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| The solar reactor and researcher team at ETH Zürich |
THERE is a ray of hope for us car addicts who must pay whatever
the pushers demand for our next fix of diesel or petrol, for scientists at the EU-funded Solar Jet this week showed how
concentrated sunlight can be used to convert carbon dioxide and water into jet
fuel.
Their proof-of-concept is a major step towards the new scientific
holy grail: finding ways to convert, store and transport the energy in a beam of
sunlight using thermodynamic theory.
A ray of sunshine does not have a lot of energy, but if you focus a
few rays of sunlight with a parabolic dish they will quickly melt a hole through
most metals. Enough heat from concentrated sunlight also splits water into its
hydrogen and oxygen components.
The process is now long proven — the challenge is to leave the
laboratory standing when the split happens.
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| The jet fuel and by-products produced by Solar Jet. |
The red-ox cycle and some WWII know-how
One way is the red-ox
cycle, which abbreviates reduction oxidation and first uses the sun’s heat to
heat up a metal oxide until all the oxygen has parted ways with the metal.
The red-ox cycle then uses the naked metal to lure the oxygen
molecules in water to make a bit of rust, leaving the hydrogen free to become
fuel for someone’s car or aeroplane.
Solar Jet added carbon dioxide to the red-ox cycle to let the fake
sun turn water into hydrogen and carbon monoxide, also known as syngas (for
synthesis gas).
Syngas is organic chemistry’s Lego, being the building block of
several commodities, including methanol.
Dr Andreas Sizmann, the project co-ordinator at Bauhaus Luftfahrt,
said they then used the Fischer-Tropsch process, first used by the Nazis, to
turn the syngas into methanol.
Sasol has since perfected the 1925 German technology to turn coal
into South Africa’s cleanest diesel and petrol, while Shell uses it to make jet
fuel for aeroplanes.
Counting the cost
Solar Jet now has to
count the cost of implementing the technology on an industrial scale.
When Sasol expanded globally after 1994 and fuel was still at $60
(R631,17) a vat of Brent crude, its refineries cost a lot more than a “normal”
oil refinery, but once in place, Sasol could (and can) make oil quite a bit
cheaper than $60 per vat.
Currently, with oil artificially maintained at over $100
(R1 051,95) per vat, according to oil pundit Leonardo Maugeri, Sasol is making a
lot more money from us fuel addicts than what any right-thinking people, and
even members of the SA Communist Party, deem fair.
Which is why we have to yell encouragement to the white coats at
Solar Jet. They have, to date, made only one glass of jet fuel in a lab using
simulated sunlight to prove the concept, and said it will take until next year
to determine if the technology can scale up and remain both cost and
energy-efficient.
‘Double toil, no trouble’
If Solar Jet does
manage to make jet fuel from CO², H²O
and lots of Vitamin D, they will have, in Sizmann’s words: “Truly sustainable
fuels with virtually unlimited feedstocks”.
The ramifications are enormous for all humankind. As Professor Aldo
Steinfeld, who led the fundamental research and development of the solar reactor
at ETH Zürich, said in the paper Fuel from Sunlight, such a
clean, universal sustainable energy source would avoid a major worldwide energy
crisis.
Borrowing from Macbeth’s “Double, double toil and trouble, fire
burn and cauldron bubble”, Steinfeld wrote that solar-based fuel research, such
as he led at ETH Zürich, hopes “to avoid the bubbling cauldrons by riding out
the 21st century on a sunbeam”.
