Post on 14-Dec-2015
Definition
Biofuel: Fuel made from biological ingredients instead of fossil fuels Starting ingredients range from corn to soybeans to animal fat Non-toxic and renewable Is usually blended with pure diesel Numbering system: B20 is most common, meaning the fuel is
20% biodiesel A fuel comprised of mono-alkyl esters of long chain
fatty acids derived from vegetable oils or animal fats, designated B100, and meeting the requirements of ASTM D 6751 (National Biodiesel Board)
History of biodiesel
Transesterification of vegetable oil before first engine, in 1853 by E. Duffy and J. Patrick
Rudolf Diesel 1900 World’s Exhibition in Paris Engine ran on peanut oil, the world’s first
biodiesel Used until the 1920’s when petroleum diesel
more common due to superior pricing
Plant oil is the largest source
Soybean Rapeseed Canola Palm Cottonseed Sunflower Peanut Why? These compounds contain
triacylglycerols, or fat
C63 H12
2O6
Abbreviated process
Transesterification Fat or oil is first purified then reacted with an
alcohol, usually methanol or ethanol Sodium or potassium hydroxide is used as a
catalyst The triacylglycerol is then transformed into esters
and glycerol Remaining esters are biodiesel
Block Flow Diagram
Oils and fats are preprocessed to remove water and contaminants
Pretreatment removes FFA Oils and fats are mixed with
an alcohol and catalyst Triglycerides are broken
apart and reformed into methyl esters and glycerin
Separated and purified
Titration
Why? To find out how much catalyst is needed, since oil will first react with lye to make soap before desired reaction, biodiesel, can occur
Reaction is complete at pH of 8.5 – use phenol red Lye/free fatty acid reaction Every 1 mL titration will tell you to add an extra gram of lye for
each liter of oil/ffa to compensate for the side reaction
Washing process
Unwashed biodiesel contains soap If mixed, the water, soap, and biodiesel will form an emulsion –
takes longer to separate Perform washes by adding water, GENTLY mixing, and
decanting water As number of washes increases, will be able to mix more
vigorously Washing is complete when water is clear
Glycerin
Every gallon of biodiesel produces a pound of glycerol Settling stage of production: mix of glycerin, methanol, lye
catalyst, soap Phosphoric acid
precipitates out the catalyst Converts soap back to FFA 95% pure
Hard to purify: BP 290 °C
Soap
Need to remove methanol Simple condenser recovers methanol
Saponify: better cleaner Add lye and water, heat, set for 2 weeks
NaOH: Solid soap; KOH: Liquid soap
Pros
Environmentally friendly Can help reduce dependence on oil Helps lubricate the engine, reducing wear Can be used in virtually any diesel operating vehicle Safer than conventional diesel Fewer emissions, biodegradable, renewable Is the only biofuel that has successively completed
emissions testing in accordance with the Clean Air Act
Non-toxic
Reduced emissions
Emission Component B100 B20
Total Unburned Hydrocarbons -67% -20%
Carbon Monoxide -48% -12%
Particulate matter -47% -12%
NOx +10% +2%
Sulfates -100% -20%
PAH -80% -13%
Additionally, B100 can also reduce CO2 emissions by 78% and lower carcinogenic properties of diesel fuel by 94%
Degrades at rate of four times faster than standard diesel fuel
Cons
Unfortunately, when the particulate matter is decreased, there is a corresponding increase in NOx emissions, contributing to smog formation
Because it acts as solvent and loosens things, it can clog fuel filters
Breaks down rubber components – fuel lines and fuel pump seals usually constructed of this
1.1 gallons biodiesel equals 1 gallon standard diesel – 10% reduction in energy efficiency
Corn vs Soybean
More fertilizer and pesticides required for corn Corn and soybean produce 25% and 93% more energy than
consumed, respectively 420 gallons ethanol per acre for corn and 60 gallons per acre for
soybeans
Algae?
How? Grow colonies in presence of sunlight Starve them of nitrogen Filter out cell membranes and organelles Solvent to separate out the fats Purify fats, evaporate solvent
Aquaflow in New Zealand Cold pressing: how oil is retrieved from plants 140 billion gallons of biodiesel every year
Soybeans: 3 billion acres Canola: 1 billion acres Algae: 95 million acres – only would need about size of Maryland
Glycerin By-Product Uses
Composting: Must be in hot environment; releases sulfates Soaps Nitration: produces nitroglycerin
Ascanio Sobrero discoverer 150 years ago Alfred Nobel: Nitroglycerin + Silica: Dynamite! Heart disease drug: 0.6 mg
Sweetener Health supplement Preserving plants Cosmetics Current research underway to use for fighting weeds and
growing grass
Biofuel home heating
Massachusetts: 36% of homes heat with oil New bill: must contain at least 5% of biofuel by 2013, increased
from 2% by 2010 Cellulosic ethanol not available for about three years
Concerns
Operate in cold weather? Biodiesel can gel when it gets cold
Solution Blend with standard diesel: B20 is operates well in cold
climate Additives:
Pour point depressants Filterability or flow improvers that lower CFPP Wax anti-settling additives Must be introduced in the fuel before it reaches cloud point
and properly blended Block and filter heaters Blend with kerosene
Excellent cold flow properties
Production in the US Production currently is small but tripled from 2004 to 2005 and again
from 2005 to 2006. Soy is the driving force for this industry Potential saturation of the market for glycerin could limit the growth 75 M gallons per year total; largest market fleet vehicles Potential future targets: marine and agricultural applications and
home heating
Global Production In 2005, 3.8 million tons produced
85% from European Nation United States: 8% Rest of World: 7%
Cost to produce varies considerably, from $0.29 per liter to $9.00 per liter
Questions?
Conflicting data: 4.5 M vs 95 M acres of land for production of algae for transportation needs
Biofuel: 10% energy reduction vs 8% energy reduction from diesel; also some say production process uses more energy to make than it than what you get out
Increased production of corn and soybeans: less valuable for farmers?
References
http://auto.howstuffworks.com/biodiesel.htm http://www.biodieselcommunity.org/index.php http://www.eere.energy.gov/afdc/fuels/biodiesel_production.html http://blogs.zdnet.com/emergingtech/?p=722 http://journeytoforever.org/biodiesel_glycerin.html#burn http://www.nytimes.com/2007/11/06/us/06boston.html?_r=1&oref=slogin http://www.greenchipstocks.com/aqx_p/2936?
gclid=CKqsvPTV2JICFQurPAod6ksrnA http://www.biodiesel.org/ http://www.pacfuel.com/historybd.htm Cunningham, Aimee. "Farm-Fuel Feedback." Science news 170.3 (2006): 36-7. Svoboda, Elizabeth. "The Fuel Cell." Popular Science 271.1 (2007): 76-101. Thurmond, Will. "Biodiesel's Bright Future." Futurist 41.4 (2007): 27-30. Rosner, Hillary. “Coking up more uses for the leftovers of biofuel production.”
New York Times 8 Aug. 2007.