ALGAE FUEL TECHNOLOGY-CONCEPT OF REVOLUTIONARY FUTURE

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1 International Journal of Applied Engineering Research and Development (IJAERD) ISSN Vol. 3, Issue 3, Aug 2013, TJPRC Pvt. Ltd. ALGAE FUEL TECHNOLOGY-CONCEPT OF REVOLUTIONARY FUTURE DIWESH MESHRAM 1, SHRIKANT THOTE 2, NAVNEET SINGH 3 & KAPIL PAKHARE 4 1 Department of Mechanical Engineering, DBACER, Nagpur, Maharashtra, India 2,3,4 Department of Mechanical Engineering, GHRAET, Nagpur, Maharashtra, India ABSTRACT In the latest development of engineering science and technology, the concept of the new alternative fuel was developed. The use of Algae based biodiesel will contribute in the reduction of the waste gases as used in petrol and diesel. As there is the tremendous demand for this product, maximum countries of New Zealand and Hawaii. The various production methods were also discussed in this paper. The concepts of the Compression Ignition Engine & photo bioreactors which generates the power in which the algae can be used as the alternate fuel, which reduces the cost and in support protect the Hazardous environment. With this new Algae fuel concept, the future biodiesel fuel can contribute extensively to the GDP of the individual country. KEYWORDS: Microalgae, Photo Bioreactor, Polyaromatic, SCRF INTRODUCTION As traditional oil prices continue to rise globally, the importance of alternative sources of oil or oil replacements will continue to increase. There area wide variety of options for replacing our current fuels with bio fuels produced from plant matter, including corn, switch grass, and sugarcane based ethanol, cellulosic ethanol, thermal de-polymerization, and biodiesel based on soy and algae. There are problems associated with each of these fuels, including: Energy balance, Competition with food crops, Economic viability, Environmental impact, Viability as a direct replacement for current fuels. Algae based biodiesel has the capacity to successfully meet all of these primary challenges to bio fuel adoption. Algae grows extremely quickly, and has a very high lipid content of as high as 77% in wild strains, allowing the production of around gallons of biodiesel per acre per year. For comparison, corn-based ethanol has the potential to produce around 328 gallons per acre of ethanol, or a mere 19 gallons per acre of biodiesel. Algae can readily grow in salt water unsuitable for use by typical food crops, and can be grown on marginal land with poor soil, or even of waste products such as sewage or CO2 emissions from power plants. Algae, due to its noncompetition with food cropland, high growth rate, ability to fixate large amounts of CO2, and potential to be grown from hazardous. Contaminants, has a very positive potential environmental impact. Finally, algae based biodiesel is similar enough to current biodiesel to be used as an immediate replacement. Current vehicles with diesel engines could use the fuel directly with no modification, allowing for the rapid incorporation of the alternative fuel into our existing fuel infrastructure and avoiding the chicken and the egg problem with alternative fuels. ALGAE-BASED BIODIESEL Algae-based biodiesel has the potential to produce over gallons of Bio-diesel per acre of land. Additionally, algae can be easily grown in a growth media composed primarily of seawater. Finally, because the algae is grown in liquid,

2 16 Diwesh Meshram, Shrikant Thote, Navneet Singh & Kapil Pakhare typically inside either a raceway or photo-bio-reactor, the algae can readily be grown on so-called marginal land land where either thenutrient content, salinity, or ph is inappropriate for terrestrial crop growth. Additionally, the energy content of biodiesel is typically around 33 MJ/L so to produce the 26.5 quads of transportation energy required in the U.S. will require 803L or 212 gallons of biodiesel. Thus, using the best current scenario of gallons per acre for algae based biodiesel, it is possible to completely meet the transportation needs of the United States using 15 million acres of land, none of which needs to be farmland. The energy balance of algae is less well established than for ethanol, as the total balance will depend in large part on the specific technologies chosen for the production. However, if we assume that algae based biodiesel is the same as for corn-based ethanol, we end up requiring 60 million acres of marginal land to give the United States a completely self-contained transportation fuel infrastructure. Using any terrestrial crop as a fuel source will inevitably lead to competition for farmland and fresh water with valuable food crops needed for the well-being of the world s population. The use of algae capable of growing on marginal land in water with high salinity is the only practical and closes to commercially viable biofuel in this respect. Figure 1: Algae Process for Biodiesel Production ALGAE CULTIVATION Algae can produce up to 300 times more oil per acre than conventional crops, such as rapeseed, palms, soybeans, or jatropha. As algae have a harvesting cycle of 1 10 days, it permits several harvests in a very short time frame, a strategy differing from yearly crops. Algae can also be grown on land that is not suitable for other established crops, for instance, arid land, land with excessively saline soil, and drought-stricken land. This minimizes the issue of taking away pieces of land from the cultivation of food crops. Algae can grow 20 to 30 times faster than food crops (Figure 1) PHOTO-BIOREACTORS Most companies pursuing algae as a source of bio-fuels are pumping nutrient-rich water through plastic or borosilicate glass tubes (called "bioreactors" ) that are exposed to sunlight (and so called photo-bioreactors or PBR). Running a PBR is more difficult than an open pond, and more costly, but may provide a higher level of control and productivity. Algae farms can also be set up on marginal lands, such as in desert areas where the groundwater is saline, rather than utilize fresh water. They can also be grown on the surface of the ocean.

