The 11:00 session on Tuesday (2010-4-20) was about the development of microalgae as a biomass for biofuels. Micro aquatic crops such as duckweed, macroalgae, and microalgae are all currently being researched; this group of researchers, A. Darzins, L. Elliot, L. Laurens, E.J. Wolfrum, and M. Posewitz, is focused on microalgae. They mention the 30 year government study that researched algae based biofuels. This is the same government study that Ian Woertz talks about in his research article on algae based biofuels grown on wastewater streams. The government study ended in 1996. However, the program was essentially revived by the NREL in 2006. This study is continuing the research of that 30 year study. This new projects goal was to isolate and characterize microalgal strains utilizing high throughput techniques. They have research locations in Colorado, New Mexico, and several other locations elsewhere. Freshwater, brackish water, and saline/brine waters were brought back to the lab and they put one alga cell and 1 droplet into 96 well plate and allowed them to propagate themselves. High speed FACS sorting was utilized. They did clonal isolation and then used image positive brightfield microscopy. The green algae were found to be the most prominent, but many were fast growing. They currently think that the water vacuole in diatoms is lipids, but this remains a hypothesis for the time being. They are now working on a “bioprospecting project” using FACS, or florescence activated cell sorting. They are also studying high throughput methods for lipid extraction and identificaltion.
A recent article on Biodiesel Magazine’s website talks about the interaction between the truck-stop/travel plaza industry and the government in regards to the loss of subsidization for biodiesel. The National Association of Truck Stop Operators, NATSO, has sent a letter to several Congressmen, asking them to re-establish the subsidy for producing biodiesel that expired December 31, 2009. Three other groups joined NATSO in this effort: The National Association of Convenience Stores, the Society of Independent Gasoline Marketers of America, and the Petroleum Marketers Association of America. Lisa Mullings, the President of NATSO, claims that these groups are strongly “supporting U.S. environmental efforts.” Mullings says that, unfortunately, travel plazas are unable to make profits without this tax credit. Biodiesel production in the U.S. has dropped by 80% since the government dropped the credit in December. Since the government no longer provides biodiesel manufacturers with the $1/gallon credit, most of these manufacturers have simply added a dollar onto their price at the pump. Thos has led to a decrease in demand for biodiesel because most consumers do not want to pay an extra dollar per gallon when they could buy conventional diesel for less. If the subsidy were renewed, biodiesel production would once again be profitable.
While the truck stop industry is advocating for cleaner burning biofuels, a truck engine manufacturer, Cummins Inc., is now having to pay fines for some engines produced 4 to 12 years ago. According to Biodiesel Magazine, Cummins recently had to pay heavy fines because it failed to put proper emissions equipment on several of its engines produced in the 1998-2006 period. The settlement agreed upon was 2.1 million dollars. A total of 570,000 truck engines were sent to vehicle and equipment manufacturers without sufficient emissions control systems (which had been on the engines when the government tested them). These engines made by Cummins failed to meet the standards of the Clean Air Act. Some missing equipment included parts like diesel particulate filters and diesel oxidation catalysts. Cummins apparently expected the vehicle manufacturers to either make their own or purchase them separately.
On the flip side, a major car company, General Motors, is working together with the United States Department of Energy in an attempt to show that jatropha can produce sufficiently high yields of fuel to serve as a petroleum fuel alternative. Central Salt and Marine Chemicals Research Institute in India is starting two jatropha farms, one will be 39.5 acres in Bhavngar and the other a 93.9 acre plot in Kalol. This research institute is part of th Indian government and is lab-optimizing jatropha for fuel production. G.M. has a plant in Kalol and is supporting this research for their interests in the Indian car market; G.M.’s partnership with the Department of Energy in funding this project is largely due to their mutual interest in maximizing jatropha growth in temperate climates with frosts.
