Biodiesel Fuel

Alexis Aberle

CBE 555

Spring 2008

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.