3.3 Biofuel and land and water use
Appendix
1 - Algae as CO2 fixing
Appendix
2 – Canadian Cost to Warm Water
Appendix
3 – Crops and Biofuel Production Constraints
Appendix
4 - Energy Returned On Energy Invested (EROEI) ratio
The use of algae for biofuel has been studied for more
than 30 years in USA. For economic reasons, research on algae has lost funding
to other biofuel sources such as crops; however, current price scenarios for
fossil fuels, crops and food as well as improvements in technology have led to
resurgence in studies of algae technology and the initiation of pilot projects.
Around the world, more than 200 algae projects are
being developed, involving several universities, companies and government
agencies in multidisciplinary study groups. The studies focus on genetic
combination and manipulation of algae, and improvement in facility engineering
costs.
Algae are a highly efficient converter of solar
energy into fuel, fertilizers, hydrogen, and oxygen, needing only sunlight,
fertilizer, water and carbon dioxide (CO2) to grow. This combination of
characteristics gives algae a strong potential for further development.
Additionally,
algae have strong advantages over crops for energy production:
·
Use of marginal land, avoiding competition with
crops land use;
·
Lower water quantity and quality requirements,
avoiding competition for fresh water resources;
·
Continuous consumption and production;
·
Higher energy efficiency than crops; and
·
Feed CO2 can be provided from carbon capture in
other industries.
Disadvantages
for development of algae projects in Albertan are:
Otherwise,
current disadvantages in Albertan project development are:
According to recent feasibility studies and
pilot projects in US deserts, technological improvements and increases in
fossil fuel prices are making competitive algae technology. In a Canadian
context, weather conditions significantly increase energy costs for algae
production, and algae technology needs more development in all areas to be economically
competitive; however, CO2 fixing gives algae technology a particular interest
in those regions with high CO2 emissions.
In Alberta and Canada, a lack of
studies for real Canadian conditions is observed; this could be in detriment of
this promissory technology and its wide range of application in Alberta and
Canada.
The US Department of Energy has funded research
into algal fuels under the Aquatic Species Program from 1978 to 1996, but then
switched resources to other programs such as using maize as a feedstock for
bioethanol.
Climate change and rising oil and food prices
intensify the search for alternative energy sources. Algae technology appears
to provide a complete solution to address these three main issues: climate
change and oil and food prices.
Algae’s capacity for
CO2 fixation and bio-energy production, as well as other by-products (e.g.
oxygen, hydrogen, fertilizers) increase algae’s potential. Several studies and
pilot plants are being developed using micro-algae technology.
Thousands of species
and sub-species of algae are available today to study their properties and
adaptation to different land and weather conditions. Most of these studies are
being developed with green algae, which show the most important characteristics
associated to the requirements demanded for the energy industry.
The principle for
algae growth is photosynthesis, the process used by crops and plants when they
grow. The photosynthesis process needs water, nutrients and solar energy for
algal growth. In the case of algae, special water requirements are not necessary.
Between the more important nutrients that algae need to grow are nitrogen,
heavy metals and most importantly, carbon. In the natural photosynthesis
process, carbon is taken from CO2 in the atmosphere; for algae, the physical
disposition of CO2 injected into the ponds helps controlling the CO2 feeding;
this principle does that algae technology could be used for CO2 fixing.
Algae composition depends
on the type of algae, but typical components and values are:
·
Lipids,
from 1.9 to 32% and used for biofuel production;
·
Proteins,
from 49 to 79% and used as by product for animal feed;
·
Carbohydrates,
from 9 to 25% and used as by product for animal feed; and
·
Ash,
from 4 to 7%.
An
algae producer has three primary processing options:
·
dry and pelletize; to feed various markets, protein
extractions and nutritional products;
·
extract oils for biofuels;
·
hydrogen or oxygen production; and
·
use the algae like biomass to produce electricity
and use the remaining solids for fertilizer.
The characteristic of each algae specimen and the addition of fertilizer could optimize different constraints such as CO2 consumption or the proportion of protein, carbohydrates and lipids produced. This proportion could be maximized according with the goal for the use of algae. Several studies are being carried out with different goals for the use of algae.
In industrial algae use, large pond surfaces are necessary, requiring commercial-scale facilities. Facility location becomes an important consideration. Some possibilities include building adjacent to coal-fired power plants or oilsands projects to be close to a source of CO2, or next to ethanol plants to decrease transportation of the algae once it's grown. Others are considering utilizing wastewater produced by municipalities, although that particular possibility has potential drawbacks for the control of algae contaminant.
