Cardiff University
A new way of deriving hydrogen from grass has now been developed using just sunlight and a cheap catalyst. Garden grass could become a source of cheap and clean renewable energy, scientists have claimed in a new report.
Garden grass could
become a source of cheap and clean renewable energy, scientists have claimed.
A team of UK
researchers, including experts from Cardiff University's Cardiff Catalysis
Institute, have shown that significant amounts of hydrogen can be unlocked from
fescue grass with the help of sunlight and a cheap catalyst.
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 the fact that it does not release toxic or greenhouse gases when it is burnt.
Co-author of the study
Professor Michael Bowker, from the Cardiff Catalysis Institute, said:
"This really is a green source of energy.
"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."
The team, which also
includes researchers from Queen's University Belfast, have published their
findings in the Royal Society journal Proceedings A.
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.
In their study, the
team 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, from a practical point of view, 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.
Professor Michael
Bowker continued: "Up until recently, the production of hydrogen from
cellulose by means of photocatalysis has not been extensively studied.
"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.
"Furthermore,
we've demonstrated the effectiveness of the process using real grass taken from
a garden. To the best of our knowledge, this is the first time that this kind
of raw biomass has been used to produce hydrogen in this way. This is
significant as it avoids the need to separate and purify cellulose from a
sample, which can be both arduous and costly."