Summary of “Extraction of Hydrocarbons from Microalga Botryococcus braunii with Switchable Solvents” by Samori et al.March 25, 2010
In a paper published in Bioresource Technology in 2010, Samori et al. examine a new procedure for extracting hydrocarbons from Botryococcus braunii. Botryococcus braunii is a species of colonial, freshwater, green, microalga that holds high potential as a renewable biofuel source. Samori et al. divide biofuels into first, second, and third generations. According to the authors of this study, ethanol from sugar cane or corn and biodiesel from seeds are considered first generation biofuels; lignocellulosic fuels based fuels are second generation fuels; and, algae/ microalgae based biofuels are the third generation. The rationale behind placing algal fuels at the forefront of biofuel sources lies in algae’s more efficient light usage, ability to grow in otherwise unusable areas, potential to multitask by cleaning up waste water flows, and ease of genetic modifications. Furthermore, biodiesel produced from algae tends to be more readily usable than biodiesel from seed plants. Drawbacks of algal fuel sources include energy intensive harvesting procedures and high economic costs from pond operation and bioreactors according to Samori et al. Despite these hindrances, algae-based biofuels are an upcoming and promising source of energy and as such, should be researched.
One of the most challenging aspects of biofuel production is the extraction of lipids or hydrocarbons from the fuel source. Samori et al. central focus was the comparison of two different SPS systems’ (DBU/ethanol and DBU/octanol), DBU’s, and n-hexane/chloroform/methanol’s lipid extraction efficiencies. An SPS is a switchable-polarity solvent that is based on DBU; DBU is an acronym for 1,8-diazabicyclo-[5.4.0]-undec-7-ene. They found that the alcohol used with the DBU is essential to assembling the liquid carbonate anion. Total hydrocarbon yield was greatest with DBU/octanol (16 ± 2%), second best with DBU alone (15 ± 6%), and third with DBU/ethanol (12 ± 2%); n-hexane yielded only 7.8% (± 3%). All DBU systems posted fatty acid extraction yields in the 0.6 to 0.7% range, while n-hexane/chloroform/methanol yielded around 2.7%. After 4 hours, DBU/octanol and DBU/ethanol yielded similar quantities of hydrocarbons—14% and 13%. The cycle between non-ionic and ionic was done by bubbling CO2 gas through equimolar solutions of DBU/octanol and changing DBU-octylcarbonate salt to its non-polar variant with N2 gas. A hydrocarbon extraction efficiency of 81% was achieved with ionic/ non-ionic cycling. Samori et al. concluded that SPS are promising as a “green technology” for hydrocarbon extraction from dried and aqueous growth microalgal. DBU/octanol had the highest extraction efficiency in both dried and liquid algae samples. SPS are also promising because they serve as a non-hazardous hydrocarbon extraction method for small biofuel production indistries.
Samori, Chiara, Cristian Torri Giulia Samori, Daniele Fabbri, Paola Galletti, Franca Guerrini, Rossella Pistocchi, and Emilio Tagliavin. 2010. “Extraction of hydrocarbons from microalga Botryococcus braunii with switchable solvents.” Bioresource Technology. 3274-3279.
A 2009 study by Converti et al. studied two species of microalgae: Nannochloropsis oculata and Chlorella vulgaris. Both are considered phytoplankton. These algae range in size from 2 micrometers to 4 micrometers and are photosynthetic, eukaryotic microorganisms. Their lipid content serves as a source for biodiesel. Temperature and nitrogen concentration typically play a vital role in the growth and production of plants and photosynthetic life forms. The two species were grown at a central temperature for a control; other tests were run at 5ْْ C. above and 5ْ C. below the middle temperature. Nannochloropsis oculata had a central temperature of 20ْ while Chlorella vulgaris had a central temperature of 30. An additional temperature experiment was performed on C. vulgaris at 38 degrees Celsius. Lipid production of N. oculata was tested at 0.300 gL-1, 0.150 gL-1, and 0.075 gL-1 of nitrogen. Lipid production of C. vulgaris was tested at nitrogen concentrations of 1.50 gL-1, 0.750 gL-1, and 0.375 gL-1. N. oculata lipid content virtually doubled (7.9 % to 14.92%) with the 5 degree increase from 20 to 25; C. vulgaris lipid content dropped from 14.71% to 5.90% with the temperature change from 25 to 30 degrees. Conversely, a 75% decrease in N concentration promoted lipid content production in both species: N. oculata content increased from 7.90 to 15.31% and C. vulgaris content increased from 5.90 to 16.41%.
