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Algae biofuels as an alternative to Alga Extract

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					         ALGAE BIOFUELS AS A POSSIBLE ALTERNATIVE TO
    ENVIRONMENTALLY DOUBTFUL CONVENTIONAL METHODS OF
                   BIODIESEL PRODUCTION

                          B.Sc. Tomislav Kurevija(1), B.Sc. Nenad Kukulj(2)

1
   Faculty of Mining, Geology and Petroleum Engineering, University of Zagreb, Pierottijeva 6, Zagreb, Croatia;
Tel: 385 1 4605 174, Fax: 385 1 4836 074; email: tomislav.kurevija@rgn.hr
2
  Faculty of Mining, Geology and Petroleum Engineering, University of Zagreb, Pierottijeva 6, Zagreb, Croatia;
Tel: 385 1 4605 481, Fax: 385 1 4836 074; email: nenad.kukulj@rgn.hr


Abstract: In last ten years there was significant rise in transportation fuel consumption in Europe
from 180 Mt in 1985. to 270 Mt in 2004., with gasoline representing 40% and diesel 60%. To
decrease dependence upon imported fossil fuels, EU aim is to introduce biodiesel in share of 5,75%
in transportation sector until 2010. and finally 8% until 2020. Because of limited production
potential from some EU countries, today and in near future, large quotas of import would be
required. Biodiesel is often called clean, ecological and renewable alternative fuel, but with present
land-intensive methods of production it could easily be named as one of the most dangerous sources
of energy for Earth’s ecosystem. Main threat from large scale biofuels utilization comes from
deforestation of land that is needed for cultivation of crops. Every year large areas of rainforests in
South East Asia and South America are irretrievably lost due to increasing demand. Combustion of
wood and oxidation of peat during drying emits enormous quantities of CO2 into the atmosphere
which is contrary to biodiesel appellation as “CO2 balanced fuel”. Unlike conventional crops that
are used for production of biodiesel (rapeseed, soybean, palm etc.), possible production from algae
would significantly lower unit of land needed for biofuel production. Contemporary researches give
some estimation of about 25 times greater yield than palm plantation and 100 times over rapeseed,
which is common biodiesel production crop in EU. Regarding lately high world oil prices, greater
investment in researches upon algae, as a new source of biofuel, are bringing technological
solutions for economically production start-up.


1. INTRODUCTION

The European Union is heavily dependent upon energy imports and particularly to oil imports,
which leads to large emissions of greenhouse gases (GHG) and contributes to global warming and
climate changes. In an effort to slow down this increase, most industrialized countries have joined
in to Kyoto protocol policy to hold carbon dioxide emissions in the year 2000 to 1990 levels.
Transport is a main oil consuming and GHG generating sector in the EU, and therefore the
reduction of energy consumption and emissions from the road transport will be an important step on
the way of reaching these EU policy objectives. Although the importance of the biofuels use in
transport has already been stressed in the EU White Paper on renewable sources of energy (1997)
and the Green Paper on a European strategy for the security of energy supply (2000), this has not
led to the development of specific biofuel national policies in many EU Member States. Some
countries support the use of biodiesel by exempting them from excise duties or environmental taxes
and in June 2001 two EU Directive proposals passed, concerning the promotion of biofuels. The
first draft Directive obligates the EU Member States to sell a certain amount of biofuels on their
national markets in the period 2005 - 2010. In order to support this, the second draft Directive
provides the opportunity to the Member States to adjust their national excise duty systems for
automotive fuels in favour of biofuels. EU directive proposal also obligates the Member States to
establish a minimum percentage of 2% of biodiesel share in the total transport fuel consumption till
31st December 2005. This amount must be increased every year by 0.75% to 5.75% by the 2010 and
8% by the end of 2020. [3] Biodiesel is cleaner than gasoline and diesel and it is virtually sulphur
free. Hydrocarbons and carbon monoxide emissions and particles during combustion process are
also significantly reduced but with slight increase in nitrogen oxides emissions. Another advantage
is that biodiesel blends may potentially be utilized in a standard, unmodified diesel engine. While
positive impacts such as reduction in CO2 emissions at the combustion stage are evident, the
indirect impacts such as deforestation, the danger of reducing biodiversity, competition for land
with food production sector, contamination of land and water with nitrates, phosphates and
pesticides are more complex and have global impact on environment as well. Opposite to terrestrial
plants which are favourable for production of biodiesel, microalgae have the advantages of greater
efficient photosynthesis, fast proliferation rates, wide tolerance to extreme environments, potential
for intensive cultures and lesser land area requirement. These advantages promise the reduction of
carbon dioxide if microalgae production ponds would be build near fossil fired power plants.
Exhaust gases from heavy industries commonly contain carbon dioxide levels significantly higher
than that found in the atmosphere, 10-20% for coal plants and around 4% for natural gas [4] what
could be use for growing of microalgae cultures and sequestration of CO2 at the same time. Once
the lipids are extracted from the harvest algae, potential use for the microalgae residue include
fodder for livestock, food and chemicals, colorants, perfumes, and vitamins, which leads to greater
economically feasibility of the project.