In Canada, special concerns for algae production
are:
A lot of factors affect the growth
rate of algae, including energy radiation (e.g. solar intensity and sun
inclination), kind of algae, nutrients and water temperature. There are two different parameters to measure
algae growth:
Algae have a very quick growth rate
compared with crops and needs to be harvested once a day under normal conditions.
This growth allows continuous algae production, which means a continuous CO2
consumption, and a continuous energy and by-products production.
Algae can act as a sink for CO2 because they
absorb it during photosynthesis. The rule of thumb is that it takes two million tons of algae to be able
to capture one million tons of CO2.
Typical values for CO2 fixation are 2.5
gCO2/L/d (0.65 to 4 gCO2/L/d)
The relationship between CO2 and algae growth is:
Appendix 1 provides a detailed
description of data for the application of fixing CO2 from a typical Coal-Fired
Power Plant.
The use of crops for biofuels presents some
important concerns (Appendix 3); algae production, with its more efficient use
of resources, eliminates or minimizes many of the concerns associated with crop
use for biofuels:
The average yearly
yield for algae can be as high as 47,000 litres of biodiesel per hectare.
In comparison, a hectare of soybeans can typically only produce 655 litres,
with corn capable of producing only 3930 litres of ethanol per hectare
(Appendix 3 provides comparisons with others crops).
Biomass produced by algae can be
used to feed a biomass power plant. A typical algal mass has a heating value of
16.3 to 20.9 MJ/Kg (7,000-9,000 BTU/lb), which is better than lignite[1];
but the heating value of algal oil and lipids is 37.2 MJ/Kg (16,000 BTU/lb),
which is better than anthracite1.
For comparison, the heating values
of different sources are:
Natural Gas: 52 MJ/Kg
Heavy Fuel Oil: 42 MJ/Kg
Coal: Bituminous 28 MJ/Kg, Sub-Bituminous 20 MJ/Kg and Lignite 15 MJ/Kg
Algae: 19 MJ/Kg
For the example given in the
appendixes, Algae could produce 24.8 MW/Km2 (6.9 to 42.6 MW/Km2) when is used
for biomass for electricity generation.
Algae can be used as a biological source for the production of hydrogen. When algae are deprived of
sulphur, they will switch from the production of oxygen (normal photosynthesis) to the production of hydrogen. Up to 0.15 Kg of hydrogen
could be produced by Kg of dry Algae.
Crops have around
1.05 Energy Returned On Energy Invested (EROEI) ratio (from 0.8 to 1.2). Algae increase this
energy efficiency ratio up to 1.3 (Appendix 4).
Algae technology is improving cost and
efficiency in biofuel production. Algae is touted as a cheaper alternative to
traditional biofuel feedstock, producing 30 times more oil with one hundredth
the water per hectare required in comparison to traditional crops. Despite the
benefits of algae technology, investors have balked at the prohibitive capital
costs, which can run up to M$ 1.5 per hectare. Future projects in the USA
aim to reduce the capital cost by a factor of sixteen.
According to National
Renewable Energy Laboratory (NREL), typical
USA algae project has:
Capital Cost: 145 M$/Km2
Operation and Maintenance cost: 27 M$/Km2/y
Canadian environmental conditions
add:
Capital Cost:
Quonset cover and warm
up and light installation: 51 M$/Km2
Operation cost:
Electricity for lighting
and gas to warm water: 43 M$/Km2/y
These combine to provide the
following cost comparison for algae projects in the USA and Canada:
Capital
Expenditure |
USA |
Canada (Alberta) |
Capital Cost [M$/Km2] |
145 |
197 |
Operation and Maintenance
[M$/Km2/y] |
27 |
70 |
Income |
Canada (Alberta) [M$/Km2/y] |
||
|
Low |
Medium |
High |
CO2 saving |
0.4 |
1.4 |
2.4 |
By Products |
0.6 |
2.1 |
3.6 |
Oil or Electricity
production |
5.2 |
18.4 |
31.9 |
Essentially, in Canada algae has four main
concerns:
Industry is working on cost reduction and
improvement in the following areas:
There are more than 200 algae projects
around the world in different stages and with different goals. The main targets
in order of application are:
·
Biofuel
production;
·
CO2 fixation; and
·
Hydrogen
production.
The LiveFuels Alliance leads by
Sandia National Laboratories, a U.S. Department of Energy National Laboratory, follows
a collaborative project that will sponsor dozens of labs and hundreds of
scientists within the next three years making it the largest endeavor focused
on commercial biocrude from algae.
The biggest challenge is to make
algae biocrude for less than $60 a barrel.
