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					           GREEN FUEL:
RESOURCES FOR ALGAE PRODUCTION IN
              TEXAS




Prepared by Allison Osborne
December 5, 2008
CE 394K
CONTENTS
INTRODUCTION..................................................................................................................................................................................3
    ALGAE AS A BIOFUEL FEEDSTOCK .....................................................................................................................................3
    RESOURCES FOR ALGAE GROWTH .....................................................................................................................................3
METHODOLOGY..................................................................................................................................................................................4
DATA SOURCES ...................................................................................................................................................................................5
RESOURCES FOR ALGAE PRODUCTION IN TEXAS...........................................................................................................6
    SITES WITHIN 0.5 MILES .........................................................................................................................................................6
    SITES WITHIN 1.0 MILES .........................................................................................................................................................8
    LAND AND BIOREACTOR REQUIREMENTS.................................................................................................................10
REVIEW OF METHODS.................................................................................................................................................................11
CONCLUSIONS ..................................................................................................................................................................................11
REFERENCES.....................................................................................................................................................................................12




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INTRODUCTION
High energy prices, environmental concerns over global climate change, and political instability in the
Middle East are driving the development of domestic, renewable sources of energy in the United States.
With the price of oil exceeding $100 USD per barrel, technologies that were considered cost prohibitive
in the past have become much more appealing, particularly in light of recent government incentives for
alternative energy sources. In response to these conditions, the production of ethanol and biodiesel has
rapidly expanded, despite questionable energy benefits and the competing use of feedstocks as food
and biofuel. Thus, there is a need to develop feedstocks that are not used for food and processes that
minimize energy inputs. This report investigates where the growth of one non-edible feedstock, algae,
can be coupled to other processes to minimize energy requirements and thereby make it a low-cost,
low-energy feedstock for biodiesel production. Specifically, it maps sources and volumes of wastewater
and carbon dioxide (CO2) in Texas, which are basic requirements for algae growth. Further, this report
quantifies the amount of algae, and algae oil, that can be produced from those resources, with
consideration of the sunlight and land area available.

Most fundamentally, this analysis allows for the strategic planning of algae production facilities and
resources. In addition, though research on algae production for biodiesel is well underway, there
remain significant questions with regard to the long-term feasibility of known, quantified energy and
material needs for the process. For this reason, geographic information systems (GIS) provides a unique
tool for mapping and calculating the energy needs, possible production rates, and, subsequently,
volumes of biosiesel that can be obtained from such coupled processes. Anticipating that coupled
production processes might be the only option for economical and energy-positive biodiesel production
from algae, it is also important to be able to estimate the maximum potential production volumes that
can be expected in Texas.

ALGAE AS A BIOFUEL FEEDSTOCK
Microalgae are estimated to be the most productive biofuel feedstock, in terms of the volume of biofuel
that can be produced per land area cultivated. It is estimated that microalgae can produce 30 times
more energy per acre than other US crops like soybeans, reaching 5,000 to 15,000 gallons of oil per year
(Hartman, 2008). However, the number of variables associated with producing this fuel is exponentially
greater than any other feedstock because of the immaturity of the industry, vast number of species, and
absence of long-standing selective breeding for agriculture. As such, algae-to-biodiesel start-up
companies have yet to succeed in producing algae for biofuels cost-effectively and many have failed.

RESOURCES FOR ALGAE GROWTH
Algae are photosynthetic, marine organisms that span many phylogenetic groups. To meet basic growth
needs via photosynthesis, all algae need sunlight, a carbon source (i.e., carbon dioxide), water, and
nutrients such as nitrogen and phosphorus, consistent with the basic photosynthesis equation provided
in the methodology section. At a minimum, any type of algae production operation must provide these
basic requirements.




                                                   3
Because the use of potable water, fertilizers, and carbon dioxide come with an associated cost, there is
an incentive to identify less- or no-cost sources of those resources. Coincidentally, wastewater and
smokestacks can provide some of these requirements. Specifically, treated municipal and industrial
wastewater that is discharged into natural bodies of water is regulated according to permitted
concentrations of nitrogen, phosphorus, and other nutrients, which cause environmental problems such
as eutrophication. If repurposed for algae-production, the water and excess nutrients can be used to
meet the growth needs of algae. Similarly, emissions of carbon dioxide to the atmosphere, which
contribute to global warming, can be pumped into an algae growth pond, allowing the algae to grow as
well as reducing harmful environmental impacts.

In addition, any algae production facility has some space requirements. Traditionally, algae are grown in
large ponds or raceway-style ponds; however, in the interest of growing algae in urban environments,
numerous styles of photobioreactors have been designed. Images of such designs are provided in Figure
1 and Figure 2. As such, land-use characteristics can dictate what types of photobioreactors need to be
used at a given location, which can have an impact on set up and operational cost.

