Seperation of light olefins from paraffins using olefin-selective adsorbents via kinetic and equilibrium discrimination

Promovendus/a: Mahsa Najafi Lahiji

Promotor(en): Prof. dr. ir. Joeri Denayer

Light olefins such as ethene and propene are essential building blocks for
the petrochemical industry. Their large-scale production through cracking
yields mixtures with paraffinic impurities (ethane and propane), which
must be removed to meet downstream requirements. Today, polymergrade olefins are produced mainly by cryogenic distillation which is an
extremely energy-intensive process that contributes heavily to CO₂
emissions because of the nearly identical physicochemical properties of
olefin/paraffin pairs. Developing alternative, energy-efficient separation
methods is therefore a scientific and industrial priority, with adsorption
on porous materials emerging as a promising pathway.
For equilibrium-based separation, the study focuses on metal–organic
frameworks (MOFs), examining their adsorption behavior, selectivity, and
uptake capacity. Special attention is given to the influence of surface
functionalities and open metal sites, which provide valuable insights into
the molecular mechanisms that enable efficient separation. In another
approach, titanosilicate ETS materials with finely tuned pore sizes were
evaluated for their potential in kinetic separations. Through systematic
equilibrium and diffusion studies, as well as binary mixture experiments
in a dynamic system, the work reveals how the interplay between
competitive adsorption and molecular diffusion governs separation
performance.
Together, these findings advance the fundamental understanding of
adsorptive separation mechanisms and highlight that a systematic
evaluation of adsorption behavior and mixture separation performance is
essential for identifying the potential of porous adsorbents in developing
practical and energy-efficient light olefin/paraffin separation processes.