Biodiesel is an alternate, renewable fuel made from seed oils, waste vegetable oils and waste animal fats. It recently received publicity when Willie Nelson announced that he was becoming involved with the biodiesel industry. It has a relatively small portion of the diesel fuel market, but could become much larger as demand becomes greater and pricing becomes more competitive with petroleum diesel. It can be used in most diesel powered vehicles without modification. Currently it is more popular in the farming community, for school and transit buses, and fleets of diesel powered vehicles. These markets use all the biodiesel that is produced and until more fueling stations are built there it will not have popular appeal.
Biodiesel is an attractive fuel from many points of view:
- Biodiesel emissions are essentially free of sulfur and aromatics and have less hydrocarbons, carbon monoxide and particulate matter.
- In its total lifecycle, from planting through making fuel, it produces less CO2 than petroleum diesel does in its lifecycle.
- Biodiesel can be used in most diesel engine powered vehicles with no modification.
- A byproduct, glycerol is also produced.
- Biodiesel has a higher cetane number than petroleum diesel. The higher the cetane number the quicker a fuel ignites. High centane numbers are generally recognized as reducing emissions of engine pollutants, including NOx, and improving fuel economy,
- It has superior lubricity than petroleum diesel, an important factor when sulfur content is reduced from petroleum diesel, lowering its lubricity.
- Biodiesel produced in the US decreases our dependence on oil from countries with political unrest and terrorism.
- Biodiesel reduces our balance of trade deficit to the extent that it offsets imports of crude oil.
- Biodiesel creates a higher demand for seed oil crops thus causeing an increase in prices for oil seed crops which increases the income to the agricultural industry.
- Some land that was landbanked is brought back into productive use, reducing government subsidies for this purpose.
- It produces about 5% less power per gallon
- It jells during cold weather thus limiting the usable concentration in blends during cold weather or some sort of fuel heater, which is not difficult to implement, is required during periods of cold weather.
- It Increases nitrogen oxide emissions.
- Because feedstock costs are the largest single cost in the production of biodiesel, the cost of biodiesel increases slightly with greater demand, because this higher demand results in a higher feedstock price.
- Biodiesel made from soybean oil, using current technology, is more expensive than petroleum diesel.
- Our exports of oil seed crops are decreased because of its higher value and more of the output is devoted to biodiesel production.
- As long as subsidies are required to make biodiesel competitive, government spending for these subsidies increases proportionately to production.
Biodiesel is produced through a process in which organically derived oils and fats are combined with alcohol (usually methanol) in the presence of a catalyst (usually sodium or potassium hydroxide) to form ethyl or methyl ester which can either be used directly as diesel fuel or blended with conventional diesel. According to NREL you can use up to 35% blends (B35) in all diesel powered vehicles without modification and B100 in all vehicles made after 1993. Vehicles made before 1994 require the replacement of natural rubber seals in fuel pumps and fuel systems with non-rubber seals such as Viton. However many engine manufacturers do not warrant their engines to operate on biodiesel. Biodiesel acts as a detergent and loosens dirt and scale accumulations in the fuel system on older vehicles and care must be taken to change fuel filters during the first few weeks of operation with biodiesel.
High production costs continue to limit commercialization. Currently biodiesel receives a government subsidy of $1.00 per gallon and with the subsidy and current petroleum prices (April 2005) it is competitive with petroleum diesel in some states that give an additional incentive.
Biodiesel production capacity from soy beans is estimated to be 80 million gallons in 2006 with an additional capacity of 200 million gallons possible from oleo-chemical producers such as Proctor & Gamble. The capacity in the oleo-chemical industry will not come on stream until the price biodiesel becomes high enough to divert their output from other uses. Production of biodiesel from waste animal fats and vegetable oils, because of their extremely low cost reduces the cost of biodiesel significantly, however the quantity available limits them from making a significant impact on biodiesel pricing.
The cost of biodiesel can be lowered somewhat by process improvements and the economies of scale obtained by producing it in larger plants. However the primary limit to the cost of biodiesel is the cost of the feedstock, which increases in cost as the demand for soybeans is increased. Other feedstocks may offer better economics. Without subsidies the largest market for soybean biodiesel probably will be as a fuel additive. When ultra low sulfur diesel is required in 2006 a market for biodiesel as a lubricity additive and perhaps as a cetane booster will develop. Biodiesel may also be marketed for uses where reducing emissions of particulates and unburned hydrocarbons is of great importance, such as school and transit buses. Because diesel additives can sell for a price above that of the diesel fuel, the cost disadvantage for soybean biodiesel would not be as great in the additive market.
