How is biodiesel made

This effect occurs because when the oil crop grows it absorbs the same amount of CO2 as is released when the fuel is combusted. In fact this is not completely accurate as CO2 is released during the production of the fertilizer required to fertilize the fields in which the oil crops are grown.

Fertilizer production is not the only source of pollution associated with the production of biodiesel, other sources include the esterification process, the solvent extraction of the oil, refining, drying and transporting. All these processes require an energy input either in the form of electricity or from a fuel, both of which will generally result in the release of green house gases. To properly assess the impact of all these sources requires use of a technique called life cycle analysis.

Our section on LCA looks closer at this analysis. Biodiesel is rapidly biodegradable and completely non-toxic, meaning spillages represent far less of a risk than fossil diesel spillages.

Biodiesel has a higher flash point than fossil diesel and so is safer in the event of a crash. There are three basic routes to biodiesel production from oils and fats: Base catalyzed transesterification of the oil. Direct acid catalyzed transesterification of the oil. Conversion of the oil to its fatty acids and then to biodiesel. For this reason only this process will be described in this report.

A triglyceride has a glycerine molecule as its base with three long chain fatty acids attached. The characteristics of the fat are determined by the nature of the fatty acids attached to the glycerine. The nature of the fatty acids can in turn affect the characteristics of the biodiesel.

During the esterification process, the triglyceride is reacted with alcohol in the presence of a catalyst, usually a strong alkaline like sodium hydroxide. Raw or refined plant oil, or recycled greases that have not been processed into biodiesel, are not biodiesel and should not be used as vehicle fuel. Fats and oils triglycerides are much more viscous than biodiesel, and low-level vegetable oil blends can cause long-term engine deposits, ring sticking, lube-oil gelling, and other maintenance problems that can reduce engine life.

Research is being conducted on developing algae as a potential biodiesel feedstock. It is expected to produce high yields from a smaller area of land than vegetable oils. Fuel-grade biodiesel must be produced to strict industry specifications in order to ensure proper performance. Raw vegetable oil cannot meet these diesel fuel specifications and therefore is not considered biodiesel. Biodiesel, n - a fuel comprised of mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats, designated B, and meeting the requirements of ASTM D Biodiesel is made through a chemical process called transesterification whereby the glycerin is separated from the fat or vegetable oil.

The process leaves behind two products — methyl esters and glycerin. Methyl esters is the chemical name for biodiesel and glycerin is used in a variety of products, including soap.

Today, more than 78 percent of diesel vehicles coming off production lines are approved for up to B20 use. Biodiesel production spans across the US and has grown to more than plants with the capacity to produce 3 billion gallons. In , the US biodiesel industry produced 2. Until , the United States consumed only small amounts of biodiesel.

Since then, U. In , the United States produced about 41 million barrels 1. Biofuels explained Biomass-based diesel fuels. What is energy? Units and calculators. Use of energy. Energy and the environment. Also in What is energy? Forms of energy Sources of energy Laws of energy. Also in Units and calculators explained Units and calculators Energy conversion calculators British thermal units Btu Degree days. Also in U. Also in Use of energy explained Use of energy Energy use in industry Energy use for transportation Energy use in homes Energy use in commercial buildings Energy efficiency and conservation.

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