12
June 2024 ESRFnews
C
ARBON DIOXIDE was once the planet’s
friend. It is the atmospheric ingredient for
photosynthesis, the reaction that sustains all
life – indeed, for millennia, nature has happily recycled
several hundred gigatonnes of the gas every year. Then
came the industrial revolution, the extensive burning of
fossil fuels, and a significant tip in the carbon balance.
Today, humans are responsible for adding more than
50 extra gigatonnes of CO
2
annually, with potentially
catastrophic consequences for the climate.
It is no wonder that CO
2
is now the world’s number
one enemy. Many governments have adopted policies to
progressively go “net zero” and put an end to emissions of
this greenhouse gas, in particular with the development of
sources of renewable power. Yet the actual progress has not
been fast enough. Most countries are still heavily reliant
on non-renewable energy, either for primary power or to
even out the irregularity of renewables. Battery-powered
vehicles are still owned by a minority of road users.
Fertiliser, fabrics, drugs, medical supplies, cosmetics,
electronics, food packaging, steel and many other
products still derive in critical ways from oil and natural
gas. Arguably, our habits have not changed radically.
Against this uncomfortable backdrop some scientists
have been rethinking our relationship with CO
2
Rather
than regard it as a friend or enemy these scientists have
begun to think about the greenhouse gas as something
in between a kind of necessary evil The idea would
be to capture and then with some renewablepowered
chemistry convert it into useful products from
chemical feedstocks for manufacturing to synthetic
fuels. Known as “power to X” – the “X” being certain
products that would previously have derived from oil
and natural gas – the process itself cannot permanently
reduce atmospheric CO
2
, but it can stop levels increasing
further, and go a long way to help the fight against
climate change. “The truth is, achieving global net-
zero emissions is a formidable challenge,” says Pieter
Glatzel, the ESRF’s group head of electronic structure,
magnetism and dynamics. “We need to reduce emissions,
but we’re going too slow. People are beginning to accept
that CO
2
conversion has to be part of the solution.”
In fact, to some extent, it already is. In Patagonia
last year, the German sports car manufacturer Porsche
opened one of the first electrofuel, or “efuel”, pilot plants.
Fed with electricity from a large wind turbine, the Haru
Oni plant (pictured opposite) filters CO
2
from the air
while splitting water into its constituent hydrogen and
oxygen via electrolysis. The oxygen is released back
into the atmosphere, while the hydrogen is employed to
chemically reduce CO
2
into methanol. That methanol
feedstock is then further processed to make ordinary
petrol – about 130,000 litres a year currently, but rising
to 550 million litres by 2027, if Porsche succeeds.
Porsche is not the only embracer of CO
2
reduction for
chemical synthesis. The multinational consumer-goods
company Unilever has piloted the use of captured and
reduced CO
2
for the manufacture of surfactants for
laundry detergent Another multinational Honeywell
has announced a plan to use it to make aviation fuel
But these are at present modest steps For the process
to operate at any kind of scale scientists must develop
catalysts that perform the reduction much more
effectively
Roham Dorakhan a doctoral student at the University
of Toronto in Canada is working on this Under the
supervision of his group leader Edward Sargent he has
been using Xray absorption spectroscopy XAS at the
ESRFs ID26 beamline to analyse catalysts before and
Instead of avoiding emissions of carbon dioxide entirely,
should we convert this greenhouse gas into useful products?
ESRF users explore the possibilities.
Big carbon
blueprints
“We need to reduce emissions, but we’re
going too slow People are beginning to
accept that CO
2
conversion has to be
part of the solution
P O R S C H E A G
CO
2
REDUCTION