January 2010 Vol. 237 No. 1
From the Burner Tip
Liquid Fuels From Algae Show Many Advantages
Algae – black, slimy, and obnoxious – just may be the next black gold of energy products, especially for liquid fuels! While other agriculture products have gotten a head start as possible replacements for crude oil, the best candidate currently is one of the lowest forms in the plant kingdom, algae.
For well-known reasons ranging from perceived running out of crude oil to placating environmentalists, there is a current demand to find new, renewal fuel sources. Ethanol as an additive to gasoline and various biodiesels from different agricultural products have taken center stage in efforts to date. Ethanol has many disadvantages from efficiency to economics and none of the agricultural oils have sufficient oil production to meet the requirements for replacing fossil fuels.
Algae, especially the microalgae which are organisms less than 0.4mm in diameter and capable of photosynthesis as opposed to larger algae such as seaweed, has shown such promise that many large and small companies have active programs to commercialize fuel from the plant. The list of advantages continues to grow as more work is done to make the product commercial. The advantages of microalgae come from its simple structure, the ability to genetically engineer many its properties, its fast growth rate, and perhaps most important, its high oil content for certain species. Additional benefits are possible as growing algae takes large quantities of carbon dioxide, which can be obtained from power plants, and other large fuel consumers’ exhaust stacks. Also, water for production can be of low quality, allowing the use of wastewater and sewage effluents.
Most people think of algae as an environmental nuisance and, in more extreme cases, as an environmental threat. While there are some fears that as a commercial enterprise, raising algae could have environmental dangers, under proper conditions and practices this should be of no concern. Further, environmentalists accept biofuels though they give off the same carbon dioxide as fossil fuels when burned. The difference is biofuels take up carbon dioxide in their growth so that on combustion there is no new carbon dioxide put into the environment. Fossil fuels release carbon dioxide from historical times and add to the current balance.
With proper genetic design, microalgae can produce high amounts of oil very similar to crude oil for the production of various fuels ranging from gasoline and diesel to jet fuel. The oil produced can easily be processed in existing refineries to make commercial products. Different from other agriculture products, algae now play no role in the food chain and would not be in competition for food uses. This is a major problem with ethanol, which competes for corn used in food products.
The potential volume of oil possible from algae compared to other bioproducts might be its most important feature. Algae feeding on sunlight, a little carbon dioxide and nutrients, grows at incredible rates. Some species can double their population twice a day and some can produce extraordinary amounts of oil. Nick Hodge in the publication, Green Chip Stocks, July 2008, gives the following information on oil from various agricultural crops.
More current information has some producers (Valcent Products in California) claiming oil yields as high as 150,000 gallons per acre. The oil, which is the lipids in the algae, could go to a refinery for fuel production while the carbohydrates could be fermented and made into ethanol and other products.
The overall process of growing algae and producing the oil are relatively simple. The algae are grown in open ponds, giving it exposure to sunlight. Most of the companies developing algae for fuel are using clear plastic tubes called “Bioreactors” for growing the “crop”. The nutrient-laden aqueous slurry of algae is pumped through the tubes while exposed to sunlight (making the reactors “PhotoBioreactors”). Concentrated carbon dioxide is pumped into the tubes to increase production. Major nutrients are nitrogen, phosphorus and potassium, the normal constituents of regular agriculture fertilizer. Trace nutrients such as iron and silica are claimed to play an important role in growth.
Water quantity and quality are a plus factor in algae growth. The amount of water needed is relatively small. Some data indicate as little as 16 trillion gallons of water would be needed to make 60 billion gallons of biodiesel per year, the diesel demand in the U.S. According to the same source, Green Chip Stocks advisory information, the amount of water needed in the U.S. for its corn crop is 4,000 trillion gallons per year.
Equally important is the water quality. Brackish, saline or even wastewater can be used. In the poorer water quality sources, the contaminates could be a source of nutrient. Like placing the algae plant next to facilities with large combustion volumes to capture the carbon dioxide, it might be beneficial to place it near a sewer plant to take advantage of cleaning the waste streams.
Once the algae “crop” is mature – anywhere from one to 10 days depending on the algae strain, it is then harvested and the oil phase (the lipids) separated from the slurry and solids. Typically, large centrifuges are used but this is a relatively high cost part of the process. Once the oil is separated, it can then be processed and refined like other hydrocarbon oils.
Different companies are looking at other processes for oil separation and this could contribute significantly to lowering the cost.
Estimates for biodiesel production is around $10 per gallon compared with diesel costs of $2 per gallon. Genetically engineering higher oil strains of algae and improved processing methods are objectives in ongoing research and development programs.
The list of companies working with algae to develop new fuel sources continues to grow. In addition to some of the major energy companies having active programs-including those with smaller companies as a joint effort-many non-energy companies are also exploring the possibilities. In addition to fuel, some are interested in using the oil as raw material in their own list of products that now rely on fossil fuels for feedstocks.
Among the major energy companies with known algae development program are the following:
- BP in a joint project with Martek
- Chevron with Solazyme
- ExxonMobil with an investment of $600 million in Synthetic Genomics
- Indian Oil, India’s largest company, in a joint project with PetroAlgae
- Shell in a joint project with Cellana
Chemical giant Dow has a joint project with Algernol for algae development and consumer products company Procter & Gamble has a partnership with LS9 for algae development.
A partial list of smaller, independent companies working on algae for fuel development include:
- GreenShift Corporation (GERS.OB)
- Greenstar Star Pproducts (Pink Sheets: GSPI)
- Nanoforce Inc. (NNFC.PK)
- OriginOil, INC. (OTCBB:OOIL)
- PetroSun Inc. (Pink Sheets: PSUD)
- Valcent Products Inc. (OTCBB: VCTPF)
Some operations claim they will be commercial in a few years. The advantages of fuel from algae are so many with so few disadvantages that making liquid fuel from algae is a high-priority, high-potential play. Its advantages far outweigh ethanol as a biofuel and, with the potential yields as indicated, no oil crop can come close to the algae fuel output. Equally important is that algae production would not interfere with other agriculture crop production and algae farms could be located throughout the country. The biggest obstacles are scaling up to the size needed for fossil-fuel replacement and lowering costs.
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