is a fuel made from vegetable oils or animal fats. It provides similar
fuel economy and horsepower to petroleum diesel and has many
environmental and safety advantages. Biodisel can power any diesel (not
Biodiesel is a
clean-burning 100% renewable fuel. It is made in America and can be
made from a variety of plant and animal fats (as well as many waste
grease products). Thus, biodiesel shifts our economic reliance from
unstable foreign fuel sources to American farmers, ranchers, and in our
case, urban waste streams.
plans to provide biodiesel to public fleets in the Kalamazoo area and
develop greener technologies for biodiesel production. We are also
working to elucidate regional waste-grease ordinance structures.
Biodiesel from Trap Grease
Our focus is on recovering
trap grease from commercial kitchens to convert it into biodiesel that
meets all industry and government quality specifications. Using this
process, we are not using virgin vegetable oils and are thus not
competing with agricultural food production to create biofuels.
How does it work?
a byproduct of food processing and preparation, cooking grease collects
in plumbing traps and interceptors that must be pumped on a regular
basis, in accordance with state and local codes. The resulting liquid
waste is typically processed by commercial haulers and then disposed of
— fats bound with solids are sent to landfill and separated water is
returned to the sewer system. This grease often goes unused, but is a
resource for sustainable, renewable biodiesel. Trap grease has great
potential as a biodiesel feedstock — it is comprised of both
triglycerides and free fatty acids. In Kalamazoo, we estimate that
it could power 4,000,000 vehicle miles per year. Nationally, biodiesel
from trap grease could yield 600,000,000 gallons per year (Dept. of
Energy estimates). However, collection, processing, and efficient
conversion into high-quality fuel pose significant challenges that we
have begun to address.
Poorly maintained grease traps cost American cities millions of dollars
a year in line blockages and breaks. At wastewater treatment plants,
greases suffocate the organisms that decompose sewage. By recovering
the waste that grease traps catch, Bronco Biodiesel is playing a part
in solving these local problems.
Virgin oil and "yellow grease"
Biodiesel is often produced using virgin soybean or rapeseed oil. Due
to the many problems inherent in using these feedstocks, Bronco
Biodiesel does not use virgin oil. Growing vast amounts of vegetable
oil for fuel can result in increased fertilization, pesticide use,
harmful land use, and additional pressure on food markets. "Yellow
grease" is reused vegetable oil that is discarded after making fried
foods. Yellow grease, unlike trap grease, is already being used in a
variety of commercial applications to produce new goods. However, trap
grease has little commercial value and is expensive to regularly
dispose of in landfills. We use trap grease to tap into potential
energy that is not already being commercially exploited.
properties as a fuel are similar to petroleum diesel (petro-diesel), so
it can be used interchangeably with petro-diesel or mixed with
petro-diesel for use in unmodified conventional diesel engines.
is significantly higher than petro-diesel, which prevents wear in fuel
system components and increases engine life span.
- Flash Point is higher than petro-diesel, making the fuel safer for storage and transport.
- Density is comparable to petro-diesel.
- Viscosity is approximately 1.5 to 2 times as high as petro-diesel.
number is higher than petro-diesel, which means it burns more
completely, resulting in more power, better engine performance, and
- Cold flow properties are not as desirable as petro-diesel, but blending and other treatments rectify this issue.
- Oxygen content reduces particulate matter, hydrocarbon, and carbon monoxide emissions and increases efficiency.
density, while slightly lower than petro-diesel, results in increased
or equal fuel economy (due to efficiency and lubricity benefits).
- Sulfur content is lower than the 2007 federal ultra-low sulfur diesel requirements.
is most commonly mixed in a ratio of 20% biodiesel: 80% petro-diesel.
The 20:80 blend is commonly referred to as “B20.” Similarly, other
blends are referred to by including a “B” followed the percentage of
biodiesel in the mixture (e.g. a 5% biodiesel: 95% petro-diesel blend
would be “B5”). In the past few years, the biodiesel industry has grown
exponentially. Over 600 fleets in the United States now operate on
biodiesel fuel (or some blend of biodiesel greater than B2). Washington
and Minnesota recently passed laws mandating that all diesel fuel sold
must contain at least 2% biodiesel (B2). A current bill in the Michigan
legislature would require all diesel fuel sold in Michigan to include
at least 2% biodiesel.
addition to being a renewable resource and reducing petroleum
dependency, particularly from foreign sources, biodiesel has a number
of beneficial environmental characteristics. Because it is
non-flammable, as biodegradable as table sugar, and no more toxic than
table salt, its use can significantly decrease stormwater problems
stemming from pollution runoff from roads and parking lots.
Additionally, as an oxygenated fuel, biodiesel reduces incomplete
combustion and thus reduces the production of many harmful air
pollutants. The National Renewable Energy Laboratory says that a 20%
blend of biodiesel (B20) will significantly reduce tailpipe emissions
(relative to pure biodiesel) accordingly:
- 30% reduction in carbon monoxide emissions
- 40% reduction in hydrocarbon emissions
- 25% reduction in particulate emissions
- 20% reduction in carbon dioxide emissions
- 20% reduction in sulfur emissions