607
adsorption studies. The MOF with desired porosity and cavity is considered to be
more suitable for selective gas adsorption. The materials can be designed with
desired pore size, active sites, polar functional groups and also with alkali metal
cations that are essential for selective adsorption. MOFs are suitable for capturing
CO 2 under elevated pressure sceneries such as natural gas purification and coal gasification. At low CO 2 partial pressures, zeolites and activated carbons perform better
than MOFs. However, the MOF with excellent adsorption capacity under mild reaction conditions is rare in the literature [44, 45].
2.4 Separation Through Membrane
Membranes, another kind of fascinating separation material, are generally applied
for gas separation. In general, the membrane-type materials are fabricated using the
permeable or semipermeable materials, and such permeable and semipermeable
membranes showed better selectivity towards CO 2 . The major advantage for the
membrane separation includes (1) simple operational techniques with minimum
energy, (2) compactness in their design with suitable concentration of adsorbent
material, and (3) simple installation of modules into existing infrastructures without
any movable parts.
The zeolite membranes are most explored for the pre- and post-combustion CO 2
capture, when compared to other inorganic membranes [46, 47]. The highlighted
advantages of zeolite membrane [48] include (1) outstanding mechanical properties, (2) thermal stability, (3) least fabrication costs, etc. Such properties made zeolites as efficient materials for post- [49] and pre-combustion CO 2 capture [50]. The
MOF membrane with extremely high porosity and surface areas is found efficient
for selective trapping of CO 2 [51].
Mixed matrix membranes [52] include a bulk and uniform polymer phase in
combination with a homogeneously assembled inorganic distinct phase. Both of
them are promising, because they enable synergistic enhancements in CO 2 permeability and selectivity with desirable mechanical and thermal stability.
2.5 CO 2 Capture from Atmosphere
The industrial process for capturing CO 2 from ambient air is one of an emerging set
of technologies for making clean environment. This CO 2 capture is having great
impact on geological storage of biotic carbon as well as the acceleration of geochemical weathering [53, 54]. In order to address this global climate change problem, the capture of atmospheric CO 2 is very crucial in addition to the CO 2 capture
from the industrial stationary points. The CO 2 removal from atmospheric air has
become a very critical area of research [55, 56], alternatively avoiding CO 2 to mix
with the air and capturing them at the mixing point from industry/vehicles, etc.
Efficient Homogeneous Catalysts for Conversion of CO 2 to Fine Chemicals
adsorption studies. The MOF with desired porosity and cavity is considered to be
more suitable for selective gas adsorption. The materials can be designed with
desired pore size, active sites, polar functional groups and also with alkali metal
cations that are essential for selective adsorption. MOFs are suitable for capturing
CO 2 under elevated pressure sceneries such as natural gas purification and coal gasification. At low CO 2 partial pressures, zeolites and activated carbons perform better
than MOFs. However, the MOF with excellent adsorption capacity under mild reaction conditions is rare in the literature [44, 45].
2.4 Separation Through Membrane
Membranes, another kind of fascinating separation material, are generally applied
for gas separation. In general, the membrane-type materials are fabricated using the
permeable or semipermeable materials, and such permeable and semipermeable
membranes showed better selectivity towards CO 2 . The major advantage for the
membrane separation includes (1) simple operational techniques with minimum
energy, (2) compactness in their design with suitable concentration of adsorbent
material, and (3) simple installation of modules into existing infrastructures without
any movable parts.
The zeolite membranes are most explored for the pre- and post-combustion CO 2
capture, when compared to other inorganic membranes [46, 47]. The highlighted
advantages of zeolite membrane [48] include (1) outstanding mechanical properties, (2) thermal stability, (3) least fabrication costs, etc. Such properties made zeolites as efficient materials for post- [49] and pre-combustion CO 2 capture [50]. The
MOF membrane with extremely high porosity and surface areas is found efficient
for selective trapping of CO 2 [51].
Mixed matrix membranes [52] include a bulk and uniform polymer phase in
combination with a homogeneously assembled inorganic distinct phase. Both of
them are promising, because they enable synergistic enhancements in CO 2 permeability and selectivity with desirable mechanical and thermal stability.
2.5 CO 2 Capture from Atmosphere
The industrial process for capturing CO 2 from ambient air is one of an emerging set
of technologies for making clean environment. This CO 2 capture is having great
impact on geological storage of biotic carbon as well as the acceleration of geochemical weathering [53, 54]. In order to address this global climate change problem, the capture of atmospheric CO 2 is very crucial in addition to the CO 2 capture
from the industrial stationary points. The CO 2 removal from atmospheric air has
become a very critical area of research [55, 56], alternatively avoiding CO 2 to mix
with the air and capturing them at the mixing point from industry/vehicles, etc.
Efficient Homogeneous Catalysts for Conversion of CO 2 to Fine Chemicals