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Faster biodiesel production is about to begin |
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Wednesday, 05 September 2007 |
 | Making biodiesel involves a reaction called transesterification in which the triglycerides and free fatty acids in oils from plants such as corn or linseed react with methanol to form methyl esters of 16-18 carbon atoms in length. Purified methyl esters can then be used in place of diesel fuel.
| | The problem is that transesterification is a slow process and currently the only way to speed it up is to cook chemicals in batch reactors at high temperatures and pressures. But having to produce fuel in batches also limits the rate at which biodiesel can be made. |
Now Christian Fleisher and colleagues at Cornell University have developed a way of making biodiesel continuously, without the need to fill and empty batch reactors.
The trick is to produce the transesterification reaction as the necessary chemicals mix and flow through a pipe. The result is a system – known as a "plug flow" reactor – in which plant oil and methanol is added continuously at one end, while biodiesel flows out of the other.
Fleisher achieves this speed increase by using a catalyst, such as sodium hydroxide. So, instead of taking hours, the transesterification reaction then takes place in under three minutes. Fleisher has even set up a company called Biodiesel Technologies to commercialise the idea. |
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