Closing The Biodiesel Loop Through Recycling and Renewable Energy

1. Closing the biodiesel loop
through recycling and
renewable energy.
By Richard Freudenberger
The Collaborative
staff photos
Biodiesel Project
P roponents of biofuels have always
maintained that sourcing energy
from domestic renewables such
as plant biomass and bio-based wastes
reduces our dependence on imported
Appstate Appropriate Technology
For Jeremy Ferrell, a graduate stu-
dent in the A-T Department at Appala-
chian State University, biodiesel is far
photovoltaics to run the pumps, light-
ing, and system controls.
How the System Works
petroleum, diversifies our energy base, more than an academic topic of discus-
and offers cleaner end-use emissions. sion. After completing his undergradu- The process begins with 80 gallons
One particular biofuel—liquid bio- ate studies in1999, he went to work of waste vegetable oil collected each
diesel derived from soybeans, waste for the U.S. Park Service, then served week from the ASU cafeteria. It’s a
cooking oil, or animal fats—has re- a three-year stint in the Peace Corps, mixture of soy, peanut, and canola (a
ceived prominent national attention and working with subsistence farmers in low-acid rapeseed oil) and comes to the
enough investment that the number of Paraguay on agroforestry, apiary, and facility in five-gallon carboys.
commercial production facilities has tilapia projects. Subsequent permacul- The containers are stowed in cov-
grown from 65 in mid-2006 to 145 in ture studies in Brazil exposed him to ered storage outside a 280-square-foot
June of this year. farm-scale biofuels potential and laid greenhouse, where the initial processing
But critics aren’t so convinced. Their the groundwork for his ensuing interest begins. The first step is to empty the
concern is that biodiesel fuel is not in renewable fuels back home. waste oil into the collection barrel, a
sustainable on a large scale. First, they Ferrell and an interdisciplinary team 55-gallon drum fitted with a 400-micron
question whether the energy invested of ASU students began the biodiesel drumhead filter, recessed to capture
in growing, harvesting, and processing project with the goal of “closing the solids and thwart spillage. From there,
soybean feedstocks will surpass or even loop”—designing the entire production the strained oil is pumped into two
approach the energy available from the facility to be self-contained and wholly 120-gallon storage and settling tanks
finished product. Further, they hold sustainable so that every by-product linked in series. Here, excess water can
that the by-products of manufacture— either found a use within the system or be drawn off and the oil sent through a
glycerin and wash water from the fuel- had marketable value outside of it. To 30-micron filter before being moved
cleaning process—have limited value carry this through to completion, they on through an insulated chase to a 120-
and are essentially contributing to the had to develop a solar thermal hot water gallon processor tank in the adjacent
waste stream themselves. system for heat processing and rely on processing shed.
BackHome Magazine Sept/Oct 2007 17

2. Collaborative Biodiesel Project
The processor tank is one of several
purchased at a salvage yard. (Stainless
steel dairy equipment often finds its
way to auctions and scrap yards and
has proved ideal for biodiesel produc-
tion.) This tank is equipped with an
internal heat exchanger to heat the oil
and was modified by adding a lid to seal
the reactor chamber. This prevents the
escape of methoxide fumes and also
allows for methanol recovery through fuel to the wash tanks, two vertically A grid-tied PV system provides power for
vacuum distillation as part of the recy- stacked stainless steel containers, each pumps and lighting. Four solar thermal
cling process. 210 gallons capacity. There, a three- panels on the processing shed at right
To achieve the necessary reaction stage water-washing procedure car- heat the oil.
temperature of 130°F, a series of four ried out over a period of several days
solar thermal collectors mounted on removes remaining impurities (free through the use of biological organisms
the processing shed—144 square feet methanol, glycerin soaps, fatty acids, such as wetland plants, algae, plankton,
of total surface—supply a superinsu- etc.) that can lead to corrosion, sediment and aquatic wildlife. Currently, a small
lated 30-gallon water tank in the lab buildup, and injector blockage in a die- wetland pond built just behind the
below. A 60-watt pump circulates the sel engine. The washed biodiesel is then polycarbonate glazing at the front of
water through the thermal system. circulated through a perforated annular the greenhouse contains water hyacinth
Individual valves control where in the ring in the wash tank to evaporate out and azolla, more commonly known as
process heat needs to be distributed by the last traces of moisture from the fuel, duckweed fern. Future plans include
feeding exchanger coils built into the then the finished product is pumped one the addition of cattails, mollusks, and
tanks. A backup hydronic oil-burner, last time through a 5-micron filter and possibly some water-loving trees such
operating on either biodiesel or clean into a 55-gallon storage drum, where as figs and willows.
vegetable oil, can be called into use it’s hand-pumped into Ferrell’s 1985 Water from the lab sink and the
when needed. Toyota diesel pickup or transported to fuel-washing process is piped into two
A smaller 35-gallon HDPE conical the project’s Fuel Sampling Partners 350-gallon containers at the rear of the
mix tank next to the processor allows to be used in various off-road applica- structure. A single solar thermal panel
for safe and consistent blending of the tions such as farm equipment and home on top of the greenhouse preheats the
methyl alcohol and potassium hydrox- heating. water prior to introduction. The first
ide catalyst. Methanol from a 55-gallon stage is the treatment of 120 gallons
drum is pumped into the methoxide Reuse and Recycle with anaerobic bacteria to break down
tank through a stainless steel funnel that any solid material. Following that,
holds the potassium hydroxide (KOH) None of this is unique for biodiesel an open aerobic tank of 150 gallons
flakes. They dissolve in the filling processing plants of this size. What capacity further clarifies the water
process, and the resulting methoxide makes the Appstate Collaborative and removes objectionable odors. The
mix is transferred to the oil-filled pro- Biodiesel Project distinctive is that the final step is the wetland pond, where
cessor tank through a mixing tube to team has consciously sought practical the water is purified by the plants and
start the biodiesel reaction. The mixing end-use applications for the by-products eventually is returned to wash subse-
itself is carried out over one and a half that habitually have been difficult to quent batches of biodiesel. A 25-watt
hours using a stainless steel centrifugal dispose of, mainly wastewater from the pump on a scheduled timer circulates
pump, which is the most workable washing cycle and glycerin from the the water at a rate of 100 gallons, or
choice for a closed container system. transesterification reaction. about 10 percent, every hour.
The liquid is then pumped into a Wastewater is an issue especially in Glycerin from the reaction process
120-gallon settling tank, where it’s larger operations because the system has always been a question, even for
kept for at least 48 hours to allow the produces too much volume over time home producers. Approximately 20
glycerin to separate from the biodiesel to simply discard. To alleviate that, the percent of the yield is a crude glycerin
fuel. Glycerin can be drawn off at both ASU students have built an “ecological composed of free fatty acids, glycerol,
the processor and settling stages. Eighty machine” within the greenhouse to treat excess methanol, and residual catalyst.
gallons of raw biodiesel will yield about the spent water for reuse. The living That’s 20 gallons of material for every
16 gallons of glycerin by-product. machine is a micro-ecosystem designed 100 gallons of biodiesel made. Glycerin
A third pump moves the biodiesel to treat a specific volume of influent soap has typically been a marketable
18 www.BackHomeMagazine.com

