Chemical Engineering May 2020 - 10

incident light. Increasing the
thickness of the foil extends
the reflectance to 80 to 90%.
The sponge-like microstructure
was applied to acryl glass,
but the process may be transferred
to many other polymers,
says KIT.
CO2 CAPTURE
At the end of March, Calix Ltd.
(Pymble, New South Wales,
Australia; www.calix.global)
announced final project agreements
were made for the
scaleup of its Low Emissions
Intensity Lime And Cement
(LEILAC) technology for capturing
unavoidable CO2 process
emissions during the production
of lime and cement.
The LEILAC-2 demonstration
plant will be a four-fold scaleup
of the LEILAC-1 pilot plant,
currently undergoing operational
testing at HeidelbergCement
AG's (Germany; www.
heidelbergcement.com) Lixhe
cement production facility in
Belgium. Early results from the
pilot have proven the technology
concept, and work continues
on the gradual increase in
operational throughputs, temperatures
and durability testing
in a test program that will run
until the end of 2020.
Officially launched on April 7,
LEILAC-2 will run to the end of
2024. It will involve the design,
construction and operational
testing of a 100,000 ton/yr
CO2-capture facility at a working
cement plant in Europe. The
LEILAC-2 consortium consists
of industrial partners HeidelbergCement,
Cimpor, Engie,
IKN and Lhoist, as well as universities,
research institutes and
various statutory organizations,
and will be led by Calix, co-ordinated
through its Calix-Europe
subsidiary in France. The LEILAC
2 project is based on Calix's
calcination technology and
is supported with €16 million
from the E.U. research funding
program Horizon 2020.
More CO2 is emitted from
cement production than any
other industry. Many countries,
regions, and companies are
now pledging net-zero CO2
emissions by 2050. In May
2019, HeidelbergCement also
committed to net zero CO2
emissions by 2050, the first
cement company to do so. ❒
10
'Artificial photosynthesis' system design
overcomes problem of fast proton flow
A
rtificial photosynthesis
systems
seek to
harvest sunlight
and carbon dioxide
to make fuels.
Among the many challenges
for making solar
fuels has been achieving
a fast flow of protons
from where they
are generated to where
they combine with CO2
and electrons to make
fuel.
Now,
scientists
at Lawrence Berkeley
National Laboratory
(Berkeley, Calif.; www.lbl.gov) led by Heinz
Frei have demonstrated the rapid transfer of
electrons in a design for " solar fuel tiles " that
could allow the efficient generation of fuels
from sunlight.
A recent paper from Frei's group in Advanced
Functional Materials describes how the solar
fuel tiles - which contain billions of hollow, nanoscale
tubes - are able to facilitate proton
transfer. The hollow tubes consist of three layers:
an inner layer of cobalt oxide, where energy
from sunlight is harnessed to split water
molecules into protons and oxygen; and an
outer layer of titanium dioxide, which supports
Berkeley National Laboratory
1 µm
O2
H+
12 nm Co3O4
a catalyst to promote the
reaction of CO2 into fuel.
Between them, a thin
layer of amorphous silica
allows linkages between
the
two
nanolayers,
which provides " fast proton
hopping pathways
across the solid-to-solid
interfaces, " Frei says.
While
allowing
2 nm SiO2
5 nm TiO2
layer
fast
proton transfer, the
silica
separates
the two chemical reaction
zones. " This design
mimics actual living photosynthetic
cells, which
separate oxidation and reduction reactions
with organic membrane compartments inside
the chloroplast, " the Berkeley Lab researchers
say. " Similarly in line with nature's
original blueprint, the team's membrane
tubes allow the photosynthetic reaction to
occur over a very short distance, minimizing
the energy loss that occurs as ions travel and
prevent unintended chemical reactions that
would also lower the system's efficiency. "
Right now, CO is generated in the sunlight
reaction, but the researchers are currently
working toward producing methanol with
the membrane.
New catalyst selectively promotes
hydrodeoxygenation reaction
S
cientists at Brookhaven National
Laboratory (BNL; Upton, N.Y.;
www.bnl.gov) and the University of
Delaware (Newark; www.udel.edu)
have designed a catalyst capable of selectively
removing oxygen atoms from the side
chain of an aromatic compound without
affecting the ring. The team demonstrated
the catalyst by converting the plant derivative
furfuryl alcohol into the potential biofuel
2-methylfuran through a hydrodeoxygenation
reaction.
The catalyst consists of highly dispersed
platinum atoms (single atoms or sub-nanometer
clusters) doped onto the surface of
a support, the moderately reducible metal
oxide TiO2. TiO2 was chosen because it
avoids bulk reduction, which is observed
with other metal oxides that are the most
active for C-O bond breaking. The catalyst
design selectively breaks the carbon-oxygen
bond on the side group of the plant alcohol
without sparking any reactions involving the
aromatic ring (diagram).
Selective
C-O bond activation
O
OH
O
O
O
OH O
O
Ti
Pt
OH
Ultra-low loading
Brookhaven National Laboratory
When only a low concentration of Pt is
used, the ring reactions are negligible, but as
the Pt concentration is increased, the platinum
atoms begin to aggregate into larger
clusters, which incite
team says.
ring
reactions,
the
The BNL-Delaware study of biomass conversion
to biofuels used a combination of experiments,
characterization techniques and
computer simulations that allowed a detailed
understanding of the surface chemistry. This
approach could help predict additional catalyst
designs that could carry out other conversions
of desired products, the scientists say.
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM MAY 2020
http://www.calix.global http://www.lbl.gov http://www.heidelbergcement.com http://www.bnl.gov http://www.udel.edu http://WWW.CHEMENGONLINE.COM
Chemical Engineering May 2020

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