Converti, Attilio, Allessandro Casazza, Erika Ortiz, Patrizia Perego, and Marco Del Borghi. 2009. Effect of temperature and nitrogen concentration on the growth and lipid content of Nannochloropsis oculata and Chlorella vulgaris for biodiesel production. Chemical Engineering and Processig. 48: 1146-1151.
A recent article by Jennifer Bogo in Popular mechanics tells how Dave Hubbard makes his own biofuel; he makes this biodiesel from the vegetable oil used at a nearby tavern for cooking wings. Fatty acids from burned food must be removed from the oil before fuel is available for use. These acids are converted to glycerin using a solution of sodium hydroxide (NaOH (aq)) to titrate. A small additional amount of NaOH is needed to catalyze the reaction of “virgin bean oil.” According to Hubbard, most restaurants produce chemically consistent cooking oil if they change it on a regular basis. Conversely, other restaurants that do not change their oil frequently produce oil that either is no longer usable for biofuel or conversion of it to biofuel is no longer cost-effective. That oil which is suitable for conversion to fuel is mixed with methanol (45 gallons of oil with 9 gallons methanol), kept at a temperature of 120ْ F, and stirred for 45 minutes using a modified drill press. The final yield is typically around 40 gallons of biodiesel and 5 gallons of glycerin. Hubbard leaves the mixture sitting overnight. During this period, the glycerin precipitates out. The biodiesel is then washed and ready to use. Hubbard claims that the total cost of materials, heat, and power add up to a grand total of 50 cents per gallon. He sells this fuel to local farmers and uses it in his diesel Volkswagen Jetta.
An article by Chris Ladd, another writer for Popular Mechanics, a slightly more sophisticated, albeit much more expensive, method of producing biodiesel is being developed in California by LS9 Inc. and Amyris Biotechnologies. These companies are engineering the genetic make-up of bacteria to produce hydrocarbons rather than triethylglycerides. Amyris first determined the properties that make good biofuels and are now genetically modifying E. coli and other micro-organisms (yeast and bacteria) to produce these fuels. With approximately 2 million tons of sugar (used as feed for the bacteria), Amyris claims to be able to produce 30 million gallons of diesel.
According to Ladd, J. Craig Venter, who was involved with the mapping of the human genome, is currently working with LS9 on designing bacteria to produce hydrocarbons from atmospheric CO2. LS9 recently purchased a “state-of-the-art production facility.” They are now updating it and should have it ready to produce between 50 and 100 million gallons of fuel by next year. However, this fuel will be more conventional in production methods, using “renewable raw materials.” This plant is located on the opposite side of the country in southern Florida. Here, they will also use sugar cane as a feedstock; but, this feedstock will be feeding fuel, not bacteria. Nothing is mentioned on the company’s page for the facility about the use of bacteria in the method being developed by Venter.
In “Biodiesel: Cultivating Alternative Fuels,” Charles Schmidt provides a fairly comprehensive overview of the basic effects of producing biodiesel. He first examines the recent history of biofuels in America, starting with the early 1990’s when the realization that biofuels could be an economically advantageous solution to petroleum based fuels occurred. From there, Schmidt moves on to a description of basic diesel engine operations, and finally to the advantages and disadvantages of different sources of biofuels. Most of these advantages and disadvantages have been discussed in class recently, such as the area required for corn based ethanol and the displacement of cropland for fuel-land. However, two arguments were new or discussed differently.
One of these new arguments against biodiesel was that it tends to gel up easier and at higher temperatures than petroleum based diesel. Summer grade petroleum diesel does this too, albeit to a lesser degree, in the winter. Most fuel companies in colder climates switch to a different grade of diesel fuel in the winter that is less prone to this problem. The problem can be reduced in petroleum based summer diesel fuels by adding a small amount of gasoline to the tank. However, Schmidt did not mention this as a possible solution with biodiesel. Therefore, it would seem this still remains a problem for biodiesel.