3 Algae Fuel Technology-Concept of Revolutionary Future 17 Figure 2: Photo Bioreactors Because algae strains with lower lipid content may grow as much as 30 times faster than those with high lipid content, the difficulties in efficient biodiesel production from algae lie in finding an algal strain, with a combination of high lipid content and fast growth rate, that isn't too difficult to harvest; and a cost-effective cultivation system (i.e., type of photo-bioreactor) that is best suited to that strain. There is also a need to provide concentrated CO 2 to increase the rate of production. (Figure 2) CLOSED LOOP SYSTEM Another obstacle preventing widespread mass production of algae for bio-fuel production has been the equipment and structures needed to begin growing algae in large quantities. Maximum use of existing agriculture processes and hardware is the goal. In a closed system (not exposed to open air) there is not the problem of contamination by other organisms blown in by the air. The problem for a closed system is finding a cheap source of sterile CO 2. Several experimenters have found the CO 2 from a smokestack works well for growing algae. To be economical, some experts think that algae farming for biofuels will have to be done as part of cogeneration, where it can make use of waste heat, and help soak up pollution. OPEN POND SYSTEM Open-pond systems for the most part have been given up for the cultivation of algae with high-oil content. Many believe that a major flaw of the Aquatic Species Program was the decision to focus their efforts exclusively on open-ponds; this makes the entire effort dependent upon the hardiness of the strain chosen, requiring it to be unnecessarily resilient in order to withstand wide swings in temperature and ph, and competition from invasive algae and bacteria. Open systems using a monoculture are also vulnerable to viral infection. The energy that a high-oil strain invests into the production of oil is energy that is not invested into the production of proteins or carbohydrates, usually resulting in the species being less hardy, or having a slower growth rate. Algal species with lower oil content, not having to divert their energies away from growth, have an easier time in the harsher conditions of an open system. Some open sewage ponds trial production has been done in Marlborough, New Zealand. Research into algae for the mass-production of oil is mainly focused on microalgae; organisms capable of photosynthesis that are less than 0.4 mm in diameter, including the diatoms and cyanobacteria; as opposed to macroalgae, such as seaweed. The preference towards microalgae is due largely to its less complex structure, fast growth rate, and high oil content (for some species). However, some research is being done into using seaweeds for biofuels, probably due to the high availability of this resource. The following species listed are currently being studied for their suitability as a mass-oil producing crop, across various locations worldwide: Botryococcus braunii, Chlorella, Dunaliella tertiolecta, Gracilaria, Pleurochrysis carterae (also called CCMP647), Sargassum, with 10 times the output volume of Gracilaria.

