Biodiesel: An Environmental Evaluation Chrissy Warrilow Mike Young Jordon Beckler

What is Biodiesel (cont.)  Transparent amber-yellow liquid  2 Kinds:  ester (oxygenate), made from the oil and methanol.  alkane (non-oxygenate) biomass-to-liquid fuel.  Biodiesel is defined as mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats which conform to ASTM D6751 specifications for use in diesel engines. Biodiesel refers to the pure fuel before blending with diesel fuel. Biodiesel blends are denoted as, "BXX" with "XX" representing the percentage of biodiesel contained in the blend (ie: B20 is 20% biodiesel, 80% petroleum diesel).  Not unrefined vegetable oil.  Function in normal diesel engines  OSHA classified non-flammable liquid (flash point 160 deg C)

Ancient History  1853: E. Duffy and J. Patrick  Transesterification of vegetable oil  August 10 th, 1893: Rudolph Diesel  Prime model  International Biodiesel Day  1900:  World Fair in Paris: “Grand Prix”  1912:  “the use of vegetable oils for engine fuels may seem insignificant today, but such oils may become, in the course of time, as important as petroleum and the coal-tar products of the present time.”  1920s: Diesel engine manufacturers alter engine to utilize lower viscosity of petrodiesel.

Sources  ASTM D 6751  DIN EN  Rapeseed methyl ester –RME  Vegetable methyl ester –PME  Fat methyl ester -FME  Virgin oil feedstock: rapeseed, soybean oils. mustard, palm oil, hemp, jatropa, algae ponds at wastewater treatment  Waste vegetable oil  Animal fats: tallow, lard, yellow grease, Omega-3 fatty acid biproducts.

Methods of production  Base catalyzed transesterification of the oil  Low temperature  High conversion  Direct conversion to biodiesel- no intermediates  No exotic materials of construction needed  Direct acid catalyzed transesterification of the oil  Conversion of the oil to its fatty acids and then to biodiesel.

Reactors

Transesterification 100 lbs Oil or Fat + 10 lbs Alcohol 10 lbs glycerin + 100lbs biodiesel

The Cycle

Production  5 Factors  Complete Reaction  Removal of glycerin  Removal of catalyst  Removal of alcohol  Absence of free fatty acids  GC test for confirmation  Pure product LD50 > 50mL/kg

Biodiesel Emissions  Biodiesel decreases emissions of all greenhouse gases except for NO x.  There is higher aldehyde concentration in biodiesel exhaust.  However, biodiesel decreases polycyclic aromatic hydrocarbons by around 80%.

Mutations and Cancer  Biodiesel has much lower mutagenicity than normal fuel (60%).  No poisonous effect on organisms.  Much less likelihood on cancerous cells developing in organisms.

Some Advantages  Biodiesel does not contain sulfur.  Generally, lowering sulfur in fuel decreases lubrication, and this is not seen in biodiesel.  Treatment of exhaust is simpler with biodiesel.

Anthropogenic N 2 O  Agriculture generally doesn’t contribute to N 2 O fluctuations in the atmosphere.  The exception is soy fields.  Studies show, however, that the amount of atmospheric CO 2 saved by the processing of soy biodiesel is more than is created by N 2 O emissions.

The Bad News  Considerable amounts of N 2 O are generated by fertilizer production.  However, treating fertilizer with urea eliminates these emissions of N 2 O.  In general, fertilizer decreases biodiesel’s CO 2 -saving power by only 13%.

Tropospheric Acidization  Emission of acid producers (NH 3, NO 2, HCl, etc.) combines with H + in a catalytic process to create SO 2.  NH 3 emissions from biodiesel increase SO 2 concentrations by 32%.  Taking efficiency into account, biodiesel is at a 16% acidity disadvantage than it would be (the no sulfur argument).

