Plant Oils

Some fruits, seeds and nuts are rich in useful oils For Example –Olives –Sunflowers –Rapeseeds –Lavenders –Soybeans –Peanut –Coconut –Palm –Corn –Grape Seed –Hazelnuts –Linseed –Rice Bran –Safflower –Sesame –Truffle

Plant Oils are good sources of energy We can eat them or Burn them as a fuel We also get some other nutrients from the oil if eaten

The cells each have a small droplet of the oil The oil must be extracted from the plant material before it can be used Some oils are extracted through pressing eg Olives, Sunflowers The plant material is crushed and the oil oozes out and is collected

An ancient olive press

A Modern olive press

Other plant oils are distilled eg Lavender, Orange This involves heating the plant material until the oil evaporates The oil vapour is then condensed and the liquid oil collected Apparatus Diagram

After either method of extraction, any water or other impurities are removed

Rudolf Diesel Between 1893 and 1897 he perfected his engine It was designed to run on peanut oil Later a waste fraction of crude oil was named diesel fuel, which we now use

Recently a better fuel has been developed from vegetable oil called biodiesel Advantages of Biodiesel: –Renewable as long as we plant more crops –Carbon neutral It only releases as much carbon dioxide as the plant used to grow –Low Sulfur content Little Acid rain created –Can be used in standard diesel engine Can be used in blend with petrol diesel –Waste oil from restaurants can be used

Disadvantages of Biodiesel –More expensive than petrodiesel Petrodiesel is produced with many other fractions of crude oil in the refinary Biodiesel requires: –Planting of crop –Harvesting of crop –Oil extraction –Oil Processing –There isn’t enough space to grow enough crops, to make enough biodiesel to replace fossil foods In some areas of the world farmers have been left without food because they have grown fuel crops rather than food