4 18 Diwesh Meshram, Shrikant Thote, Navneet Singh & Kapil Pakhare The amount of oil each strain of algae produces is extremely different. To put it in perspective a list of microalgae and its various oil yields are listed below: Ankistrodesmus TR-87: 28 40% dw; Botryococcus braunii: 29 75% dw; Chlorella sp: 29%dw Chlorellaprotothecoides(autotrophic/heterothrophic): 15 55% dw; Cyclotella DI- 35: 42%dw Dunaliella tertiolecta : 36 42%dw; Hantzschia DI:160: 66%dw; Nannochloris: 31(6 63)%dw Nannochloropsis : 46(31 68)%dw; Nitzschia TR-114: 28 50%dw Phaeodactylum tricornutum: 31%dw; Scenedesmus TR-84: 45%dw; Stichococcus: 33(9 59)%dw Tetraselmis suecica: 15 32%dw; Thalassiosira pseudonana: (21 31)%dw Crypthecodinium cohnii: 20%dw; Neochloris oleoabundans: 35 54%dw; Schiochytrium 50 77%dw In addition, due to its high growth rate, Ulva has been investigated as a fuel for use in the SOFT cycle, (SOFT stands for Solar Oxygen Fuel Turbine), a closed-cycle power generation system suitable for use in arid, subtropical regions. Figure 3: Flow Diagram of Raceway Figure 4: The Raceways The raceway is an open pond which requires little capital investment and is very simple to operate. (Figure 4) ALGAE WILL REPLACE PETROLEUM WITH BIODIESEL, BIOGASOLINE, AND EVEN PLASTIC Here are some important products that can be derived from processing petroleum OR algae: Gasoline (biogasoline)

5 Algae Fuel Technology-Concept of Revolutionary Future 19 Diesel fuel (biodiesel) Jet fuel (aviation biofuel) Plastics (bioplastic) The algae-based fuels (and plastics) work just as well as the petroleum-based fuels, and can be used in existing engines without any modification. Engines will run the same and burn cleaner (although they still emit CO2). Of course algae and petroleum aren t exactly the same. Petroleum can be processed to get: tar, asphalt, and pesticides. Algae can be processed to get: nutrients, animal feed, and vegetable oil. Biofuels (like biodiesel) can be produced from any biomass (like corn, soy, or even wood chips). However, the efficiency (in terms of oil yield per acre) of algae is astronomical compared any other feedstock. (Figure 5) Figure 5: Production Cycle of Algae Bio Fuels ALGAE BIODIESEL VS. CONVENTIONAL DIESEL: COMPARISONS AND TRADEOFFS There is a lot of current research and development to push algal biofuels toward commercialization as a replacement for existing fossil fuels - namely diesel and jet fuel. But is algal biodiesel really the same as conventional diesel? As you probably know, biodiesel refers to fuels comprised of mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats [1]. In general, biodiesel has similar properties to fossil-fuel derived diesel fuel and can be used in existing diesel engines. There are, however, some key differences and tradeoffs to be considered for the use of algal biodiesel. The purpose of this post is to highlight and describe those differences. But first, some basics - an overview of the diesel engine (Figure 6) and fuel production processes of diesel and algal biodiesel.

6 20 Diwesh Meshram, Shrikant Thote, Navneet Singh & Kapil Pakhare COMPRESSION IGNITION ENGINE OPERATION The Compression Ignition (CI) or diesel engine operates on a four-stroke cycle similar to a gasoline engine, except that the combustion takes place via autoignition of the fuel in compressed air instead of by a spark from a spark plug. The components of the combustion system in the CI engine include an intake and exhaust valve, to allow air to flow in and exhaust gases to flow out, respectively. It has a direct fuel injector to inject fuel into the combustion chamber. The valves and injector are located in the cylinder head, which is positioned above the piston. The piston is enclosed with cylinder walls, completing the boundary of the combustion chamber. When the position travels laterally up and down the cylinder, it transfers its linear mechanical energy to rotational mechanical energy via a rotating crankshaft. Figure 5 illustrates each component of the system. The Compression Ignition (CI) or diesel engine operates on a four-stroke cycle similar to a gasoline engine, except that the combustion takes place via auto ignition of the fuel in compressed air instead of by a spark from a spark plug. The components of the combustion system in the CI engine include an intake and exhaust valve, to allow air to flow in and exhaust gases to flow out, respectively. It has a direct fuel injector to inject fuel into the combustion chamber. The valves and injector are located in the cylinder head, which is positioned above the piston. The piston is enclosed with cylinder walls, completing the boundary of the combustion chamber. When the position travels laterally up and down the cylinder, it transfers its linear mechanical energy to rotational mechanical energy via a rotating crankshaft. Figure 5 illustrates each component of the system. Figure 6: Diagram of Diesel Combustion System [21] The cycle starts with the piston at top dead center (TDC). The intake valve opens as the pistons moves down the cylinder, pulling in fresh air (and possibly some re circulated exhaust as described in later sections). The next stroke begins with the piston at bottom dead center (BDC). Both valves are closed as the piston moves up the cylinder, compressing all of the air into a small space, drastically increasing its temperature and pressure. The third stroke begins as the piston approached TDC again, and the fuel injector quickly pumps fuel into the chamber. The fuel auto ignites from the high temperature in the compressed air, transforming its chemical energy into heat energy. The heat energy is transformed into mechanical energy as is pushes the cylinder back down to BDC. The fourth stroke begins with the piston at BDC. The exhaust valve opens as the piston moves up the cylinder, pushing the combustion products out of the chamber. Then the cycle starts all over from the beginning. An animation of the cycle can be found here. PRODUCTION OF FOSSIL-FUEL DERIVED DIESEL Conventional diesel fuel (and other petroleum products) starts as crude oil pumped from the ground. Crude oil is a mixture of hydrocarbon molecules of varying sizes. A process called fractional distillation is used to separate the molecules using their inherent nature of having different boiling points. A fractional distiller is essentially a large vertical furnace in