2.     STATUS OF WORLD BIODIESEL PRODUCTION

At present, the biofuel producing countries in the European Union only have a small share in global
production of biofuels, namely a little less than 6%. Most of the global biofuel production consists
of ethanol and the main producers are the USA and Brazil, whereas the share of Europe is rather
small. However, Europe is the most important producer of biodiesel on the global market. From
1993, the European production level has increased by almost forty times, from 80.000 tons in 1993
to 780.000 tons in 2001, and finally to 3.184.000 tons in 2005. [3]




Picture 2-1: World production of biodiesel from 1991 till 2003, [3]

Germany is the leading European producer, followed by France, Italy and Czech Republic.
Throughout the European Union, biodiesel is applied in automotive engines in various blends with
regular diesel. In Germany, Austria and Sweden, it is used in pure form in adapted captive fleet
vehicles. Currently, only biodiesel (mainly Rapeseed Methyl Ester, RME) and ethanol (and its
derivative ETBE) produced from food crops are applied on a commercial basis on the European
market. Around 12% of total biodiesel volume, EU is importing from East Asia (Malaysia and
Indonesia) in form of crude palm oil. Biodiesel production currently uses around 1,4 million
hectares of arable land in the EU and today there are approximately 40 plants in the EU producing
up to 3.184.000 tonnes of biodiesel annually. These plants are mainly located in Germany, Italy,
Austria, France and Sweden. In the USA, the most common crop for producing biodiesel is soy
while in East Asia (Malaysia and Indonesia) biodiesel is mainly produced from crude palm oil. As
the demand for biodiesel in EU rises, there is a problem of meeting consumption by domestic
production of rapeseed oil. It is estimated that until 2010, 20% of total biodiesel on EU market will
come from SE Asia in form of crude palm oil. [3] This share could go even bigger taking into
account that palm oil is more economically favourable than rapeseed.

Table: EU biodiesel production and import in 2005. [3]

                                       Production of      Production capacity   Share of biodiesel in diesel
              COUNTRY                biodiesel in 2005.        in 2005.           consumption in 2005.
                                      (×1000 tonnes)        (×1000 tonnes)                 (%)
     Germany                               1669                  2681                      2,00
     France                                492                   775                       2,00
     Italy                                 396                   857                       2,00
     Czech Republic                        133                   203                       3,03
     Poland                                100                   150                         -
     Austria                                85                   134                       2,50
     Slovakia                               78                    89                       2,00
     Spain                                  73                   224                       2,00
     Denmark                                71                    81                       0,00
     UK                                     51                   445                       0,30
     Slovenia                               8                     17
     Estonia                                7                     20                       0,00
     Lithuania                              7                     10                       2,00
     Latvia                                 5                     8                        2,00
     Other EU states                        9                    375                         -
     TOTAL                                 3184                  6069                      1,50
     Imports of palm oil from East
                                             500                   -                         -
     Asia for biodiesesel purposes



