This research paper examines published opinion on the merits of biodiesel as an available alternative fuel, seeking to confirm for those considering the best alternative fuel to use (e.g. fleet operators) why it is indeed the best overall choice of alternative fuels available.
The first source examined was the U.S. Department of Energy’s Alternative Fuels Data Center. Their published article “Biodiesel Benefits and Considerations” (Jan 2013) defines biodiesel as “a domestically produced, clean-burning, renewable substitute for petroleum diesel.” According to the article, a vehicle fuelled by biodiesel “increases energy security, improves public health and the environment, and provides safety benefits.” The article notes that the U.S. currently imports around half of its petroleum, of which circa two thirds provides vehicle fuel – either gasoline or diesel. Being so dependent on oil imports increases the risks of adverse factors such as trade deficits, disruptions of supply and price fluctuations. In contrast, biodiesel produced domestically can replace normal petroleum-based diesel fuel in conventional diesel power units. The article discusses air quality benefits of using biodiesel, stating that compared with conventional diesel fuel, running a normal diesel engine on biodiesel “substantially reduces tailpipe emissions of unburned hydrocarbons (HC), carbon monoxide (CO), sulfates, polycyclic aromatic hydrocarbons, nitrated polycyclic aromatic hydrocarbons, and particulate matter (PM).” The following figure extracted from that article illustrates those beneficial effects in graphical form:
(Figure extracted from “Biodiesel Benefits and Considerations” Jan 2013)
The “Biodiesel Benefits and Considerations” article (Jan 2013) also claims that greenhouse gas emissions are reduced by using biodiesel, because the carbon dioxide released in its combustion is offset by the carbon dioxide absorbed in the growing of the crops from which the biodiesel is produced (e.g. soybeans). A one hundred percent biodiesel fuel reduces those emissions by circa 75 percent compared with using normal petroleum-based diesel, although it can increase emissions of nitrogen oxide. Another advantage of biodiesel as claimed in the article is that it has increased “lubricity” compared with petroleum-based diesel. As noted in the article, diesel engines depend on the lubricity of the fuel to avoid premature wear of moving engine parts. Additionally and importantly, biodiesel is “non-toxic.” Not only do spillages cause much less environmental damage compared with petroleum-based diesel, but biodiesel is also less combustible, having a flashpoint of around 130 degrees Centigrade compared with a flashpoint of circa 52 degrees Centigrade for petroleum-based diesel fuel. According to the article, these properties make biodiesel “safe to handle, store, and transport.”
Davis (Sep 2013) cites biodiesel as a front runner for the alternative fuel choice for commercial fleets operation. He refers to a recent article published on Truckinginfo.com which indicates that although there are various alternative fuel solutions available, including “gas, hybrid, electric and even hydrogen fuel cells”, clean diesel (and biodiesel is the cleanest) may be the best solution for fleet operators. Davis also notes that “the best part about biodiesel is, you don’t have to change out engine parts or delivery infrastructure to make it work right now!” He also comments that there is a good degree of flexibility in blending it with petroleum-based diesel.
Schmidt (2007) provides a wealth of information about alternative fuels and biodiesel in his paper “BIODIESEL: Cultivating Alternative Fuels” (Feb 2007). He notes that in 1992 the National SoyDiesel Development Board was established, changing its name in 1994 to the National Biodiesel Board (NBB), producing fuel from soybeans on a relatively small scale (a few thousand gallons annually). However, ten years on, that output had increased to 25 million gallons. Then in 2005 the introduction of a $1 per gallon tax subsidy dramatically increased demand, and production was predicted to hit 1.5 billion gallons in 2007. According to Robert McCormick (“a principal engineer at the DOE National Renewable Energy Laboratory”), the biodiesel produced domestically could provide in the longer term circa 25 percent of the nation’s diesel fuel needs. The article also provided the critical information that biodiesel “generates 3.2 times more energy than is required to produce it.” One drawback of pure biodiesel (known as B100) is that it is only useful in its pure form at temperatures above the freezing point of water, unless supplementary fuel heating systems are utilized. Blending biodiesel with conventional diesel fuel can overcome that problem. Another development in the biodiesel story mentioned in the article is the diversification of crops used to produce it. For example, whereas soybeans yield between 18 and 20 percent oil, other crops such as canola produce much more – perhaps double that of soybeans. Even greater returns can be achieved from algae. According to the article, while 50 gallons of biodiesel per acre can be achieved from soybeans, algae can produce annually up to 8,000 gallons per acre! Algae promises fantastic increases in biodiesel production; possibly enough to replace most of the fuels currently used by all cars in the U.S. today. And that volume could be generated from a total area of about 15,000 square miles (9.5 million acres). To put that into perspective, the U.S. currently has 442 million acres used for growing crops, and 586 million acres for livestock grazing. A cautionary note in the article is that increased production of biodiesel using imported palm oil could exacerbate the undesirable practice of deforestation of rain forests to create palm oil plantations in other countries.
Another “plus” for biodiesel is provided in “Biodiesel Commonly Asked Questions” (2012), where it is stated that “Biodiesel is the best greenhouse gas mitigation strategy for today’s medium and heavy duty vehicles.” It reports a 1998 study which showed that compared with conventional petroleum-based diesel fuel, biodiesel reduced net carbon dioxide emissions by no less than 78 percent.
Allen (2006) published a useful source comparing various alternative fuels (including biodiesel), entitled “Crunching the Numbers on Alternative Fuels.” He notes that various factors including the Iraq war, global warming concerns and rising oil prices triggered the U.S. into investigating ways to reduce dependence on fossil fuels. The article includes a comparison chart illustrating the costs using different fuels for a car journey from New York to California. However, the cars used were all different, so true comparisons are difficult. Nonetheless, some of the data is interesting, and is reproduced here for information:
* Gallons of gasoline equivalent
Although biodiesel only comes out roughly midway in total costs in this comparison, there are numerous other factors to consider such as capital costs of the vehicles and equipment, availability of the different fuels, price changes of the fuels as development progresses, and more. Perhaps the major advantage of biodiesel is that it can be used in conventional diesel engines without modifications and that blends are becoming increasingly widely available. Also there are the general advantages of diesel engines (as re-stated in this article) that they “extract more energy from each gallon than gasoline engines, and less energy is lost as heat leaving the exhaust pipe than with a gasoline engine.” Not only that, but biodiesel actually provides cleaner running than petroleum-based diesel fuels and generates less emissions. Additionally – on a technical level – because biodiesel molecules are (unlike petroleum-based diesel) oxygen-bearing, they partly help combustion of the fuel. The main disadvantages cited are the higher costs per gallon (up to $1 more than its petroleum-based counterpart) and the need for heating it at low temperatures to maintain it in liquid form.
Allen, Mike. (2006). “Crunching the Numbers on Alternative Fuels.” Popular Mechanics. Web. 3 October 2013.
“Biodiesel Commonly Asked Questions.” (2012). National Biodiesel Board. Web. 3 October 2013.
“Biodiesel Benefits and Considerations.” (Jan 2013). U.S. Department of Energy’s Alternative Fuels Data Center. Web. 3 October 2013.
Davis, John. (Sep 2013). “Biodiesel Might Be Fleets’ Best Clean Diesel Optic.” Domestic Fuel. Web. 3 October 2013.
Schmidt, Charles, W. (Feb 2007). “BIODIESEL: Cultivating Alternative Fuels” (Feb 2007). Environmental Health Perspectives 2007 February; 115(2): A86–A91. Web. 3 October 2013.