7 Algae Fuel Technology-Concept of Revolutionary Future 21 which crude oil is heated in progressively hotter chambers, each of which route the resulting gases into separate condensers and containers. In this way diesel, gasoline, kerosene, and other oil products are separated from the crude oil feedstock. The distillation temperature for diesel fuel is in the range of 250 o C o C [2]. PRODUCTION OF ALGAL BIODIESEL In the case of algal biodiesel, the fuel is harvested and processed from oils contained in three main types of algae: microalgae, cyano bacteria, and macro algae. Algae are naturally composed of three main components: proteins, carbohydrates, and lipids. It is the lipids (fatty acids) that are the source of the fuel. While there are several extraction and conversion methods currently being researched, a common method is harvesting of microalgae via filtration, drying the algae to reduce water content, pressing the resulting algae to remove the oil, and then converting the oil to biodiesel through chemical transesterification. ANALYSIS OF FUEL CONSIDERATIONS The comparison of fuels used in transportation should include a wide variety of performance indicators that have a direct impact on engines, consumers, and the environment. A fuel that seems far superior in one category could have clear disadvantages when evaluated in another category. Societies must consider these tradeoffs when investing in the infrastructure required for the mass production and distribution of transportation fuels. Here, the performance of diesel and algal biodiesel characteristics are compared in seven categories: availability, cost, ease of use, energy properties, physical properties, safety, and emissions. AVAILABILITY According to BP, global crude oil reserves are about 1333 billion barrels [3]. According to the same source, the world is consuming over 84 million barrels of oil per day. At the current rate of consumption (and assuming no new discoveries), this reserve will last 15,855 days, or about 43 years. In addition, the majority (56.6%) of proven reserves are in the Middle East, with only 5.5% of reserves in North America [3]. This is clearly an unsustainable trend. Energy is a major factor in the average standard of living, and upcoming scarcity of fossil fuels has the potential to cause major political upheaval and regional conflict in the next few decades. In the short term, diesel fuel is widely available (at least in the developed world). All gasoline stations have pumps dedicated to diesel fuel, and a widely developed infrastructure exists to produce and distribute diesel fuel to stations and consumers. On the contrary, biodiesel derived from algae is not yet commercially available on a widespread basis, even as millions of research dollars and many young start-up companies are trying to develop cost-effective production methods. It is noteworthy that the US Navy recently purchased 1500 gallons of algal jet fuel for testing and certification [4]. Unlike traditional biofuel feed stocks which require lots of land and fresh water, algae is unique in that it doesn t have to be grown on arable land or require much fresh water. Algae can be grown in bioreactors on arid or non-arable land or in large farms offshore. It can also be grown in brackish water. This means that it can be produced locally or regionally. This benefit would reduce the world s reliance on a few nations for oil and reduce the need to transport crude around the world. If and when biodiesel from algae is ramped up to larger scale production, it could be distributed using the existing diesel infrastructure. Although biodiesel yields vary by species, environment, and location, here is a rough order of magnitude calculation to determine how much area might be required to grow enough algae to replace all diesel consumption in the US. In 2008, the US consumed over 41 billion gallons of diesel for on-road transportation [5]. According to a recent study,

8 22 Diwesh Meshram, Shrikant Thote, Navneet Singh & Kapil Pakhare producers can practically expect a yield of about gallons per acre-year from algae [6]. Dividing 41 billion by this yield range shows that 10,900 14,400 square miles would be required to produce enough biodiesel to replace all onroad transportation needs in the US. This is roughly the size of the state of Maryland. COST The cost of conventional diesel fuel in the last 16 years has ranged between $1/gallon and $4.70/gallon, with the current price just under $4/gallon. Figure 7 shows the pump price of diesel fuel from June 1994 through March 2011 [7]. Figure 7: Average Pump Price of Diesel Fuel in the U.S. from June 1994 through March 2011 [7] While the price has been volatile in recent years, it is still less than biodiesel production from algae. Since there are no large-scale production facilities of algal biodiesel, an accurate comparative cost per gallon is difficult to estimate. Some rough estimates put the current production price at around $50/gallon [8]. However, an anecdotal comparison can be made to algal jet fuel, which is farther along the path to commercialization. In February 2010, the