3.       RESEARCH AND DEVELOPMENT OF MICROALGAE BASED BIODIESEL

Currently most research into efficient algal-oil production for biodiesel purposes is being done in
the private sector in the view of small scale pilot-projects. Mass-production of oil is mainly focused
on microalgae, organisms capable of photosynthesis that are less than 2 mm in diameter, including
the diatoms and cyanobacteria. This preference towards microalgae is due to its less complex
structure, fast growth rate, and high oil content for some species (as many as 70% in favourable
conditions). Commercial microalgal culture in a food sector today is a well established industry and
much of the early work on microalgae oil production focused on closed culture systems
(photobioreactors). A photobioreactor is basically a bioreactor which incorporates some type of
light source and because these systems are closed, everything that the algae need to grow (carbon
dioxide, nutrient-rich water and light) must be introduced into the system.
Large commercial systems that are used today are almost always open-air systems design types, due
to economical reason. Closed culture systems are very expensive and many of them are difficult to
scale up. Furthermore, most closed systems are operated indoors with artificial lighting and this
result in high energy costs. However, the number of species that has been successfully cultivated for
a given purpose (for the production of biodiesel and as food source) in an outdoor system is
relatively small. In open systems there is no control over water temperature and lighting conditions
and due to the fact that these systems are atmospherically open, they are much more vulnerable to
be invaded by other algal species and bacteria. The growing season is largely dependent on location
and apart from tropical areas it is limited to the warmer months with productivity achieved lesser
than it is theoretically possible.

Table 4: Comparison of microalgae bio-oil yield and common cultures for biodiesel production [1]


               Plant           Microalgae        Soybean        Rapeseed        Jatropha      Palm
                  3    2
     Yield       m /km /y         >15000           35 - 45       100 - 130         160         580
       of        bbl/acres/y       >380          0,90 - 1,15    2,55 - 3,30        4,10       14,80
     bio-oil     GJ/km2/y         >500000        1165 -1500     3330 - 4330        5330       19315



The pond depth is often compromised between the need of providing adequate light to the algal
cells (the shallower it is, the more light is available to the cells) and the need of maintaining an
adequate water depth for mixing, regarding large changes in ionic composition due to evaporation.
Algae only need about 1/10th of the light amount they receive from direct sunlight. In order to have
ponds that are deeper than 4 inches, various methods of water agitation in ponds need to be used,
exposing the algae below to light and keeping algae on the surface from being over-exposed. Paddle
wheels can be used to circulate the water in a pond and compressed air can be introduced into the
bottom of a pond to agitate the water, bringing algae from the lower levels upwards. Aside from
agitation, light algae supply could be done by introducing the light into the system by using glow
plates, submerging them into the water, providing in that way light directly to the algae at the right
concentration. Algae can be harvested using microscreens, by centrifugation, or by flocculation
methods.
Microalgae have much faster growth-rates than terrestrial crops. The yield of oil from algae is
estimated to be between 5000 and 15.000 m3/km2/y which is around 8 to 25 times greater than the
next best crop, palm oil. [6] In order to obtain high algal production rates, many of pilot projects
harvested the biomass daily. If unharvested, production rates will reach a peak and then decline
with increasing biomass concentration because of reduced available light (mutual shading) and
depletion of nutrients. Therefore, harvesting is an essential part of maintaining high microalgal
productivity rates. Algal-oil is transformed into biodiesel as easily as oil derived from land-based
crops and the difficulties in the efficient biodiesel production from algae lie not in the extraction of
the oil, but in finding an algal strain with a high lipid content and fast growth rate that is not too
difficult to harvest, and a cost-effective cultivation system that is best suited to that strain. The
knowledge of the biochemistry and physiology of lipid synthesis, combined with basic studies on
microalgal molecular biology and genetic engineering to develop algae strains with optimal
properties of growth and lipid production, may lead to great improvement and enhance the
commercial viability of this alga as an optimum hydrocarbon source.


