Chemical Engineering April 2013 - 16

(Continued from p. 14)
ChementatoR
MOFs that reversibly capture CO2
A
n Australian team has developed a structure
made of a metal organic framework
(MOF) that captures and then releases CO2
using natural sunlight. The team includes
researchers from: CSIRO Division of Materials
Science and Engineering, (Clayton
South, Victoria; www.csiro.au) the Dept. of
Chemical Engineering, Monash University
(www.monash.edu.au) and the School of
Chemistry, University of Sydney (www.sydney.edu.au).
" The
capture and release process can be
compared with soaking up water with a
sponge and then wringing it out, " explains
Matthew Hill, who led the CSIRO group.
" When ultraviolet (UV) light hits the material,
its structure bends and twists and
stored gas is released. "
MOFs are among the most attractive potential
adsorbents to replace more energy-demanding
commercial adsorbents, because of
MOFs' high adsorption capacity, and the possibility
of incorporating light-responsive organic
groups within the MOFs' pore structure.
The large internal surface areas of the newly
developed MOFs can adsorb large quantities
of gases, including H2, CH4 and CO2.
Azobenzene and its derivatives, in particular,
can undergo clean and efficient reversible
photoisomerization about the azo
bond to cis and trans states upon irradiation
(coordinated trans: lmax ≈ 370 nm, cis: lmax
≈ 460 nm). Conversion of azobenzene to the
4,4'-dicarboxylate (AzDC) delivers a ligand
that can be incorporated into MOF architectures.
Besides, the pillar ligand trans-1,2bis(4-pyridyl)ethylene
(4,4'-BPE) also exhibits
cis-trans photoisomerizability when
coordinated to a metal complex.
Combination of these two ligands within
zinc-based MOFs generates the triply
interpenetrated framework Zn(AzDC)
(4,4'-BPE)0.5,which exhibits a selective and
high capacity adsorption of H2 and CO2.
Exposure to UV light results in an instantaneous
release of up to 64% of the
absorbed CO2 using broadband radiation,
similar to concentrated solar sources. Furthermore,
the response was found to be
fully reversible.
■
example, it is 20% stiffer and
can be processed to create intricate
structures. Applications
for the new composite include
the heat-treatment of steel
components for the automotive
and aerospace industries,
and in the coating of silicon
wafers in the photovoltaic industry,
says the company.
Largest CSP launched
Last month, Masdar (Abu
Dhabi, UAE; www.masdar.
ae) and partners inagurated
Shams 1, which is said to be
the largest concentrated solar
power (CSP) plant operating
in the world. The 100-MW CSP
incorporates 258,000 mirrors
mounted on 768 tracking parabolic-trough
collectors, which
concentrate heat from sunlight
onto oil-filled tubes. The heat
is used to make steam to drive
a turbine for generating electricity.
The $600-million facility
was designed and developed
by Shams Power Co., a joint
venture of Masdar, Total and
Abengoa Solar. ❏
Simultaneous heat transfer
and mass transfer model
in column.
Good thinking.
Feedback from our users is what inspires us to keep making
CHEMCAD better. Many features, like this one, were added to
the software as a direct response to user need. That's why we
consider every CHEMCAD user part of our development team.
Get the whole story behind this user-inspired feature and
learn more about how CHEMCAD advances engineering
at chemstations.com/InspireUs.
C
Aaron Herrick, CHEMCAD Developer →
Engineering advanced
© 2013 Chemstations, Inc. All rights reserved. | CMS-2336 4/13
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Chemical Engineering April 2013

Table of Contents for the Digital Edition of Chemical Engineering April 2013