New processing methods are being developed which reduce the cost of production. A 16 million U.S. gallons (60 million liter) per year biodiesel plant, using the Biox process, is under construction in Canada and is scheduled for operation this October. The plant owners project that the cost of building the plant will be reduced 40% and the operating costs reduced 50% compared to other biodiesel facilities. A pilot plant that started up four years ago has been producing 260,000 U.S. gallons (one million liters) of biodiesel per year. The technology was developed at the University of Toronto and adds a co-solvent to the process that reduces the reaction time from hours to less than 10 minutes, has a recycle stream of methanol and the co-solvent that uses the latent heat of condensation to heat the incoming feedstock, and a continuous process is used which allows use of more automatic controls which reduces operational labor.
A process for making even higher cetane biodiesel is undergoing testing which perhaps would make it more valuable as an additive to regular diesel. 75-80% yields have been achieved with a cetane number of 100. No data on projected costs of this fuel were given in the referenced article.
Soybeans are not a very efficient crop for the production of biodiesel, but their common use in the United States for food products has led to soybean biodiesel becoming the primary source in the US. The land area required to produce soy beans limits the quantity of biodiesel that could ultimately be produced. Using data from USDA and other sources, I calculated that about 3.3 billion gallons of biodiesel could be produced per year if all the soybeans produced in the US were used to produce biodiesel, which of course is impossible. This compares with about 45 billion gallons per year of diesel consumed in the U.S. in 2003 by the total transportation industry -- on-highway, off road, farms and railroad.
The yields of various sources of oil in gallons of oil per acre are: soybeans 40-50 , canola (rapeseed) 110-145, mustard 140, palms 650, and algae 10,000-20,000 according to this source. Bioengineering can be used to develop soybeans that are more suited to the biodiesel industry, producing as much as 20% more oil (my optimistic estimate after reading several articles). Europe, which has a much larger biodiesel industry, produces most of its biodiesel from canola oil. A large plant using canola oil as a feedstock has been announced for construction in North Dakota, the largest producer of canola oil in the U.S.
The Crestone Eagle website has a discussion/comparison of producing biodiesel from genetically engineered canola vs open pollinated canola as well as descriptions of producing biodiesel from canola, mustard and algae. Contrary to my conclusion on genetically engineered soybeans, they make the case that open pollinated "mustard canolas" could provide a lower cost feedstock than GMO (genetically engineered organism) canola. They claim that mustard has an aditional advantage in that growing it does not require any pestisides, thus lowering its cost. DOE and University of Idaho also have information making the case for mustard oil as a lower cost feedstock.
A study indicates that only 15,000 square miles, 0.3% of the land area of the U.S., would be needed to produce enough algae to replace all transportation diesel in the U.S. Furthermore the most effective land for this purpose would be desert land. Much R & D is required before algae could even be considered as a viable option.
In a life-cycle analysis of biodiesel and petroleum diesel, accounting for resource consumption and emissions for all steps in the production and use of the fuel, EIA reported that biodiesel from virgin vegetable oil reduces carbon dioxide emissions and petroleum consumption when used in place of petroleum diesel. Biodiesel produces 78% less carbon dioxide than petroleum diesel.
Biodiesel: Is It Worth Considering? is a paper written in support of biodiesel giving the arguments for increasing biodiesel production.
I have found very few negative comments about biodiesel except for its cost. I would appreciate your comments - either pro or con.
In Summary: Biodiesel is a renewable biofuel that has environmental and lubricity advantages and provides a degree of energy independence and the associated economic advantages. However using current technology soybean oil biodiesel without subsidies is more expensive than petroleum diesel. Although the cost of biodiesel can be lowered a small amount by process improvements and the economies of scale obtained by producing it in larger, more automated plants, the cost of biodiesel is primarily limited by the cost of the feedstock. Other seed oil crops offer potential for cost reduction and should be pursued more vigorously.
Quoting from EIA report "Biodiesel Performance, Costs, and Use" "Unless soybean oil prices decline dramatically, it does not appear that biodiesel can be produced in large quantities at a cost that is competitive with petroleum diesel. The largest market for biodiesel probably will be as a fuel additive, because EPACT (energy policy act) requirements are unlikely to increase significantly over the next 20 years. The ultra-low-sulfur diesel program will offer an opportunity for biodiesel as a lubricity additive and perhaps as a cetane booster as well. Biodiesel may also be marketed for applications in which reducing emissions of particulates and unburned hydrocarbons is paramount, such as school and transit buses. Because additives that improve diesel fuel properties can sell for a price above that of the diesel fuel, the cost disadvantage for biodiesel would not be as great in the additive market."