4.      POSSIBILITY OF CO2 SEQUESTRATION IN THE ALGAE CULTURE PLANTS

Much of the carbon dioxide that is released into the atmosphere is from the burning of fossil fuels
for the production of energy (coal power plants are especially major source of carbon dioxide
emissions) or in the heavy industry. Regarding global warming effect, new methods for the
thorough and efficient sequestration of CO2 are being sought out and selection of the most
appropriate technology to limit the amount of carbon dioxide entering the atmosphere is the major
focus of research. Carbon dioxide could be captured and sequestrated into the aquifers or depleted
oil and gas wells. This is an expensive option (potentially more than doubling the cost of electrical
generation via fossil fuels) with no opportunity for profit to displace the cost, except if the CO2 is
used as part of tertiary methods of oil recovery. Biofixation of carbon dioxide using microalgae has
emerged as a potential option. Commercial interests into large scale algal-cultivation systems could
be obtained by placing algae plants near coal power plants, sewage treatment facilities or any
industry that emit large quantities of carbon-dioxide into the atmosphere. This approach not only
provides the raw materials for the system, such as CO2 and nutrients making in that way greater
yield of biodiesel, but it changes those wastes into resources.




Picture 4-1: Simplified schematic of the algae biodiesel production with introduction of CO2 from
fossil fuel fired power plant.

Much work has been done on the effect of different flue gas constituents on microalgal growth rates
and carbon dioxide fixation. Typical coal power plant flue gases have carbon dioxide levels ranging
from 10%–15% (4% for natural gas fired ones). At the typical carbon dioxide percentages in the
atmosphere of 0,036%, microalgae show no signs of significant growth inhibition. Furthermore,
various studies have shown that microalgae respond better to increased carbon dioxide
concentrations, outgrowing (on a biomass basis) microalgae exposed only to ambient air.

Table 4-1: Example of typical flue gas composition from coal fired power plant [4]

      Component            N2         CO2         O2         SO2         NOx         Soot dust
      Concentration       82%         12%        5,5%      400 ppm     120 ppm       50 mg/m3

Sulfur oxides, particularly SO2, can have a significant effect on the growth rates and health of the
microalgae, especially effect that SO2 has on the pH of the microalgal growth. When the SO2
concentration reaches 400 ppm, the pH of the pond water can become as lower as 4, which
significantly affects the productivity of the microalgae. However, if the pH is maintained at 8 using
NaOH, the productivity does not decrease. [4] Nitrogen oxides also comprise a significant portion
of power plant flue gas. As with the sulphur oxides, nitrogen oxides can affect the pH of the algal
medium, but to a lesser degree. Microalgae have been shown to tolerate and grow in a medium
containing as many as 240 ppm of NOx, with pH adjustment. The effect of soot dust and ash
containing heavy metals has limited attention. When soot dust concentration is greater than
200.000 mg/m3, algal productivity is influenced. [4] It is rare for the soot dust concentration to
reach such a value. Higher concentrations of heavy metals in gas flue can affect algal productivity,
but only in rare situations will the concentrations exceed those that will result in a significant
impact. Another concern with the flue gas is the elevated temperatures. In a commercial application,
flue gas from the desulfurization scrubbers would be sent to the CO2 sequestration ponds for
treatment. Temperatures exiting the scrubbers are usually around 60°C. Therefore, microalgae
would need to exhibit tolerances at temperatures of this magnitude. Although most organisms
cannot survive at these higher temperatures, some cyanophycean algae have been shown to grow at
80°C.
Some investigations showed carbon fixation rate of 14.6 g C/m2 (basal area) per day at a growth rate
of 30.2 g dry wt/ m2 per day. [7] as well as range of 0.65–4.0 g CO2/ L per day at growth rates of
0.4–2.5 g dry wt/L per day. [6] Results were corroborated using direct measurements of the inlet
and outlet gas streams and indirectly estimated from the carbon content of the cell and the cell
growth rate. The capture of carbon dioxide by large pond-type systems when operating under
optimum conditions has been shown to be as high as 99%. [4] Pond sizes should not exceed 20 ha
each (a larger pond would be difficult to operate). It is estimated that for a 500-MW power plant
open pond surface area of 14.000 ha is needed. [4] These results show the potential for using
microalgae for carbon dioxide fixation, especially because of large investment costs in alone
standing algae plants. By introduction of CO2 source and construction of algae plants near fossil
power plants projects are becoming more economically feasible concerning sequestration of carbon-
dioxide and, in that way, contributing to global warming effect decrease. There are some estimation
of $80.000 per hectare for the construction costs of algae ponds and $12.000 per hectare for
operating costs (including power consumption, labour, chemicals, and fixed capital costs). [4] With
further research and development, as well as high oil prices, this method of biodiesel production
could be very interesting in future.


