So what exactly is Biodiesel?
Posted by Mark Campanale
By Kate Heller, QA/QC Chemist, Triumvirate Environmental
As environmental sustainability and green living start to become more and more mainstream in today’s society, the question of biodiesel has become a major factor in most climate change discussions. The production and manufacturing of biodiesel is regulated via ASTM D6751 specifications, and is defined as “mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats for use in diesel engines.” Biodiesel is generally formed through transesterification which can occur via three basic methods: base catalyzed transesterification of the lipid with alcohol, conversion of the lipid to a fatty acid and then to alkyl esters by acid catalysis, or direct acid catalyzed esterification of the lipid with methanol.
In its pure form, biodiesel does not contain any petroleum, and thus is biodegradable and nontoxic. The omission of petroleum also allows for a closed carbon cycle burning process which reduces net CO2 emissions by up to 78%, as well as decreasing the levels of polycyclic aromatic hydrocarbons (PAH) and nitrited PAH (nPAH) compounds by 85%. In fact, biodiesel is the only alternative fuel approved by the EPA, and is registered as a fuel and fuel additive by meeting the clean diesel standards of the California Air Resources Board by fully completely the health effects testing requirements as outlined in the 1990 Clean Air Act.
Pure Biodiesel is referred to as B100, while biodiesel blends are denoted B## depending on the percentage of biodiesel in the mixture. B20 is the most common biodiesel blended fuel with 20% biodiesel and 80% by volume petroleum diesel. Despite the majority of petroleum diesel in the B20 blend, it has demonstrated significant environmental benefits with a minimum increase in cost for consumers, and thus is most often distributed at biodiesel and diesel refueling stations, for use in either biodiesel or regular diesel engines (with no modifications necessary).
As consumer awareness and the quest for green living has risen, the production volume of biodiesel has increased at a steady rate, primarily due to the passage of the Energy Policy Act of 2005. In 2008 there were 700 million gallons of biodiesel produced in the United States, compared to the 500,000 gallons produced only ten years ago. Furthermore, in Europe, the Renewable Transport Fuel Obligation requires suppliers to include a minimum of 5% renewable fuel in all transport fuel sold in the EU by 2010. Climate change and global warming are not going to disappear, but they can be lessened by taking steps towards a more eco-friendly lifestyle, and by becoming more knowledgeable about greener options and alternative fuels.