Figure 1: Vertical Photobioreactors




Source: Greenfuel Technologies, Corp.


Figure 2: Bag Photobioreactors




Source: Greenfuel Technologies, Corp.



METHODOLOGY
In order to identify the low- to no-cost resources for algae production in Texas and the associated
quantities of algae and algae oil that can be produced from those resources, the following research
approach was undertaken:


                                                   4
    (1) Identify sources and volumes of wastewater in Texas
    (2) Identify sources and masses of carbon dioxide in Texas
    (3) Map candidate locations where wastewater and carbon dioxide sources exist within a threshold
        distance of each other (0.5 miles and 1.0 miles)
    (4) Identify available sunlight at candidate locations
    (5) Identify land-use patterns at candidate locations
    (6) Quantify amount of algae and algae oil that can be produced at candidate locations
    (7) Assess bioreactor requirements at each location

All the steps identified above required manipulations of data in ArcGIS. In addition, step 6, quantifying
the amount of algae and algae oil that can be produced at each location, required the use of several
equations and assumptions. First, algae yield is calculated from quantities of water and carbon dioxide
according to the photosynthesis equation, provided below. Photosynthesis is the pathway used by cells
to convert energy, carbon, and water into cellular material. Because the sources of carbon dioxide and
water are limited, one of them is the limiting component to calculating productivity.

        6(CO2) + 6(H2O) + light -> C6H12O6 + 6(O2)

Yield based on available sunlight is calculated according to the yield equation provided below. This
equation estimates algal yield per hectare, assuming algae are grown in a pond-type design. Recent
innovations in closed photobioreactors may prove to achieve higher yields, but little has been
documented to quantify such yields so it is assumed this equation applies to all bioreactor designs.

        Y = (CIE)/F

        Y = yield (tons/ha)
        C = 3.1536
                                     2
        I = average insolation (W/m )
        E = solar energy capture efficiency (5-6% for algae)
        F = energy content of dry biomass (21 MJ/kg for algae)

Lastly, algal oil is estimated according to an assumed percent oil content by mass. This percentage
varies greatly among species and growth conditions, varying from 1-2% up to 60-70%. A conservative
estimate for a high-oil yielding species of 20% is assumed for this calculation.



DATA SOURCES
The data sources for each resource type are provided in Table 1. Sunlight data is the annual direct
normal solar radiation, obtained from the National Renewable Energy Laboratories (NREL). Sources and
volumes of wastewater were obtained through EPA’s Envirofacts database, which provides data
reported by companies that discharge water into rivers via the permit compliance system (PCS). EPA’s
Emissions & Generation Resource Integrated Database (eGRID) is the source of carbon dioxide emission
data. Lastly, Land use data was obtained from the MRLC National Land Cover Database.



                                                       5
Table 1: Data Sources for Each Data Type
Resource         Data Source
Sunlight         National Renewable Energy Laboratory (NREL), operated by the Alliance for Sustainable
                 Energy, LLC for the U.S. Department of Energy (DOE).
Wastewater       EPA’s Envirofacts Database, information on companies that discharge wastewater per the
                 Permit Compliance System (PCS).
Carbon Dioxide   EPA’s Emissions & Generation Resource Integrated Database (eGRID)
Land Use         Multi-Resolution Land Characteristics Consortium (MRLC)’s National Land Cover Database.



RESOURCES FOR ALGAE PRODUCTION IN TEXAS
The map provided in Figure 3 identifies the locations and relative quantities of wastewater and carbon
dioxide sources in Texas. There are a total of 1,690 wastewater sources and 260 carbon dioxide sources
identified, many of which are clustered in or near urban areas.

Figure 3: Sources of Wastewater and Carbon Dioxide in Texas




             Ü
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                                                           j                                                                                                                                                                    Carbon Dioxide (annual tons)
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                                                  j                                                                                                                                                                              j   0.000000 - 107576.02
                                                                                                                                                                                                                                 j   107576.020001 - 311876.853
                                                                                                                                                                                                                                 j   311876.853001 - 619174.7313
                                      jj                                                           j   j                                                                                                                        j    619174.731301 - 1083189.9
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                                                                                                                                                                j       j             j                                         j    1083189.900001 - 2227785.416
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                                                                                                                                                                                               jj j                             j    2227785.416001 - 3872747.965
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                                                                                                                                                                                                                                j    3872747.965001 - 7538482.528
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                                                                                                                                                                                                        j                       j    7538482.528001 - 13486035.05
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                                                                                                                                                                                                                                j    13486035.050001 - 21593119.47
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                                                                                                                                                                            j                                                   Wastewater
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                                                                                                                                                                                                                            j   Flow Rate (MGD)
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                                                                                                                   j                                    j                        jj                                                  0.001000 - 2.40
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                                                                                                                                                                                                                            j        2.400001 - 8.50
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                                                                                                                                                                                                                                     8.500001 - 22.00
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                                                                                                                                                                                                                                     22.000001 - 54.70
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                                                                                                                                                        j                                                                            54.700001 - 111.00
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                                                                                                                                                                                                                                     111.000001 - 253.80
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                                                                                                                                                                                                                                     253.800001 - 435.00
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         0       62.5   125                       250 Miles                                                                                 j
                                                                                                                                              jj                                                                                     435.000001 - 740.00
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                                                                                                                                                                                                                                     740.000001 - 1165.00
                                                                                                                                                                                                                                     1165.000001 - 1785.00
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                                                                                                                                                                                                                                     1785.000001 - 3045.00
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SITES WITHIN 0.5 MILES
A distance of 0.5 miles between facilities reflects a practical, cost-effective candidate site for algae
production. Of the numerous mapped locations, there are only two sites that have a wastewater source


