New novel use of glycerol helps make renewable hydrogen and propane fuel gases

GLYCEROL, a naturally occurring alcohol made from the hydrolysis of fats and oils, is being used as a raw material by researchers at Aston University to make hydrogen gas and biopropane. 

Aiming to make use of a cheap and abundant supply of crude glycerol from biodiesel production plants, the project, led by IChemE member Jude Onwudili from Aston’s Energy and Bioproducts Research Institute, is dubbed HYDROGAS. 

Glycerol (C₃H₈0₃) is a simple triol compound made up of carbon atoms connected to hydrogen atoms and hydroxyl, while propane is a hydrocarbon molecule comprising carbon and hydrogen atoms only. 

Propane can be obtained from glycerol by removing its three oxygen atoms. This involves finding a catalyst that uses hydrogen gas to selectively remove the oxygen to leave just propane molecules. 

Producing hydrogen gas (H2) and biopropane from glycerol is not a new technique, but typically relies on using external H2 which can be expensive and is often produced from fossil fuels. 

HYDROGAS’s innovation involves a two-stage catalytic reforming process whereby hydrogen is produced from glycerol, and then used to transform glycerol into biopropane. This will avoid the need for expensive imports, while benefiting the environment, Onwudili said.  

The team’s first objective of developing a process to generate sufficient H2 to convert glycerol to biopropane was successful, but its second objective of obtaining high yields of biopropane, is still being investigated. “Through HYDROGAS, we discovered that the second-stage reactions can work in different conditions to those that make the H2, so will explore this alternative route,” said Onwudili. 

The project has received funding from Marie Skłodowska-Curie Actions, the European Union’s reference programme for doctoral education and postdoctoral training, as well as from Aston University. 

It now aims to establish a dedicated research programme in the area of reforming and transformation of glycerol and other biomass-derived feedstocks to sustainable gaseous and liquid fuels.