Why use biodiesel?  “Biodiesel reduces emissions of carbon monoxide (CO) by approximately 50 % and carbon dioxide by 78 % on a net lifecycle basis because the carbon in biodiesel emissions is recycled from carbon that was already in the atmosphere, rather than being new carbon from petroleum that was sequestered in the earth's crust.” (Sheehan, 1998)  Sulfur is not a constituent of biodiesel, and so burning it does not produce S02 emissions  Burning biodiesel can reduce the amount of particulate matter emissions by as much as 65%  Biodiesel the highest British Thermal Unit (BTU) of any alternative fuel in its purest form (B100). The BTU describes the heating value of a fuel.  Biodiesel is biodegradable and non-toxic  Pure biodiesel (B100) can be used in any petroleum diesel engine; engine modifications are not necessary

Not convinced?…  “When reviewing the high costs associated with other alternative fuel systems, many fleet managers have determined biodiesel is their least-cost-strategy to comply with state and federal regulations.” (  “Biodiesel is the only alternative fuel to have fully completed the health effects testing requirements of the Clean Air Act.” (  “Biodiesel emissions have decreased levels of polycyclic aromatic hydrocarbons (PAH) and nitrited PAH compounds that have been identified as potential cancer causing compounds.” (

So whats the downside?  Biodiesel products have a problem of gelling when the temperatures get below ~40 °F; the temperature depends on the particular mix of esters in the fuel. Currently, a product that will significantly lower the gelling point of straight biodiesel is commercially unavailable.  Biodiesel emits more NOx than petroleum diesel; however, properly designed and maintained engines in addition to catalytic converters can help reduce the amount of NOx being emitted into the atmosphere.

Engine Troubles  Biodiesel is soluble in water (due to hydrogen bonding). Water can mix into the biodiesel during fuel processing and condensation from the vehicle’s fuel tank. Water’s presence in biodiesel is problematic due to many reasons:  Water can reduce the heat of combustion, which results in a vehicle exhibiting difficulty starting and running with less power  Water can cause corrosion of fuel system components such as fuel pumps, injector pumps, fuel lines, etc  When water freezes, it produces ice crystals which encourage gelling of fuel residue by providing sites of nucleation.  Microbe colonies that live off of water and biodiesel constituents can cause a serious plug in the fuel system.

Availability  Biodiesel is commercially available in most of the United States. In Atlanta, it can be purchased from Robert Del Bueno, author of call (404) or write to for details.  As of 2005, it is slightly more expensive than petroleum diesel; this is due to the fact that it is still produced on a smaller scale as compared to petroleum diesel.  Many farmers now use a biodiesel in tractors and equipment to foster production of biodiesel and to raise public awareness. Thus, biodiesel is usually more available in rural areas of the nation as opposed to cities.  In 2005, U.S. entertainer Willie Nelson was selling B20 Biodiesel in four states under the name BioWillie. By late 2005 it was available at 13 gas stations and truck stops (mainly in Texas). Most purchasers were truck drivers. It was also used to fuel the buses and trucks for Mr. Nelson's tours as well as his personal automobiles.

Distributors

In the media  As of 2003 some tax credits are available in the U.S. for using biodiesel. In 2004:  30 million US gallons (110,000 m³) of commercially produced biodiesel were sold in the U.S., up from less than 0.1 million US gallons (380 m³) in  Projections for 2005:  were 75 million gallons produced from 45 factories.  Projections for 2010:  Due to increasing pollution control requirements and tax relief, the U.S. market is expected to grow to 1 or 2 billion US gallons (4,000,000 to 8,000,000 m³)  The price of biodiesel in the United States has come down from an average $3.50 per US gallon ($0.92/l) in 1997 to $1.85 per US gallon ($0.49/l) in This appears economically viable with current petrodiesel prices, which as of 9/19/05 varied from $2.648 to $  In February of 2006, a team of high school students showed a sports-economy car, fueled by soybean bio-diesel, that became a star of the Philadelphia Auto Show.  zero to 60 in four seconds and gets more than 50 miles to the gallon.  March 2002, the Minnesota State Legislature passed a bill which mandated that all diesel sold in the state must contain at least 2% biodiesel. The requirement took effect on June 30, In March 2006, Washington State became the second state to pass a 2% biodiesel mandate, with a start-date set for December 1, 2008.