XL Renewables, Inc, has developed a low-cost algae system
for the large-scale production of algae biomass called Withrow 40. Based on 16 ha (40 acres) fields that grow and
harvest the algae, the XL project provides to algae farm a constant flow of CO2
enriched air to stimulate growth. The project
will be open to the public on November 1, 2008 and sales will begin January 1,
2009.
NRG Energy, which is
field testing the technology at one of its coal-fired plants in Louisiana, is
using naturally-occurring algae to capture and reduce flue gas CO2 emissions.
The energy-rich algae are harvested daily and can be converted into a broad
range of bio-fuels or high-value animal feed supplements.
AlgaeLink and KLM expect to conduct test flights
this fall relative to algae biofuel. AlgaeLink will also open two plants this
year in the Netherlands and Spain. KLM hopes to have 12 of their Fokker-50
planes (7% of their air fleet) running on the fuel by 2010, with the eventual
goal of running their entire fleet of airplanes on fuel made from algae.
In Canada, some laboratories are studying algae
genomes for their growth in Canadian conditions and developing a mapping of
algae growth base on different fertilizers and nutrients. Some enterprises have
been developing some kind of algae study:
-
SFN Biosystems Inc.
-
Innoventures Canada Inc.
-
Lipidipod Inc.
-
Proges S.A., a enterprise based in Caribbean region, but studying an algae
project in Fort McMurray
Renewables
and Alternatives Unit, Alberta Department of Energy, is supporting two
projects:
-
I-CAN’s project
-
SFN Biosystems Inc.’s project
In contrary to
what happens in other jurisdictions, in all analyzed algae project in Alberta
it was observed until now:
-
lacks of pre study of algae technology as well as pre-engineering of
the project,
-
lacks of base knowledge and optional studies; and
-
lacks of complete analysis from Canadian conditions.
Algae are a highly
efficient converter of solar energy into fuel for cars, homes, fertilizers,
hydrogen, oxygen and power generators, needing only sunlight, water and CO2
to grow. The more interesting applications for algae projects today are
biofuel production and CO2 consumption.
The emergence of
algae biomass as a renewable source of vegetable oils, proteins and
carbohydrates decreases demand pressures on corn and soybeans. Algae compete with crops
in biofuel production with a lot of advantages:
And
some disadvantages are present in this technology:
Economical and technical analysis
of algae technology relates it more with biodiesel production than CO2
consumption. The CO2 consumption appears like a by-product of this technology
considering the high land extension required for CO2 fixing.
Canadian weather conditions do not
help to the development of this technique in Canada, scenario that is commonly
not considered in the feasibilities studies of algae projects in Canada.
Taking Coal-Fired Genesee #3
Power Plant as application, we have:
·
Power Capacity: 450 MW
·
CO2 emission: around 842
kgCO2/MWh
For pond requirements:
·
14.3 cm of depth
·
11 cm of algae
The following figure shows the
side long in Km for the necessary pond as function of the percentage of the
fixed CO2.
Following figure shows the cost
in $M/Celsius degree for warm up the water in the algae pond as function of the
percentage of the fixed CO2 for the case in Appendix 1.
Considering:
CO2 @ 15 $/tCO2
Oil @ 135 $/bbl
Gas @ 12 $/GJ
Electricity @ 90 $/MWh
There are several concerns about
the use of crops for biofuels[2]. The most common concern
are the relationship of biofuels with increases in food prices[3], the use of fertile lands
to produce energy without efficient energy programs, and the emphasis on the
difference between rich and poor countries and increasing world poverty. In
addition, there are some technical concerns about the use of crops for
biofuels:
·
Low efficiency; the
relationship between energy obtained and energy inverted to produce biofuel is
around 1.05 (0.8 to 1.2);
·
Increase in the use of
oil; crop harvest requires extensive use of agricultural machinery, which is a
major user of oil derivatives. Also, the use of biofuels in this agricultural
machinery decreases biofuel energy efficiency and the full replacement of oil
by biofuels is impossible today
·
Capacity limitations:
o
Canadian oil consumption: 840 M bbl/y (450 M bbl/y for transportation
sector)
o
Alberta oil consumption:
around 110 M bbl/y
o
The following table
presents the land surface necessary as percentage of Canadian land use, to
replace, by different crops, the total oil consumption for transportation in
Canada. For example, for Sunflower, a surface of 780 km x 780 km, or 6.1% of
Canada’s land surface (or the similar Alberta’s land surface) would be needed
compared to only 0.1% for algae.
