Chemical Engineering October 2020 - 5

Chementator
A more efficient way to upgrade lignin bio-oils
H2 Gas
L
ignin bio-oil is a common
waste stream formed during
the production of cellulose
and ethanol from biomass.
Due to its high oxygen and low hydrogen
content, lignin bio-oil must
be upgraded via hydrogenation and
deoxygenation before it can be used
as a fuel. Furthermore, because of
the very low hydrogen solubility in
water and high activation energy of deoxygenation,
lignin bio-oil upgrading typically
requires processing at very high temperatures
and hydrogen pressures.
Now, a team of scientists from Georgia
Institute of Technology (Atlanta, Ga.; www.
gatech.edu), led by professor Yulin Deng,
has studied a solution-based, dual-catalyst
system for combined hydrogenation and
deoxygenation of lignin bio-oil that operates
at ambient conditions (diagram). They
found that polyoxometalate acid (SiW12)
can react with H2, transfer H+ to water,
and release hydrogen as an active species
inside the water in the presence of a
platinum-based catalyst.
H2 gas and alkane vapor
H2 for recycling
Bio-oils
feedstock
H2catalyst
solution
Heater
Alkane
products
GA Tech
The team also observed that SiW12 can
significantly reduce the activation energy of
deoxygenation. As a result, SiW12 can act
as both a hydrogen-transfer agent and a
deoxygenation catalyst, which overcomes
issues associated with hydrogen's low solubility
in water at low pressures and the
high activation energy of deoxygenation.
So far, the technology has been demonstrated
in a laboratory-scale batch reactor.
According to Deng, the process is versatile
enough to produce many products beyond
fuels, including benzene, cyclohexane, toluene,
cyclohexanol and many others. " The
key parameters to control the product selectivity
include the type of catalyst, reaction
time and temperature. Using different
catalysts, the same lignin monomer may
be converted to different final products, "
adds Deng. " We have only tested platinum
and palladium so far, and we found
the ratio of the final products shifts, which
means the product selectivity can be adjusted
by using different catalysts. This is
one of our future research topics. " The
team is also looking at how lignin monomers
can be partially hydrogenated or hydrodeoxygenated
in the early stages of the
reaction, and how the reaction progression
over time can be controlled to yield
different final products.
Increasing energy density in capacitors
C
apacitors are attractive in largescale
energy-storage applications,
such as electric vehicles
or grid storage, because of their
ability to rapidly charge and discharge, but
their energy densities have been too small
to allow their use in such applications. Researchers
at Lawrence Berkeley National
Laboratory (Berkeley, Calif.; www.lbl.gov)
have developed a technique to boost the
energy density of a " relaxor ferroelectric, " a
ceramic material commonly used as a capacitor
in applications like ultrasonics, pressure
sensors and voltage generators.
When a relaxor ferroelectric material is
subjected to an electric field, a charge
builds up, but the material will fail in the
presence of strong electric fields. When
discharging, the amount of energy available
for use depends on the degree of electron
polarization (orientation) in the ceramic. So
the Berkeley team needed to find a way to
render the material capable of withstanding
high voltages while still retaining the electron
polarization.
To do this, they bombarded a thin film
of the relaxor ferroelectric material (specifically,
niobite lead titanate) with high-energy
helium ions, which introduced isolated point
defects into the atomic structure of the film.
The material with the targeted defects had
more than twice the energy storage density
than previously reported values, the researchers
found.
Studies on the material revealed that the
induced defects reduced the charge leakage,
but also shifted the material's polarization-electric-field
relationship, which means
that it takes a higher voltage to reach the
maximum electron polarization. The results
suggest that ion bombardment can help to
overcome the trade-off between being a
highly polarizable material and being easily
breakable, the researchers say.
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
OCTOBER 2020
ETHYLENE DICHLORIDE
Recently, Chemetry (Moss Landing,
Calif.; www.chemetrycorp.
com) and Braskem (Sao Paulo,
Brazil; www.braskem.com) announced
their intent to construct
and operate a demonstration
plant using Chemetry's eShuttle
technology for the production of
ethylene dichloride (EDC) in Brazil.
The initial focus of this agreement
will be the construction of a
demonstration unit to be installed
at Braskem's Chlor-alkali Maceió
site, Alagoas State, Brazil. Chemetry's
eShuttle technology eliminates
chlorine generation from the
traditional chlor-alkali process. It
replaces the chlor-alkali and directchlorination
processes with a single,
integrated process that uses
a circulating stream of aqueous
copper chloride to transfer chloride
ions from NaCl to ethylene.
Like the processes it replaces,
the eShuttle technology uses the
same feedstocks - NaCl brine,
water and ethylene - to produce
the same products - EDC, caustic
and H2 - but at much lower
energy and operating cost and
without Cl2 gas generation.
Li EXTRACTION
Energy Exploration Technologies
(EnergyX; Newark, Calif.;
www.energyx.com) recently announced
a development partnership
with Australian mining company
Orocobre Ltd. (Brisbane;
www.orocobre.com) on technology
to extract lithium ions from
salt brines. EnergyX's technology
uses metal-organic frameworks
(MOFs) embedded inside nanoscale
channels in a polymer
membrane to selectively separate
lithium ions from salt brines. The
method is envisioned as a more
environmentally friendly lithiumharvesting
alternative to conventional
methods, such as mining
lithium-containing ores and evaporating
brine ponds under the sun.
EnergyX anticipates full commercialization
of the direct lithium-extraction
technology in 2022.
SUPER-AUSTENITIC ALLOY
In late August, Sandvik Materials
Technology, a part of the Sand(Continues
on p. 6)
5
Edited by:
Gerald Ondrey
Cooling column
http://www.chemetrycorp http://www.braskem.com http://www.gatech.edu http://www.energyx.com http://www.orocobre.com http://www.lbl.gov http://WWW.CHEMENGONLINE.COM
Chemical Engineering October 2020

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