Defense Advanced Research Projects Agency (DARPA) announced plans to build a large-scale algal jet fuel facility by It expects the production price to be under $3/gallon [9]. If this becomes a reality, and similar large-scale operations could be developed to produce biodiesel, it will be competitive in the marketplace. EASE OF USE & COMPATIBILITY Since biodiesel fuel can be provided to the customer through the existing diesel infrastructure, there would be no difference in convenience or refueling time to a consumer. Since most newer diesel engines are designed to accept lowsulfur diesel fuel and biodiesel blends up to 20% (B20), most consumers can use biodiesel in their existing diesel engines without any modification. However, in higher percent blends like B100, it is possible that certain natural rubber seals or hoses could degrade at an increased rate [10]. People who make the switch to B100 should check with the manufacturer to determine if any engine modifications are necessary. However, if it becomes clear that biodiesel is becoming more common in the marketplace, auto makers will inevitably start considering that in the design process so that diesel engines would be able to accept B100 blends with no modification. ENERGY PROPERTIES Energy-related properties of biodiesel should be considered when comparing to conventional diesel. One of the most important properties is cetane number. This is the measure of a fuel s ignition delay, or the amount of time between the start of fuel injection and the start of combustion. A higher cetane number corresponds to a shorter ignition delay, so for diesel fuel a higher cetane number is generally better, since a shorter ignition delay will increase the cutoff ratio α and thus increase engine efficiency based on the equation for diesel cycle thermal efficiency:

9 Algae Fuel Technology-Concept of Revolutionary Future 23 The cetane number in conventional diesel varies between 40 and 45 in the US. The cetane number in biodiesel depends on feedstock, but usually varies between 45 and 67 [11]. A recent study of algal biodiesel reports a cetane number of 52 [12]. The increased cetane number in algal biodiesel will have a positive effect on engine efficiency. Another important property of a fuel is its energy density. This matters because the higher the energy density, the better the fuel economy one can expect from the fuel, and the longer the range that can be achieved per tank. The energy density of conventional diesel is about 43.1 MJ/kg, or 35.9 MJ/L [13]. For biodiesel, this property also varies by feedstock. The same recent study of algal biodiesel reports an energy density of 40 MJ/kg, or MJ/L [12]. This is about 7% less energy by mass, or 11% less by volume than conventional diesel. Some proponents of algal biodiesel report that some of these energy losses are offset by the higher combustion efficiency and better lubricity such that overall fuel economy (and range) is only decreased by 2% [14]. If this is true than decreases in fuel economy and range from algal biodiesel would be barely noticeable to the average driver. Performance on some detailed calculations surrounding the adiabatic flame temperature of combustion in each fuel. The thermodynamics can get a little eye-glazing, so I m not including the details but they are here if you are interested. In summary, the flame temperature of conventional diesel is 2831 K, while the flame temperature from algal biodiesel is only slightly higher at about 2855 K. In theory, this slight increase in temperature indicates a slightly higher increase in efficiency, and might also result in increased NOx emissions (since NOx are formed in atmosphere at high temperatures). However, the relative temperature difference is so small that an actual difference in efficiency and NOx emissions may not be measurable. PHYSICAL PROPERTIES There are some important physical characteristics of biodiesel that should be considered when comparing with conventional diesel fuel. These properties include lubricity, API gravity, and cloud point. In diesel engines, the fuel is what lubricates the fuel injection pumps and injectors. The lubricity of a fuel is the measure of the wear or scarring that occurs between two metal parts covered with the fuel as they contact each other. Better lubricity results in less wear and scarring. Lubricity is generally measured by the wear scar diameter (WSD) that results on a specific test rig. The lubricity of conventional diesel is 536 microns, whereas B100 has been measured at 314 microns, an indication of better lubricity [15]. The API gravity and its inverse specific gravity are basically a measure of fuel density, and can be used to provide an indication of how the density of a fuel varies with temperature. Studies have shown that the density of biodiesel varies in a linear fashion that is very similar to conventional diesel [16]. The cloud point is the temperature below which wax molecules in the diesel fuel begin to solidify, potentially resulting in gelling of the fuel. Gelling is a serious functional problem since it reduces or eliminates the ability of the fuel to flow through the injection system essentially not allowing the engine to run. The cloud point of conventional diesel varies, but can be as high as -15 C Fuel additives, electric engine block or fuel warmers, and heated garages are commonly used in colder climates to work around this problem. The cloud point in biodiesel also varies, but is generally higher than conventional diesel. A recent study shows the pour point of algal biodiesel to be -14 C, which corresponds to a cloud point of about -11 C to -8 C [12]. A switch to algal biodiesel would require the adoption of the same workarounds to a wider section of the population.

