Renewable Energy in the Coastal Environment: Biodiesel from multiple
feedstocks
Dr. Patrick G. Hatcher
Batten Endowed Chair in Physical Sciences, Professor of Chemistry and Biochemistry
Old Dominion University, Norfolk, VA 23529
The era of increased consumption of fossil fuels brought about by increasing
energy demands of a global economy is upon us. Associated with this increased global
appetite for conventional fuels is the realization that the environment cannot longer
sustain rising carbon dioxide levels. Aside from the increased costs of a dwindling supply
of fossil fuels, our dependence on unstable governments for supplying many of these
fuels, and the nearly complete dependence on non-renewable fossil energy, it is time to
seriously examine, with the commitment like that of the Manhatten Project, the feasibility
of developing an energy policy that incorporates more renewable resources. One can
make analogies to economic investment strategies where a balanced portfolio helps to
mitigate economic downturns due to unstable investments. A balanced energy portfolio
would serve to prevent an energy “disaster” should the source of a conventional fossil
fuel be shut down or depleted. Thus, increased reliance on renewable energy and
diversification of energy sources is a policy which provides the greatest degree of
stability and self-sufficiency. Brazil is country that has implemented this policy
successfully and is making great strides towards economic growth. The United States and
the State of Virginia need to consider seriously the steps towards a diversified energy
portfolio- the purpose of this hearing.
The US coastal zone and, in particular, that of Virginia offer many attractive
aspects for energy production, both fossil fuel-related and renewable. The State of
Virginia has approved legislation creating the Virginia Coastal Energy Research
Consortium (VCERC) whose mission is to be a Center of Excellence for research in the
development, use, and impact of expanding coastal energy resources. Old Dominion
University will serve as the lead institution for VCERC which includes other Virginia
Universities as partners (Virginia Tech, Norfolk State, James Madison, William & Mary).
Efforts are underway to launch VCERC activities. The following is taken from the
approved legislative amendments to the 2006 budget document for the State of Virginia:
§ 67-701. Functions, powers, and duties of the Research Consortium.
The Coastal Energy Research Consortium shall serve as an interdisciplinary study, research, and
information resource for the Commonwealth on coastal energy issues. As used in this chapter,
"coastal energy" includes wave or tidal action, currents, offshore winds, thermal differences, and
methane hydrates. The Research Consortium shall (i) consult with the General Assembly, federal,
state, and local agencies, nonprofit organizations, private industry and other potential users of
coastal energy research; (ii) establish and administer agreements with other universities of the
Commonwealth to carry out research projects relating to the feasibility of recovering fuel gases
from methane hydrates and increasing the Commonwealth's reliance on other forms of coastal
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energy; (iii) disseminate new information and research results; (iv) apply for grants made
available pursuant to federal legislation, including but not limited to the federal Methane
Hydrate Research and Development Act of 1999, P.L. 106-193 and from other sources; and (v)
facilitate the application and transfer of new coastal energy technologies.
There are numerous offshore energy resources that will become the focus of
VCERC in years to come and the current strategy is one consistent with a diversified
portfolio of energy generation. These include offshore wind energy, offshore fossil
energy, waves and current energy, and coastal biomass energy.
Coastal Biomass energy:
Perhaps the least publicized form of biomass energy is that which can be obtained
from algae (Sheehan et al., 1998). The biomass can be efficiently converted to biodiesel
and utilized for internal combustion engines. One attractive feature of algal biomass over
conventional higher plant biomass is that algal production rates can be more than 5 times
those of land plants. Other features are that one need not sacrifice crop-producing land
for biomass production as the algae are grown in ponds or can be harvested from
eutrophied water bodies in coastal areas. Estimates have been made for the cost of algal
biomass production and they range from $60 to $100 per barrel of oil equivalent. What
really makes algal biomass feasible for biodiesel production is the high hydrocarbon
contents of many forms of algae, some up to 50% or more of their dry weight, and much
of the biomass is convertible to biodiesel.
