glycerin is expected to become a
developmental platform from which an
array of chemical applications will
spring as a replacement of a
petrochemical equivalent.
An often discussed idea is to convert
glycerin to antifreeze. Researchers at
the University of Missouri and the
Columbia, Mo.-based Renewable
Alternatives LLC have completed the
first phase of a project using
hydrogenation to convert glycerin to
propylene glycol. The process turns
glycerin and hydrogen into equal parts
propylene glycol and water. Plans are
underway to scale-up the process for
commercialization.
Researchers at Washington State
University's Biological Systems
Engineering Department are studying
how to develop omega-3 fatty acids,
succinic acid and succinate salts from
glycerol. The U.S. Department of
Energy recently identified succinic acid
as one of the top 12 biorefinery
chemicals to be derived from biomass.
The USDA Agricultural Research
Service's Environmental Quality
Laboratory in Beltsville, Md.,
discovered that glycerin from biodiesel
production and citric acid can be
chemically combined to produce
biodegradable polymers, which could be
used to produce packaging and other
products. An important feature of the
process is the use of unrefined glycerol
specifically from biodiesel production.
Citric acid is reacted with various
alcohols, or hydroxyl-containing
materials such as glycerol, to obtain a
polyester polymer that is biodegradable,
edible, biocompatible and useful in the
making of films, sheets, plastics and gellike
coatings. Because it is
biodegradable, the material holds
significant promise for use in packaging
materials.
Soy Oil-glycerin products explored
The Ohio Soybean Council and the
Battelle Memorial Institute are working
together to pioneer new uses for
soybean oil and glycerin in the
development of polyols, which are used
to make polyurethane foams, polyester,
adhesives and other goods. Glycerin
and soybean oil can be chemically
modified (using ozone treatment and/or
selective oxidation) to make soyapolyols
that are competitive with the
petroleum-based products.
The U.S. polyol market is nearly 1
billion pounds and represents a
significant value-added opportunity for
the biodiesel co-ops and other
producers to pursue. Because of what is
called “low reactivity,” however, soybased
polyols need to be blended with
petroleum counterparts, just as
biodiesel is blended with petroleum
diesel, to make specialty products.
Battelle’s business strategy is to
license technology to interested
companies. Ideally, the new technology
will alter a biodiesel plant into a multifaceted
biorefinery with multiple
product streams, just as with a
petroleum refinery. A 100-milliongallon
biodiesel refinery generates from
60 to 75 million pounds of glycerin, or
about 200 million pounds of polyols per
year. At the current price of about $1
per pound, polyols can add another
$200 million in revenue to a biodiesel
plant’s bottom line.
Battelle’s vision is for these refineries
to produce biodiesel for transportation
fuel, and to invest in the process to
manufacture polyols for the plastics and
polymers industries as a springboard to
multiple processes, products and
revenue streams. Ultimately, every
product stream from the plant will
become a value-added revenue source.
Battelle isn’t alone in the
development of polyols. Cargill Inc.
recently announced that it had won a
technology award from the Alliance for
the Polyurethanes Industry for its
BiOH bio-based brand of polyols.
ADM plans to produce propylene
glycol and other “large-volume”
chemicals from glycerin. Many people
are aware that propylene glycol is used
for antifreeze/deicer, but it is also used
for fiberglass resins, personal care
products and cosmetics.
Alternative energy source
The “floor value” of any material,
including glycerin, can be determined
by the point at which it can be used as
an energy source. For example,
distillers grains produced as a byproduct
of the ethanol industry can be used as a
supplemental energy source. Of course,
burning distillers grains and glycerin is
a last resort and is best avoided, because
glycerin typically doesn't burn well, and
crude glycerin gives off toxic fumes
when burned, limiting its energy
potential.
However, Virent Energy Systems
and the University of Wisconsin-Madison Department of Chemical and
Biological Engineering believe that
glycerol can be an energy source
through aqueous phase reforming
(APR). APR generates hydrogen from
aqueous solutions of oxygenated
compounds in a single-step reactor
process.
Low-grade crude glycerin is
especially favored because it is cheaper
and readily converts to hydrogen. Its
sodium hydroxide, methanol and the
high pH levels actually help the process.
About 10 pounds of glycerin can be
converted to 1.5 pounds of hydrogen in
Virent's process for less than $2 per
kilogram.
Electricity
Researchers at eTEC Business
Development Ltd., a biofuels research
company based in Vienna, Austria, have
devised mobile facilities that
successfully convert the biodiesel byproduct glycerin into electricity. The
facilities, according to researchers, will
provide substantial economic growth
for biodiesel plants while turning
glycerin into productive renewable
energy.
The glycerin is burned in specially
adapted engines to produce electricity.
Stable and virtually maintenance-free,
eTEC’s units consist of a glycerin
processing module, a combustion
engine with a generator and a control
unit that is compatible with any
biodiesel plant. With the unit’s low
malfunction rate and compact design, it
can be integrated into a transfer
encasement, making it easy to be
transported, assembled and moved from
one biodiesel plant to another, if
desired.
Because electricity is expensive in
Europe, biodiesel producers will be able
to create their own electrical energy
using eTEC’s technology to help offset
feedstock cost. In addition, heat is
simultaneously released during the
electricity conversion process, which
can be used for heating the plant’s tank
facilities. eTEC also has plans to
reconvert heat back into electricity.
Unused electricity can also be fed into
the main supply grid for use at the
European sponsored eco-electricity
rates. Having this kind of ‘green’
electricity is supported by the local
states in the EU, so it is quite profitable
for biodiesel projects.
Biogas, methane digester
A Belgian biogas firm, Organic
Waste Systems (OWS), is building a
methane digester system that uses crude
glycerin and resulting biogas from a
commercial-scale biodiesel facility to
power the plant itself. Such an
integrated, closed-loop system has
many benefits and makes the biodiesel
production process “greener.” Glycerin
is reported to increase biogas yields
considerably, provided the right
microbial populations are used.
The Agricultural Utilization
Research Institute (AURI) in Marshall,
Marion and has additional facilities in
Freeman and Dimock. Its services
include agronomy, grain and feed.
Fremar has developed one of the
largest producer-owned ethanol projects
in South Dakota. Construction on
Millennium Ethanol, a 100-milliongallon
ethanol plant, is expected to be
completed by the end of 2007. US
BioEnergy has announced a plan to
acquire the plant.
