How do you make biodiesel?

Answer 1

Biodiesel is made by vegetable oils to which methanol (or ethanol) and caustic soda (or potash soda) is added.

It can be mixed with petrol oil in different quantities. The most popular is biodiesel 98 which has 2% of vegetable oil. To further expand on the above answer. Biodiesel is only part of the biofuel family, which also includes the use of straight vegetable oil, ethanol for petrol cars etc. It is made by a chain reaction process called transesterification, whereby the molecular structure of vegatable oil is changed to form esters, which leave it much thinner and more like the viscosity of petro diesel. To make this reaction a mix of methanol [or sometimes other alcohols] and a predetermined amount of catalyst, usually sodium hydroxide[caustic soda] or pottasium hydroxide[potash] then on called methoxide, is used and processed under heated conditions to form biodiesel and a crude form of glycerine, which is drained from the fuel. The biodiesel is then cleaned by various methods, including water washing, the use of resins, or magnesium silicate to remove all traces of methanol, glycerol, caustic, and soap from the finished fuel, leaving us with a fuel that can be made from sustainable sources, or even waste veg oil, and a host of other fats and oils including animal fat and algie. The emmisions given off by the burning of biodiesel are considerably less than those of petro diesel. And in cases of spillage it is totally bio-degradable. Many European countries mix a small amount of it in standard low sulpher diesel, to help with climate change and help with the lubrication lost by removing the sulpher from modern fuel. biodiesel can be made in homebrew form in the UK, where 2500lts a year are allowed duty free. Help on this subject can be found on the vegoildiesel forum by goat industries, where I advise daily on problems relating to the manufacture and use of biodiesel.