5.     ENVIRONMENTAL ISSUES CONCERNING CONVENTIONAL BIODIESEL
       PRODUCTION

As world population is continuously increasing and consequently energy demand as well, especially
in the transport sector, there is lesser arable land needed for growing food crops and energy
interesting crops for production of biodiesel. To satisfy biodiesel demand, especially from EU
which has limited arable area for reaching 8% of biodiesel share in 2020, production is moved from
EU to the other continents, especially SE Asia. Because EU is currently short of biodiesel, as some
Member States have underinvested in refinery production in recent decades experts estimates that
palm oil bio-diesel in a few years could account as much as 20 percent of Europe's biodiesel
consumption and cause the destruction of some of the most valuable forests of the world because of
the land clearance.




Picture 5-1: Necessary total arable area for EU goal of 8% biodiesel share in comparison to 100%
biodiesel share in total diesel consumption, according to rapeseed yield
Reason of increased share of palm-oil in total EU biodiesel consumption lies in greater yield per
area of palm plantation over rapeseed and lower cost production which influences final purchase
price. Until today, rapeseed is still dominant source for biodiesel in EU with share of some 80% but
competition with food sector has driven its price to somewhat 600€ per ton in 2005. At the same
time, price of crude palm-oil was around 33% cheaper, making it about 400€ per ton. [2] The main
world producers of crude palm oil are Indonesia and Malaysia. Between 1989 and 2000, the area of
oil palm harvested in Indonesia more than tripled. In 2003, 75 per cent of Indonesia’s 5.2 million
hectares of oil-palm plantations were located in Sumatra, with a further 18 per cent in Kalimantan
[2]. It is expected that this total will more than triple to approximately 20 million hectares in
Indonesia and 10 million hectares in Malaysia by 2020. Between 1985 and 2000 the development of
oil-palm plantations was responsible for an estimated 87 per cent of deforestation in Malaysia, and
an estimated 66 per cent of Indonesia’s plantations have involved forest conversion. By the
beginning of 2004, there were 6.5 million hectares of oil-palm plantations across Sumatra and
Borneo. [2] Of this total area, almost 4 million hectares had previously been forested. Currently,
every year about 2 million hectares of Indonesian virgin forest, a total area half the size of Belgium,
are turned over to palm oil production.




Picture1.: Example of Indonesia’s rainforest destruction due to palm-oil production expansion [2]

The palm-oil business is often advertised by governments and companies as making an important
economic contribution to development. However, this analysis is often one-sided, and fails to take
into account the substantial social and environmental costs. These include the ecological price of
removing rainforest such, as well as pollution and damage to water and air that are rarely taken into
account. However, the area released for conversion does not necessarily reflect the real area
planted, and the palm-oil industry is habitually associated with deforestation beyond establishing
oil-palm estates on previously forested land. The amount of forest removed under the plantation
development, regardless of whether palms have ever been planted, may be as much as 10 million
hectares. Around 40 per cent of Indonesia’s legal timber supply results from land clearance for
conversion to plantations. In the past, if the remaining timber stands are not commercially valuable,
burning has been a widely-used method of land clearance. The forest fires of 1997/98 were
responsible for the devastation of over 5 million hectares of forest and often the major fires are in
oil-palm plantations [8]. Peat-swamp forests, including those in Tripa, Singkil, and Kluet in
Sumatra, and Sebangau, Mawas, and Tanjung Puting in Borneo, play a major role in carbon
sequestration and biodiversity. This forest type is being promoted as a carbon sink and used in
international carbon offset agreements, while palm oil is concurrently publicised as a carbon
emission-reducing fuel. Peat-swamp forests, however, are increasingly becoming prime targets for
oil-palm expansion, despite regulations against the development of deep peats and lower
productivity relative to other soils. It is crucial that the expansion of oil-palm plantations does not
lead to the clearance of forests and, in particular, peat forests. It is difficult to cultivate oil palms on
peat land greater than 1 metre thick [9], and the costs of establishing a plantation on this soil type
tend to be 40 per cent higher than on dry land but nevertheless, numerous companies continue to
apply for licences to allow the conversion of deep peat land.

