Chemical Engineering April 2022 - 6

taining alkali, alkaline earth and
heavy metals at relatively high
concentrations, ranging from
100 mg up to several grams per
liter. Such solutions occur,
for
example, during the treatment
of geothermal brine following the
desorption from primary adsorber
material. The removal of the polyvalent
ions - mainly calcium -
from these solutions takes place
very efficiently, with low leakage,
and at high flowrates owing to the
exceptional exchange kinetics. At
the same time, the pressure drop
across the resin bed is low.
The resin has a high total capacity
of more than 4.3 equivalents per
liter, which translates into longer
intervals between the regeneration
phases than standard resins.
This reduces the amount of regeneration
chemicals and water
required, the company says.
MOLECULAR SIEVE
Graphene has many remarkable
properties, but because the material
has no pores, it cannot act
alone as a molecular sieve without
piercing the material with high
precision pores. There have been
many attempts to do this, but the
result has been unfruitful due to a
breakdown in structural integrity.
Although it has been known since
2010 that 2-D silicon dioxide has
pores naturally in its crystal lattice,
it is very expensive to manufacture,
and can only be done on
a small scale. Now, scientists at
Bielefeld
University
(www.unibielefeld.de),
Ruhr-University
Bochum (both Germany; www.
ruhr-uni.de) and Yale University
(New Haven, Conn.; www.yale.
edu) have developed a fabrication
process for making a layer
of porous, 2-D SiO2. " This is very
exciting because 2-D SiO2 has a
very high density of tiny pores by
nature that is simply not possible
to be created in artificial membranes, "
says Petr Dementyev
from the Physics of Supramolecular
Systems and Surfaces
research group in Bielefeld.
As described in a recent issue
of Nano Letters, the researchers
devised a new material fabrication
process, which used atomiclayer
deposition to deposit a
large-area single layer of SiO2
on a gold/mica substrate. The
film was then transferred onto
Si3N4 windows for characterization.
Permeation experiments
with gaseous and vaporous sub(Continues
on p. 8)
6
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
APRIL 2022
Phosphine-based ligand now available on the
kilogram scale
S
inocompound
Catalysts Co.,
Ltd. (Zhangjiagang,
China;
en.sinocompound.com)
says it is now producing
the phosphinebased
QPhos ligand in
kilogram quantities for
commercial use. With
this ligand now accessible
on a large scale,
scientists across the globe can incorporate
QPhos-based catalysts into their
drug discovery, screening and processdevelopment
programs to optimize and
streamline product development.
QPhos is a promising ligand in metalcatalyzed
cross-coupling reactions,
which are fundamental to building carbon-carbon
bonds featured in most drug
scaffolds. However, until now QPhos has
not been readily available in commercial
quantities, hindering its adoption in
process development and scale-up programs,
says the company.
QPhos is a robust dialkylarylphosphine
ligand (diagram) first developed by John
Hartwig, the Henry Rapoport Professor of
Chemistry at the University of California,
Berkeley (hartwig.cchem.berkeley.edu) for
metal-catalyzed cross-coupling reactions,
Sinocompound
and reported in a 2002 article published
in J. Org. Chem. Bulky and electron-rich,
QPhos performs " excellently " in many
transformations, including α-arylation of
carbonyl compounds and late-stage C-C
bond formation, says the company.
" There's an enormous amount of untapped
potential in ligands that scientists
simply can't access on a large scale, so
they discount them from their screening
programs, " says Carin Seechurn, associate
director - Technology Solutions, Sinocompound.
" Our capability to scale-up
the QPhos ligand represents a significant
milestone in improving ligand accessibility
for researchers. As we continue to expand
our manufacturing processes thanks to
our new plant in Tongling, we're excited
to provide more overlooked ligands and
products commercially. "
A simpler way to recover purified graphite from
spent batteries
A
new recycling process claims
to significantly reduce the complexity
of recovering graphite
from spent lithium-ion battery
(LIB) materials by leaching out impurities
rather than leaching out metal. By extracting
impurities and recovering high-grade
graphite,
the Hydro-to-Anode technology,
developed by Ascend Elements, Inc.
(Westborough, Mass.; www.ascendelements.com)
and Koura Global (Waltham,
Mass; www.kouraglobal.com), keeps all
critical metals, such as Li, Co, Ni and
Mn, in solution, which greatly simplifies
the process flow for the production of LIB
precursor materials.
" Typical LIB-recycling processes either
destroy the graphite or recover lowerquality
graphite that cannot be used in
the manufacture of new batteries. Our
process extracts and purifies graphite
before the critical cathode materials are
recovered, " explains Eric Gratz, chief
technology officer at Ascend Elements.
The Hydro-to-Anode process has yielded
over 99.9% pure graphite with comparable
energy density and cycle life to
" virgin " battery-grade graphite. In combination
with Ascend's Hydro-to-Cathode
technology, which separates impurities
from Li, Ni, Mn and Co with significantly
fewer steps than hydrometallurgy or pyrometallurgy
processes, the Hydro-toAnode
process extends the company's
capacity to recover more value from
spent LIBs by producing both cathode
and anode materials.
Currently, Ascend Elements is recovering
and purifying graphite in small batches
at its recycling and manufacturing facility in
Westborough, Mass., and work is underway
for a commercial-scale plant in Covington,
Ga., says Gratz. The new plant is
scheduled to start up in the third quarter
of 2022, and it will process 30,000 metric
tons per year (m.t./yr) of battery materials.
http://en.sinocompound.com http://hartwig.cchem.berkeley.edu https://www.uni-bielefeld.de/(en)/ https://www.uni-bielefeld.de/(en)/ https://www.ruhr-uni-bochum.de/en http://www.yale.edu https://www.ascendelements.com https://www.ascendelements.com https://www.kouraglobal.com http://WWW.CHEMENGONLINE.COM
Chemical Engineering April 2022

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