10 24 Diwesh Meshram, Shrikant Thote, Navneet Singh & Kapil Pakhare SAFETY Safety is obviously an important consideration when analyzing a fuel. Important measures of fuel safety are its stability, flame visibility, and flash point. Fuel stability can refer to thermal, oxidative, and storage stability. The most common comparison between biodiesel and diesel is oxidative stability, or the tendency of the fuel to react with oxygen at near-ambient temperatures. Biodiesel is more prone to oxidation because of the increased proportion of carbon-carbon double bonds. Oxygen atoms can more easily bond with adjacent carbon atoms, forming a hydro peroxide molecule. This reaction reduces molecule chain length, which can reduce the flash point, cause undesirable odors, and cause the formation of sediments in the fuel. ASTM D2274 test standards are usually used to measure stability in diesel fuel. However, this test is not adequate to measure biodiesel stability because of its incompatibility with the filters used in the test [17]. This instability should continue to be a focus of improvement for biodiesel. Stability can be improved through the manufacturing process and by the use of fuel additives or blends [18]. Flame visibility is simply how well you can see a flame resulting from the combustion of a fuel. It is more commonly a concern in industrial environments. The literature on flame visibility of diesel and biodiesel is thin. This suggests that there is likely not much of a difference in this factor. At ambient temperatures, a fuel can mix with the surrounding air and become ignitable, causing a serious safety concern. The temperature at which this mixing begins to occur is called the flash point. A higher flash point is safer. The flash point of conventional diesel fuel is 52 C [19]. The flash point of algal biodiesel is around 98 C [12]. Biodiesel is therefore better in regards to the flash point, presenting a very low fire hazard. EMISSIONS With so many vehicles on the road, tailpipe emissions are important to consider since they influence human health, quality of life, and global warming. The EPA produced a report in 2002 that compared emissions of various blends of biodiesel with conventional diesel. For B100, they found that biodiesel produced 67% less hydrocarbons, 48% less carbon monoxide, 47% less particulate matter, 80% less polyaromatic hydrocarbons, and 10% more NOx [20]. Figure 8 is from the EPA report and shows the relation between emissions and biodiesel blend percent. Figure 8: The Effect on Exhaust Emissions for a Range of Biodiesel Blends [20] Biodiesel also produces no sulfate emissions since it does not contain sulfur, unlike conventional diesel. The higher oxygen content in biodiesel results in a higher combustion efficiency, which increases the combustion temperature and thus increases the amount of NOx emissions, since NOx are only formed above approximately 1500 C. The CO2

11 Algae Fuel Technology-Concept of Revolutionary Future 25 emissions from biodiesel combustion are the same as that from conventional diesel. However, since the CO2 in biodiesel was captured through the process of photosynthesis in the feedstock, the algal biodiesel has an overall life-cycle CO2 impact that is less than conventional diesel, assuming the CO2 emitted in the processing of the biodiesel is less than the CO2 saved. The relative value of each emission species is debatable, but overall the biodiesel has a clear advantage when it comes to emissions. Regardless of the fuel used in a vehicle, there are two basic ways to reduce emissions: pretreatment or after treatment. It is noteworthy that diesel engines have traditionally not been treated, and therefore have higher polluting emissions than gasoline engines. In the last decade, the US has implemented low-sulfur regulations in diesel. Now all diesel fuel must meet the standard of having less than 15 ppm of sulfur. This is an example of pretreatment, where pollutants are removed from the fuel before it is burned. Another example of pretreatment is exhaust gas recirculation (EGR), where a portion of the exhaust stream is routed back into the intake of the engine and fed into the combustion chamber. This has the effect of lowering the flame temperature of the combustion event. Exhaust gas is able to absorb more heat energy from the combustion event than air since it is composed of inert tri atomic molecules. This technology is common in diesels manufactured today. Another technology that increases the combustion efficiency and reduces pollutants is better fuel injection technology that uses higher pressures and pulsed injection, helping the fuel mix with the air more rapidly and evenly. After treatment is when pollutants are removed after combustion, in the exhaust stream. One potential after treatment device for diesel engines are particulate matter traps. This comes with a tradeoff in efficiency and cost since traps block the flow of exhaust gases, thus the need for two separate traps and a mechanism to switch between the two when one is sufficiently full and needs to have the particulates burned off. Another potential after treatment method involves