Recent achievements in facilitated transport membranes for separation processes

Abstract

-Membrane separation processes have been extensively used for some important industrial separations, substituting traditional methods. However, some applications require the development of new membranes. In this work, we discuss recent progress achieved in this field, focusing on gas and liquid separation using facilitated transport membranes. The advantages of using a carrier species either in a liquid membrane or fixed in a polymer matrix to enhance both the flux and the selectivity of the transport are summarized. The most probable transport mechanisms in these membranes are presented and the improvements needed to spread this technology are also discussed. As examples, we discuss our very successful experiences in air fractioning, olefin/paraffin separation and sugar recovery using liquid and fixed carrier membranes.

Organic-inorganic hybrid membranes in separation processes: a 10-year review

“…In the last three decades, significant improvements in the performance of polymeric membranes for ultrafiltration, nanofiltration, pervaporation, gas separation, and fuel cells have been made (Malekpour et al, 2011;Yi et al, 2010;Ferraz et al, 2007;Mehta and Zydney, 2005;Nyström et al, 1995;Pagliero et al, 1993;Vittadello et al, 2003;Thayumanasundaram et al, 2010), and our understanding of the relationships between the structure, permeability and selectivity of polymeric membranes has been greatly advanced (Geise et al, 2011;Dal-Cin et al, 2008;Cong et al 2007). Polymeric membrane materials such as polytrimethylsilyl propyne (PTMSP), poly(amide imide) (PAI), polyphosphazene (PPN), Poly(dimethylsiloxane) (PDMS), cross-linked polyethylene glycol (PEG) and polyoctylmethylsiloxane (POMS) have been continuously studied (Ozdemir et al, 2006).…”

Polymeric membranes containing silver salts for propylene/propane separation

“…The use of membrane separation as an alternative approach for propylene/propane separation has been investigated and reported in recent years (Ferraz et al, 2007;Burns and Koros, 2003;Kang et al, 2004;Liu et al, 2004). Due to the similar physical and chemical properties and molecular size of propane and propylene, conventional polymeric membranes are not competitive for the separation of these mixtures based only on the sorption/diffusion mechanism.…”

Myoglobin entrapment in poly(vinyl alcohol) dense membranes

“…However, the facilitated mechanism is favored for low partial pressures of the solute, like oxygen in air. The increase of the partial pressure of the component may cause the saturation of the carrier sites (Baker, 2004, Ferraz et al, 2007.…”