20 February 2019
More efficient production of plant biodiesel
Published online 17 September 2015
A team of chemists devised a strategy to make the production of diesel oil from plant fats much less wasteful.
Biodiesel can be manufactured from plant lipids through a process that uses methanol derived from fossil fuels — an expensive, arguably unsustainable and wasteful process that produces a relatively large amount of undesired impure glycerol as a byproduct.
A team of researchers from the United Kingdom and Saudi Arabia have found a way to effectively recycle this crude glycerol byproduct into methanol and other useful products, markedly improving the appeal of this process1.
It began when the team wondered if they could use a basic oxide instead of the conventional acid catalyst to catalyse the dehydration of glycerol to acrolein. To their surprise, they did not get acrolein, but methanol.
The researchers went on to investigate this interesting new chemistry and found out that instead of the intended dehydration, glycerol reacted with water under the catalyst conditions they used and was reduced to methanol via an intermediate radical bond cleavage of the hydroxyl group.
Publishing their results in Nature Chemistry, the team demonstrated for the first time that impure aqueous glycerol could be converted to methanol in one step without the need for high pressure or external hydrogen, unlike what was previously reported.
“We have closed the sustainability loop for the biodiesel manufacturing process in two important aspects”, said lead author M. H. Haider “one, getting rid of fossil fuel derived methanol and secondly the use of crude glycerol in an efficient way […] to produce diesel oil."
Haider, M.H. et al. Efficient green methanol synthesis from glycerol. Nat. Chem http://dx.doi.org/10.1038/nchem.2345 (2015).