Garden grass could become a source of cheap and clean renewable energy, say scientists who have developed a novel way of deriving hydrogen from grass using just sunlight and a cheap catalyst. Researchers, including experts from Cardiff University in the UK, have shown that significant amounts of hydrogen can be unlocked from fescue grass. It is the first time that this method has been demonstrated and could potentially lead to a sustainable way of producing hydrogen, which has enormous potential in the renewable energy industry due to its high energy content and does not release toxic or greenhouse gases when it is burnt.
“This really is a green source of energy,” said Professor Michael Bowker, from the Cardiff Catalysis Institute.”Hydrogen is seen as an important future energy carrier as the world moves from fossil fuels to renewable feedstocks, and our research has shown that even garden grass could be a good way of getting hold of it,” said Bowker. Hydrogen is contained in enormous quantities all over in the world in water, hydrocarbons and other organic matter.
Up until now, the challenge for researchers has been devising ways of unlocking hydrogen from these sources in a cheap, efficient and sustainable way.
A promising source of hydrogen is the organic compound cellulose, which is a key component of plants and the most abundant biopolymer on Earth.
Researchers, including those from Queen’s University Belfast, investigated the possibility of converting cellulose into hydrogen using sunlight and a simple catalyst – a substance which speeds up a chemical reaction without getting used up. This process is called photoreforming or photocatalysis and involves the sunlight activating the catalyst which then gets to work on converting cellulose and water into hydrogen.
The researchers studied the effectiveness of three metal-based catalysts – Palladium, Gold and Nickel.
Nickel was of particular interest to the researchers as it is a much more earth-abundant metal than the precious metals, and is more economical.
In the first round of experiments, the researchers combined the three catalysts with cellulose in a round bottom flask and subjected the mixture to light from a desk lamp.
At 30 minutes intervals the researchers collected gas samples from the mixture and analysed it to see how much hydrogen was being produced.
To test the practical applications of this reaction, the researchers repeated the experiment with fescue grass, which was obtained from a domestic garden.
“Up until recently, the production of hydrogen from cellulose by means of photocatalysis has not been extensively studied,” Bowker said. “Our results show that significant amounts of hydrogen can be produced using this method with the help of a bit of sunlight and a cheap catalyst,” he added. The finding was published in the journal Proceedings A.