Use |
Crop |
Oil equivalent [tonne/ha] |
Surface to produce 450
Mbbl/year [km2] |
Canadian land cultivated [%] |
Oil |
Colza |
1.37 |
470,000 |
4.7% |
Oil |
Sunflower |
1.06 |
607,000 |
6.1% |
Oil |
Canola |
1.25 |
515,000 |
5.2% |
Oil |
Algae |
84.20 |
7,600 |
0.1% |
Ethanol |
Sugar beet |
28.00 |
23,000 |
0.2% |
Ethanol |
Wheat |
1.76 |
366,000 |
3.7% |
Ethanol |
Switchgrass |
2.55 |
253,000 |
2.5% |
Ethanol |
Corn |
1.67 |
385,000 |
3.9% |
Ethanol |
Soybeans |
0.36 |
1,800,000 |
18.1% |
o
The following table
presents the necessary percentage of Alberta’s land surface to replace, by
different crops, total oil consumption in Alberta. For example, for Sunflower,
a surface of 385 km x 385 km, or 22.4 % of Alberta’s land surface would be
needed compared to only 0.3% for algae.
Use |
Crop |
Oil equivalent [tonne/ha] |
Surface to produce 110
Mbbl/year [km2] |
Albertan land cultivated [%] |
Oil |
Colza |
1.37 |
115,000 |
17.4% |
Oil |
Sunflower |
1.06 |
148,000 |
22.4% |
Oil |
Canola |
1.25 |
126,000 |
19.0% |
Oil |
Algae |
84.20 |
1,900 |
0.3% |
Ethanol |
Sugar beet |
28.00 |
5,600 |
0.8% |
Ethanol |
Wheat |
1.76 |
89,000 |
13.5% |
Ethanol |
Switchgrass |
2.55 |
62,000 |
9.3% |
Ethanol |
Corn |
1.67 |
94,000 |
14.2% |
Ethanol |
Soybeans |
0.36 |
442,000 |
66.7% |
Energy
Return On Energy Investment (EROEI) is an important concept to understand and a
concept that is severely lacking in our current political debate on new energy
sources.
EROEI is
simply defined as = 1+ Energy Produced / Energy Used
This definition is based in the relationship between
produced and consumed energy for a technology; it stresses in how much energy
as balance we can obtain for each technology.
This coefficient has strong arguments of both detractors
and supporters; these two positions remember the attention that we need to have
in its utilization. Detractors say:
In other way, supporters trust in this simple and powerful
ratio at the extreme of explaining the fall or surfacing of cultures (e.g.
Roman or several theories for the future of the nations).
Nowadays, with the coming out of new or improved
technologies, the use of EROEI such as a simple technology comparison is much
extended. The following tables present the range of EROEI for the more common
technologies evaluated at this moment.
Technology |
Description |
EROEI |
Oil
and gas (domestic wellhead) |
1940's |
>100 |
1970's |
8
to 27 |
|
Coal
(mine mouth) |
1950's |
80 |
1970's |
50 |
|
Oil
shale |
0.7 to 13.3 |
|
Coal
liquefaction |
0.5 to 8.2 |
|
Geopressured
gas |
1.0 to 5.0 |
|
Ethanol
(sugercane) |
0.8 to 1.7 |
|
Ethanol
(corn) |
1.3 |
|
Ethanol
(corn residues) |
0.7 to 1.8 |
|
Methanol
(wood) |
2.6 |
|
Solar
space heat (fossil backup) |
Flat-plate collector |
1.9 |
Concentrating collector |
1.6 |
The EROEI for electricity production:
Technology |
Description |
EROEI |
Coal |
U.S. average |
9 |
Western surface coal- No scrubbers |
6 |
|
Coal
(mine mouth) |
Western surface coal- scrubbers |
2.5 |
Hydropower |
11.2 |
|
Nuclear
(light-water reactor) |
4 |
|
Solar |
Power satellite |
2 |
Power tower |
4.2 |
|
Photovoltaics |
1.7 to 10 |
|
Geothermal |
Liquid dominated |
4 |
Hot dry rock |
1.9 to 13 |
|
These tables could orient a lot of conclusions, some of
them are:
[1] Coal quality is
characterized in the following growing order according to their heat capacity: Peat, Lignite,
Sub-bituminous, Bituminous,
Anthracite
and Graphite.
Electricity sector in Alberta usually consume sub-bituminous coal.
[2] UK announced in G8 meeting in Japan, the reduction in the expansion rate
for biofuels.
[3] The increase in the food price is due the 75%
to the use of biofuels, according to World Bank report.