Biodiesel and its Effects on Air Quality in Carlisle

What is Biodiesel?

As an alternative fuel, biodiesel, greatly reduces harmful emissions. “Biodiesel is defined as the mono-alkyl esters of fatty acids derived from vegetable oils or animal fats” (Building a Successful Biodiesel Business, 2006, Page 3). Simply put, biodiesel is an alternative to petrodiesel which is derived from vegetable oils or animal fats. The process in which the vegetable oils must go through to be turned into biodiesel is call transesterification. “Transesterification is the process of reacting a triglyceride molecule with a excess of alcohol in the presence of a catalyst (KOH, NaOH, etc.) to produce glycerol and fatty esters” (Building a Successful Biodiesel Business, 2006, Page 4). The vegetable oils are brought to a temperature of 130º Fahrenheit and then reacted with a mixture of methanol or ethanol and lye, potassium or sodium hydroxide. The lye acts as a catalyst to neutralize the free fatty acids in the oil. Once the reaction is complete biodiesel and glycerin are left. For every gallon of oil put into the reaction you receive a gallon of biodiesel and for every gallon of methoxide, methanol and lye mixture, you receive and gallon of glycerin. Due to the nature of lye, soap is created in this process as well. To make the biodiesel usable in engine the soap must be washed out with water. The water is passed through the biodiesel slowly collecting the soap, this mixture of water and soap separates from the biodiesel and is then put down the drain. Now the biodiesel is almost entirely free of soap, but the soap has been replaced with water. The water must be removed from the biodiesel by either, heating and circulating it or by placing a vacuum over the biodiesel. Once the biodiesel is “dry” it can go out to for use in cars, trucks, furnaces, farm equipment, etc.