Table 5: Plantation area and estimated forest area cleared based on industry estimates (mil.ha) [9]

                                 Share of oil                  Total oil
                                                Forest area                 Additional
                                    palm                         palm                      Additional
                   Oil Palm                     cleared for                    area
                                 plantations                     area                      forest to be
      Country     plantation
                                  involving
                                                     oil
                                                               target /
                                                                               to be
                                                                                             cleared
                  area (2002)                   palm (end                   established
                                    forest                    allocation                  (after 2004)
                                                  of 2002)                 (after 2004)
                                 conversion                     (2003)
     Malaysia         3,67           33%           1,21          3,74         0,07            0,02
     Indonesia        3,10           66%           2,05          9,13         6,03            3,98
     Total            6,77          48%            3,26         12,87         6,10            4,00

If the palm-oil plantation is planned on peat swamp tropical forest, which is promoted as large
carbon sink, forest fires necessary for land clearance would emit approximately 8000 tons of GHG
per km2, drained peat-swamp land will additionally release about 1000 tons/km2/year of GHG
emissions, mostly CO2, for period of 5 years needed for complete drainage. It is estimated that in
the whole of SE Asia about 7 million ha of peat lands are drained now, mainly for palm-oil
cultivation purposes. In that case the drained peat lands used for agriculture in SE Asia will
contribute to about 0.35-0.7 gigaton CO2/year, or about 5-10% of the total yearly worldwide CO2
emissions [9].
As oppose to this problems with land clearance and competition of conventional biodiesel crops
with food sector, algae cultures could be grown even in desert regions and some brackish waters
locations, as well as at the sea near the cost. All of these projects would be placed aside the existing
industry because of necessary CO2 input from power plants. Aside that, algae cultures have
significantly greater yield than terrestrial crops making in that way lesser arable land needed for the
same amount of biodiesel produced.


6.      CONCLUSION

In the global trend of increased primary energy consumption and large carbon dioxide emission into
the atmosphere, it is necessary to raise production of energy from renewable resources, as well as
promote cleaner alternative fuels than oil refined products. Due to EU Directive of 5,75% biodiesel
share aim until 2010, in total diesel market, EU Member States are facing difficulties to fulfil these
obligation because of insufficient arable area needed for crop cultivation, especially for states which
are populous or have unfavourable climatic conditions. It is certain that goal of 5,75% until 2010.
and finally 8% till 2020 would not be possible just relaying on domestic rapeseed production which
will result in increased import of bio-oil, especially palm crude oil from SE Asia. Some estimations
give share of at least 20% until 2010 or even more, regarding lower market price of palm oil than
rapeseed. Production of palm oil is related with deforestation and peat drying which emit large
quantities of carbon dioxide into the atmosphere which is contrary to biodiesel appellation as CO2
balanced fuel. Unlike biodiesel produced from terrestrial crops, microalgae have greater yield per
area for the same amount of energy produced. Moreover, they can be even cultivated in arid and
warm regions where there is no huge impact on environment or competition with food sector for
arable area. Likewise, to produce algae biodiesel, on economically favourable conditions, it is
needed that outside CO2 source is introduced into the system. Algae production plants should be
placed near large fossil fired power plants or any other industry that emits carbon dioxide. In this
way, not only that alternative clean transport fuel is produced, but CO2 is permanently sequestrated
by means of biofixation.
REFERENCES

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[8]    UNEP (1999). Levine, J.S.; Bobbe, T.; Ray, N.; Singh, A.; Witt R.G.: Wildland Fires and
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