Saturday, July 19, 2008

Biodiesel Flower Power

Preface - Biodiesel has become an established fuel in the last ten years and is available in Germany at nearly every tenth filling station. Among the alternative fuels, biodiesel has conquered substantial share of the fuel market. However, biodiesel customers have wish to engage in experiments, they want an easy to use, environmentally friendly, economical and efficient alternative to mineral oil fuels. This brochure provides an overview of the technical background, environmental advantages, restrictions and perspectives of biodiesel.

The information on the following pages is based on research reports and studies and on over ten years of experience by the "Union zur Förderung von Oel- und Proteinpflanzen e. V." (UFOP) with this alternative fuel. Further information and the sources of the material presented here is to be found at our Internet site: http://www.ufop.de/

Flower power - Biodiesel is genuine Flower Power, it is biogenic fuel or, more precisely, a fuel produced from plants. To be very exact: biodiesel is manufactured from high-quality vegetable oils. Biodiesel manufactured and sold in Germany is nearly always manufactured from the most important indigenous oil-bearing plant - rape. The oil is converted into a modern diesel fuel with flow and combustion properties very closely approximating those of conventional mineral fuels by a simple rebuilding process of its molecular chains. Biodiesel thereby fulfils the highest requirements of engine technology such as the modern high-pressure fuel injection systems (Common Rail).

Manufacture - The manufacture of a high-performance biodiesel from pure vegetable oil, a so-called ester interchange process is necessary. Oil and lipid molecules of both vegetable and animal fats always have the same structure. They consist of so-called triglycerides, a compound of the trivalent alcohol glycerine with three fatty acids.

In addition to the vegetable oil, methanol (formerly called wood alcohol) is necessary to manufacture biodiesel. Methanol can be manufactured by the alcoholic fermentation of regenerative raw materials (starch or sugar). However, methanol is still produced from natural gas for economic reasons.
The reaction of vegetable oil with methanol in a ratio of around 9:1 by weight in the presence of a small quantity of an alkaline catalyst (for example 0.5 % to 1 % sodium hydroxide, potassium hydroxide or potassium methylate) occurs at 50 to 80 °C under normal pressure in a mixing machine. The glycerine of the vegetable oil molecule is detached from its three fatty acids and is replaced by three methanol molecules. The result is a fuel with flow properties (viscosity) approximating that of diesel fuel, which is prerequisite to its use in modern fuel injection pump systems and diesel engines. The produced glycerine is used largely as a raw material in the chemicals industry.
The production of biodiesel, as it is executed in Germany by around 20 companies with a total capacity of over 1 million tonnes per annum, is therefore practically waste-free, as the meal produced in the processing of rapeseed rapeseed is displacing imported soy meal as a high-quality protein-bearing fodder. High-quality natural raw materials are refined without losses into environmentally friendly energy, chemicals and raw materials for fodder. These aspects largely determine the ecological balance of biodiesel.
Source: a brochure from http://www.ufop.de/