the addition of urea to the exhaust gas stream, followed by a Selective Catalytic Reduction (SCR) converter. Through a complex series of reactions, the doping urea and the catalyst turn much of the NOx emissions into water and nitrogen. OVERALL ECONOMICS Even Chisti s more optimistic recent study suggests a cost of $2.80 /L for algae-based biodiesel using 30% lipid content strains grown in photo-bioreactors. Similarly, a 70% lipid content strain might have a cost as low as $1.20 /L. This is still higher than the $0.81 /L target at which it is directly competitive with gasoline. For comparison, palm oil can produce biodiesel at a cost of around $0.66 /L, and should be currently competitive with gasoline. Although palm oil is cheaper than algae-based biomass currently, as a terrestrial crop palm oil has the same problems as corn in terms of competing with food crops and a fundamental limit to the amount of land area available. Algae, due to its ability to use marginal land, its high productivity, and its high photo-synthetic ciency, remains the only feasible way to replace our entire fuel infrastructure with a closed system that does not require foreign sources of energy. If the potential price of algae-based biodiesel is actually as low as Chisti estimates, then it is very likely that in the next 5-10 years we could expect that between technological advancements and a continued increase in the price of oil, algae will become a viable direct competitor to oil. In particular,if gasification is proved to be a viable option for converting algae biomass into hydrogen, methane, or directly into liquid fuels, the price of algae-based biodiesel grown in photo-bioreactors will likely drop below gasoline. For the case of open pond systems, it seems very likely that due to the immensely lower capital costs that it may already be less expensive to pro-16 duce than using imported oil. The DOE estimated that open ponds may already be able to produce gasoline at a cost of $1.70/gallon ($0.45/L), which is already cheaper than both gasoline and biodiesel farmed using palm oil.

12 26 Diwesh Meshram, Shrikant Thote, Navneet Singh & Kapil Pakhare Overall, this suggests that it is inevitable that algae-based biodiesel will become the best available option for growing bio-fuels. Photo-bioreactors from high capital costs (in particular, the cost of polycarbonate tubes) while being beneficial in terms of land usage, productivity, and harvesting costs. However, open ponds may already be economically favorable compared to the current price of oil. Much of the current work being done in the field of alga culture is focused on photo bioreactors. Many recent papers have suggested that despite their higher capital costs, photo bioreactors are less costly per unit of biomass to grow and harvest than open ponds. However, the DOE report on open ponds suggests that those costs may actually end up being lower. It seems that we should investigate further over the next several years which of these routes will result in lower actual costs when implemented on a large scale. One huge problem with photo-bioreactors is that the large capital costs are largely in materials costs (polycarbonate, etc). When implemented on a very large scale, it may become impossible to meet those requirements at all, much less meet them economically. Another serious problem with algae, as well as with all bio fuels, is the relience on fertilizers to grow. Algae, for example, have less than 1% phosphate. However, to meet the full needs of our transportation infrastructure in the United States would require (given the best caps 70% lipid content strains) 1_1012 kg of algae biomass. Suddenly, 1% of that mass is an extremely large number 11 million tons of phosphate fertilizers like ammonia (and this is an optimistically low number). Current US production of phosphate is only 40 million tons, with current thinking being that we are already limiting food production due to a lack of enough phosphate. Thus, it is also clear that on a very large scale, we will have to find a way to recover phosphate from our farming. With latest rounds of investments announced for Asia, Algae research and developments are gaining interest as companies race to develop and validate technology solutions for the commercial production of algae. With the involvement of agribusiness and big food conglomerates like the Salim Group, it s evident that algae focus has expanded beyond fuels and into foods, feed and fertilizers industry. Analysts say that over the next few years, a number of algal companies will hinge on to the feed and food sectors, en route to entering fuels. Yet, many established companies are focussed on feed and food. While these are smaller markets than fuels, they offer vast opportunities, and higher per-ton prices. One promising market is astaxanthin estimated to be worth $200 million by 2015 Microalgae are a highly promising resource for the sustainable production of a wide variety of biomaterials for a wide range of applications and Asia represents a promising market. Figure 9: Could Algae & Seaweed Production in India be Explored as Potential Source for Biofuels?