The second topic, discussed only briefly in class, is that using nutrients from wastewater plants to fertilize algae sources of biodiesel. Schmidt claims that the most promising source of biodiesel comes from algae (because it can produce up to 8,000 gallons per acre compared to soybeans which can produce around 50 gal. per acre) that is fertilized with wastewater. This does seem an highly viable route. However, it is not the best. In both a 2009 abstract and his 2007 master’s thesis, Ian Woertz studies the use of algae to simultaneously produce lipids for use as biodiesel and clean up wastewater. Currently, Woertz is continuing bench tests of this treatment form. These tests seem highly promising. Common levels of orthophosphate removal are on the scale of 88-92% and removal of nitrogen is around 95-96% in wastewater treatment plants. This is typically done with single celled organisms. The results from Woertz’s bench tests indicate that phosphate removal with certain types of algae (that could then be used for fuel) is around 96% and N removal is “>99%” (Woertz, 2009). The double use of algae seems an even more promising option.
Schmidt, Charles W. 2007. “Biodiesel: cultivating alternative fuels.” Environmental Health Perspectives. 115:2, A86-A91. URL.: < http://www.jstor.org/stable/4133105?seq=4&Search=yes&term=wastewater&term=biodiesel&list=hide&searchUri=%2Faction%2FdoBasicSearch%3FQuery%3Dbiodiesel%2Band%2Bwastewater%26wc%3Don%26dc%3DAll%2BDisciplines&item=1&ttl=6&returnArticleService=showArticle&resultsServiceName=doBasicResultsFromArticle >.
Woertz, I. 2007. Lipid production of algae grown on dairy wastewater as a possible feedstock for biodiesel. (Master’s Thesis, California Polytechnic University: San Luis Obispo). 1-87. URL.: < http://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=1193&context=theses >.
Woertz, I, A Feffer, T Lundquist, and Y Nelson. 2009. “Algae grown on dairy and municipal wastewater for simultaneous nutrient removal and lipid production.” Journal of Environmental Engineering-ASCE. 135:11, p. 1115-1122. URL.: < http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOEEDU000135000011001115000001&idtype=cvips&gifs=yes&ref=no >.
A 2007 article by Groom et al. in Conservation Biology reviews different variants of biofuels and their impacts on biodiversity. The authors acknowledge biofuels’ capability to lessen or slow the effects of global warming; however, they stress the importance of regulation and legislation in order to preserve both diversity and maintain a beneficial energy input: output ratio. Their results are interesting. They examined five broad categories of biofuels: grasses, woody biomass, residues, oil crops, and microalgae. Corn based ethanol, the most commonly used biofuel in the U.S., is worst for decreasing biodiversity and has the worst energy conversion efficiency of only 10-25%. At the time of this study, the energy conversion efficiency for microalgae based biodiesel was not available. Although these data were unavailable, the authors conclude microalgae are the most promising biofuel. This conclusion is derived from the fuel yield per hectare: corn yields between 1135 and 1900 litres per hectare; microalgae yields between 49,700 and 108,800 litres per acre. Most other fuels fall in between these two when all factors are considered. The advantages and disadvantages of each source are discussed in detail. The largest problem with using both woody biomass and crop waste as a fuel source is that of erosion. Obviously, growing corn for fuel reduces land area for crops or reduces biodiversity when new land is cleared. Microalgae, on the other hand, have none of these problems. Brackish and even salt water can be used for growing this valuable crop. Furthermore, the area needed to produce 50% of the nation’s transportation fuel is only 1.5 to 3.2 million hectares. Corn would require at least 90.6 times that area (290-485 million hectares). The article can be found at the following url: < http://journals.ohiolink.edu/ejc/pdf.cgi/GROOM_MARTHA_J.pdf?issn=08888892&issue=v22i0003&article=602_babpfcbpfbp >.
Groom, M. J., E. M. Gray, & P.A. Townsend. 2008. Biofuels and biodiversity: Principles for creating better policies for biofuels. Conservation Biology. 22:3, 602-609.