ABSTRACT
This chapter aims to offer a review on recent advances and appli-
cations of metal-organic frameworks (MOFs) in modeling of cyclic
adsorptive separations. Adsorption processes, such as pressure
swing adsorption (PSA) or simulated moving bed (SMB) present
opportunities for energy savings, process intensification, and costs
reduction. In recent years MOFs have been pointed out as promising
adsorbents to carry out several different separations, either in gas
or in liquid phase. The number of microporous/mesoporous MOFs
proposed for adsorptive separations, exploiting molecular sieving
or specific interactions, is clearly growing since more and more
MOFs are being synthesized every day. However, new approaches
will be required in the future in terms of material design to
overcome the bottlenecks in the most challenging separations. In this chapter we will address two of those cases, paraffin/olefin
separation (propane/propylene) in the gas phase and the separation
of isomeric mixtures (xylene isomers) in the liquid phase. The
most studied material for propane/propylene separation is Cu-
BTC (also known as HKUST-1), which selectively adsorbs the olefin
in detriment of the paraffin. In the liquid phase separation of
xylene isomers there are several materials being explored (e.g.,
Mate´riaux de l’Institut Lavoisier [MIL]-53(Al), MIL-47(V), UiO-
66(Zr)). However, the most promising materials are the ones
with the topology of MIL-125(Ti), such as MIL-125(Ti) itself, MIL-
125(Ti) NH2, and CAU-1, which are p-xylene selective. After a brief introduction of MOF-and adsorption-based cyclic processes, this
review will focus on adsorptive gas-phase separations, with the
example of propane/propylene separation. The present review will
be concluded with a short summary and future challenges.