The green colonial alga Botryococcus braunii has been widely studied because of
its unusual features and also its high hydrocarbon content of 15 to 75%, which is
conspicuously higher than that commonly observed in other unicellular algae (ca. 0.110% for most unicellular algae (Weete, 1976; Ben-Amotz, 1985). Besides Botryococcus
braunii, the only other hydrocarbon rich algae known at the present time is the halophilic
species Dunaliella salina (Tornabene et al., 1980). Recent studies of the alga
Botryococcus braunii indicate that, in addition to the high extractable hydrocarbon and
fatty acids contents, up to 30% of its dry weight is composed of biologically refractory
biopolymers (Plain et al., 1993), which we and others have shown can be converted to
hydrocarbons and/or oils by pyrolytic means (Largeau et al., 1984: de Leeuw and
Largeau, 1994; Nguyen et al., 2003). The NREL study relating to the feasibility of using
algae for biodiesel production (Sheehan et al., 1998) cites the existence of numerous algal
forms that can be suitably used for biodiesel production. The report also mentions that
one can genetically modify algae to be a high biodiesel producer. Thus, it appears that
sufficient knowledge exists to select algal strains that can efficiently produce biodiesel.
There are at least 3 strategies being examined for the production of algae for
biodiesel. The first involves the growth and harvesting of appropriate algae in ponds
associated with agricultural systems. The second is similar growth in ponds but
associated with electricity-generating powerplants, using their CO2 effluents to stimulate
algal growth and their waste heat to maintain year-round constant temperatures in ponds.
Growth of algae in ponds, a strategy being employed commercially by PetroSun, Inc. and
promoted by the NREL report (Sheehan et al., 1998), provides advantages that algal
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growth can be stimulated to high levels, but issues regarding the maintenance of algal
species and the need for transportation costs are all disadvantages. The third involves the
harvesting of algae from existing waterways choked with high algal production due to
nutrient-laden agricultural runoff. Unlike the first two strategies where one could partly
control growth environments, the third strategy is dependent on the annual growth cycle
of the algae but carries with it some advantages and disadvantages that are not inherent in
the other two strategies. One important advantage is that harvesting of the algae would
provide a strategy for cleanup of the waterways.
Virginia is ideally suited for coastal pond algal production as there are vast areas
of coastline where suitable sites could be located. Furthermore, many areas along the
coast are impacted by nutrient-rich agricultural or wastewater runoff and algal
proliferation leads, in many instances, to hypoxia. Finally, along the coastline and inland
waters, there is an abundant supply of another critical ingredient for algal biomasssunlight. Research is needed to evaluate algal biodiesel as a viable renewable energy
source for coastal areas of Virginia under the three possible scenarios mentioned above.
Old Dominion University is developing and testing, in a pilot facility, the
feasibility of using a natural assemblage of algae in a coastal pond situated on the ODU
campus for the on-site production of a biodiesel fuel. Our goal is to demonstrate that one
can engineer a small-scale biodiesel plant that can be cited at or near fuel depots, such a
gas stations near inland water bodies, to provide a commercially available fuel for the
public. We are simultaneously, in the laboratory, examining the feasibility of producing
algal biodiesel from ponds in which algal populations are stimulated by a variety of
agricultural and wastewater runoffs and fossil fuel powerplant effluents.
Our strategy is to grow and collect sufficient quantities of algae and to convert
them by a pyrolytic or chemical process to biodiesel fuel that can be used to power
campus vehicles. We are developing a proprietary transesterification process that can
effectively convert algal biomass to fatty acid methyl esters. Transesterification has been
proposed as the major production process to convert algal triglycerides to biodiesel
(Sheehan et al., 1998). We will be evaluating conversion efficiencies throughout the
process and testing numerous variables to provide an informed decision on the economic
feasibility and most efficient pathway for such energy conversion.
Biodiesel from Cooking Oils
Old Dominion is supporting an undergraduate student project to evaluate the
feasibility of recycling cooking oils from its campus cooking facility into diesel fuel. The
project will investigate a process designed to remove unwanted products from recycled
cooking oils and to transesterify the oils to produce the desired biodiesel. A group of
undergraduates from the College of Engineering led by Professor Han Bao are
conducting these studies.
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