13 Algae Fuel Technology-Concept of Revolutionary Future 27 To spotlight on demand for astaxanthin products is Dr. Sebastian Thomas, Technical Advisor, Parry Nutraceuticals with his session entitled Commercial production of Astaxanthin by large scale cultivation of Haematococcus pluvialis Prospects and Concern. Besides microalgae, macro algae commonly known as seaweed, also has a variety of applications - as a food source, fertilizer and other industrial applications. Managing Director of Aquagri Processing Pvt Ltd, Abhiram Seth will elaborate more on seaweeds and algae at the conference, in his session Looking Beyond Carraggeenan, from Red Sea Weeds and Algae Algae biofuel could be the answer to India s energy crisis, as coal and liquefied natural gas may not be able to meet the demand. Over 99% of commercial algae biomass produced globally are mainly from seaweeds farmed near the seashore. Algae can be used as a source for biofuel and bioethanol, as well as in the production on hydrogen (used in fuel cells) and methane (Figure 9). The US Department of Energy s (DOE), National Algal Biofuels Technology Roadmap foresees a vital role for algae in the coming years, in energy management. Between now and 2020, developed countries will embark on large scale production of algae based biofuels. Meanwhile, in India, the development of technology and engineering practices for production of algae biofuel is in its initial stages. Some salient features that prove advantageous for algae in India include diversity, vast coastline, sufficient solar energy, does not compete with food crops for land availability, can grow in places away from forests, thus reducing the damages caused to the eco-and-food chain systems. Algae biofuel could therefore present a great opportunity. At the 5th Algae World Asia in Singapore on November, and in his talk entitled India -Microalgae Cultivation using Industrial and Agricultural Waste Streams for the Production of Biofuels, Senthil Chinnasamy, Chief Technology Officer, Biotechnology Division at Aban Infrastructure Pvt Ltd will discuss at length on the production of biofuels from microalgae. At the 5th Algae World Asia in Singapore on November, and in his talk entitled India -Microalgae Cultivation using Industrial and Agricultural Waste Streams for the Production of Biofuels, Senthil Chinnasamy, Chief Technology Officer, Biotechnology Division at Aban Infrastructure Pvt Ltd will discuss at length on the production of biofuels from microalgae. ADVANTAGES TO ALGAE OIL PRODUCTION No need to use crops such as palms to produce oil. Algae Oil Extracts can be used as livestock feed and even processed into ethanol. A high level of poly unsaturated in algae biodiesel is suitable for cold weather climates. Grows practically anywhere. Can reduce carbon emissions based on where it s grown. CONCLUSIONS Algae-based biodiesel has a great deal of potential as a bio fuel. It does not compete with food crops, requires a very small amount of land, can be used to treat wastewater and absorb CO2 emissions, remove heavy metals and toxic chemicals from the environment, and is very likely to be competitive with oil in the near future. The primary issues which

14 28 Diwesh Meshram, Shrikant Thote, Navneet Singh & Kapil Pakhare remain with algae are finding technical and engineering solutions which allow for lower capital costs in building photo bioreactors which have a high productivity, or finding biological and engineering solutions which allow for better protection and processing of algae grown in raceway ponds. Estimates as to the price of algae-based biodiesel are expected to be $50-$100 per barrel (based on the National Renewable Energy Laboratory report from 1998) or $160 based on Chisti s estimate using raceway ponds. For photo bioreactors, the price is estimated to be between $122 (Chisti) and $800 (Dimitrov and Grima) for photo bioreactors. It is likely that the substantial di_erence in estimates for photo bioreactors is due to di_erent accounting of capital expenses in the plants, and will likely fall somewhere in between in actual implementation. Additionally, advanced processing methods may reduce the cost of biodiesel manufactured using either technology. REFERENCES 1. J Sheehan, T Dunahay, J. B. A Look Back at the U.S. Department of Energy s Aquatic Species Program Biodiesel from Algae, Technical Report, National Renewable Energy Laboratory, Y Chisti, Biotechnology Advances 2007, 25, Gopalakrishnan, Environment Science & Engineering 2006, 4, Amanda Leigh Haag, Nature 2007, 447, Pimentel, Encyclopedia of Physical Sciences and Technology M Gross, Current Biology 18, R R Muñoz, B. G. Water Research 2006, 40, G Knothe, Journal of the American Oil Chemists Society 2006, 83, J Struben, J. S. Forthcoming, Environment and Planning B. 10. Nate Hagens, At $100 Oil - What Can the Scientist Say to the Investor?, Energy Information Administration, Production and end-use data, 2002, Technical Report, Energy Information Administration, David Lide, Handbook of Chemistry and Physics;. 13. J Bourne, R. C. National Geographic Magazine 2007, J Deutch, J. S. National Security Consequences of U.S. Oil Dependency, Technical Report, Council on Foreign Relations Press, M Aresta, A Dibenedetto, G. B. Fuel Processing Technology 2005, 86,