                                                                                                               6
and carbon dioxide source within 0.5 miles of each other. An image of those locations in Texas and the
sunlight and land-use characteristics is provided in

Figure 4, Figure 5, and Table 2.


Figure 4: Sunlight at Wastewater and Carbon Dioxide Sources within 0.5 Miles of Each Other.


                                                Legend
                                                DNIAN
                                                N   3897.000000 - 4270
                                                     4270.000001 - 4507
                                                     4507.000001 - 4772
                                                     4772.000001 - 5075
                                                     5075.000001 - 5364
                                                     5364.000001 - 5651
                                                     5651.000001 - 5931
                                                     5931.000001 - 6206
                                                     6206.000001 - 6572
                                                     6572.000001 - 7044




                                         j
                                         j




Figure 5: Land Use at Wastewater and Carbon Dioxide Sources within 0.5 Miles of Each Other




Table 2: Water Flow, Carbon Dioxide, Sunlight, and Land Use at 2 Candidate Locations
Name                            Flow Rate (MGD) CO2 (tons)          Sunlight         Land Use
                                                                           2
                                                                    (Wh/m /d)
Texas Petrochemicals Houston    6.5                 933,161         4,088            Hay/Pasture
Bayport Complex                 0.072               1,629,460       4,208            Woody Wetlands




                                                    7
According to the water, carbon dioxide, and sunlight resources available at these two sites, a total
estimated 66.4 thousand barrels of oil can be produced. The calculated biomass yields, as limited
by each resource, and corresponding maximum oil yield, are provided in Table 3. The annual
production of 66.4 thousand barrels of oil represents approximately 0.007% of annual crude oil
consumption in Texas.

Table 3: Achievable Biomass Yields at Each Site and Total Annual Oil Yield
Name                               Biomass Yield     CO2 Limited     Water Limited         Maximum Oil
                                   (tons/ha)         Yield (tons)    Yield (tons)          Yield (barrels)
Texas Petrochemicals Houston       1.408             399,421         51,791                65,671
Bayport Complex                    1.449             697,458         574                   727
Total                                                                                      66,398



SITES WITHIN 1.0 MILES
In order to estimate potential algae production within a maximum possible practical distance, sites
located within 1.0 miles of each other were identified. A total of 8 sites are so collocated; images of
those locations in Texas and the sunlight and land-use characteristics are provided in Figure 6, Figure 7,
and Table 4.

Figure 6: Sunlight Resources at Wastewater and Carbon Dioxide Sources within 1.0 Miles of Each
Other

                                                     DNIAN
                                                     N   3897.000000 - 4270
                                                          4270.000001 - 4507
                                                          4507.000001 - 4772
                                                          4772.000001 - 5075
                                                          5075.000001 - 5364
                            j                             5364.000001 - 5651
                                                          5651.000001 - 5931
                                    j   j   j             5931.000001 - 6206
                                                          6206.000001 - 6572
                                                 j
                                                          6572.000001 - 7044
                                   j




                                            jj




                                                          8
Figure 7: Land Use Characteristics at 6 Additional Sites within 1.0 Miles




                                                   9
Table 4: Water Flow, Carbon Dioxide, Sunlight, and Land Use at 8 Candidate Locations
Name                         Flow Rate (MGD)      CO2 (tons)     Sunlight        Land Use
                                                                        2
                                                                 (Wh/m /d)
Liberty City WSC WWTP                      0.18     21,593,119        4,366      Developed, Low Intensity
Rhodia, Inc. Guar Processing                1.3      4,829,977        5,032      Herbaceous
Polk Street WWTP                            0.4          27,533       4,730      Developed, Open Space
Texas Petrochemicals Houston                6.5         933,161       4,088      Hay/Pasture
City of Sanger WWTF                        0.98               0       4,884      Developed, Low Intensity
City of Winfield WWTP                     0.084     17,491,542        4,458      Shrub/Scrub
Bayport Complex                           0.072      1,629,460        4,208      Woody Wetlands
City of Celeste WWTP                     0.0948          39,661       4,554      Developed, Open Space


According to the water, carbon dioxide, and sunlight resources available at these 8 sites, a total
estimated 87.2 thousand barrels of oil can be produced. The calculated biomass yields, as limited by
each resource, and corresponding maximum oil yield, are provided in Table 5. The annual production of
87.2 thousand barrels of oil represents approximately 0.01% of annual crude oil consumption in Texas.

