che_november-2024 - 5

Chementator
Edited by: Dorothy Lozowski
A low-cost method for bio-based production of acrylic acid
A
crylic acid, a commodity chemical used widely
in superabsorbent polymers, paints, coatings,
adhesives and more, is typically produced from
fossil-based propylene at relatively high temperatures.
As part of an initiative supported by the U.S. Dept.
of Defense, funding was recently awarded to Industrial
Microbes, Inc.
(iMicrobes; Alameda, Calif.; www.imicrobes.com)
towards commercializing a new bio-based
manufacturing process for acrylic acid that reduces both
the cost and carbon footprint (diagram). " We are using
the support to plan our first commercial facility that will
use a fermentation process to convert ethanol into acrylic
acid and derivatives, " says Noah Helman, iMicrobes
CEO. The company has engineered microorganisms to
consume plant-based ethanol as a carbon and energy
source. Within a proprietary engineered bacterial cell, an
intermediate polymer (a polyester of 3-hydroxypropionate,
or P3HP) is readily accumulated as fermentation
takes place. " That polymer can be converted to acrylic
acid via a very simple catalytic
cracking process.
With heating to a moderate
temperature, the catalyst
decomposes the polymer
into acrylic acid vapors,
which can be captured and
purified using standard unit
operations like distillation, "
says Helman.
In June, iMicrobes
began scaling up the process
at a facility in Emeryville,
Calif., operating at the kilogram scale for the
first time outside of the laboratory. " Then, in August,
with support from BioMADE, we began operating that
same process in a 1,500-L fermenter at a site in Illinois,
generating several more kilograms of product, "
adds Helman.
The key to the process' efficiency is the accumulation
of the intermediate polymer, which is generated at very
high concentrations inside the bacterial cell. " In our cost
modeling, we estimate that we should be able to produce
acrylic acid at about 20% lower cost than today's
existing methods, and the carbon footprint should be reduced
by 75% or even more, depending on the source
of the ethanol, " says Helman.
The first applications for iMicrobes' acrylic acid products
will be in consumer personal-care products, where
bio-based raw materials carry a particular premium, and
the company is also looking at routes to additional products
beyond acrylic acid.
iMicrobes
'Frugal' method adsorbs and destroys PFAS with photocatalyst
R
emoving per- and polyfluoralkyl substances
(PFAS) from surface and groundwater has become
an environmental and public health imperative,
but methods for doing so are often
complicated and costly, and may not destroy the molecules.
Researchers at the University of British Columbia
(UBC; Vancouver, B.C.; www.ubc.ca) have developed a
hybrid iron-oxide and graphenic-carbon photocatalyst
that can degrade PFAS efficiently in the presence of ultraviolet
(UV) light.
The UBC system combines an activated carbon filter,
which adsorbs the PFAS species, with its patented
photocatalyst, which destroys the PFAS molecules.
" We can put huge volumes of water through this catalyst,
and it will adsorb the PFAS and destroy it in a quick
two-step process, " says Johan Foster, UBC professor
of chemical and biological engineering. " Many existing
solutions can only adsorb [PFAS], while others are designed
to destroy the chemicals. Our catalyst system
can do both. "
The UBC work involves immobilizing a photoactive
iron oxide on solid surfaces of mesoporous carbon.
The researchers developed a " frugal " approach for preCHEMICAL
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paring the photocatalyst that takes advantage of iron
oxide, which is known for its photoactivity and ability to
drive charge separation.
In tests, the UBC system demonstrated the ability to
capture and destroy up to 90% of perfluorooctanoic acid,
a common PFAS pollutant, in 3 hours under UV light.
" The catalyst is not limited by ideal conditions, " explains
Raphaell Moreira, a professor at the Universität Bremen
who conducted the research while working at UBC. " Its
effectiveness under varying UV light intensities ensures
its applicability in diverse settings, including regions with
limited sunlight exposure. " The catalyst also maintains
high degradation rates over extended periods, demonstrating
its stability and potential for long-term use, the
researchers say.
The UBC team believes their catalyst could be a lowcost
solution for municipal water systems, as well as
specialized industrial projects, like cleaning up PFAScontaining
waste streams. The researchers have set up
a company, known as ReAct Materials, to explore commercial
opportunities for the technology. Details of the
work were published recently in the Nature journal Communications
Engineering.
NOVEMBER 2024
5
http://www.imicrobes.com http://www.imicrobes.com http://www.ubc.ca http://WWW.CHEMENGONLINE.COM
che_november-2024

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