(484a) Selective Adsorption of CO2 On Flexible Ni/Dbm-Bpy MOF | AIChE

(484a) Selective Adsorption of CO2 On Flexible Ni/Dbm-Bpy MOF


Matranga, C., National Energy Technology Laboratory
Culp, J., National Energy Technology Laboratory

Adsorption of CO2 on Flexible

Fan Shi1,2,*,  Jeffrey
Culp1,2 and Christopher Matranga1,

(1)U.S. Department of Energy, National
Energy Technology Laboratory, Pittsburgh, PA, USA (2)URS
Corporation, South Park, PA, USA

* fan.shi@netl.doe.gov

To maintain fossil fuels as
viable energy source, carbon capture and storage technology is essential. Recent
novel sorbents for CO2 capture 1-3, including Metal
Organic Frameworks (MOFs), have attracted a lot of interests. Flexible MOFs
have one attractive feature that their structure become
dynamic only in the presence of suitable guests such as CO2, CH4,
N2, and H2. These flexible materials can show interesting
host-guest phenomena including crystal-crystal transformations and gated
adsorption behaviors due to the structural transitions which occur between the
guest free and guest-loaded states.4-6 Such dynamic host-guest
behavior is particularly attractive for applications involving sorbent-based
gas separations and selective adsorption such as CO2 and CH4
separations.7-9 In order to develop materials for these
applications, a detailed understanding of the adsorption mechanisms of these
flexible hosts is needed.

The material in this study
is the linear chain coordination polymer catena-bis (dibenzoylmethanato)-(4,4′-bipyridyl)nickel(II),
or referred as ?NiDBM-BPY?. This neutral
one-dimensional polymer was propagated by a bridging 4,4′-bipyridine
ligand bound to the z-axes of the nickel complexes
which were bischelated in a planar fashion by two
anionic DBM ligands. CO2 breakthrough from
binary mixtures, including CO2/N2, CO2/H2,
and CO2/CH4, was performed in a fix-bed reactor with ID
of 0.375? and a length of 12?. The average particle size of NiDBM-Bpy
was around 100 mm to minimize external mass transfer limitations. The gas composition
of effluent was analyzed by a Mass Spectrometry (Pfeiffer Vacuum). The breakthrough curve of CO2
from a fixed-bed reactor packed with NiDBM-Bpy showed
a step-shape curve, which also indicated the structure expansion above the structure
transition threshold pressure. The selectivity for CO2 over N2,
H2, and CH4 was calculated and results confirmed the
sorbent's affiliation to CO2 than other gases.


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