che_february-2025 - 28

factors, regulatory environments and
access to transportation, utilization or
storage opportunities all play a role in
determining the most suitable downstream
destination, and by extension,
the most suitable capture solution.
Given this complexity, it is clear
that no single technology will be the
best across the entire spectrum of
applications and CO2 concentrations.
Instead, the industrial sector
will require a combination of technologies
to achieve cost-effective
CCUS at scale.
Conventional CCUS strategies
It's not what we say or think about
technologies that defines their place,
it's what they do - and don't do.
Before delving into the potential of
advanced membranes, it is worth
examining the limitations of existing
carbon capture technologies. While
existing technologies have an important
role to play in industrial decarbonization,
they tend to be better
suited for either large-scale capture
in chemical plants or capture from
high-pressure applications (Figure 2),
leaving a wide range of applications
underserved across many industries,
including cement, steel, glass, pulpand-paper
and waste-to-energy, to
name a few.
Amines - best for large chemical
plants. Amine scrubbing is the
go-to technology for large-scale carbon
capture in chemical plants [2].
In large-scale applications able to
handle the energy and chemical requirements,
amines work well, can be
deployed now, and are low risk. However,
there are thousands of industrial
applications where amines are not a
natural fit. Amine-based systems suffer
from high energy
requirements
(parasitic load) for
solvent
and potential for
chemical
TABLE 1. FIELD-VALIDATED CARBON-CAPTURE APPLICATIONS
FOR ADVANCED MEMBRANES
Location
regeneraissues,
emisVoestalpine
tion,
solvent degradation
sions.
They also
rely on economies
of scale, making
them unsuitable
RHI Magnesita
OMV Austria
Norcem/Norwegian University of
Science and Technology [4 ]
Wyoming Integrated Test Center/
Ohio State University [5 ]
for smaller applications. The extensive
balance-of-plant equipment essentially
requires a chemical plant
on-site, access to large amounts of
steam, and the technology has limited
potential for significant performance
improvements due to its maturity.
Traditional membranes - best for
high-pressure applications. What
about traditional membranes? What
role might they play in carbon capture?
Traditional membranes, while
already used in CO2 processing,
have primarily been developed for
high-pressure applications. The lowpressure
nature of fluegas presents
challenges, including high energy
costs associated with pressurizing
fluegas streams, which can add
more than $80 per ton to the cost of
capture. Furthermore, solution-diffusion
membranes require large membrane
surface areas and have limited
fouling tolerance, necessitating
additional feed conditioning for gas
streams with high impurities. The limitations
of existing amine and membrane
technology have created a gap
in the market for a technology that
can efficiently and cost-effectively
capture CO2 from diverse industrial
sources, particularly those with lower
pressure streams, low CO2 concentrations,
smaller
distributed operations,
or challenging
operating conditions.
Shutterstock
FIGURE 2. Conventional amine-based carbon-capture processes are
well-suited for large-scale, established processes, such as those found in
chemical plants
28
New membranes
Facilitated transport
is an advanced
membrane technology
that is emerging
as a natural fit
for carbon-capture
applications. Facilitated
transport
membranes (FTMs)
Industry/application
Steel production
Refractory materials production
Petrochemicals production
Cement manufacturing
Natural-gas combined-cycle
power plant
offer several advantages for carboncapture
applications that allow them
to fill the gaps left by conventional
technologies. FTMs can effectively
separate CO2 from dilute streams at
pressures as low as 1.4 bara, significantly
reducing energy requirements.
Their high selectivity and flux allow
for processing large gas flows in a
relatively small footprint, resulting in
a modular and compact design.
FTMs represent a significant leap
forward in membrane technology.
Unlike conventional separation technologies,
FTMs rely on the chemistry
of the membrane itself for energyefficient
separation. They contain
embedded carrier molecules that selectively
interact with and transport
target molecules (in this case, CO2)
across the membrane. This selective
transport results in high selectivity,
as the carrier molecules facilitate the
transport of CO2 while impeding the
passage of other gases.
Unlike amine-based systems,
FTMs do not rely on chemical solvents,
eliminating issues related to
degradation, emissions and regeneration.
Utilizing FTMs as part of
a composite membrane typically
consisting of a thin, selective layer
supported by a porous substrate,
allows for high flux rates along with
good selectivity. This unique combination
of properties allows FTMs
to achieve efficient CO2 separation
without the need for high pressure
or chemical regeneration, making
them an attractive option for a wide
range of industrial applications.
Modular and scalable technology
Next-generation membrane solutions
boast a modular, scalable and
flexible design that makes them
highly adaptable to the needs of
different industrial applications and
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
FEBRUARY 2025
http://WWW.CHEMENGONLINE.COM
che_february-2025

Table of Contents for the Digital Edition of che_february-2025