Table 5: Achievable Biomass Yields at Each Site and Total Annual Oil Yield
Site Name                    Biomass Yield        CO2 Limited Yield   Water Limited          Maximum Oil
                             (tons/ha)            (tons)              Yield (tons)           Yield (barrels)
Liberty City WSC WWTP                       1.5           9,242,509                 1,434                  1,819
Rhodia, Inc. Guar Processing                1.7           2,067,377                10,358                13,134
Polk Street WWTP                            1.6              11,785                 3,187                  4,041
Texas Petrochemicals Houston                1.4             399,421                51,791                65,671
City of Sanger WWTF                         1.7                     0               7,808                      0
City of Winfield WWTP                       1.5           7,486,910                   669                    849
Bayport Complex                             1.4             697,458                   574                    727
City of Celeste WWTP                        1.6              16,976                   755                    958
Total                                                                                                    87,199


At nearly all sites, water is the limiting resource that dictates how much algae can be produced. If a
plant were to institute a degree of water recycle, whereby some of the water is reused after harvesting
algae from it, the potential algae production increases greatly. For a conservative 50% water recycle,
production at these 8 sites rises to 2.2 billion barrels, which represents 0.2% of oil consumption in Texas.

LAND AND BIOREACTOR REQUIREMENTS
Given the land-use characteristics at each of the 8 candidate sites, the appropriate bioreactor types are
provided in Table 6. In general, undeveloped land can support any type of bioreactor, and, in such
areas, horizontal or pond-type systems are reported because they are typically the most economical
option. In low to medium intensity-type development pond type systems may be appropriate but a
combination of bioreactor types may be required, and mixed is reported. Lastly, high intensity
development or other occupied land (e.g., wetlands) requires vertical/other engineered
photobioreactors.




                                                    10
Table 6: Land and Bioreactor Requirements at 8 Candidate sites.
Site Name                            Land Required (ha)                 Bioreactor Type(s)
Liberty City WSC WWTP                954                                Horizontal/Ponds
Rhodia, Inc. Guar Processing         5,977                              Horizontal/Ponds
Polk Street WWTP                     1,956                              Horizontal/Ponds
Texas Petrochemicals Houston         36,785                             Horizontal/Ponds
City of Sanger WWTF                  4,642                              Mixed
City of Winfield WWTP                436                                Horizontal/Ponds
Bayport Complex                      396                                Vertical Photobioreactors
City of Celeste WWTP                 482                                Horizontal/Ponds



REVIEW OF METHODS
The data sources used for this analysis have some shortcomings. Firstly, the wastewater flow rates are
estimated according to the flow rates for which each facility is permitted, which may differ from the
actual discharge volumes. Further, several facilities (642) are not associated with geographic
coordinates and, as such, had to be excluded from the analysis. The carbon dioxide data obtained from
eGRID is comprehensive; however, it includes emissions of carbon dioxide from power plants only.
Other sources of carbon dioxide such as anaerobic digesters are not captured in this data set. Thus, this
analysis may significantly underestimate the number of collocated facilities due to these data
limitations.



CONCLUSIONS
Using geographic information systems to map resources for algae production in Texas proved fruitful for
determining the extent that existing wastewater and carbon dioxide resources can be used to cost-
effectively support the production of algae for biofuels. It is immediately evident that such resources
can provide limited support to the emerging industry and that achieving the long-term goals of
significant biofuel production will require some mode for transporting the resources or obtaining
alternate resources. However, implementing innovative bioreactor types to accommodate diverse land
uses and water recycle to minimize the water requirements has the potential to maximize production
from the existing collocated resources.




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REFERENCES
eGRID: http://www.epa.gov/cleanenergy/energy-resources/egrid/index.html.

EPA’s Envirofacts Database: http://oaspub.epa.gov/enviro/ef_home2.water.

Greenfuel Technologies Corp. http://www.greenfuelonline.com/index.html.

Hartman, 2008. A Promising Oil Alternative: Algae Energy. The Washington Post. January 6, 2008.

MRLS Land Cover Database: http://www.mrlc.gov/nlcd_multizone_map.php.

NREL Solar maps: http://www.nrel.gov/gis/solar.html.




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