Biodiesel is a renewable energy, alternative to rapidly depleting fossil fuels. Its main drawback is the production of low value crude glycerol, which potentially threatens the environment. But researchers say they've found the perfect solution to this.
Scientists at the University of Leeds in the UK not only have found a perfect alternative to simply disposing of glycerol, they've discovered a valuable hidden energy source. They've succesfully started turning low-grade sludge into high-value, hydrogen-rich gas.
Hydrogen is itself viewed as a future ‘clean’ replacement for hydrocarbon-based transport fuels, and most countries currently reliant on these fuels are investing heavily in hydrogen development programmes. At the moment, hydrogen is mostly in demand for use in fertilisers, chemical plants and food production.
The novel process was developed by Dr Valerie Dupont at
Leeds University's Faculty of Engineering. Dupont and colleagues mix glycerol with steam at a controlled temperature, separating the waste product into hydrogen, water and carbon dioxide, with no residues. A special absorbent material filters out the carbon dioxide, which leaves a much purer product.
“Hydrogen has been identified as a key future fuel for low carbon energy systems such as power generation in fuel cells and as a transport fuel", says Dupont.
The way hydrogen is produced at the moment is a lot more expensive. Scientists use either increasingly scarce fossil fuel sources to create hydrogen, or they turn to less efficient methods such as water electrolysis.
“Our process is a clean, renewable alternative to conventional methods. It produces something with high value from a low grade by-product for which there are few economical upgrading mechanisms” says Dr Dupont.
She adds that her method is also a near ‘carbon-neutral’ process. "The CO2 generated is not derived from the use of fossil fuels,” according to Dr Dupont.
As the race towards the ‘hydrogen economy’ accelerates, the process needs to become scalable to industrial production, something which Dr Dupont says is definitely a possibility. Glycerine derived hydrogen gas could be an economically important and sustainable way of meeting the growing demand for hydrogen, she believes.
Dr Dupont’s research has been funded with a £270k grant from the Engineering and Physical Sciences Research Council (EPSRC) under the Energy programme.