3. end product, and the Appstate group has fuel-quality monitoring with near in- crop has left many in the agricultural
been successful in finding applications frared spectroscopy, waste composting community searching for viable market
not only for industrial cleaners but also for CO2 and methane production, and alternatives.
in composting operations and as fire- expanded educational and outreach In the meanwhile, the project is
starter briquettes, using wood chips as programs. moving forward and taking advantage
a substrate. Members of the program have also of the successes and interdisciplinary
Part of the project’s “loop” includes cast their eyes toward the area’s farmers approach that has served it well thus far.
the use of renewable energy to run the and its extension service in hopes that Both the algae and composting research
various pumps. Ten 170-watt Sharp the growth of biofuels may be an op- may well prove viable additions to the
modules and a Sunny Boy inverter are portunity for local growers to find new ongoing biodiesel loop.
the key components in the grid-tied sys- markets for feedstock material and oil-
tem, which provides lighting and power seed by-products such as high-protein For more information visit www.bio-
for the controls as well. Conveniently, seed meal. The ongoing loss of tobacco diesel.appstate.edu
the pump motors are not required to
operate simultaneously, so there’s no
large surge demand in the system, and
with one-inch line and no appreciable
elevation, no single pump is particularly
Western North Carolina
large. Renewable Energy Initiative
Where From Here?
2007 Workshop Schedule
In 2006, the Appstate team exhib- 4/21-22 Small Scale Wind Energy with Southwest Windpower
ited the project in Washington, D.C.,
as part of the Environmental Protec- & WNCREI staff at Beech Mountain R&D site
tion Agency’s EP3 Student Design 5/26-27 Microhydro with Don Harris and WNCREI staff
Competition for Sustainability. As
one of the winners of the competition, at Appalachian State University
the team was awarded further funding 6/2 Domestic Solar Water Heating Design & Construction
for continuing Phase 2 of the project, with Fred Stewart at Appalachian State University
which includes continued research into
biodiesel feed stocks such as algae and 6/22-23 Sustainable Community-Scale Biodiesel Production
alternate oilseed crops, reaction and Workshop at Appalachian State University
A micro-ecosystem within the 8/29 PV and the National Electrical Code with John Wiles
greenhouse treats system waste- at Appalachian State University
water using wetland plants.
9/15 Active Solar Hydronic Space Heating with Fred Stewart
at Appalachian State University
9/22-23 Small Scale Wind Energy Installation Workshop with
Robert Preus of Abundant Renewable Energy
at Beech Mountain R&D site
10/20–21 Small Scale Wind Energy with Southwest Windpower
& WNCREI staff at Beech Mountain R&D site
www.wind.appstate.edu
828-262-2933 • 828-262-7333
Bachelors and Masters degree programs available
BackHome Magazine Sept/Oct 2007 19